A battery

Abstract

The utility model provides a kind of battery, battery includes shell, electric core, heating sheet and heating wire, electric core is arranged in shell;Heating sheet is arranged in shell, to be used for heating electric core;And, heating wire is connected in heating sheet, to be used for power supply to heating sheet;By heating sheet is arranged in the shell interior of battery, to heat the electric core in shell interior, to be able to cause the thermal runaway phenomenon of electric core from battery interior, for the simulation more real of the case that battery occurs thermal runaway, and then improve the accuracy of thermal runaway test.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, specifically to a battery. Background Technology

[0002] Lithium-ion batteries are being used more and more widely in new energy vehicles, and they are the main component of their power output. Therefore, vehicle safety is receiving increasing attention. Thus, safety verification is particularly important in the development of lithium-ion batteries, especially verification regarding thermal runaway.

[0003] In related technologies, existing lithium battery thermal runaway tests mainly target the external thermal runaway heating of the entire battery, thus failing to obtain heating data inside the battery, resulting in poor test accuracy. Utility Model Content

[0004] The present invention provides a battery that can improve the technical problem that existing lithium battery thermal runaway testing mainly targets the external thermal runaway of the entire battery, resulting in poor accuracy.

[0005] An embodiment of this utility model provides a battery comprising:

[0006] case;

[0007] The battery cell is housed within the casing;

[0008] A heating element is disposed inside the housing for heating the battery cell;

[0009] A heating wire is connected to the heating element to supply power to the heating element. In some embodiments, the heating element is attached to the outer surface of the battery cell.

[0010] By attaching the heating element to the outer surface of the battery cell, the entire battery cell can be heated more evenly. This causes the external temperature of the battery cell to rise first, and then the heat is gradually transferred to the inside, eventually resulting in a relatively uniform increase in the overall temperature of the battery cell.

[0011] Furthermore, the heating element is attached to the outer surface of the battery cell, which can quickly raise the external temperature of the battery cell to a high level, thereby making it easier to trigger the thermal runaway response of the battery cell. This heating method can simulate the thermal runaway situation caused by external heating of the battery cell during actual use (such as external short circuit, external high temperature environment, etc.), making the test results closer to the actual application scenario. In some embodiments, the heating element is disposed inside the battery cell.

[0012] By attaching the heating element to the inside of the battery cell, the core part of the battery cell can be heated directly, allowing the internal temperature of the battery cell to rise rapidly. This reduces the delay in heat transfer, resulting in a smaller temperature difference between the inside and outside of the battery cell, and thus enabling more precise control of the overall temperature of the battery cell.

[0013] For example, for some multi-layered battery cells, heating elements attached to the inside can quickly bring the active materials and other key components inside the cell to the required temperature, thereby raising the temperature of the entire cell and improving heating efficiency and uniformity.

[0014] Furthermore, the heating element is attached inside the battery cell, allowing it to directly act on the core reaction area of ​​the cell. This enables more precise triggering of the cell's thermal runaway response and more accurate simulation of the internal thermal runaway process. This heating method allows for better research into the internal thermal runaway mechanism of the battery cell, providing more accurate data support for battery safety design.

[0015] In some embodiments, the battery cell includes a wound electrode sheet, and a heating element is attached to the electrode sheet along the radial direction of the battery. The electrode sheet includes a wound end, and when the electrode sheet is in an unfolded state, the ratio of the distance between the heating element and the wound end to the length of the electrode sheet is ≥1 / 5.

[0016] By controlling the distance between the heating element and the winding end of the electrode to more than 1 / 5 of the overall length of the electrode, the heating element is positioned in the inner part of the cell. This ensures that the heat from the heating element is preferentially applied to the main area of ​​the electrode where the coating is uniform and the reactivity is stable. This makes the thermal runaway phenomenon closer to the internal failure mode when the battery is working normally, thus obtaining more realistic thermal runaway data of the cell.

