Battery cell heating triggering device and method
By using the battery cell heating trigger device in the battery pack, the heating module, the temperature acquisition module and the control module are used to ensure that the battery cell is heated until the heat is out of control at a specific temperature and time, solving the problem of inconsistent thermal diffusion testing conditions of the battery pack. Improved the accuracy and consistency of test conclusions.
Patent Information
- Application Number
- CN202411352649.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-26
- Publication Date
- 2024-12-17
AI Technical Summary
The existing battery pack thermal diffusion test scheme has inconsistent testing conditions, resulting in low accuracy of the test conclusions.
Provide a battery cell heating trigger device, including a heating module, a temperature acquisition module and a control module. Through real-time temperature acquisition and control heating module, the target battery cell is heated to a specific time at different heating temperatures until a thermal runaway state occurs and stops Heat to ensure consistency of test conditions.
The target cell is heated through the control module to ensure the unity of temperature and time, improve the accuracy of the test conclusions, reduce the chance of experimental results, and save development cycle and verification costs.
Smart Images
Figure CN119153855A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of thermal management technology, and in particular to a battery core heating triggering device and method. Background Art
[0002] At present, new energy vehicles are becoming more and more popular, and thermal safety accidents often occur on the market, posing a threat to the lives and property of passengers. The thermal diffusion test of the battery pack of new energy vehicles is one of the mandatory safety test items. The accuracy of the thermal diffusion test results is the only indicator to evaluate whether the design of the battery pack meets the thermal diffusion safety requirements. There has always been the randomness of the thermal runaway test results during the test process. The test results of the same batch of samples vary greatly, which is largely caused by inconsistent test conditions. For example, the opening and closing time of the heating plate is inconsistent, the total heating time is inconsistent, and the heating stop conditions are inconsistent. There is no unified rule when testing multiple samples, and the experimental results cannot guide the design. In addition, the preparation cycle of the thermal diffusion test is long and the test cost is expensive. If the accuracy and consistency of the test conditions can be guaranteed, it will be of great help to R&D personnel in saving development cycles and improving the accuracy of verification conclusions.
[0003] In summary, the existing thermal diffusion test schemes for battery packs have the problem of inconsistent test conditions, resulting in low accuracy of test conclusions. Summary of the invention
[0004] In view of this, it is necessary to provide a battery cell heating trigger device and method to solve the technical problem that the existing thermal diffusion test scheme of the battery pack has inconsistent test conditions, resulting in low accuracy of the test conclusion.
[0005] In order to solve the above problems, on the one hand, the present invention provides a battery cell heating triggering device, comprising: A heating module is disposed between the two battery cells and is used to heat the target battery cell among the two battery cells; Temperature acquisition module, used to collect the real-time temperature of the target cell; A control module is communicatively connected with the temperature acquisition module, and is used to control the heating module to heat the target cell according to different heating temperatures in sequence in combination with the real-time temperature of the target cell, and obtain the heating time corresponding to the different heating temperatures, and control the heating module to stop heating when it is determined that the target cell has thermal runaway based on the real-time temperature of the target cell and the heating time.
[0006] In a possible implementation, the heating module includes: a heating film and a power supply box; The positive and negative electrodes of the heating film are connected to the power supply box through a wire, and a switch is provided on the wire; The control module is used to turn on the heating function of the heating film by controlling the switch.
[0007] In a possible implementation, thermal insulation cotton is arranged between the non-target battery cell of the two battery cells and the heating film.
[0008] In a possible implementation, the temperature acquisition module includes a thermocouple sampling line made of glass fiber.
[0009] In a possible implementation, the two battery cells are disposed in a battery casing, and an explosion-proof valve is provided on the battery casing.
[0010] In a possible implementation, the heating module is controlled in combination with the real-time temperature of the target cell to heat the target cell at different heating temperatures in sequence, including: Controlling the heating module to heat the target cell until the real-time temperature of the target cell reaches a first target temperature, and then stopping the heating; Within a first target time after the real-time temperature of the target cell reaches the first target temperature and the explosion-proof valve is not exhausted, controlling the heating module to heat the target cell until the real-time temperature of the target cell reaches the second target temperature, and then stopping the heating; Within a second target time after the real-time temperature of the target cell reaches the second target temperature and the explosion-proof valve is not exhausted, the heating module is controlled to heat the target cell until thermal runaway occurs in the target cell.
