Method, system and related equipment for suppressing battery thermal runaway and heat spread

Abstract

The present application provides a method, system and related equipment for suppressing battery thermal runaway and heat spread, which monitors the temperature rise rate and / or cell voltage of each single cell. When it is determined that the temperature rise rate and / or cell voltage of a single cell meet the self-heating conditions, it means that the single cell has entered the self-heating stage. At this time, the single cell temperature and electrochemical information of the single cell are obtained. Based on the electrochemical information and the single cell temperature, the target discharge rate is determined, and the battery is controlled to discharge at the target discharge rate. In this way, by actively electrically regulating the battery in the self-heating stage of the battery and applying the target discharge rate to the battery to cause it to discharge, the reaction concentration of the negative electrode electrolyte interface reaction can be reduced, thereby reducing the thermochemical heat generated by the interface reaction, thereby reducing the total heat generation of the entire battery, lowering the battery temperature, and suppressing the occurrence of battery thermal runaway and heat spread.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a method, system, and related equipment for suppressing battery thermal runaway and heat spread. Background Art

[0002] Battery thermal runaway poses a significant threat to the safe operation of energy storage power plants and electric vehicles. Once a single battery cell experiences thermal runaway, it can trigger a chain reaction, causing heat to rapidly spread throughout the battery module. In extreme cases, this thermal runaway process can rapidly generate excessive heat and gas, leading to overall failure of the battery system and potentially even fire, resulting in serious consequences.

[0003] Therefore, how to effectively suppress battery thermal runaway is an urgent problem that needs to be solved. Summary of the Invention

[0004] In view of this, the purpose of this application is to propose a method, system and related equipment for suppressing battery thermal runaway and heat spread.

[0005] Based on the above objectives, the first aspect of the present application provides a method for suppressing thermal runaway and heat spread of a battery, wherein the battery includes a plurality of single cells, and the method includes:

[0006] monitoring the temperature rise rate and / or cell voltage of each of the single cells;

[0007] In response to a temperature rise rate and / or a cell voltage of a single cell meeting a self-heating condition, obtaining cell temperature and electrochemical information of the single cell;

[0008] determining a target discharge rate based on the electrochemical information and the temperature of the single battery;

[0009] The battery is controlled to discharge at the target discharge rate.

[0010] Based on the same inventive concept, a second aspect of the present application provides a system for suppressing thermal runaway of a battery, wherein the battery includes a plurality of single cells, and the system includes:

[0011] A monitoring module configured to monitor the temperature rise rate and / or cell voltage of each of the single cells;

[0012] an acquisition module configured to acquire a single cell temperature and electrochemical information of a single cell in response to a temperature rise rate and / or a single cell voltage of the single cell meeting a self-heating condition;

[0013] a determination module configured to determine a target discharge rate based on the electrochemical information and the temperature of the single battery;

[0014] The control module is configured to control the battery to discharge at the target discharge rate.

[0015] Based on the same inventive concept, the third aspect of this application provides an electronic device, including a memory, a processor, and a computer program stored in the memory and running on the processor, wherein when the processor executes the computer program, it implements the method described in any one of the first aspects above.

[0016] Based on the same inventive concept, the fourth aspect of this application provides a computer-readable storage medium, which stores computer instructions, and the computer instructions are used to enable a computer to execute any method described in the first aspect.

[0017] Based on the same inventive concept, the fifth aspect of this application provides a computer program product, including computer program instructions. When the computer program instructions are run on a computer, the computer executes the method described in any one of the first aspects above.

[0018] As can be seen from the above, the method, system and related equipment for suppressing battery thermal runaway and heat spread provided by the present application monitor the temperature rise rate and / or cell voltage of each single cell. When it is determined that the temperature rise rate and / or cell voltage of a single cell meet the self-heating conditions, it means that the single cell has entered the self-heating stage. At this time, the single cell temperature and electrochemical information of the single cell are obtained. Based on the electrochemical information and the single cell temperature, the target discharge rate is determined, and the battery is controlled to discharge at the target discharge rate. In this way, by actively electrically regulating the battery in the self-heating stage of the battery, applying the target discharge rate to the battery to discharge it can reduce the reaction concentration of the negative electrode electrolyte interface reaction, thereby reducing the thermochemical heat generated by the interface reaction, thereby reducing the total heat generation of the entire battery, lowering the battery temperature, and thus suppressing the occurrence of battery thermal runaway and heat spread; in addition, the target discharge rate determined based on the electrochemical information matches the current single cell, and is suitable for regulating the current battery to suppress the occurrence of thermal runaway and heat spread. This method can be actively regulated for batteries of different systems and batteries under different application environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in this application or related technologies, the following briefly introduces the drawings required for use in the embodiments or related technical descriptions. Obviously, the drawings described below are merely embodiments of this application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0020] Figure 1 Schematic diagram of a flow chart of a method for suppressing battery thermal runaway and heat spread according to an embodiment of the present application;

[0021] Figure 2 Schematic diagram of the negative electrode interface reaction and electrical regulation mechanism of the embodiment of the present application;

[0022] Figure 3 A comparison chart of the measured unregulated model data and the TR model data of the embodiment of the present application;

[0023] Figure 4 A comparison chart of the measured electrical control model data and the EC model data of the embodiment of the present application;

[0024] Figure 5 A comparison chart of the measured unregulated model data, TR model data, measured electrically regulated model data, and EC model data of an embodiment of the present application;

[0025] Figure 6 This is a test result diagram of the negative electrode interface reaction concentration in Example 4 of the present application;

[0026] Figure 7 This is a graph showing the test results of the heating power of the battery in Example 4 of the present application;

[0027] Figure 8 This is a graph showing the test results of the heat generation of the battery in Example 4 of the present application;

[0028] Figure 9 This is a graph showing the temperature test results at different discharge rates in Example 5 of the present application;

[0029] Figure 10 This is a graph showing the heating rate test results at different discharge rates in Example 5 of the present application;

[0030] Figure 11 This is a test chart of temperature, voltage, and temperature rise rate of a 50Ah square battery before and after electrical control of thermal runaway in Example 6 of the present application;

[0031] Figure 12 Photos of the 50Ah prismatic battery before and after thermal runaway electrical control in Example 6 of this application;

[0032] Figure 13 This is a test chart of temperature, voltage, and temperature rise rate of the 89Ah soft-pack battery before and after electrical control of thermal runaway in Example 7 of this application;

[0033] Figure 14 Photos of the 89Ah soft-pack battery before and after thermal runaway electrical control in Example 7 of this application;

[0034] Figure 15 This is a schematic diagram of the structure for electrically controlling the battery module in Example 8 of the present application;

[0035] Figure 16This is a graph showing the test results before and after electrical regulation of the battery module (1mm insulation layer) in Example 8 of the present application;

[0036] Figure 17 This is a graph showing the test results before and after electrical regulation of the battery module (2mm insulation layer) in Example 9 of the present application;

[0037] Figure 18 This is a schematic diagram of the structure for electrically controlling the battery module in Example 10 of the present application;

[0038] Figure 19 This is a graph showing the test results before and after the battery module is electrically controlled in Example 10 of the present application;

[0039] Figure 20 Photos of the battery module before and after electrical control in Example 10 of the present application;

[0040] Figure 21 This is a graph showing the test results before and after the battery module is electrically controlled in Example 11 of the present application;

[0041] Figure 22 Photos of the battery module before and after electrical regulation in Example 11 of the present application;

[0042] Figure 23 Schematic diagram of a system for suppressing battery thermal runaway and heat spread according to an embodiment of the present application;

[0043] Figure 24 A schematic diagram of an electronic device according to an embodiment of the present application. DETAILED DESCRIPTION

[0044] In order to make the objectives, technical solutions and advantages of this application more clear, this application is further described in detail below in combination with specific embodiments and with reference to the accompanying drawings.

[0045] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present application should have the usual meanings understood by people with ordinary skills in the field to which this application belongs. The "first", "second" and similar words used in the embodiments of the present application do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0046] It should be noted that, unless otherwise defined, the technical terms used in the following examples have the same meanings as commonly understood by those skilled in the art to which this invention belongs. The experimental reagents used in the following examples, unless otherwise specified, are all conventional biochemical reagents; and the experimental methods, unless otherwise specified, are all conventional methods.

[0047] Existing solutions to thermal runaway mainly focus on passive insulation measures and firefighting methods, in order to promptly control and extinguish the fire source when thermal runaway occurs, but the results are often less than ideal.

[0048] For example, when a fire breaks out in an existing large-scale energy storage power station, the firefighting system is unable to effectively extinguish the fire, resulting in the power station being unable to operate normally, causing a large number of energy storage facilities to be idle, and thus bringing huge economic losses. In addition, the batteries of existing electric vehicles gradually age with the increase in usage time, and early warning signals frequently appear. There is currently a lack of effective active electrical control strategies to deal with this problem. At the same time, due to the use of a highly compact system design, the insulation layer space of ultra-large capacity batteries is very limited, which makes it more difficult to control thermal runaway and heat spread.

[0049] Related technologies use high-power, long-duration discharge to reduce the battery's remaining charge in order to mitigate the risk of thermal runaway. However, high-rate discharge is accompanied by the generation of significant Joule heat and the release of heat from side reactions, which can accelerate the thermal runaway process, prematurely triggering thermal runaway and causing heat spread during the thermal runaway period.

[0050] Therefore, there is currently a lack of effective active electrical control strategies to suppress battery thermal runaway.

[0051] Furthermore, when a battery is about to experience thermal runaway or has already experienced it, the heat generated primarily comes from the intense chemical reactions within the battery. However, different battery systems have different internal chemical reaction systems, and the amount of heat generated by these reactions also varies. Therefore, implementing different active electrical control methods to suppress thermal runaway in different battery systems is an urgent issue that needs to be addressed.