[0017] In addition, setting an appropriate distance between the winding ends of the heating element and the electrode allows the heat from the heating element to be gradually conducted through the electrode first, avoiding an instantaneous thermal runaway. Therefore, it allows the external sensor more time to collect complete data on the initial stage of thermal runaway, ensuring the effectiveness of the thermal runaway test.

[0018] In some embodiments, the cell includes an electrode, and a heating element is attached to the electrode along the radial direction of the battery, wherein the ratio of the height of the heating element to the height of the electrode is between 7 / 10 and 9 / 10.

[0019] The effective reaction area of ​​the electrode is usually concentrated in the middle, while there may be blank areas at the top and bottom where no active material is coated. Therefore, setting the height of the heating element to 70%-90% of the electrode height can accurately cover the main area of ​​the electrode coating, ensuring that heat is directly applied to the core reaction area of ​​the battery charging and discharging, and efficiently triggering thermal runaway reaction.

[0020] If the height of the heating element is too high, it may cause overheating in the inactive areas at the top or bottom of the electrode, leading to localized thermal runaway rather than overall failure, causing the test results to deviate from the actual situation. If the height of the heating element is too low, it may be too short and only trigger a localized reaction. Therefore, by setting reasonable parameters to match the height of the heating element with that of the electrode, the heat from the heating element can be evenly diffused along the plane of the electrode, avoiding abnormal temperature gradients caused by excessive or insufficient height difference, and ensuring that thermal runaway occurs throughout the main body of the cell.

[0021] In some embodiments, the electrode includes a positive electrode and a negative electrode, and at least one of the positive electrode and the negative electrode is attached to the heating element along the radial direction of the battery.

[0022] The positive and negative electrodes are the core areas where electrochemical reactions occur inside the battery. Therefore, placing a heating element on the positive or negative electrode allows for direct heating of the electrode materials, thereby more precisely triggering the thermal runaway reaction of the battery cell. In some embodiments, the battery cell includes at least a separator disposed between the positive and negative electrodes, with one end of the heating wire passing through the separator to connect to the heating element.

[0023] In this embodiment, the heating wire extends out from the diaphragm, which will not damage the positive or negative electrode, while achieving the purpose of leading out the heating wire, thereby ensuring the smooth conduct of the thermal runaway test.

[0024] In some embodiments, the battery includes an explosion-proof valve with an opening, through which a heating wire passes. The heating wire located inside the housing is electrically connected to the heating element, while the heating wire located outside the housing is used to connect to a power source.

[0025] An explosion-proof valve is a standard component installed on the battery casing to release gas when the internal pressure is too high. By providing an opening in the explosion-proof valve and passing the heating wire through it, additional openings in other locations on the casing can be avoided, reducing the complexity of the battery structure.

[0026] Furthermore, the heating wires need to carry high current, which can easily generate electromagnetic interference. Therefore, by concentrating the heating wires from the explosion-proof valve, the exposed length of the heating wires inside the casing can be shortened, and interference with the signals inside the battery cell can be reduced, thus ensuring the test effect of thermal runaway testing.

[0027] Furthermore, traditional heating wire lead-out methods may require reserving space on the side or bottom of the casing, potentially causing conflicts with the installation positions of monitoring devices such as temperature and pressure sensors. In contrast, the explosion-proof valve is located at the top of the battery, and the heating guide extends along the height direction, avoiding interference with the placement of side or bottom sensors and improving the accuracy of thermal runaway data acquisition.

[0028] In some embodiments, the heating wire and the opening are sealed together by a sealant.

[0029] Setting a sealed connection between the heating wire and the opening can prevent the electrolyte inside the battery from leaking out, thus avoiding any impact on the battery's thermal runaway test. Furthermore, setting a sealed connection between the heating wire and the opening can also effectively prevent external moisture and oxygen from entering the battery, thus avoiding the risk of explosion caused by the reaction of the negative electrode material (such as lithium metal) with moisture to generate hydrogen gas.