[0011] In a possible implementation, determining whether the target cell has thermal runaway based on the real-time temperature of the target cell and the heating time includes: The real-time temperature of the target cell and the heating time are used to determine the temperature rise rate of the target cell; When the duration of the temperature rise rate being greater than the preset rate threshold reaches a target duration, it is determined that thermal runaway occurs in the target battery cell.
[0012] In a possible implementation, when the duration of the temperature rise rate being greater than a preset rate threshold reaches a target duration, determining that the target cell has thermal runaway includes: The voltage drop value of the target battery cell during the heating process is obtained, and when the voltage drop value is greater than a preset drop amplitude and the duration of the temperature rise rate being greater than a preset rate threshold reaches a target duration, it is determined that thermal runaway occurs in the target battery cell.
[0013] In a possible implementation, when the duration of the temperature rise rate being greater than a preset rate threshold reaches a target duration, determining that the target cell has thermal runaway includes: When the real-time temperature of the target cell is greater than a preset maximum temperature value, and the duration of the temperature rise rate being greater than a preset rate threshold reaches a target duration, it is determined that thermal runaway occurs in the target cell.
[0014] On the other hand, the present invention further provides a method for triggering heating of a battery cell, which is applied to the above-mentioned device, and comprises: The real-time temperature of the target cell is collected based on the temperature collection module; Based on the control module, the heating module is controlled in combination with the real-time temperature of the target battery cell to heat the target battery cell according to different heating temperatures in sequence, and the heating times corresponding to the different heating temperatures are obtained. When it is determined that the target battery cell has thermal runaway based on the real-time temperature of the target battery cell and the heating time, the heating module is controlled to stop heating.
[0015] The beneficial effects of adopting the above implementation method are: the battery cell heating trigger device and method provided by the present invention collects the real-time temperature of the target battery cell through the temperature acquisition module; the control module controls the heating module in combination with the real-time temperature of the target battery cell to heat the target battery cell in sequence according to different heating temperatures, and obtains the heating time corresponding to the different heating temperatures, and controls the heating module to stop heating when it is determined that the target battery cell has thermal runaway based on the real-time temperature of the target battery cell and the heating time. The present invention adopts a control module to control the heating module to heat the target battery cell, and heats the target battery cell to a state of thermal runaway. The heating temperature and heating time can be set by the control module. Even if different batteries are heated, the heating temperature and heating time can be guaranteed to be uniform, thereby solving the technical problem that the existing thermal diffusion test scheme of the battery pack has inconsistent test conditions, resulting in low accuracy of the test conclusion. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.
[0017] Figure 1 A principle block diagram of an embodiment of a battery core heating trigger device provided by the present invention; Figure 2 A schematic diagram of the structure of the battery cell provided by the present invention; Figure 3 A flow chart of an embodiment of a method for triggering heating of a battery cell provided by the present invention; Figure 4 This is a flow chart of another embodiment of the battery cell heating triggering method provided by the present invention. DETAILED DESCRIPTION
[0018] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.
[0019] In the description of the embodiments of the present application, unless otherwise specified, “plurality” means two or more than two.
[0020] The terms "including" and "having" and any variations thereof in the embodiments of the present invention are intended to cover non-exclusive inclusions. For example, a process, method, apparatus, product or equipment comprising a series of steps or modules is not necessarily limited to those steps or modules clearly listed, but may include other steps or modules not clearly listed or inherent to these processes, methods, products or equipment.
[0021] The naming or numbering of the steps in the embodiments of the present invention does not mean that the steps in the method flow must be executed in the time / logical sequence indicated by the naming or numbering. The execution order of the named or numbered process steps can be changed according to the technical purpose to be achieved, as long as the same or similar technical effects can be achieved.
[0022] Reference to an "embodiment" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiment may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.
[0023] The present invention provides a battery cell heating triggering device and method, which are respectively described below.