[0052] Based on this, see Figure 1 and Figure 2 As shown, the present application provides a method for suppressing thermal runaway and heat spread of a battery, wherein the battery includes a plurality of single cells, and the method includes:

[0053] Step S100, monitoring the temperature rise rate and / or cell voltage of each of the single cells;

[0054] Step S200, in response to a temperature rise rate and / or cell voltage of a single cell meeting a self-heating condition, obtaining the cell temperature and electrochemical information of the single cell;

[0055] Step S300: determining a target discharge rate based on the electrochemical information and the temperature of the single battery;

[0056] Step S400: Control the battery to discharge at the target discharge rate.

[0057] Specifically, if Figure 2 As shown, battery thermal runaway includes three stages, namely T1 stage (corresponding to Figure 2 T1 to T2 stage), T2 stage (corresponding to Figure 2 T2 to T3 stage) and T3 stage (corresponding to Figure 2 T3 and subsequent stages in the process of

[0058] The T1 stage (i.e., the self-heating stage) is the initial stage of self-heating and is also known as the critical stage before thermal runaway. During this stage, the battery's heating rate exceeds the normal heating rate (the normal heating rate is the heating rate range of the battery in normal conditions), indicating that the chemical reactions within the battery are accelerating. The generated heat cannot be dissipated in time, causing the temperature to rise rapidly. This is the key stage of thermal runaway. The various chemical reactions within the battery promote each other, forming a positive feedback loop, causing the temperature to rise sharply.

[0059] At this stage, the thermal stability of the battery is greatly challenged, which may lead to a series of serious consequences, such as electrolyte decomposition, destruction of the electrode material structure, reaction and decomposition of the negative electrode solid electrolyte interphase (SEI), etc., causing the negative electrode to come into direct contact with the electrolyte, resulting in side reactions between the electrolyte and the lithium in the negative electrode and the generation of gas, causing the temperature to rise sharply.

[0060] T2: This is the stage that triggers thermal runaway. During this stage, the cathode material decomposes to release oxygen, and lithium salts such as LiPF6 decompose to produce LiF and the Lewis acid PF5. The Lewis acid reacts with the electrolyte at high temperatures, producing large amounts of gas. Furthermore, a violent exothermic reaction occurs at the anode, further driving the battery temperature up to the thermal runaway range. At this point, the battery enters thermal runaway.

[0061] T3 stage: This is the highest temperature stage of thermal runaway. In this stage, the positive / negative electrode materials and the electrolyte undergo a violent exothermic reaction, the internal temperature of the battery rises sharply, the battery pressure relief valve opens or causes spontaneous combustion.

[0062] The temperature and reaction processes in these three stages together constitute the complete process of battery thermal runaway. Each stage has its own specific temperature threshold and chemical reaction, which ultimately leads to thermal runaway and possible explosion of the battery.

[0063] Therefore, in the present application, when the battery enters the self-heating stage, the battery is actively regulated to prevent thermal runaway of the battery.

[0064] Specifically, the heating rate and / or cell voltage of each cell is monitored to determine whether the heating rate and / or cell voltage of each cell meets the self-heating condition. The self-heating condition is a preset condition for the cell to enter the self-heating stage.

[0065] When the temperature rise rate and / or cell voltage of a single cell meet the self-heating conditions, it indicates that the single cell has entered the self-heating stage and thermal runaway may occur. At this time, it is urgent to intervene in the impending thermal runaway of the battery, otherwise there will be danger caused by thermal runaway.

[0066] When a battery is about to experience thermal runaway, its temperature rises. The heat generated mainly comes from the violent chemical reactions inside the battery and the heat generated by side reactions. Specifically, this includes the heat generated by the decomposition of the negative electrode material on the negative electrode sheet, the heat generated by the decomposition of the electrolyte, and the heat generated by the decomposition of the solid electrolyte interface layer.

[0067] Different battery systems have different internal chemical reaction systems, and the heat generated by these chemical reactions also varies. Therefore, the temperature and electrochemical information of the individual cells are obtained. The electrochemical information can characterize the electrochemical system of the individual cells, and the electrochemical information of individual cells of different systems varies. The electrochemical information can include the electrochemical information of the negative electrode sheet, the electrochemical information of the electrolyte, or the electrochemical information of the solid electrolyte interface layer.

[0068] Then, based on the electrochemical information and the temperature of the single cell corresponding to the single cell, a target discharge rate is determined. The target discharge rate determined in this way corresponds one-to-one with the electrochemical information and further corresponds to the single cell, ensuring that the determined target discharge rate is suitable for the current single cell.

[0069] Finally, the battery is controlled to discharge at the target discharge rate. In this way, by actively electrically regulating the battery during the self-heating stage of the battery, a discharge current of the target discharge rate is applied to the battery to discharge it, thereby forming electron competition at the negative electrode interface, reducing the reaction on the electrolyte side, and reducing the reaction concentration of the negative electrode electrolyte interface reaction, thereby reducing the thermochemical heat generated by the interface reaction, thereby reducing the total heat generation of the entire battery, lowering the battery temperature, and suppressing the occurrence of battery thermal runaway and heat spread.

[0070] In addition, since the target discharge rate is determined based on the electrochemical information of the single cell, the determined target discharge rate matches the current single cell and is suitable for regulating the current battery to suppress the occurrence of thermal runaway and heat spread. This method can actively regulate batteries of different systems and batteries in different application environments, and can effectively solve the safety problems caused by battery thermal runaway.

[0071] In some embodiments, determining whether the temperature rise rate and / or cell voltage of a single cell meet the self-heating condition includes:

[0072] When the temperature rise rate of a single cell is greater than a preset temperature rise rate and / or the cell voltage of a single cell exceeds a preset voltage range, it is determined that the temperature rise rate and / or cell voltage of the single cell meets the self-heating condition.

[0073] The preset heating rate is a preset heating rate for the single cell battery to enter the self-heating stage. For example, the preset heating rate may be 0.1°C / min or 0.2°C / min.

[0074] The preset voltage range is a preset voltage range for a single cell battery during normal operation. For example, the preset voltage range may be 3.2V to 4.2V. When the cell voltage is less than 3.2V or greater than 4.2V, it indicates that the cell voltage of the single cell battery meets the self-heating condition.

[0075] In the present application, only the heating rate may be monitored, or only the cell voltage may be monitored, or both the cell voltage and the heating rate may be monitored simultaneously, without specific limitation.

[0076] In some embodiments, the electrochemical information includes target partial electrochemical information; and determining the target discharge rate based on the electrochemical information and the single cell temperature includes:

[0077] Determining an allowable discharge rate allowed to be applied to the target portion of the battery based on the electrochemical information of the target portion and the temperature of the single battery; wherein the target portion is a negative electrode sheet, an electrolyte, or a solid electrolyte interface layer, and the electrochemical information of the target portion is electrochemical information of the negative electrode sheet, electrochemical information of the electrolyte, or electrochemical information of the solid electrolyte interface layer;

[0078] The minimum rate among all the allowable discharge rates is determined as the target discharge rate.

[0079] Specifically, as mentioned above, when the battery is about to experience thermal runaway, its heat generation mainly includes heat generated by the decomposition of the negative electrode material on the negative electrode plate, heat generated by the decomposition of the electrolyte, and heat generated by the decomposition of the solid electrolyte interface layer.

[0080] Therefore, in the present application, by controlling the battery to discharge at the target discharge rate, the application of the target discharge rate is mainly to simultaneously regulate the decomposition of the battery's negative electrode material, the decomposition of the electrolyte, and the decomposition of the solid electrolyte interface layer, so as to suppress the thermal runaway of the battery.

[0081] However, since the electrochemical reactions of the three parts, namely, the decomposition of the negative electrode material, the decomposition of the electrolyte, and the decomposition of the solid electrolyte interface layer, are different, the allowable discharge rates applied to these three parts are also different.

[0082] Therefore, it is necessary to first determine the allowable discharge rate that can be applied to the target portion of the battery based on the electrochemical information of the target portion and the temperature of the single cell. The target portion is the negative electrode sheet, electrolyte, or solid electrolyte interface layer, and the electrochemical information of the target portion is the electrochemical information of the negative electrode sheet, the electrochemical information of the electrolyte, or the electrochemical information of the solid electrolyte interface layer.

[0083] The allowable discharge rate is the maximum discharge rate that can be applied to the corresponding target part. If the discharge rate applied to the target part is greater than the allowable discharge rate corresponding to the target part, the basic electrochemical reaction in the target part will not proceed normally, thereby affecting the normal use of the battery.

[0084] Specifically, based on the electrochemical information of the negative electrode plate and the temperature of the single cell, the allowable discharge rate allowed to be applied to the negative electrode plate of the battery is determined; based on the electrochemical information of the electrolyte and the temperature of the single cell, the allowable discharge rate allowed to be applied to the electrolyte of the battery is determined; based on the electrochemical information of the solid electrolyte interface layer and the temperature of the single cell, the allowable discharge rate allowed to be applied to the solid electrolyte interface layer of the battery is determined.

[0085] After determining the allowable discharge rate corresponding to each target part (i.e., the allowable discharge rate of the negative electrode plate, the allowable discharge rate of the electrolyte, and the allowable discharge rate of the solid electrolyte interface layer), the minimum rate among all the allowable discharge rates is determined as the target discharge rate to ensure that the basic electrochemical reactions of each part of the battery can proceed normally, thereby ensuring the normal use of the battery.

[0086] In some embodiments, the electrochemical information of the target portion includes target portion mass information, target portion reaction enthalpy information, target portion activation energy information and target portion concentration ratio, wherein the target portion mass information includes the sum of the masses of the components in the target portion, the target portion reaction enthalpy information is the inverse of the enthalpy change value of the chemical reaction of the components in the target portion, the target portion activation energy information is the activation energy of the chemical reaction of the components in the target portion, and the target portion concentration ratio is the minimum ratio of the sum of the concentrations of the components in the target portion to the sum of the concentrations of all components in the battery.