[0030] In addition, setting a sealed connection between the heating wire and the opening can prevent the internal pressure of the battery from being slowly released through the opening during the test, thereby ensuring that the internal pressure of the battery can accumulate to the opening threshold of the explosion-proof valve, so that the explosion-proof valve can work normally under preset conditions, accurately simulate the real thermal runaway scenario, and ensure the thermal runaway test effect of the battery.

[0031] In some embodiments, the thickness of the heating element is ≤0.1mm.

[0032] By setting the heating element thickness parameters as described above, a thinner heating element can be directly embedded inside the battery, avoiding deformation of the battery's internal structure or changes in electrode spacing due to excessive heating element thickness. This better maintains the battery's original performance and safety, ensuring that thermal runaway test data closely reflects real-world conditions.

[0033] In addition, the thinner heating element structure can maximize the contact area between the heating element and the internal materials of the battery. When the heating element is heated, the heat can be quickly conducted and diffused to the core area of ​​the battery, shortening the thermal runaway trigger time and achieving a more uniform surface temperature distribution. This avoids test deviations caused by local overheating, improves the test efficiency of thermal runaway, and ensures the test effect of thermal runaway.

[0034] In some embodiments, the battery further includes a sensor disposed within the housing for detecting the temperature of the cell.

[0035] In thermal runaway testing, sensors can monitor the temperature changes of the battery cell in real time, providing continuous temperature data to help researchers better understand the propagation process of thermal runaway.

[0036] It should also be noted that the wires connected to the sensor can also pass through the opening on the explosion-proof valve together with the heating wires in this embodiment. Therefore, there is no need to set up a separate channel for the sensor wires, which improves the compactness of the battery structure.

[0037] The beneficial effects of the battery embodiment of this utility model are as follows:

[0038] By placing heating elements inside the battery casing to heat the cells inside, thermal runaway of the cells can be induced from within the battery, providing a more realistic simulation of thermal runaway and thus improving the accuracy of thermal runaway testing. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 This is a cross-sectional view of the battery provided in an embodiment of this utility model;

[0041] Figure 2 yes Figure 1 The diagram shows the connection structure of the heating element and heating wire in the battery.

[0042] Figure 3 yes Figure 1 The diagram shows the structure of the battery cell.

[0043] Figure 4 yes Figure 1 The diagram shown is a structural schematic of the separator in the battery.

[0044] Figure 5 yes Figure 1 The diagram shows the structure of the explosion-proof valve in the battery.

[0045] Marked in the image:

[0046] 1. Battery;

[0047] 100. Shell;

[0048] 200. Battery cell; 210. Electrode; 211. Positive electrode; 212. Negative electrode; 220. Separator;

[0049] 300. Heating element;

[0050] 400. Heating wire;

[0051] 500, Explosion-proof valve; 510, Opening. Detailed Implementation

[0052] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present utility model. In addition, it should be understood that the specific embodiments described herein are only for illustration and explanation of the present utility model and are not intended to limit the present utility model. In the present utility model, unless otherwise stated, directional terms such as "upper" and "lower" generally refer to the upper and lower positions of the device in actual use or operation, specifically the drawing directions in the accompanying drawings; while "inner" and "outer" refer to the outline of the device.

[0053] Lithium-ion batteries are increasingly used in new energy vehicles and constitute a major part of their power output, making vehicle safety a growing concern. During the development of lithium-ion batteries, safety verification is particularly important, especially verification regarding thermal runaway.

[0054] In related technologies, existing thermal runaway tests for lithium batteries 1 mainly target the overall cell 200 for thermal runaway testing, which has poor accuracy. The tests mainly test the overall battery 1 (using only external heating, short circuits, etc.). However, internal heating-induced thermal runaway of lithium batteries 1 and the collection of monitoring data on the thermal runaway process can provide greater assistance for the development of lithium battery safety.