[0024] like Figure 1 As shown, the present invention provides a battery core heating trigger device, comprising: A heating module 101 is disposed between two battery cells and is used to heat the target battery cell among the two battery cells; The temperature acquisition module 102 is used to acquire the real-time temperature of the target cell; The control module 103 is communicatively connected with the temperature acquisition module 102, and is used to control the heating module 101 to heat the target battery cell according to different heating temperatures in sequence in combination with the real-time temperature of the target battery cell, and obtain the heating time corresponding to the different heating temperatures. When it is determined that the target battery cell has thermal runaway based on the real-time temperature of the target battery cell and the heating time, the heating module 101 is controlled to stop heating.
[0025] It can be understood that the battery cell heating trigger device provided by the present invention can be integrated with a battery thermal management system (HMS). The heating module 101 may include a heating plate and a power supply. The heating plate and the power supply are connected by a wire, and a switch is provided on the wire. The position of the heating plate is referenced Figure 2 As shown, the heating plate is arranged between two battery cells and heats the target battery cell.
[0026] The present invention can use a thermocouple sampling line of high-temperature resistant glass fiber to collect real-time temperature data of the heating plate and the trigger battery cell (target battery cell). The real-time temperature data is uploaded to the host computer and the control module 103 of the battery cell heating trigger device through a data acquisition instrument. The control module 103 of the battery cell heating trigger device turns on and off the heating switch of the heating plate through the heating plate control device.
[0027] The battery thermal management system is responsible for monitoring the temperature of the heating plate and the triggering cell temperature and making judgments. The control logic can be updated by rewriting the software parameters.
[0028] The control module 103 of the battery cell heating trigger device is provided with a timing device, which has a timer function, can record the total heating time of the heating plate, and also has a countdown function.
[0029] In some embodiments, the heating module 101 includes: a heating film and a power supply box; The positive and negative electrodes of the heating film are connected to the power supply box through a wire, and a switch is provided on the wire; The control module 103 is used to turn on the heating function of the heating film by controlling the switch to be turned on.
[0030] It is understandable that the heating film can be a PI film (polyimide film), which is made of polyimide film as an outer insulator and metal foil and metal wire as an inner conductive heating element, and is heat-sealed at high temperature and high pressure. The polyimide film electric heating film has excellent insulation strength, excellent electrical strength, excellent thermal conductivity efficiency, and excellent resistance stability. This makes it widely applicable to the heating field and can obtain a fairly high temperature control accuracy.
[0031] In some embodiments, thermal insulation cotton is arranged between the non-target battery cell of the two battery cells and the heating film.
[0032] In some embodiments, the temperature acquisition module 102 includes a thermocouple sampling line made of glass fiber.
[0033] In some embodiments, the two battery cells are disposed in a battery casing, and an explosion-proof valve is disposed on the battery casing.
[0034] In some embodiments, the heating module 101 is controlled in combination with the real-time temperature of the target cell to heat the target cell at different heating temperatures in sequence, including: Controlling the heating module 101 to heat the target cell until the real-time temperature of the target cell reaches a first target temperature, and then stopping the heating; Within a first target time after the real-time temperature of the target cell reaches the first target temperature and the explosion-proof valve is not exhausted, controlling the heating module 101 to heat the target cell until the real-time temperature of the target cell reaches the second target temperature, and then stopping the heating; Within a second target time after the real-time temperature of the target cell reaches the second target temperature and the explosion-proof valve is not exhausted, the heating module 101 is controlled to heat the target cell until thermal runaway occurs in the target cell.
[0035] It is understandable that the control module 103 is responsible for monitoring the heating temperature of the heating module 101 and the real-time temperature of the trigger cell (target cell) and making a judgment. The real-time temperature of the target cell is the back temperature of the target cell away from the heating module 101.
[0036] The control logic of the control module 103 is as follows: when the real-time temperature of the target battery cell is T6=95°C, the heating module 101 is controlled to stop heating, and t1=5min is observed. If the explosion-proof valve is not exhausted within 5min, heating is continued to be performed until T6=100°C, and then the heating module 101 is controlled to stop heating, and t2=5min is observed. t2 may be equal to t1 or unequal. The intervals t1 and t2 may be determined according to the test standard, thermal simulation results or the residual heat heating of the heating plate.
