Thermal runaway triggering method and device of battery cell and battery cell

Abstract

The embodiment of the invention provides a thermal runaway triggering method and device of a battery cell and the battery cell. The thermal runaway triggering method comprises the following steps: providing a battery cell, wherein the battery cell comprises a battery cell body and a test electrode which is at least partially arranged in the battery cell body; connecting one end of a power supply to the extraction electrode of the cell body, and connecting the other end of the power supply to the test electrode to form a test loop; and closing the test loop so as to provide electric energy for the test electrode through the power supply and trigger thermal runaway of the battery cell. As the mechanism of the built-in high-voltage arc discharge triggering thermal runaway of the test electrode is very close to the real inner short thermal runaway triggering mechanism, the safety performance of the battery cell can be better evaluated by adopting the built-in high-voltage arc discharge triggering thermal runaway of the test electrode.

Description

Technical Field

[0001] This application belongs to the technical field of batteries, and particularly relates to a method and device for triggering thermal runaway of an electric core, and an electric core. Background Art

[0002] The occurrence of thermal runaway and thermal diffusion greatly reduces consumers' willingness to purchase new energy vehicles and greatly damages the brand power of enterprises. Therefore, higher requirements are put forward for the mechanism research of thermal runaway, the safety evaluation of products, and the safety protection of products.

[0003] In the existing technology, heating or acupuncture is usually used to trigger thermal runaway. However, due to the large difference between the above thermal runaway triggering method and the real internal short circuit thermal runaway triggering method, the consistency of the heat generation amount triggered by the above thermal runaway triggering method is poor, and the mean value of the heat generation amount has a large deviation. Therefore, in-depth mechanism research cannot be carried out using these thermal runaway triggering methods, the safety evaluation cannot represent the real safety ability, and the safety protection measures are either insufficient or redundant. That is, it is difficult to truly evaluate the safety performance of products using the existing thermal runaway triggering methods. Summary of the Invention

[0004] This application aims to provide a method for triggering thermal runaway of an electric core and an electric core to solve the problem that there is a large difference between the existing thermal runaway touch method and the real internal short circuit thermal runaway triggering method.

[0005] To solve the above technical problems, this application is implemented as follows:

[0006] In a first aspect, this application discloses a method for triggering thermal runaway of an electric core, and the thermal runaway triggering method includes:

[0007] Providing an electric core, where the electric core includes an electric core body and at least part of a test electrode disposed inside the electric core body;

[0008] Connecting one end of a power supply to the lead-out electrode of the electric core body and connecting the other end of the power supply to the test electrode to form a test circuit;

[0009] Closing the test circuit to supply electrical energy to the test electrode through the power supply and trigger thermal runaway of the electric core.

[0010] Optionally, a pole piece is disposed inside the electric core body, a part of the test electrode is disposed between the pole pieces, and the other part of the test electrode is exposed outside the electric core body.

[0011] Optionally, the step of connecting the other end of the power supply to the test electrode includes:

[0012] Connect the other end of the power supply to the part of the test electrode that is exposed outside the cell body.

[0013] Optionally, the lead electrode includes a positive tab and a negative tab, the electrode plate includes a positive electrode plate and a negative electrode plate, the test electrode is connected to the positive electrode plate or the negative electrode plate, and the power supply includes a high-voltage terminal and a low-voltage terminal;

[0014] The step of connecting one end of the power supply to the lead electrode of the cell body and connecting the other end of the power supply to the test electrode to form a test circuit includes:

[0015] When the test electrode is disposed on the negative electrode plate, connect the high-voltage terminal of the power supply to the positive tab of the cell body and connect the low-voltage terminal of the power supply to the test electrode;

[0016] When the test electrode is disposed on the positive electrode plate, connect the high-voltage terminal of the power supply to the test electrode and connect the low-voltage terminal of the power supply to the negative tab.

[0017] Optionally, in the step of closing the test circuit, the output voltage of the power supply is 80 - 100 volts, and the current in the test circuit is 0 - 30 amperes.

[0018] Optionally, the cell includes at least one of a square cell, a soft-pack cell, a cylindrical cell, and a special-shaped cell.

[0019] In a second aspect, the present application also discloses a cell, which includes a cell body and a test electrode, and at least a part of the test electrode is built into the cell body.