[0087] In some embodiments, determining the allowable discharge rate allowed to be applied to the target portion of the battery based on the electrochemical information of the target portion and the temperature of the single battery cell includes:

[0088] determining a total rate constant based on a preset minimum heat of the target portion, mass information of the target portion, and reaction enthalpy information of the target portion;

[0089] Determining a reaction rate constant based on the target portion concentration ratio, the target portion activation energy information, and the target portion single cell temperature;

[0090] The difference between the total rate constant of the target part and the reaction rate constant of the target part is determined as the allowable discharge rate of the target part.

[0091] Specifically, in this embodiment, in order to make the subsequent description clearer, each information in the electrochemical information of the target part is represented by letters. For example, Indicates the target part quality information, represents the target part reaction enthalpy information, Ea represents the target part activation energy information, f(c) represents the target part concentration ratio, and T represents the single cell temperature.

[0092] When determining the allowable discharge rate of the target part, the total rate constant is first determined based on the preset minimum heat of the target part, the mass information of the target part, and the reaction enthalpy information of the target part. The preset minimum heat of the target part is the minimum value that the heat release of the target part can reach after theoretical calculation and experimental verification. For example, Q 热反应min Indicates the minimum heat of the preset target part.

[0093] Specifically, the target part quality information and the target partial reaction enthalpy information The product of is determined as the first product of the target part, that is, · Then the preset target minimum heat Q 热反应min The first product with the target part ( · ) is determined as the total rate constant of the target part, that is, .

[0094] Then, based on the target portion concentration ratio, the target portion activation energy information and the single cell temperature, determining the target portion reaction rate constant specifically includes:

[0095] Step 1: Determine the product of the gas constant R and the temperature T of the single cell as the second product, namely RT, wherein the gas constant R, also known as the ideal gas constant, is a key physical constant characterizing the properties of an ideal gas in thermodynamics, and R is 8.314 J / (mol·K).

[0096] Step 2: Determine the inverse of the ratio of the target part activation energy information Ea to the second product RT as the first ratio of the target part, that is, .

[0097] Step 3: Take the first ratio power of the target part of the natural constant e as the initial rate constant of the target part, that is, .

[0098] Step 4: Initial rate constant of the target part The product of the target portion concentration ratio f(c) and the target portion frequency factor A is determined as the target portion reaction rate constant, that is, .

[0099] Among them, the target partial frequency factor A (also called pre-exponential factor) is an important parameter of the Arrhenius formula in chemical kinetics, which represents the frequency of effective collisions of molecules per unit time, and its unit is mol·dm -3 ·s -1 , which has the same unit as the reaction rate constant k, is used to quantify the frequency of molecular collisions and is one of the key factors affecting reaction rate.

[0100] The target frequency factor A is related to temperature and specific chemical reactions. It is a constant determined only by the nature of the reaction and has nothing to do with the reaction temperature and the concentration of the reactants. Its value is usually between 10-10 6 within the range.

[0101] Finally, the target fraction total rate constant Reaction rate constant with the target moiety The difference between the two is determined as the allowable discharge rate Crate of the target part, that is, .

[0102] The single battery includes a negative electrode plate and an electrolyte. The negative electrode plate includes a negative electrode current collector and a negative electrode active coating coated on the negative electrode current collector. The negative electrode plate and the electrolyte undergo a reduction reaction during the first charge and discharge to generate a solid electrolyte interface layer.

[0103] When determining the allowable discharge rate of the negative electrode plate, the components in the negative electrode plate include the components in the negative electrode active coating, and the components in the negative electrode active coating include at least a negative electrode active material, a conductive agent, a binder, and the like.

[0104] When determining the allowable discharge rate of the electrolyte, the components in the electrolyte include various components in the electrolyte, such as organic solvents, lithium salts, and additives.

[0105] When determining the allowable discharge rate of the solid electrolyte interface layer, the components of the solid electrolyte interface layer include inorganic / organic components such as Li2CO3, ROCO2Li (alkyl lithium carbonate), and LiF. Because the sum of the masses of the components in the solid electrolyte interface layer is difficult to accurately determine, and the maximum mass of the solid electrolyte interface layer is essentially equivalent to the maximum mass of the negative electrode active material, in this application, after experimental verification, the sum of the masses of the components in the negative electrode sheet can be directly determined as the sum of the masses of the components in the solid electrolyte interface layer. Furthermore, the concentration information of the solid electrolyte interface layer can be calculated based on the consumption of irreversibly lost lithium in fresh single cells.

[0106] For different battery systems, the components of their various target parts are different, so the specific values ​​of the corresponding parameters are also different. The specific values ​​are determined based on the actual components of the battery.

[0107] In this application, different allowable discharge rates can be determined based on the different chemical reactions within the battery system. Based on the different allowable discharge rates, different target discharge rates can be determined, so that the determined target discharge rate can match the current battery system, thereby effectively inhibiting the thermal runaway of the battery.

[0108] Moreover, in the process of determining the allowable discharge rate, by linking the rate discharge with the concentration reaction formula (i.e., the Arrhenius formula), the relationship between the allowable discharge rate and the reaction concentration is obtained, so that the target discharge rate finally determined is also related to the reaction concentration. In this way, the reaction concentration at the negative electrode reaction interface can be adjusted by applying the target discharge rate, thereby adjusting the thermochemical heat generated by the interface reaction, and ultimately reducing the total heat generation of the entire battery, lowering the battery temperature, and achieving effective suppression of battery thermal runaway and heat spread.

[0109] In some embodiments, the target discharge rate is 0.05C~1C.

[0110] Specifically, the target discharge rates of batteries of different systems can be determined by the above method, and the target discharge rates are all between 0.05C and 1C.

[0111] During the thermal runaway process, the battery has both electrochemical and thermochemical effects, that is, the total heat generation of the battery includes thermochemical heat generation and electrochemical heat generation. Under normal circumstances, during the self-heating stage, the vast majority of the total heat generation of the battery comes from thermochemical heat generation. Therefore, when the target discharge rate is between 0.05C and 1C, controlling the battery discharge by applying the target discharge rate can effectively reduce the reactant concentration at the negative electrode interface inside the battery, thereby reducing thermochemical heat generation, and ultimately reducing the total heat generation of the battery, thereby suppressing thermal runaway and heat spread.

[0112] However, if the target discharge rate applied is too large, the proportion of electrochemical heat generated at the negative electrode interface during the self-heating stage will increase, causing thermal runaway to intensify, and thus leading to an earlier time of thermal runaway; if the target discharge rate applied is too small, the discharge current of the target discharge rate will not be able to effectively reduce the thermochemical heat generated at the negative electrode interface of the battery, so that thermal runaway cannot be effectively suppressed.

[0113] Moreover, after experimental verification (see subsequent Example 5), the verification results show that for batteries of the same system, when the target discharge rate is greater than 1C (for example, 2C, 5C, 8C), the time corresponding to the battery reaching the maximum temperature is significantly shortened, indicating that the time of thermal runaway will be advanced, and the maximum temperature of the battery will also increase, indicating that the total heat generation of the battery will increase, and further indicating that compared with 1C, a target discharge rate greater than 1C will cause thermal runaway to intensify.

[0114] When the target discharge rate is less than 0.05C (for example, 0.01C), the time corresponding to the battery reaching the maximum temperature is significantly shortened and the maximum temperature of the battery is higher, indicating that the discharge current with too small a target discharge rate cannot effectively reduce the thermochemical heat generated at the battery negative electrode interface and cannot effectively suppress thermal runaway.

[0115] When the battery is in different conditions, the specific operations for monitoring the temperature rise rate and / or cell voltage of each single cell are also different. Therefore, different operations need to be performed for different conditions.

[0116] In some embodiments, monitoring the temperature rise rate and / or cell voltage of each of the single cells includes:

[0117] In response to the battery being in a thermal runaway detection state, heating the battery so that the temperature of the battery rises to a preset temperature;

[0118] Stop heating and let the battery rest for a preset time;

[0119] The temperature rise rate and / or cell voltage of each of the single cells are monitored.

[0120] Specifically, when the battery is in the thermal runaway detection state, that is, the battery is independent and not installed on a vehicle or other electrical equipment, the battery is heated at a constant power or constant rate to raise the battery temperature to a preset temperature. The preset temperature is the maximum temperature of a preset heating stage.

[0121] Then, the heating is stopped and the battery is allowed to stand for a preset time to wait for the battery to reach a temperature equilibrium state. The preset time is the shortest time that the battery can reach a temperature equilibrium state obtained through experimental testing.

[0122] After the battery reaches a temperature equilibrium state, the temperature rise rate and / or cell voltage of each single cell are monitored to further monitor whether the temperature rise rate continues to rise due to battery self-heating or whether the cell voltage becomes abnormal due to battery self-heating.

[0123] If the heating rate is greater than the preset heating rate, it means that the single cell battery has self-heating, which may further cause thermal runaway; or if the single cell voltage exceeds the preset voltage range, it means that the single cell battery has self-heating, which may further cause thermal runaway.

[0124] In some embodiments, monitoring the temperature rise rate and / or cell voltage of each of the single cells includes: in response to the battery being in a charging state, a stationary non-charging state, or a moving state, monitoring the temperature rise rate and / or cell voltage of each of the single cells in real time.

[0125] Specifically, when the battery is in a charging state, thermal runaway may also occur. Therefore, it is necessary to monitor the temperature rise rate and / or cell voltage of each single cell in real time. Once it is determined that a single cell meets the self-heating condition, the cell temperature and electrochemical information of the single cell are obtained in accordance with the method described in the aforementioned embodiment. Based on the electrochemical information and the cell temperature, the target discharge rate is determined, and the battery is controlled to discharge at the target discharge rate to reduce the heat generation of the battery. At the same time, charging of the battery is stopped to further reduce the heat generation of the battery, thereby suppressing the occurrence of thermal runaway and heat spread.