[0037] The features of explosion-proof valve exhaust judgment are as follows: by identifying the explosion-proof valve picture, judge whether the explosion-proof valve has smoke exhaust, or install a smoke alarm near the explosion-proof valve. If the smoke alarm sounds, it means that the explosion-proof valve is exhausting. The function of the explosion-proof valve is that when the battery cell is thermally out of control, a large amount of high-temperature gas will be generated inside the box in a short time. The explosion-proof valve can quickly release the internal air pressure of the box, so that the smoke is discharged in a directional manner and the internal and external air pressures are balanced. The explosion-proof valve is installed between the exhaust hole of the box and the external environment.
[0038] Repeat the above steps until the thermal runaway of a single cell is triggered (determined according to the standard of GB 38031). T6 refers to the back temperature of the triggering cell away from the heating plate, which is close to the actual temperature of the cell. The temperature threshold can be adjusted. T1 and t2 are waiting time or interval time, which can also be adjusted. The control module 103 of the cell heating trigger device has a timer function, which can record the total heating time of the heating plate.
[0039] Traditional tests cannot stop heating at a set temperature, and only visually check whether smoke is discharged from the exhaust valve as a condition for successfully triggering thermal runaway. This judgment method has too many subjective factors, which can easily cause the heat input to the battery pack to exceed the heat required for a single cell to trigger thermal runaway, resulting in harsh thermal diffusion conditions and an inability to reasonably evaluate the experimental results. The present invention uses a stepped heating method to heat a single cell, preventing the heat input from the battery pack from exceeding the heat required for a single cell to trigger thermal runaway, thereby more reasonably evaluating the experimental results.
[0040] In some embodiments, determining whether the target cell has thermal runaway based on the real-time temperature of the target cell and the heating time includes: The real-time temperature of the target cell and the heating time are used to determine the temperature rise rate of the target cell; When the duration of the temperature rise rate being greater than the preset rate threshold reaches a target duration, it is determined that thermal runaway occurs in the target battery cell.
[0041] It can be understood that the temperature rise rate of the target cell is calculated, and when the temperature rise rate of the target cell is greater than or equal to 1° C. / s and lasts for more than 3 seconds, it is determined that thermal runaway occurs in the target cell.
[0042] In some embodiments, when the duration of the temperature rise rate being greater than the preset rate threshold reaches a target duration, determining that the target cell has thermal runaway includes: The voltage drop value of the target battery cell during the heating process is obtained, and when the voltage drop value is greater than a preset drop amplitude and the duration of the temperature rise rate being greater than a preset rate threshold reaches a target duration, it is determined that thermal runaway occurs in the target battery cell.
[0043] It is understandable that when a battery cell triggers thermal runaway, a voltage drop will occur, and the voltage drop value exceeds 25% of the voltage before the thermal runaway is triggered (i.e., the initial voltage), and when the temperature rise rate of the target battery cell is greater than or equal to 1°C / s and lasts for more than 3s, it is determined that the target battery cell has thermal runaway.
[0044] In some embodiments, when the duration of the temperature rise rate being greater than the preset rate threshold reaches a target duration, determining that the target cell has thermal runaway includes: When the real-time temperature of the target cell is greater than a preset maximum temperature value, and the duration of the temperature rise rate being greater than a preset rate threshold reaches a target duration, it is determined that thermal runaway occurs in the target cell.
[0045] It can be understood that the preset maximum temperature value is the maximum operating temperature of the battery cell specified by the battery cell manufacturer. When the real-time temperature of the target battery cell is greater than the preset maximum temperature value, and when the temperature rise rate of the target battery cell is greater than or equal to 1°C / s and lasts for more than 3s, it is determined that the target battery cell has thermal runaway.
[0046] The present invention also provides a method for triggering heating of a battery cell, which is applied to any of the above-mentioned devices, such as Figure 3 As shown, the method includes: S301, collecting the real-time temperature of the target cell based on the temperature collection module 102; S302, based on the control module 103, in combination with the real-time temperature of the target battery cell, the heating module 101 is controlled to heat the target battery cell according to different heating temperatures in sequence, and the heating time corresponding to the different heating temperatures is obtained. When it is determined that the target battery cell has thermal runaway based on the real-time temperature of the target battery cell and the heating time, the heating module 101 is controlled to stop heating.