[0020] Optionally, electrode plates are disposed in the cell body, a part of the test electrode is disposed between the electrode plates, and another part of the test electrode is exposed outside the cell body, and the part of the test electrode exposed outside the cell body is used to connect to a power supply.

[0021] Optionally, the part of the test electrode built into the cell body is insulated from the electrode plate.

[0022] Optionally, an insulating film is disposed outside the part of the test electrode built into the cell body, and the insulating film is used to insulate the test electrode from the electrode plate.

[0023] Optionally, the test electrode includes a conductive member body, the conductive member body includes a first part built into the cell body and a second part exposed outside the cell body, the first part is disposed between the electrode plates of the cell body, and the second part is used to connect to a power supply.

[0024] Optionally, the test electrode further includes: a seal, which is sleeved outside the second part, and the seal is used to realize the sealed connection between the second part and the cell body.

[0025] Optionally, the cell body includes an aluminum-plastic film, and a sealing layer is arranged inside the aluminum-plastic film, and the material of the sealing layer is polypropylene;

[0026] The material of the seal is polypropylene, and the seal and the sealing layer are hot-melt bonded to realize the sealed connection between the second part and the cell body.

[0027] Optionally, the test electrode includes a conductive part body, an electrical connection part, and a test pole column, and the cell body includes a housing; wherein,

[0028] The conductive part body is arranged between the electrode sheets inside the cell body;

[0029] At least part of the test pole column is exposed outside the housing;

[0030] The electrical connection part is respectively connected to the conductive part body and the test pole column.

[0031] Optionally, the electrical connection part includes one of a nickel strip and a copper strip.

[0032] In a third aspect, the present application also discloses a thermal runaway triggering device for a cell, and the thermal runaway triggering device includes: a power supply and the cell according to any one of the above; wherein,

[0033] One end of the power supply is connected to the lead-out electrode of the cell body of the cell, and the other end of the power supply is connected to the test electrode of the cell body to form a test circuit.

[0034] Optionally, the power supply has a control module, and the control module is used to control the voltage of the test circuit and limit the current of the test circuit.

[0035] Optionally, the thermal runaway triggering device further includes: a data acquisition instrument, the data acquisition instrument is connected to the cell, and the data acquisition instrument is used to acquire the voltage and temperature of the cell.

[0036] In the embodiments of the present application, by providing an electric core, the electric core includes an electric core body and at least a part of a test electrode built in the electric core body; one end of a power supply is connected to the lead-out electrode of the electric core body, and the other end of the power supply is connected to the test electrode to form a test circuit; the test circuit is closed to supply electric energy to the test electrode through the power supply, triggering thermal runaway of the electric core, and triggering thermal runaway of the electric core through high-voltage arc striking inside the test electrode. Since the mechanism of triggering thermal runaway by high-voltage arc striking inside the test electrode is very close to the real triggering mechanism of internal short circuit thermal runaway, therefore, using the high-voltage arc striking inside the test electrode to trigger thermal runaway can better evaluate the safety performance of the electric core.

[0037] Additional aspects and advantages of the present invention will be given in part in the following description, become apparent in part from the following description, or be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The above and / or additional aspects and advantages of the present invention will become apparent and be readily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0039] Figure 1 is a flowchart of the steps of a method for triggering thermal runaway of an electric core according to an embodiment of the present application;

[0040] Figure 2 is a schematic connection diagram of an electric core and a power supply according to an embodiment of the present application;

[0041] Figure 3 is a schematic structural diagram of a test electrode according to an embodiment of the present application;

[0042] Figure 4 is Figure 3 a schematic connection diagram of the test electrode shown and the electric core body;

[0043] Figure 5 is another schematic connection diagram of an electric core and a power supply according to an embodiment of the present application.

[0044] Reference numerals: 100 - electric core body, 101 - positive lead-out electrode, 102 - negative lead-out electrode, 103 - positive electrode plate, 104 - negative electrode plate, 105 - separator, 106 - aluminum plastic film, 200 - test electrode, 201 - insulating film, 202 - conductive part body, 2021 - first part, 2022 - second part, 203 - seal, 204 - electrical connection part, 205 - test terminal post, 300 - power supply. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0045] Embodiments of the present invention will be described in detail below. Examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention and should not be construed as limiting the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in this application without creative efforts belong to the scope of protection of this application.

[0046] The terms "first" and "second" in the description and claims of this application may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, the meaning of "a plurality" is two or more. In addition, "and / or" in the description and claims means at least one of the connected objects. The character " / " generally indicates an "or" relationship between the associated objects before and after.