[0126] When the battery is installed on an electrical device such as a vehicle, the battery may move with the vehicle, and the battery is in a moving state; the battery may also be in a charging state, or the battery may also be in a stationary non-charging state.

[0127] When the battery is in a stationary non-charging state or in a mobile state, it is also necessary to monitor the temperature rise rate and / or cell voltage of each single cell in real time to accurately detect whether the battery enters a self-heating state.

[0128] The thermal runaway suppression method described in the present application can be widely applied to a variety of scenarios and can effectively suppress thermal runaway or heat spread of batteries.

[0129] In some embodiments, a heat insulation layer is provided between two adjacent single batteries, and the thickness of the heat insulation layer is less than or equal to 2 mm.

[0130] Specifically, when the positive electrode material of the single cell is a ternary material, the thickness of the thermal insulation pad is preferably greater than 1 mm and less than or equal to 2 mm. This ensures that the thermal insulation pad can effectively isolate the spread of heat and prevent the battery from thermal runaway due to thermal runaway of adjacent cells. For example, the thickness of the thermal insulation pad can be 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, or 2 mm.

[0131] When the positive electrode material of the single battery is lithium iron phosphate, the thickness of the thermal insulation layer is preferably less than or equal to 1 mm, so as to ensure that the battery will not cause thermal runaway due to thermal runaway of adjacent batteries.

[0132] The thermal insulation layer may be made of thermal insulation material and / or aerogel, and the thermal insulation material may be at least one of glass fiber, ceramic fiber, silicate fiber, polyimide film, polyethylene film, sheet polypropylene, and silicone rubber.

[0133] In the present application, active regulation is performed when the single cell enters the self-heating stage, so that the battery is discharged according to the target discharge rate to reduce the heat generation of the battery. Therefore, the heat generation of the battery decreases. Therefore, it has been verified through experiments that only a thermal insulation pad with a thickness of less than or equal to 2 mm is required to isolate the heat spread between adjacent single cells. Compared with the thermal insulation pad in the existing battery, the thickness of the thermal insulation pad in the present application is significantly reduced, thereby reducing the space occupied by the entire battery and improving its adaptability.

[0134] The present application is further described below through examples.

[0135] Example 1

[0136] Continue to see Figure 1 As shown, the battery has both electrochemical and thermochemical effects during the thermal runaway process. This embodiment mainly suppresses the thermal runaway of the lithium-ion battery in the T1 stage.

[0137] The following takes the target part as an electrolyte as an example to further illustrate how to determine the allowable discharge rate allowed to be applied to the target part of the battery based on the electrochemical information of the target part and the temperature of the single battery.

[0138] like Figure 1As shown, in the interface reaction between the electrolyte and the negative electrode of the lithium-ion battery, the thermochemical reaction current I T , electrochemical reaction current I E (i.e. reverse discharge current), so the electrochemical and thermochemical models are derived.

[0139] In terms of thermochemical reactions, the thermochemical reaction formula is: ;in, is the sum of the masses of the components in the target part (i.e., the mass information of the target part), is the opposite of the enthalpy change value of the chemical reaction of each component in the target part (that is, the target part reaction enthalpy information, because the enthalpy change value of the exothermic reaction is a negative number, so here is the opposite of the enthalpy change value), It is the rate of change of the concentration dc of the reactants of each component in the target part with time dt within a certain period of thermal runaway, which is used to characterize the concentration reaction rate.

[0140] By linking the rate discharge with the concentration reaction formula in the chemical reaction, that is, the Arrhenius formula, and the functional relationship between the Arrhenius formula and the reaction concentration c, the negative electrode reaction interface equation is obtained as follows:

[0141] ,

[0142] Among them, A is the target part frequency factor in the Arrhenius formula, e is a natural constant, Ea is the activation energy of the chemical reaction of each component in the target part (i.e., the target part activation energy information), R is the gas constant, T is the temperature of the single cell, and f(c)0 is the ratio of the sum of the concentrations of each component in the target part to the sum of the concentrations of all components in the battery (expressed as a normalized numerical value).

[0143] The current of the thermochemical reaction I T To pass The concentration change, the current change and the current generated by the interface reaction I T (i.e. I 热反应 ), so I 热反应 The formula is:

[0144] .

[0145] in, is the Faraday constant, is the current of the interfacial reaction, I 热反应 The current of the thermal reaction.

[0146] At the same time, in terms of electrochemical reaction, for a single cell with a voltage of U and an internal resistance of R, the R of the battery is short-circuited in the thermal runaway state, and the entire internal resistance of the battery is , so the electrochemical current I generated by the battery under thermal runaway can be obtained E (i.e. I 电 ), I 电 The calculation formula is:

[0147] .

[0148] The Joule heat Q generated by the electrochemical process under thermal runaway of the battery can be 电池 and I 电 , and the following calculation formula is obtained:

[0149] ,

[0150] in, is the interface reaction current variable constant.

[0151] Based on this, we can derive the total heat generated by the battery when thermal runaway occurs, Q, that is, Q = Q 热反应 +Q 焦耳热 .

[0152] In this application, in order to suppress the thermal runaway of the battery, it is necessary to minimize Q, that is, Q 热反应 +Q 焦耳热 The sum of is the smallest.

[0153] Through multiple tests and verifications, the applicant found that in the case of thermal runaway, for the total heat generation Q, Q 焦耳热 The proportion is very small and can be almost ignored. Therefore, when ignoring Q 焦耳热 In the case of 热反应 Minimum.

[0154] because ,in, and Is a fixed value. If you want to make Q 热反应 At least, you need to make Minimum.

[0155] because , where A, e, Ea, and R are fixed values, and T is the actual measured value. Therefore, if you want to use To minimize, we need to minimize f(c)0.

[0156] Based on this, in this application, the inventors found through continuous attempts that in thermal runaway, the rate discharge will affect the change in the reaction concentration of the negative electrode electrolyte interface reaction. The greater the applied discharge rate, the greater the concentration reaction rate of the negative electrode electrolyte interface reaction, and the smaller the reaction concentration of the negative electrode electrolyte interface reaction, so f(c)0 will decrease, making Reduce, thus making Q热反应 Decrease.

[0157] Based on this, when controlling the battery that is about to thermal runaway to discharge at a rate of C rate During discharge, the battery can be actively controlled electrically. At this time, the controlled concentration ratio f(c)0 is affected by the discharge rate C. rate The influence of f(c)0 will become the concentration ratio after regulation (with f(c) 00 denoted by f(c) 00 Will follow C rate At the same time, due to C rate The application of will also directly affect the concentration reaction rate. Therefore, after electrical regulation, the negative electrode reaction interface equation is updated as follows:

[0158] ,

[0159] Apply active electrical regulation to obtain the thermochemical heat generation Q of the electrolyte for the interface reaction 热反应 The control formula of the heat production process is:

[0160] .

[0161] It can be seen that after controlling the battery that is about to thermal runaway to discharge at a certain discharge rate, the thermochemical heat Q generated in the target part 热反应 It consists of two parts, one of which is related to the reaction rate Related items , the other part is with C rate Directly related items.

[0162] Therefore, if we want Q 热反应 At least, you need to make C rate As small as possible, because C rate is an additive term. As Crate decreases, Q 热反应 Will decrease.

[0163] However, due to C rate The size of will affect the concentration ratio f(c) after regulation 00 If the size of C rate Decrease, the concentration ratio after regulation is f(c) 00 will increase, and accordingly, the reaction rate of the negative electrode electrolyte interface reaction will decrease. rate If it is small enough, the reaction rate will be very low, and the chemical reaction inside the battery will be almost impossible to proceed, thus affecting the normal use of the battery.

[0164] Therefore, it is necessary to rate and f(c) 00 Find a balance between the two, so that the final Crate The value is the best, apply C rate The discharge current can reduce Q 热反应 , without affecting the chemical reaction inside the battery.

[0165] Therefore, in this application, since C rate f(c) 00 As well as the effect of reaction rate, set a constraint to ensure that the reaction in the battery can proceed. For example, set f(c) 00 The lower limit of . Among them, f(c) 00 The lower limit is the minimum ratio (expressed as normalized data) of the sum of the concentrations of the components in the target portion to the sum of the concentrations of all components in the battery to ensure that the chemical reaction of the target portion in the battery can proceed. The minimum ratio can be determined based on the concentrations of the components in the target portion and the concentrations of all components in the battery.

[0166] Determine f(c) 00 The lower limit is the concentration ratio of the target part (i.e., f(c) above), that is, the minimum ratio of the sum of the concentrations of the components in the target part to the sum of the concentrations of all components in the battery.

[0167] After determining f(c), the above formula Update to , we can get C by conversion rate The calculation formula is:

[0168] ,

[0169] In this formula, A, e, Ea, and R are all constants. For a specific battery system, and is a fixed value, f(c) is the above f(c) 00 The lower limit is also a fixed value, and T is the measured value. In this case, only Q 热反应 and C rate is a variable.

[0170] Then, make Q 热反应 The value of is the preset minimum heat of the target part, and the allowable discharge rate C of the target part corresponding to the preset minimum heat of the target part can be obtained. rate value.

[0171] After determining the allowable discharge rate of each target part, the minimum rate among the multiple allowable discharge rates is determined as the target discharge rate. Controlling the battery to discharge at the target discharge rate can make the battery's thermochemical heat generation Q 热反应 Minimize the total heat generation of the battery, thereby suppressing the thermal runaway and heat spread of the battery.

[0172] Example 2

[0173] A ternary soft-pack battery with a capacity of 50 Ah and an energy density of 280 Wh / kg is used. The battery is heated to 130°C and maintained at the T1 stage. Calculate the total heat generated by the battery before regulation.

[0174] When the battery is in the T1 stage, the heat generated by the thermochemical reactions of the battery mainly includes the heat generated by the decomposition of the negative electrode material, the heat generated by the decomposition of the electrolyte, and the heat generated by the decomposition of the solid electrolyte interface layer (hereinafter referred to as "SEI film").