[0047] It is understandable that the specific method of triggering the heating of the battery cell can be referred to Figure 4 As shown, when the real-time temperature of the target cell is T6=95°C, the heating module 101 is controlled to stop heating, and t1=5min is observed. If the explosion-proof valve is not exhausted within 5min, heating is continued to be performed until T6=100°C, and then the heating module 101 is controlled to stop heating, and t2=5min is observed. t2 may be equal to t1 or unequal to t1. The intervals t1 and t2 may be determined according to the test standard, thermal simulation results or the residual heat heating of the heating plate.
[0048] The battery cell heating trigger device and method provided by the present invention are introduced in detail above. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea; at the same time, for technical personnel in this field, according to the idea of the present invention, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.
Claims
1. A battery cell heating trigger device, characterized in that: include: A heating module is disposed between the two battery cells and is used to heat the target battery cell among the two battery cells; Temperature acquisition module, used to collect the real-time temperature of the target cell; A control module is communicatively connected with the temperature acquisition module, and is used to control the heating module to heat the target cell according to different heating temperatures in sequence in combination with the real-time temperature of the target cell, and obtain the heating time corresponding to the different heating temperatures, and control the heating module to stop heating when it is determined that the target cell has thermal runaway based on the real-time temperature of the target cell and the heating time.
2. The battery cell heating triggering device according to claim 1, characterized in that: The heating module comprises: a heating film and a power supply box; The positive and negative electrodes of the heating film are connected to the power supply box through a wire, and a switch is provided on the wire; The control module is used to turn on the heating function of the heating film by controlling the switch.
3. The battery core heating triggering device according to claim 2, characterized in that: Heat insulation cotton is arranged between the non-target battery cell of the two battery cells and the heating film.
4. The battery core heating triggering device according to claim 1, characterized in that: The temperature acquisition module comprises a thermocouple sampling line made of glass fiber.
5. The battery core heating triggering device according to claim 1, characterized in that: The two battery cells are arranged in a battery casing, and an explosion-proof valve is arranged on the battery casing.
6. The battery core heating triggering device according to claim 5, characterized in that: In combination with the real-time temperature of the target cell, the heating module is controlled to heat the target cell at different heating temperatures in sequence, including: Controlling the heating module to heat the target cell until the real-time temperature of the target cell reaches a first target temperature, and then stopping the heating; Within a first target time after the real-time temperature of the target cell reaches the first target temperature and the explosion-proof valve is not exhausted, controlling the heating module to heat the target cell until the real-time temperature of the target cell reaches the second target temperature, and then stopping the heating; Within a second target time after the real-time temperature of the target cell reaches the second target temperature and the explosion-proof valve is not exhausted, the heating module is controlled to heat the target cell until thermal runaway occurs in the target cell.
7. The battery cell heating triggering device according to any one of claims 1 to 6, characterized in that: Determining whether the target cell has thermal runaway based on the real-time temperature of the target cell and the heating time includes: The real-time temperature of the target cell and the heating time are used to determine the temperature rise rate of the target cell; When the duration of the temperature rise rate being greater than the preset rate threshold reaches a target duration, it is determined that thermal runaway occurs in the target battery cell.
8. The battery cell heating triggering device according to claim 7, characterized in that: When the duration of the temperature rise rate being greater than the preset rate threshold reaches a target duration, determining that the target cell has thermal runaway includes: The voltage drop value of the target battery cell during the heating process is obtained, and when the voltage drop value is greater than a preset drop amplitude and the duration of the temperature rise rate being greater than a preset rate threshold reaches a target duration, it is determined that thermal runaway occurs in the target battery cell.
9. The battery cell heating triggering device according to claim 7, characterized in that: When the duration of the temperature rise rate being greater than the preset rate threshold reaches a target duration, determining that the target cell has thermal runaway includes: When the real-time temperature of the target cell is greater than a preset maximum temperature value, and the duration of the temperature rise rate being greater than a preset rate threshold reaches a target duration, it is determined that thermal runaway occurs in the target cell.
10. A method for triggering heating of a battery cell, characterized in that: The method is applied to the device according to any one of claims 1 to 9, and the method comprises: The real-time temperature of the target cell is collected based on the temperature collection module; Based on the control module, the heating module is controlled in combination with the real-time temperature of the target battery cell to heat the target battery cell according to different heating temperatures in sequence, and the heating times corresponding to the different heating temperatures are obtained. When it is determined that the target battery cell has thermal runaway based on the real-time temperature of the target battery cell and the heating time, the heating module is controlled to stop heating.