[0047] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as limiting the present invention.

[0048] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "mounted", "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0049] The embodiments of this application provide a method for triggering thermal runaway of an electric cell, and an electric cell capable of implementing the above thermal runaway triggering method is designed based on this method.

[0050] Referring to Figure 1 , a flowchart of the steps of a method for triggering thermal runaway of an electric cell according to an embodiment of this application is shown. As Figure 1 shown, the thermal runaway triggering method may specifically include the following steps:

[0051] Step 101: Provide an electric cell, which includes an electric cell body and at least a part of a test electrode built in the electric cell body.

[0052] In an embodiment of the present application, an Figure 2 electric cell as shown can be provided, and the electric cell can be used to trigger thermal runaway. As Figure 2 shown, the electric cell specifically includes an electric cell body 100 and at least a part of a test electrode 200 built in the electric cell body 100. As Figure 2 shown, the electric cell body 100 may include lead-out electrodes at least partially exposed outside the electric cell body 100. Specifically, the lead-out electrodes may include a positive electrode tab 101 and a negative electrode tab 102.

[0053] Optionally, the electric cell may include at least one of a square electric cell, a soft-pack electric cell, a cylindrical electric cell, and a special-shaped electric cell. The embodiment of the present application does not specifically limit the type of the electric cell.

[0054] Step 102: Connect one end of a power supply to the lead-out electrode of the electric cell body, and connect the other end of the power supply to the test electrode to form a test circuit.

[0055] As Figure 2 shown, one end of a power supply 300 can be connected to the lead-out electrode of the electric cell body 100 through a wire, and the other end of the power supply 300 can be connected to the test electrode 200 through a wire to form a test circuit composed of the power supply 300 - the test electrode 200 and the lead-out electrode. In a specific application, the power supply 300 can be connected to the positive electrode tab 101 or the negative electrode tab 102. The embodiment of the present application does not limit this.

[0056] Referring to Figure 3 shows a schematic structural diagram of a test electrode according to an embodiment of the present application. Referring to Figure 4 shows Figure 3 a connection schematic diagram of the test electrode shown and the electric cell body. As Figure 4 shown, a pole piece is arranged in the electric cell body 100. The pole piece specifically may include a positive electrode plate 103 and a negative electrode plate 104. A part of the test electrode 200 is arranged between the pole pieces, and another part of the test electrode 200 is exposed outside the electric cell body 100. The part of the test electrode 200 exposed outside the electric cell body 100 can be used to connect to the power supply 300.

[0057] Specifically, Figure 3The shown battery cell can specifically be a soft-pack battery cell. A separator 105 can also be arranged inside the battery cell body 100, and the separator 105 is arranged between the positive electrode sheet 103 and the negative electrode sheet 104. In a specific application, a part of the test electrode 200 can be arranged on the positive electrode sheet 103 or the negative electrode sheet 104. Moreover, the test electrode 200 can be arranged at any position on the positive electrode sheet 103 or the negative electrode sheet 104 according to actual needs. For example, it can be arranged in the middle area or the edge area of the positive electrode sheet 103 or the negative electrode sheet 104, etc. The embodiments of the present application do not limit this.

[0058] It should be noted that Figure 3 in, only the case where the test electrode 200 is arranged on the negative electrode sheet 104 is shown. The test electrode 200 is located in the middle area of the negative electrode sheet 104, and the test electrode 200 is led out from the side of the battery cell body 100. In actual applications, according to the type of the battery cell and the area where the battery cell commonly has thermal runaway, the test electrode 200 can also be arranged on the positive electrode sheet 103, or in other areas on the positive electrode sheet 103 or the negative electrode sheet 104, and the test electrode 200 can also be led out from other positions of the battery cell body 100 according to actual needs. The present application does not limit this.

[0059] Optionally, the part of the test electrode 200 built into the battery cell body 100 is insulated from the electrode sheet to prevent conduction between the test electrode 200 and the electrode sheet. As Figure 2 shown, an insulating film 201 is arranged on the part of the test electrode 200 built into the battery cell body 100, and the insulating film 201 can be used to achieve insulation between the test electrode 200 and the electrode sheet. By way of example, the material of the insulating film 201 can include but is not limited to polyethylene or polypropylene, etc. The embodiments of the present application do not specifically limit the material of the insulating film 201.