[0175] For the SEI film, the specific values ​​are shown in Table 1 below: SEI is the SEI film reaction enthalpy information, A SEI is the SEI film frequency factor, E aSEI is the SEI film activation energy information, f(c) SEI,0 is the initial value of the normalized concentration of the SEI film (which can be calculated based on the consumption of irreversible lithium loss in fresh batteries), m SEI Use m an Instead, m an That is, the sum of the masses of the components in the negative electrode, k SEI is a constant related to the battery temperature, used to balance the reaction rate and f(c) SEI,0 The relationship between k and , the value range is 0~1, usually when the temperature is greater than or equal to 130℃, SEI The value is 1.

[0176] Table 1 Data list of SEI film parameters

[0177]

[0178] For the negative electrode, the specific values ​​are shown in Table 2 below: an is the reaction enthalpy information of the negative electrode, A an is the negative electrode frequency factor, E aan is the activation energy information of the negative electrode, f(c) an,0 is the initial value of the normalized concentration of the negative electrode, m an is the sum of the masses of the components in the negative electrode, k an is a constant related to the battery temperature, used to balance the reaction rate and f(c) an,0 The relationship between k and , the value range is 0~1, usually when the temperature is greater than or equal to 130℃, an The value is 1.

[0179] Table 2 Data list of various parameters of negative electrode

[0180]

[0181] For the electrolyte, the specific values ​​are shown in Table 3 below, △H e is the electrolyte reaction enthalpy information, A e is the electrolyte frequency factor, E ae is the activation energy information of the electrolyte, f(c) e,0 is the initial value of the normalized concentration of the electrolyte, m e is the sum of the masses of the components in the electrolyte, k e is a constant related to the battery temperature, used to balance the reaction rate and f(c) e,0 The relationship between k and , the value range is 0~1, usually when the temperature is greater than or equal to 130℃, e The value is 1.

[0182] Table 3 Data list of various parameters of electrolyte

[0183]

[0184] Then, based on To calculate the heat generated by the decomposition of ESI membrane, electrolyte and negative electrode material respectively, the sum of the three heat generation is the total heat generation, and finally the Q is calculated. 热反应 It is 170750J.

[0185] After the battery is heated to 130°C, it is electrically regulated. Through electrical regulation, the concentration of the negative electrode interface reaction changes. Specifically, the concentration of the electrolyte, the concentration of the SEI film, and the concentration of the negative electrode material all change.

[0186] In this embodiment, through theoretical simulation and experimental verification, it is finally determined that during the application of electrical regulation, the concentration ratio of the SEI film, that is, the minimum ratio of the sum of the concentrations of each component in the SEI to the sum of the concentrations of all components in the battery (expressed as f(c) SEI The concentration ratio of the negative electrode sheet is the minimum ratio of the sum of the concentrations of the components in the negative electrode sheet to the sum of the concentrations of all components in the battery (expressed by f(c) an The concentration ratio of the electrolyte is the minimum ratio of the sum of the concentrations of the components in the electrolyte to the sum of the concentrations of all components in the battery (expressed by f(c) e ) can be 0.45.

[0187] Based on theoretical calculations and experimental verification, the preset minimum heat of the SEI film is 9455J, the preset minimum heat of the negative electrode is 21645J, and the preset minimum heat of the electrolyte is 103173J.

[0188] Then, substitute the minimum heat and minimum concentration ratio into the formula It can be obtained that the maximum allowable rate of the SEI film is 0.1C, the maximum allowable rate of the negative electrode is 0.25C, and the maximum allowable rate of the electrolyte is 0.55C.

[0189] Finally, the minimum rate of 0.1C among the maximum rate allowed by the SEI film, the maximum rate allowed by the negative electrode sheet, and the maximum rate allowed by the electrolyte is determined as the final target discharge rate.

[0190] Example 3

[0191] In this embodiment, the effectiveness of the active electrical regulation to achieve battery thermal runaway in this application is verified by using two models: the existing mature thermal runaway model TR, the equivalent circuit model EC pre-trained by the method described in this application, and a square battery of a ternary high-nickel system.

[0192] Two experiments were conducted on the same battery to verify the ternary high-nickel system's prismatic cells. The first experiment involved testing the ternary high-nickel system's prismatic cells for thermal runaway using an accelerating rate calorimeter (ARC). The battery was controllably heated to a preset temperature and then left for a preset time. The battery's temperature and voltage were then measured in real time. The test data from this experimental process is hereinafter referred to as "measured uncontrolled model data."

[0193] The second experiment used an accelerating rate calorimeter (ARC) to test for thermal runaway in a ternary high-nickel system square battery. The battery was heated in a controllable manner to a preset temperature and then placed for a preset time. The battery was then controlled to discharge at 0.05C while the battery temperature and voltage were measured in real time. The test data corresponding to this experiment is hereinafter referred to as "measured electrical control model data."

[0194] The thermal runaway model (hereinafter referred to as the "TR model") is a well-trained, mature machine learning model for battery thermal runaway testing. It outputs predicted battery thermal runaway temperatures and voltages. During validation using this model, data identical to all test data from the first experiment with the aforementioned ternary high-nickel system prismatic battery was input into the TR model to output the model's predicted data. The test data corresponding to this experiment is referred to as the "TR model data."

[0195] The equivalent circuit model (hereinafter referred to as the "EC model") is a machine learning model trained according to the methods of this application. It can simulate active electrical control of a battery experiencing thermal runaway and output the predicted battery temperature and voltage after active electrical control. When using this model for verification, data identical to all test data from the second experiment of the aforementioned ternary high-nickel system prismatic battery was input into the EC model to output the model-predicted data. The test data corresponding to this experiment is referred to as the "EC model data."

[0196] Figure 3 This is a comparison chart of the measured unregulated model data and the TR model data. Figure 3 A in the middle is the battery temperature change diagram, Figure 3 B is the battery voltage change diagram. Figure 3 As shown in the figure, during the T1 thermal runaway stage, the temperature curves of the measured uncontrolled model and the TR model are exactly the same, with the T1 thermal runaway temperature being 98°C. Comparing the voltage curves, the measured voltage of the uncontrolled model at T1 is 4.2V, while the voltage predicted by the TR model is 4.15V, a difference of less than 0.1V.

[0197] Figure 4 This is a comparison chart of the measured electric control model data and EC model data. Figure 4 A in the middle is the battery temperature change diagram, Figure 4 B is the battery voltage change diagram. Figure 4 As shown in the figure, during the thermal runaway stage T1, the experimental temperature curve of the measured electric control model is compared with the temperature curve predicted by the EC model. The measured temperature of the electric control model T1 is 98°C, while the predicted temperature of the EC model is 95.6°C, with a temperature difference of less than 3°C. A comparison of the voltage curves shows that the experimental voltage of the measured electric control model is 4.2V, while the predicted voltage of the EC model is 4.18V, with a difference of less than 0.1V.

[0198] Figure 5 This is a comparison chart of the measured unregulated model data, TR model data, measured electrically regulated model data, and EC model data. Figure 5 It can be seen that the temperature and voltage deviations between the measured uncontrolled model data and the TR model data, and between the measured electrically controlled model data and the EC model data are all within 5%. This result fully verifies the accuracy and reliability of the EC model.

[0199] Continuing to refer to the comparison between the measured uncontrolled model data and the measured electrically controlled model data, as well as the comparison between the TR model data and the EC model data, it can be seen that the use of the electrically controlled method in this application (i.e., controlling the battery to discharge at the target discharge rate) can extend the thermal runaway time of the battery by 400 minutes, which is 40% longer. The measured experimental results match the simulated results to a high degree of match.

[0200] Example 4

[0201] Six groups of batteries of the same type, numbered anele1, anele2, anele3, anele4, anele5, and anele6, with battery capacities of 5Ah, 10Ah, 20Ah, 40Ah, 60Ah, and 100Ah respectively, were tested. The test for each group of batteries included a thermal runaway test without active electrical control and an active electrical control test in which the battery was discharged at 0.05C for active electrical control.

[0202] The thermal runaway test involves heating the battery at a constant power of 250W, heating it to a preset temperature and then leaving it for a preset time, and then measuring the relevant parameters of the battery in real time.

[0203] Among them, the active electric control test is to heat the battery at a constant power of 250W, place it for a preset time after heating to the preset temperature, and then control the battery to discharge at 0.05C, while measuring the relevant parameters of the battery in real time.

[0204] Figure 6 The figure shows the test results of the negative electrode interface reaction concentration of 6 groups of batteries undergoing thermal runaway tests and active electrical control tests. In the figure, anele1, anele2, anele3, anele4, anele5, and anele6 represent the test data of the six groups of batteries undergoing thermal runaway tests, and anele1-EC, anele2-EC, anele3-EC, anele4-EC, anele5-EC, and anele6-EC represent the test data of the six groups of batteries undergoing active electrical control tests.

[0205] like Figure 6 It can be seen that as the battery capacity increases, the reaction temperature of thermal runaway gradually increases, from 100°C to over 800°C. By controlling the battery to discharge at 0.05C for active electrical regulation, the rate of decrease of the reaction concentration of the negative electrode electrolyte can be accelerated, and the reaction concentration can be quickly reduced to 0, while the maximum temperature of the battery is significantly reduced. Specifically, when no active electrical regulation is applied, when the reaction concentration of the electrolyte drops to 0, the temperature of the battery thermal runaway reaches over 800°C; by applying active electrical regulation, the reaction concentration of the negative electrode electrolyte is quickly reduced to 0, and the maximum temperature of the battery thermal runaway is only 180°C.

[0206] Figure 7 The figure shows the test results of the battery's heating power. Figure 7 As shown in the figure, the total heat generation power Ptotal of the battery is consistent with the heat generation power Panele of the negative electrode reaction interface, and the heat generation power Panele of the negative electrode reaction interface accounts for more than 90% of the total heat generation power Ptotal.