[0060] As Figure 3 shown, the test electrode 200 can include a conductive part body 202. The conductive part body 202 can include a first part 2021 built into the battery cell body 100 and a second part 2022 exposed outside the battery cell body 100. The first part 2021 is arranged between the electrode sheets of the battery cell body 100, and the second part 2022 can be used to connect to the power supply 300.

[0061] In a specific application, during the processing of the battery cell, the first part 2021 of the conductive part body 202 can be arranged on the positive electrode sheet 103 or the negative electrode sheet 104 of the battery cell body 100 to build the first part 2021 into the battery cell body 100. The second part 2022 can be exposed outside the battery cell body 100 to facilitate the connection between the second part 2022 and the power supply 300 and improve the connection convenience between the test electrode 200 and the power supply 300.

[0062] Specifically, the material of the conductive member body 202 may include high-melting-point metal sheets capable of conducting electricity, such as nickel sheets and copper sheets. The embodiments of the present application do not specifically limit the material of the conductive member body 202. The conductive member body 202 may be a copper sheet or a nickel sheet with a width of 4-6 mm and a thickness of 0.6-1 mm.

[0063] It should be noted that in specific applications, the length of the conductive member body 202 can be set according to the situation, and the length of the conductive member body 202 entering the battery cell body 100 is adjusted accordingly according to the actual situation. The embodiments of the present application do not limit this.

[0064] As Figure 3 shown, the test electrode 200 may further include: a seal 203. The seal 203 is sleeved outside the second part 2022. The seal 203 can be used to achieve a sealed connection between the second part 2022 and the battery cell body 100, so as to seal the battery cell body 100, avoid the risk of liquid leakage in the battery cell body 100, and prevent external water, dust and other impurities from entering the interior of the battery cell body 100 through the gap between the second part 2022 and the battery cell body 100, improving the use safety of the battery cell body 100.

[0065] As Figure 2 shown, in the case where the battery cell is a soft-pack laminated battery cell, the battery cell body 100 may include an aluminum-plastic film 106. A sealing layer is provided inside the aluminum-plastic film 106, and the material of the sealing layer is polypropylene; the material of the seal 203 is polypropylene, and the seal 203 and the sealing layer are adhesively bonded by hot melting to achieve a sealed connection between the second part 2022 and the battery cell body 100.

[0066] In specific applications, during the heat sealing process of the aluminum-plastic film 106, the polypropylene-based seal 203 and the sealing layer can be melted and bonded together by high-temperature heating to achieve a sealed connection between the second part 2022 and the battery cell body 100.

[0067] Referring to Figure 5 shows another schematic diagram of the connection between the battery cell and the power supply according to the embodiments of the present application. As Figure 5As shown, when the battery cell is an aluminum shell battery cell, the test electrode 200 may further include a conductive member body 202, an electrical connection member 204, and a test terminal 205. The battery cell body 100 may include a housing. Among them, the conductive member body 202 is disposed between the electrode plates within the battery cell body 100; at least a part of the test terminal 205 is exposed outside the housing; the electrical connection member 204 is respectively connected to the conductive member body 202 and the test terminal 205. In this way, by completely placing the conductive member body 202 inside the battery cell body 100 and connecting the conductive member body 202 to the test terminal 205 through the electrical connection member 204, so as to be electrically connected to the power supply 300 through the test terminal 205, the connection convenience between the test terminal 205 and the power supply 300 is improved.

[0068] Optionally, the electrical connection member 204 may include one of a nickel strip and a copper strip. The embodiment of the present application does not specifically limit the material of the electrical connection member 204.

[0069] In practical applications, Figure 5 A side plate may also be provided on the lead-out side of the electrical connection member 204 in the battery cell shown. The side plate may be an insulating side plate to achieve insulation between the electrical connection member and other positions of the battery cell body 100. Moreover, Figure 5 The battery cell structure shown usually has a positive terminal and a negative terminal. The test terminal 205 and the positive and negative terminals are completely independent structures.

[0070] Optionally, the power supply 300 may specifically be a high-voltage power supply, and the range of the power supply 300 may be 0 - 1000V. The other end of the power supply 300 may be connected to the part of the test electrode 200 exposed outside the battery cell body 100 to improve the connection convenience between the power supply 300 and the test electrode 200.