[0207] After electrical regulation, the total heating power Ptotal-EC is significantly reduced, the maximum temperature is reduced from over 800°C to 650°C, and the total heating power of the reaction is reduced by 2 orders of magnitude.

[0208] The unregulated negative electrode reaction interface heating power Panele can reach 105 W, and the negative electrode interface temperature is 690°C. After regulation, the negative electrode reaction interface heating power Panele-EC drops to 0.01W in the thermal runaway T1 stage, and the negative electrode interface temperature is controlled at 130°C. It can be seen that after active electrical regulation, the negative electrode interface reaction heating power is significantly reduced, the heat production is significantly reduced, and the interface temperature is also significantly reduced, indicating that the active electrical regulation has a very obvious inhibitory effect on battery thermal runaway.

[0209] In addition, the discharge power Pdis caused by the discharge current of the discharge rate controlled by the active electrical regulation is 0.000001W, which means that the discharge current only accounts for 0.001% of the total heat generated by the battery. Therefore, the additional heat generated by the applied discharge current can be ignored.

[0210] Figure 8 The figure shows the test results of the heat generation of the battery. Figure 8 As shown in the figure, the external discharge heat Qdis generated by the discharge current applied by active electrical regulation is 0.08J, while the total heat generated inside the battery Qtotal is 8×10 3 J, so the external discharge current contributes only 0.001% to the total heat generation of the battery, which can be ignored. In addition, after adopting active electrical regulation, the battery heat generation rate is reduced, and the maximum temperature of the battery is reduced to below 200°C, while the maximum temperature of the battery without active electrical regulation is higher than 800°C. It can be seen that discharging the battery through active electrical regulation can reduce the heat generation of the negative electrode interface reaction, lower the maximum temperature of the battery, and delay the time of battery thermal failure.

[0211] Example 5

[0212] When performing active power regulation, for the same type of battery, different discharge rates of 0.01C, 0.05C, 1C, 2C, 5C and 8C are used to test the maximum temperature that the battery can reach and the time corresponding to the maximum temperature. The test results are as follows: Figure 9 、 Figure 10 and as shown in Table 4 below.

[0213] Table 4 Test results of different discharge rates

[0214]

[0215] From the above table 1, Figure 9 、 Figure 10It can be seen that when discharging the battery at different discharge rates for active electrical control, when the discharge rate is greater than 1C, the time corresponding to the battery reaching the maximum high temperature is shortened, indicating that thermal runaway will be significantly earlier. When the discharge rate is less than 0.05C, the time corresponding to the battery reaching the maximum high temperature is also shortened, indicating that thermal runaway will also be earlier. When the discharge rate is small (for example, 0.01C) or large (for example, 5C and 8C), the maximum temperature of the battery will increase, indicating that the total heat generated by the battery is large and the risk of thermal runaway is higher.

[0216] Considering the maximum battery temperature and the time required to reach the maximum temperature, when the discharge rate is 0.05C~1C, the maximum battery temperature is the lowest and the time required to reach the maximum temperature is longer. Therefore, controlling the discharge rate to 0.05C~1C can effectively suppress the thermal runaway of the battery, prolong the thermal runaway time of the battery and reduce the thermal runaway temperature.

[0217] Example 6

[0218] The battery model is LP2468134-50Ah, and the battery energy density is 280Wh / kg. The thermal runaway test is carried out using an adiabatic accelerating rate calorimeter (ARC) to verify the impact of high specific energy batteries on battery thermal failure. The test results are as follows: Figure 11 shown.

[0219] Figure 11 In the analysis, conventional ARC temperature / voltage / temperature rise rate refers to the temperature / voltage / temperature rise rate of thermal runaway detection of the square ternary battery without active electrical control, and electrically controlled ARC temperature refers to the temperature / voltage / temperature rise rate of active control detection of the square ternary battery with active electrical control at a discharge rate of 0.05C.

[0220] like Figure 11 As shown in the figure, the conventional ARC voltage remains unchanged over time and is stable at 4.2V. The electrically regulated ARC voltage continues to decrease over time. As the thermal runaway time continues to increase, the battery voltage decreases from 4.2V to 1V.

[0221] The comparison of the conventional ARC temperature rise rate and the electrically controlled ARC temperature rise rate shows that the conventional ARC temperature rise rate is as high as 8×10 2 ℃ / s, while the electrically controlled ARC temperature rise rate is up to 1×10℃ / s, indicating that active electrical control reduces the temperature rise rate by a factor of 80. The conventional ARC temperature reaches a maximum of 795℃, while the electrically controlled ARC temperature reaches a maximum of 570℃, a maximum temperature reduction of 225℃. This shows that electrical control has a significant effect on suppressing thermal runaway in the square ternary system, significantly reducing the maximum temperature and temperature rise rate of thermal runaway.

[0222] like Figure 12 As shown in the figure, after the thermal runaway of the 50Ah battery, gas was generated by the electrically controlled battery, but no fire or explosion occurred (i.e. Figure 12 B in the figure), while the battery without power regulation caught fire and exploded (i.e. Figure 12 (As shown in A in the middle), indicating that electric control has an obvious thermal runaway suppression effect in the square ternary system.

[0223] Example 7

[0224] The test was conducted using a soft pack battery, model SP11103310, a ternary system with a capacity of 89Ah and an energy density of 290Wh / kg. A discharge rate of 0.05C was also used to actively regulate the battery's electrical behavior. See the test data for details. Figure 13 shown. Figure 13 In the test, conventional ARC temperature / voltage / temperature rise rate refers to the temperature / voltage / temperature rise rate of thermal runaway detection of the soft-pack battery without active electrical control, and electrically controlled ARC temperature refers to the temperature / voltage / temperature rise rate of active control detection of the soft-pack battery with active electrical control at a discharge rate of 0.05C.

[0225] like Figure 13 As shown in the figure, when active electrical control is not applied, the conventional ARC voltage is fixed at 4.2V. After thermal runaway occurs and the maximum temperature is reached, the conventional ARC voltage drops rapidly to 0V, and a violent thermal side reaction occurs. The maximum temperature of the conventional ARC reaches 780°C.

[0226] After applying active electrical control, the electrical control ARC voltage dropped from the initial 4.2V to 3V, the temperature rise rate dropped from 100℃ / s before control to 20℃ / s after electrical control, and the maximum temperature of the electrical control ARC temperature dropped to 498℃. It can be seen that electrical control has a significant thermal runaway suppression effect in the soft pack battery system, which can significantly reduce the maximum temperature and temperature rise rate of thermal runaway.

[0227] like Figure 14 As shown, the battery thermal runaway before the electric control caused combustion and explosion, and the battery was completely destroyed (i.e. Figure 14 As shown in A in the figure), the battery with electronic control generates gas after thermal runaway, but the battery does not catch fire or explode (i.e. Figure 14 As shown in B in the figure, it shows that electric regulation has an obvious effect of inhibiting thermal runaway in the soft-pack battery system.

[0228] Example 8

[0229] The battery module is used for testing. The structural diagram of the battery module is as follows: Figure 15The battery module was tested using LP2468134-50Ah ternary batteries. A 1mm aerogel insulation layer was used to isolate the individual cells. The module was tested in a closed environment at a low temperature of 10°C.

[0230] The battery module consists of two single cells connected in series. T1, T2 and T3 are used for temperature monitoring of the first single cell, and the monitoring locations are the large surface and two side surfaces of the battery respectively. T4, T5 and T6 are used for temperature monitoring of the second cell, and the monitoring locations are the two large surfaces and side surfaces of the battery respectively.

[0231] Thermal runaway is induced by constant power heating on the outside of the first battery, such as Figure 15 As shown, active electrical control is performed during the thermal runaway process, and T1, T2, T3, T4, T5, T6, the voltage U1 of the first battery, and the voltage U2 of the second battery are tested. The test results are shown in Figure 16 As shown, Figure 16 A represents the test data before regulation, and B represents the test data after regulation.

[0232] See also Figure 16 As shown in Figure A, before regulation, the maximum temperature of the two batteries in the battery module was 800°C. The first battery experienced thermal runaway in about 7 minutes, and the second battery experienced thermal runaway in about 18 minutes due to heat spread from the first battery. The battery voltage detection U1 and U2 quickly dropped to 0V after reaching the maximum temperature from 4.2V thermal runaway at full charge. One battery triggered thermal runaway, causing the adjacent battery to catch fire and explode, thereby causing heat spread in the battery module.

[0233] See also Figure 16 As shown in Figure B, a discharge rate of 0.05C is used for regulation, and the voltages of U1 and U2 decrease slowly. This is mainly because the battery thermal runaway time is short and the voltage drop is small. The battery voltage drops from 4.2V to 4V. The maximum thermal runaway temperatures of the two batteries are 770°C and 775°C, respectively, and the thermal runaway time is 8min and 19min. Compared with the battery module before regulation, the maximum thermal runaway temperature after regulation is lower and the thermal runaway time is delayed, but the thermal runaway of the battery module cannot be completely suppressed.

[0234] Example 9

[0235] Compared with Example 8, a 2mm aerogel insulation layer is used to isolate the single cells, and the other module connections and test methods remain unchanged. The test results are as follows: Figure 17 As shown, Figure 17 A represents the test data before regulation, and B represents the test data after regulation.

[0236] See also Figure 17As shown in Figure A, the test results at 10°C in a closed box show that the maximum thermal runaway temperatures of the two batteries before regulation are 910°C and 800°C, and the thermal runaway duration is 6 minutes and 18 minutes. The thermal runaway of the first battery causes heat spread to the adjacent batteries, causing heat spread to the entire module.