[0071] In a specific application, the power supply 300 may include a high-voltage end and a low-voltage end; when the test electrode 200 is disposed on the negative electrode plate 104, the high-voltage end of the power supply 300 may be connected to the positive electrode tab 101 of the battery cell body 100, and the low-voltage end of the power supply 300 may be connected to the test electrode 200; when the test electrode 200 is disposed on the positive electrode plate 103, the high-voltage end of the power supply 300 may be connected to the test electrode 200, and the low-voltage end of the power supply 300 may be connected to the negative electrode tab 102 to improve the stability of triggering thermal runaway.

[0072] Step 103: Close the test circuit to supply electrical energy to the test electrode through the power supply and trigger thermal runaway of the battery cell.

[0073] In the embodiments of the present application, after connecting the power supply 300 to the lead electrode of the battery cell body 100 and the test electrode 200, the test circuit can be closed to supply electrical energy to the test electrode 200 through the power supply 300, triggering thermal runaway of the battery cell. At this time, the output voltage of the power supply 300 is 80 - 100 volts, and the current in the test circuit is 0 - 30 amperes. By supplying high-voltage electrical energy to the test electrode 200, the temperature of the test electrode 200 can rise sharply within a short time, and trigger thermal runaway of the battery cell from the inside of the battery cell body 100. Since the mechanism of triggering thermal runaway by high-voltage arc discharge inside the test electrode 200 is very close to the actual triggering mechanism of internal short circuit thermal runaway, therefore, using the method of triggering thermal runaway by high-voltage arc discharge inside the test electrode 200 can better evaluate the safety performance of the battery cell.

[0074] Optionally, the power supply 300 has a control module, and the control module can be used to control the voltage of the test circuit and limit the current of the test circuit. Specifically, the high-voltage power supply can have working modes such as constant voltage mode and constant power mode. Under the control of the control module, the high-voltage power supply can work in the constant voltage mode to output a constant voltage to the battery cell and limit the maximum current to trigger thermal runaway of the battery cell efficiently and stably.

[0075] Optionally, the thermal runaway triggering device can further include: a data acquisition instrument, which is connected to the battery cell, and the data acquisition instrument can be used to collect the voltage and temperature of the battery cell to monitor the thermal runaway phenomenon of the battery cell.

[0076] In order to verify the effect of the thermal runaway triggering method, the inventor set up multiple groups of embodiments:

[0077] Embodiment 1: Adopt a soft-pack battery structure, and the positive electrode material is lithium iron phosphate. The electrode body selects a nickel sheet with a width of 5 mm and a thickness of 0.08 mm, and the test electrode 200 is arranged at the center of the large surface of the battery cell body 100. The voltage of the high-voltage power supply 300 is set to 100V, and the current is set to 20A. After closing the high-voltage power supply 300, the voltage rises briefly and then drops rapidly to 0V, and the temperature on the surface of the battery cell rises rapidly to above 500°C. The battery cell shows a smoking phenomenon and undergoes thermal runaway. The heat generation of the battery cell accounts for 60.53% of the electrical energy, and the average value of the heat generation of the battery cell accounting for the electrical energy after repeating three times is 60.97%, indicating that the consistency of this method is good. And compared with thermal runaway triggering methods such as pinprick and heating, it is closer to the heat generation of the battery cell accounting for the electrical energy in the case of internal short circuit by foreign objects (55.09%).

[0078] Table 1 Comparison of different thermal runaway triggering methods

[0079]

[0080] In practical applications, the closer the heat generation amount triggering thermal runaway is to the heat generation amount of a real internal short circuit, the closer the degrees of the two thermal runaways are, and this triggering method is more accurate for evaluating the safety performance of the battery cells. Foreign object internal short circuit is one of the most common real internal short circuit modes. Table 1 compares the heat generation amounts of different thermal runaway triggering methods, and the results show that the high-voltage arc-drawing thermal runaway triggering method in Example 1 has the advantages of low input energy and heat generation amount close to that of a real internal short circuit. In addition, the high-voltage arc-drawing built-in method has good consistency and does not affect the battery cell assembly, etc., making this thermal runaway triggering method reach the leading level in the academic and industrial fields.

[0081] Example 2: Change the above-mentioned soft-pack battery structure to a square battery structure, and other experimental methods are the same as those in Example 1. Taking a blade battery as an example, the high-voltage arc-drawing internal short circuit simulation method can also stably trigger the thermal runaway of the battery. The average value of the ratio of the heat generation amount of the battery cell to the electric energy is 61.13%, which is closer to the ratio of the heat generation amount of a foreign object internal short circuit (56.12%).