[0237] See also Figure 17 As shown in Figure B, after the module is electrically controlled, the maximum temperatures of the two batteries in thermal runaway are 920°C and 710°C, and the temperatures of adjacent batteries are significantly reduced. The thermal runaway time is 6 minutes. The voltage of battery U2 drops from 4.2V to 4V before and after thermal runaway. The battery does not short-circuit, indicating that the adjacent batteries in the module do not cause heat spread. This shows that with the use of a 2mm aerogel insulation layer, under the action of electrical control, only the heated battery will experience thermal runaway, but the adjacent batteries will not experience thermal runaway, indicating that the thermal runaway of a single battery will not cause heat spread in the entire module.

[0238] Example 10

[0239] In an open environment at room temperature of 25°C, a heat spread test is conducted on a battery module formed by three single cells connected in series. The structural diagram of the battery module is shown in the figure below. Figure 18 The battery module was tested using LP2468134-50Ah ternary battery cells. The module was tested in a closed environment at a low temperature of 10°C.

[0240] The battery module consists of two cells connected in series. T1, T3, and T5 are the temperatures at the top of the side of the first, second, and third cells, respectively. U1, U3, and U5 represent the test voltages of cells 1, 2, and 3, respectively.

[0241] The test results are as follows Figure 19 As shown, Figure 19 A represents the test data before regulation, and B represents the test data after regulation.

[0242] A constant power heating sheet is attached to the outside of the first battery as a thermal runaway initiator. Figure 19 As shown in Figure A, for a module without power control, the thermal runaway temperature of the first battery is 850°C. The second battery experiences thermal runaway 12 minutes later, with the maximum battery temperature reaching 840°C and the battery voltage dropping from 4.2V to 0V. The third battery adjacent to the second battery experiences thermal runaway 17 minutes later, with the maximum battery temperature reaching 840°C, a temperature drop of 10°C, and the battery voltage dropping from 4.2V to 0V. Due to the influence of the first and second batteries, the third battery experiences thermal runaway, resulting in a maximum thermal runaway temperature of 750°C for the third battery, and thermal spread occurs.

[0243] like Figure 19As shown in Figure B, after thermal runaway, the first battery in the module reached a maximum temperature of 800°C after electronically controlled operation. The temperature then dropped. The second battery experienced thermal runaway and a blowout after 23 minutes, but did not experience thermal runaway. Eleven minutes later, the temperature reached a maximum of 650°C. The third battery did not experience thermal runaway. As can be seen from the voltage at U3, under electronic control, the battery voltage dropped from 4.2V to 3.8V. The electronically controlled voltage dropped by 0.4V, but did not drop to 0V, indicating normal battery voltage.

[0244] Figure 20 This is a photo of the battery being tested. Figure 20 A in the middle is a photo of the module before testing. Figure 20 Picture B in the middle is a photo of the module without any adjustment. Figure 20 Figure C in the middle is a photo of the module after active electric control.

[0245] like Figure 20 As shown in Figure B, when there was no electrical regulation, all three batteries experienced thermal runaway, the explosion-proof valves opened, and the first and second batteries were severely damaged.

[0246] like Figure 20 As shown in Figure C, of ​​the three batteries that have been electronically controlled, only the explosion-proof valves of the first and second batteries are open, and the third battery is intact and has no abnormalities. This shows that the electronic control can also inhibit heat spread in the module at room temperature of 25°C.

[0247] Example 11

[0248] The LP2468134-23Ah prismatic lithium iron phosphate battery module was used for verification. The test was conducted at room temperature of 25°C. Three batteries were connected in series. No insulation layer was added between the single batteries. A constant power heater was attached to the outside of the first battery to induce thermal runaway. The battery module was tested. The test results are as follows: Figure 21 As shown, Figure 21 A represents the test data before regulation, and B represents the test data after regulation.

[0249] Figure 21 In the figure, T1, T2, and T3 refer to the temperatures on the upper sides of the first, second, and third batteries respectively, and T4 refers to the temperature in the middle of the large surface of the third battery.

[0250] like Figure 21 As shown in Figure A, the maximum thermal runaway temperatures of T1, T2 and T3 of the battery before regulation are 475°C, 325°C and 450°C respectively, and the thermal runaway time is 24min, 25min and 34min.

[0251] like Figure 21As shown in Figure B, the peak thermal runaway temperatures for the battery module with electronic regulation are 375°C, 285°C, and 150°C, respectively, with thermal runaway durations of 24 minutes, 25 minutes, and 42 minutes. This indicates that compared to the module without electronic regulation, the module with electronic regulation experiences a delayed onset of thermal runaway and a lower thermal runaway temperature, particularly in the third battery, where the temperature drops from 450°C to 150°C.

[0252] Depend on Figure 22 It can be seen that when the batteries of the three-battery module are not regulated, the explosion-proof valves of the three batteries are all open, and the first and second batteries are seriously damaged (such as Figure 22 As shown in A in the middle), after the module was electrically controlled, the first battery was severely damaged, but the explosion-proof valves of the second and third batteries were not opened, and the batteries did not cause heat spread (as shown in Figure 22 As shown in B), it shows that the three-battery module lithium iron phosphate battery can suppress the heat spread of the battery module through electrical regulation alone without adding a thermal insulation layer.

[0253] To sum up, in the present application, by actively electrically regulating the battery during the self-heating stage of the battery and applying a target discharge rate to the battery to discharge it, the thermal runaway time of the battery can be extended, the thermal runaway temperature of the battery can be lowered, the reaction concentration of the negative electrode electrolyte interface reaction can be reduced, and the thermochemical heat generated by the interface reaction can be reduced, so that the total heat generation of the entire battery is reduced, thereby suppressing the occurrence of thermal runaway of the battery and the spread of heat.

[0254] In addition, the use of this active electrical control method has a significant thermal runaway suppression effect in the square ternary battery system, which can significantly reduce the maximum temperature and temperature rise rate of thermal runaway; it has a significant thermal runaway suppression effect in the soft-pack battery system, which can significantly reduce the maximum temperature and temperature rise rate of thermal runaway; at the same time, it also has a significant inhibitory effect on the thermal runaway of battery modules with multiple single cells connected in series, which can reduce the temperature of thermal runaway, prolong the time of thermal runaway, and isolate the heat spread between two adjacent single cells.

[0255] It should be noted that the method of the embodiment of the present application can be performed by a single device, such as a computer or server. The method of this embodiment can also be applied in a distributed scenario and performed by multiple devices working together. In such a distributed scenario, one of the multiple devices may only perform one or more steps of the method of the embodiment of the present application, and the multiple devices will interact with each other to complete the method.

[0256] It should be noted that the above describes some embodiments of the present application. In some cases, the actions or steps described in the above embodiments can be performed in an order different from that in the above embodiments and still achieve the desired results. In addition, the processes depicted in the accompanying drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0257] Based on the same inventive concept, corresponding to any of the above-mentioned embodiments and methods, the present application also provides a system for suppressing thermal runaway of a battery, wherein the battery includes a plurality of single cells.

[0258] refer to Figure 23 , the system for suppressing battery thermal runaway comprises:

[0259] The monitoring module 100 is configured to monitor the temperature rise rate and / or cell voltage of each of the single cells;

[0260] The acquisition module 200 is configured to acquire the cell temperature and electrochemical information of a cell in response to the temperature rise rate and / or cell voltage of the cell meeting the self-heating condition;

[0261] A determination module 300 is configured to determine a target discharge rate based on the electrochemical information and the temperature of the single battery;

[0262] The control module 400 is configured to control the battery to discharge at the target discharge rate.

[0263] For the convenience of description, the above devices are described as being divided into various modules according to their functions. Of course, when implementing this application, the functions of each module can be implemented in the same or multiple software and / or hardware.

[0264] The device of the above embodiment is used to implement the corresponding method of suppressing battery thermal runaway and heat spread in any of the above embodiments, and has the beneficial effects of the corresponding method embodiment, which will not be repeated here.

[0265] Based on the same inventive concept, corresponding to any of the above-mentioned embodiments and methods, the present application also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and runnable on the processor, wherein when the processor executes the program, the method for suppressing battery thermal runaway and heat spread as described in any of the above embodiments is implemented.

[0266] Figure 24A more specific hardware structure diagram of an electronic device provided in this embodiment is shown. The device may include: a processor 1010, a memory 1020, an input / output interface 1030, a communication interface 1040, and a bus 1050. The processor 1010, the memory 1020, the input / output interface 1030, and the communication interface 1040 are communicatively connected to each other within the device via the bus 1050.

[0267] The processor 1010 can be implemented using a general-purpose CPU (Central Processing Unit), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits, and is used to execute relevant programs to implement the technical solutions provided in the embodiments of this specification.

[0268] The memory 1020 can be implemented in the form of ROM (Read Only Memory), RAM (Random Access Memory), static storage devices, dynamic storage devices, etc. The memory 1020 can store an operating system and other application programs. When the technical solutions provided in the embodiments of this specification are implemented through software or firmware, the relevant program code is stored in the memory 1020 and is called and executed by the processor 1010.

[0269] The input / output interface 1030 is used to connect to input / output modules to enable information input and output. The input / output modules can be configured as components within the device (not shown) or externally connected to the device to provide corresponding functions. Input devices may include a keyboard, mouse, touch screen, microphone, and various sensors. Output devices may include a display, speaker, vibrator, indicator light, and the like.

[0270] The communication interface 1040 is used to connect to a communication module (not shown) to enable communication between the device and other devices. The communication module can communicate via wired means (such as USB, network cable, etc.) or wireless means (such as mobile network, Wi-Fi, Bluetooth, etc.).

[0271] The bus 1050 comprises a pathway for transmitting information between various components of the device, such as the processor 1010 , the memory 1020 , the input / output interface 1030 , and the communication interface 1040 .

[0272] It should be noted that although the above device only shows the processor 1010, the memory 1020, the input / output interface 1030, the communication interface 1040, and the bus 1050, in a specific implementation, the device may also include other components necessary for normal operation. In addition, it will be understood by those skilled in the art that the above device may only include the components necessary to implement the embodiments of this specification, and does not necessarily include all the components shown in the figure.