[0082] Example 3: Change the above-mentioned soft-pack battery structure to a cylindrical structure, and other experimental methods are the same as those in Example 1. The high-voltage arc-drawing internal short circuit simulation method can also stably trigger the thermal runaway of the battery.

[0083] Example 4: Change the above-mentioned positive electrode material to a ternary material, and the structure is a soft-pack battery. Set the high-voltage power supply voltage to 80V and the limited current to 10A. Other experimental methods are the same as those in Example 1. The high-voltage arc-drawing internal short circuit simulation method can also stably trigger the thermal runaway of the battery.

[0084] Example 5: Change the above-mentioned positive electrode material to a ternary material, and the structure is a square battery. Set the high-voltage power supply voltage to 80V and the limited current to 10A. Other experimental methods are the same as those in Example 1. The high-voltage arc-drawing internal short circuit simulation method can also stably trigger the thermal runaway of the battery.

[0085] Example 6: Change the above-mentioned positive electrode material to a ternary material, and the structure is a cylindrical battery. Set the high-voltage power supply voltage to 80V and the limited current to 10A. Other experimental methods are the same as those in Example 1. The high-voltage arc-drawing internal short circuit simulation method can also stably trigger the thermal runaway of the battery.

[0086] The verification results of the above examples show that the feasibility of the thermal runaway triggering method described in the embodiments of the present application has been fully verified, and at the same time, the universality of this method has been confirmed in different types of battery cells. Finally, by comparing different thermal runaway triggering methods, this method has the advantages of low input energy, heat generation amount close to that of a real internal short circuit, good consistency, and no influence on the battery cell assembly, etc. This thermal runaway triggering method reaches the leading level in the academic and industrial fields. The battery cells designed to trigger thermal runaway according to this method can be applied in directions such as failure analysis, thermal diffusion research, and selection of protective materials.

[0087] In summary, the thermal runaway triggering method of the battery cells described in the embodiments of the present application can at least include the following advantages:

[0088] In the embodiments of the present application, by providing an electric cell, the electric cell includes an electric cell body and at least a part of a test electrode built in the electric cell body; one end of a power supply is connected to the lead-out electrode of the electric cell body, and the other end of the power supply is connected to the test electrode to form a test circuit; the test circuit is closed to supply electric energy to the test electrode through the power supply, triggering thermal runaway of the electric cell, and triggering thermal runaway of the electric cell by high-voltage arc striking inside the test electrode. Since the mechanism of triggering thermal runaway by high-voltage arc striking inside the test electrode is very close to the real internal short circuit thermal runaway triggering mechanism, therefore, using the high-voltage arc striking inside the test electrode to trigger thermal runaway can better evaluate the safety performance of the electric cell.

[0089] The embodiments of the present application also provide an electric cell, the electric cell includes: an electric cell body and a test electrode, and at least a part of the test electrode is built in the electric cell body. The electric cell can be applied to the above thermal runaway triggering method.

[0090] It should be noted that in the embodiments of the present application, the structure of the electric cell is the same as that of the electric cell in any of the above embodiments, and its beneficial effects are also similar, which will not be elaborated here.

[0091] The embodiments of the present application also provide a thermal runaway triggering device for an electric cell. Specifically, the thermal runaway triggering device may include: a power supply and the electric cell in any one of the above; wherein, one end of the power supply is connected to the lead-out electrode of the electric cell body of the electric cell, and the other end of the power supply is connected to the test electrode of the electric cell body to form a test circuit.

[0092] It should be noted that in the embodiments of the present application, the structures of the electric cell and the power supply are the same as those of the electric cell and the power supply in any of the above embodiments, and their beneficial effects are also similar, which will not be elaborated here.

[0093] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "schematic embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0094] Although embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the claims and their equivalents.

Claims

1. A method for triggering thermal runaway of an electric cell, characterized in that, the method for triggering thermal runaway includes: providing an electric cell, where the electric cell includes an electric cell body and at least a part of a test electrode disposed inside the electric cell body; connecting one end of a power supply to the lead-out electrode of the electric cell body, and connecting the other end of the power supply to the test electrode to form a test circuit; closing the test circuit to supply electrical energy to the test electrode through the power supply and trigger thermal runaway of the electric cell.