[0273] The electronic device of the above embodiment is used to implement the corresponding method of suppressing battery thermal runaway and heat spread in any of the above embodiments, and has the beneficial effects of the corresponding method embodiment, which will not be repeated here.

[0274] Based on the same inventive concept, corresponding to any of the above-mentioned embodiments and methods, the present application also provides a non-transitory computer-readable storage medium, wherein the non-transitory computer-readable storage medium stores computer instructions, and the computer instructions are used to enable the computer to execute the method for suppressing battery thermal runaway and heat spread as described in any of the above embodiments.

[0275] The computer-readable media of this embodiment includes permanent and non-permanent, removable and non-removable media that can be used to store information by any method or technology. The information can be computer-readable instructions, data structures, program modules, or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassettes, tape disk storage or other magnetic storage devices, or any other non-transmission media that can be used to store information that can be accessed by a computing device.

[0276] The computer instructions stored in the storage medium of the above embodiment are used to enable the computer to execute the method for suppressing battery thermal runaway and heat spread as described in any of the above embodiments, and have the beneficial effects of the corresponding method embodiments, which will not be repeated here.

[0277] Based on the same inventive concept, corresponding to any of the above-mentioned embodiments and methods, the present application also provides a computer program product, including computer program instructions. When the computer program instructions are run on a computer, the computer is caused to execute the method for suppressing battery thermal runaway and heat spread as described in any of the above embodiments, which has the beneficial effects of the corresponding method embodiments and will not be repeated here.

[0278] It is understandable that before using the technical solutions of each embodiment of the present disclosure, the type, scope of use, usage scenarios, etc. of the personal information involved will be informed to the user in an appropriate manner, and the user's authorization will be obtained.

[0279] For example, in response to a user's active request, a prompt message is sent to the user to clearly inform the user that the requested operation will require the acquisition and use of the user's personal information. This allows the user to independently choose whether to provide personal information to the electronic device, application, server, storage medium, or other software or hardware that performs the operation of the disclosed technical solution based on the prompt message.

[0280] As an optional but non-limiting implementation, in response to a user's active request, the prompt information may be sent to the user in the form of a pop-up window, in which the prompt information may be presented in text form. Furthermore, the pop-up window may also contain a selection control for the user to select "agree" or "disagree" to provide personal information to the electronic device.

[0281] It is understandable that the above notification and user authorization process are merely illustrative and do not constitute a limitation on the implementation of the present disclosure. Other methods that comply with relevant laws and regulations may also be applied to the implementation of the present disclosure.

[0282] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of the present application is limited to these examples. In line with the present application, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of the different aspects of the embodiments of the present application as described above, which are not provided in detail for the sake of simplicity.

[0283] In addition, to simplify the description and discussion, and to avoid obscuring the understanding of the embodiments of the present application, well-known power / ground connections to integrated circuit (IC) chips and other components may or may not be shown in the provided figures. Furthermore, devices may be shown in block diagram form to avoid obscuring the understanding of the embodiments of the present application, and this also takes into account the fact that the implementation details of these block diagram devices are highly dependent on the platform on which the embodiments of the present application will be implemented (i.e., these details should be fully understood by those skilled in the art). Where specific details (e.g., circuits) are set forth to describe the exemplary embodiments of the present application, it will be apparent to those skilled in the art that the embodiments of the present application can be implemented without these specific details or with variations therefrom. Therefore, these descriptions should be considered illustrative rather than restrictive.

[0284] Although the present invention has been described in conjunction with specific embodiments thereof, many alternatives, modifications, and variations of these embodiments will be apparent to those skilled in the art based on the foregoing description. For example, other memory architectures (e.g., dynamic RAM (DRAM)) may utilize the discussed embodiments.

[0285] The embodiments of the present application are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the present application. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the embodiments of the present application should be included in the scope of protection of the present application.

Claims

1. A method for suppressing thermal runaway and heat spread of a battery, wherein the battery comprises a plurality of single cells, characterized in that: The method comprises: monitoring the temperature rise rate and / or cell voltage of each of the single cells; In response to a temperature rise rate of a single battery being greater than a preset temperature rise rate, and / or a single cell voltage of a single battery exceeding a preset voltage range, determining that the temperature rise rate and / or the single cell voltage of the single battery meet the self-heating condition; In response to a temperature rise rate and / or cell voltage of a single cell meeting a self-heating condition, obtaining the cell temperature and electrochemical information of the single cell; wherein the electrochemical information includes target portion electrochemical information, the target portion electrochemical information includes target portion mass information, target portion reaction enthalpy information, target portion activation energy information and target portion concentration ratio, the target portion mass information includes the sum of the masses of the components in the target portion, the target portion reaction enthalpy information is the inverse of the enthalpy change value of the chemical reaction of the components in the target portion, the target portion concentration ratio is the minimum ratio of the sum of the concentrations of the components in the target portion to the sum of the concentrations of all components in the battery, the target portion activation energy information is the activation energy of the chemical reaction of the components in the target portion, and the target portion is a negative electrode sheet, an electrolyte or a solid electrolyte interface layer; Determining a target discharge rate based on the electrochemical information and the temperature of the single battery includes: Determining an allowable discharge rate allowed to be applied to the target portion of the battery based on the electrochemical information of the target portion and the temperature of the single battery, comprising: Determining a total rate constant of the target portion based on a preset minimum heat of the target portion, mass information of the target portion, and reaction enthalpy information of the target portion, including: determining a product of the mass information of the target portion and the reaction enthalpy information of the target portion as a first product of the target portion; and determining a ratio of the preset minimum heat of the target portion to the first product of the target portion as the total rate constant of the target portion; Determining a target portion reaction rate constant based on the target portion concentration ratio, the target portion activation energy information, and the single cell temperature, including determining the product of a gas constant and the single cell temperature as a second product; determining the inverse of the ratio of the target portion activation energy information to the second product as a target portion first ratio; raising the first ratio of the target portion to the power of the natural constant e as a target portion initial rate constant; and determining the product of the target portion initial rate constant, the target portion concentration ratio, and the target portion frequency factor as the target portion reaction rate constant; Determine the difference between the total rate constant of the target portion and the reaction rate constant of the target portion as the allowable discharge rate of the target portion; Determine the minimum rate among all the allowable discharge rates as the target discharge rate; The battery is controlled to discharge at the target discharge rate.

2. The method according to claim 1, characterized in that The target discharge rate is 0.05C~1C.

3. The method according to claim 1, characterized in that The monitoring of the temperature rise rate and / or cell voltage of each single cell includes: In response to the battery being in a thermal runaway detection state, heating the battery so that the temperature of the battery rises to a preset temperature; Stop heating and let the battery rest for a preset time; The temperature rise rate and / or cell voltage of each of the single cells are monitored.

4. The method according to claim 1, wherein In response to the battery being in a charging state, charging of the battery is stopped while the control battery is discharged at the target discharge rate.

5. The method according to claim 1, wherein A heat insulation layer is provided between two adjacent single batteries, and the thickness of the heat insulation layer is less than or equal to 2 mm.

6. A system for suppressing thermal runaway of a battery, wherein the battery comprises a plurality of single cells, characterized in that: The system comprises: a monitoring module configured to monitor the temperature rise rate and / or cell voltage of each of the single cells; and in response to the temperature rise rate of a single cell being greater than a preset temperature rise rate and / or the cell voltage of a single cell exceeding a preset voltage range, determining that the temperature rise rate and / or cell voltage of the single cell meets a self-heating condition; an acquisition module configured to acquire the cell temperature and electrochemical information of a cell in response to the temperature rise rate and / or cell voltage of a cell meeting a self-heating condition; wherein the electrochemical information includes target portion electrochemical information, the target portion electrochemical information includes target portion mass information, target portion reaction enthalpy information, target portion activation energy information, and target portion concentration ratio; the target portion mass information includes the sum of the masses of the components in the target portion; the target portion reaction enthalpy information is the inverse of the enthalpy change value of the chemical reaction of the components in the target portion; the target portion concentration ratio is the minimum ratio of the sum of the concentrations of the components in the target portion to the sum of the concentrations of all components in the battery; the target portion activation energy information is the activation energy of the chemical reaction of the components in the target portion; the target portion is a negative electrode sheet, an electrolyte, or a solid electrolyte interface layer; The determination module is configured to determine the target discharge rate based on the electrochemical information and the temperature of the single cell, including: determining the allowable discharge rate allowed to be applied to the target part of the battery based on the electrochemical information of the target part and the temperature of the single cell, including: determining the target part total rate constant based on the preset target part minimum heat, the target part mass information and the target part reaction enthalpy information, including: determining the product of the target part mass information and the target part reaction enthalpy information as the target part first product; determining the ratio of the preset target part minimum heat to the target part first product as the target part total rate constant; determining the target part total rate constant based on the target part concentration ratio, the target part activation energy information and the target part reaction enthalpy information. The temperature of the single cell is used to determine the reaction rate constant of the target part, including determining the product of the gas constant and the temperature of the single cell as a second product, determining the inverse of the ratio of the activation energy information of the target part to the second product as a first ratio of the target part, taking the first ratio of the target part raised to the power of the natural constant e as an initial rate constant of the target part, and determining the product of the initial rate constant of the target part, the concentration ratio of the target part, and the frequency factor of the target part as the reaction rate constant of the target part; determining the difference between the total rate constant of the target part and the reaction rate constant of the target part as the allowable discharge rate of the target part; and determining the minimum rate among all the allowable discharge rates as the target discharge rate; The control module is configured to control the battery to discharge at the target discharge rate.

7. An electronic device comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that: When the processor executes the computer program, the method according to any one of claims 1 to 5 is implemented.

8. A computer-readable storage medium storing computer instructions, characterized in that: The computer instructions are used to enable a computer to execute the method according to any one of claims 1 to 5.

9. A computer program product comprising computer program instructions, characterized in that When the computer program instructions are executed on a computer, the computer is caused to perform the method according to any one of claims 1 to 5.

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