2. The method for triggering thermal runaway according to claim 1, characterized in that, electrode tabs are provided inside the electric cell body, a part of the test electrode is disposed between the electrode tabs, and the other part of the test electrode is exposed outside the electric cell body.

3. The method for triggering thermal runaway according to claim 2, characterized in that, the step of connecting the other end of the power supply to the test electrode includes: connecting the other end of the power supply to the part of the test electrode exposed outside the electric cell body.

4. The method for triggering thermal runaway according to claim 2, characterized in that, the lead-out electrode includes a positive terminal tab and a negative terminal tab, the electrode tabs include a positive electrode tab and a negative electrode tab, the test electrode is connected to the positive electrode tab or the negative electrode tab, and the power supply includes a high-voltage terminal and a low-voltage terminal; the step of connecting one end of the power supply to the lead-out electrode of the electric cell body and connecting the other end of the power supply to the test electrode to form a test circuit includes: when the test electrode is disposed on the negative electrode tab, connecting the high-voltage terminal of the power supply to the positive terminal tab of the electric cell body and connecting the low-voltage terminal of the power supply to the test electrode; when the test electrode is disposed on the positive electrode tab, connecting the high-voltage terminal of the power supply to the test electrode and connecting the low-voltage terminal of the power supply to the negative terminal tab.

5. The method for triggering thermal runaway according to claim 1, characterized in that, in the step of closing the test circuit, the output voltage of the power supply is 80 - 100 volts, and the current in the test circuit is 0 - 30 amperes.

6. The method for triggering thermal runaway according to any one of claims 1 to 5, characterized in that, the electric cell includes at least one of a prismatic cell, a soft-pack cell, a cylindrical cell, and a shaped cell.

7. An electric cell, characterized in that, the electric cell includes an electric cell body and a test electrode, and at least a part of the test electrode is disposed inside the electric cell body.

8. The method for triggering thermal runaway according to claim 7, characterized in that, electrode tabs are provided inside the electric cell body, a part of the test electrode is disposed between the electrode tabs, the other part of the test electrode is exposed outside the electric cell body, and the part of the test electrode exposed outside the electric cell body is used for connection to a power supply.

9. The electric cell according to claim 8, characterized in that, the part of the test electrode disposed inside the electric cell body is insulated from the electrode tabs.

10. The electric cell according to claim 9, characterized in that, A portion of the test electrode disposed inside the battery cell body is provided with an insulating film for insulating the test electrode from the electrode tab.

11. The battery cell according to claim 8, wherein, the test electrode includes a conductive member body, which includes a first portion disposed inside the battery cell body and a second portion exposed outside the battery cell body. The first portion is disposed between the electrode tabs of the battery cell body, and the second portion is for connection to a power source.

12. The battery cell according to claim 11, wherein, the test electrode further includes a seal member sleeved outside the second portion for sealingly connecting the second portion and the battery cell body.

13. The battery cell according to claim 12, wherein, the battery cell body includes an aluminum-plastic film, and a sealing layer is disposed inside the aluminum-plastic film. The material of the sealing layer is polypropylene; the material of the seal member is polypropylene, and the seal member and the sealing layer are adhesively bonded by hot melting to achieve the sealing connection between the second portion and the battery cell body.

14. The battery cell according to claim 8, wherein, the test electrode includes a conductive member body, an electrical connection member, and a test pole. The battery cell body includes a housing; wherein, the conductive member body is disposed between the electrode tabs inside the battery cell body; at least a portion of the test pole is exposed outside the housing; the electrical connection member is connected to the conductive member body and the test pole respectively.

15. The battery cell according to claim 14, wherein, the electrical connection member includes one of a nickel strip and a copper strip.

16. A thermal runaway triggering device for a battery cell, wherein, the thermal runaway triggering device includes a power source and the battery cell according to any one of claims 7 to 15; wherein, one end of the power source is connected to the lead-out electrode of the battery cell body of the battery cell, and the other end of the power source is connected to the test electrode of the battery cell body to form a test circuit.

17. The thermal runaway triggering device according to claim 16, wherein, the power source has a control module for controlling the voltage of the test circuit and limiting the current of the test circuit.

18. The thermal runaway triggering device according to claim 16, wherein, the thermal runaway triggering device further includes a data acquisition instrument connected to the battery cell for acquiring the voltage and temperature of the battery cell.

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