[0055] Reference Figure 1 and Figure 2 As shown, this utility model embodiment provides a battery 1, which includes a housing 100, a battery cell 200, a heating element 300, and a heating wire 400. The battery cell 200 is disposed inside the housing 100; the heating element 300 is disposed inside the housing 100 for heating the battery cell 200; and the heating wire 400 is connected to the heating element 300 for supplying power to the heating element 300.

[0056] By placing the heating element 300 inside the casing 100 of the battery 1 to heat the cell 200 inside the casing 100, thermal runaway of the cell 200 can be induced from inside the battery 1. This provides a more realistic simulation of thermal runaway of the battery 1 and improves the accuracy of thermal runaway testing.

[0057] In some embodiments, the heating element 300 is disposed on the outer surface of the battery cell 200. By attaching the heating element 300 to the outer surface of the battery cell 200, the entire battery cell 200 can be heated more evenly, so that the external temperature of the battery cell 200 rises first, and then the heat is gradually transferred to the inside, so that the overall temperature of the battery cell 200 rises relatively evenly.

[0058] Furthermore, the heating element 300 is attached to the outer surface of the battery cell 200, which can quickly raise the temperature of the battery cell 200 to a higher level, making it easier to trigger the thermal runaway reaction of the battery cell 200. This heating method can simulate the thermal runaway caused by the external heating of the battery cell 200 during actual use (such as external short circuit, external high temperature environment, etc.), making the test results closer to the actual application scenario.

[0059] In some embodiments, the heating element 300 is attached to the interior of the battery cell 200 along the radial direction of the battery 1. By attaching the heating element 300 to the interior of the battery cell 200, the core part of the battery cell 200 can be directly heated, allowing the temperature inside the battery cell 200 to rise rapidly. This reduces the delay in heat transfer, resulting in a relatively small temperature difference between the interior and exterior of the battery cell 200, and thus enabling more precise control of the overall temperature of the battery cell 200.

[0060] For example, for some multi-layered battery cells 200, the heating element 300 attached to the inside can quickly bring the key parts such as the active material inside the battery cell 200 to the required temperature, thereby driving up the temperature of the entire battery cell 200 and improving the heating efficiency and uniformity.

[0061] Furthermore, the heating element 300 is attached inside the cell 200, allowing it to directly act on the core reaction area of ​​the cell 200. This enables more precise triggering of the thermal runaway response of the cell 200 and more accurate simulation of the thermal runaway process inside the cell 200. This heating method allows for better study of the thermal runaway mechanism inside the cell 200, providing more accurate data support for the safety design of battery 1.

[0062] In some embodiments, refer to Figure 3As shown, the battery cell 200 includes a wound electrode 210, and a heating element 300 is attached to the electrode 210. Along the radial direction of the battery 1, the electrode 210 includes a wound end. When the electrode 210 is in an unfolded state, the ratio of the distance between the heating element 300 and the wound end to the length of the electrode 210 is ≥1 / 5. By controlling the distance between the heating element 300 and the wound end of the electrode 210 to more than 1 / 5 of the overall length of the electrode 210, the position of the heating element 300 is located in the inner part of the middle of the battery cell 200. This ensures that the heat from the heating element 300 preferentially acts on the main area of ​​the electrode 210 where the coating is uniform and the reactivity is stable. This makes the thermal runaway phenomenon closer to the internal failure mode of the battery 1 during normal operation, thereby obtaining more realistic thermal runaway data of the battery cell 200.

[0063] In addition, setting an appropriate distance between the winding end of the heating element 300 and the electrode 210 allows the heat of the heating element 300 to be conducted gradually, avoiding the instantaneous outbreak of thermal runaway. Therefore, it can provide external sensors with more time to collect complete data on the initial stage of thermal runaway, ensuring the test effect of thermal runaway.

[0064] In some embodiments, the cell 200 includes at least an electrode 210. A heating element 300 is attached to the electrode 210 along the radial direction of the battery 1. The ratio of the height of the heating element 300 to the height of the electrode 210 is between 7 / 10 and 9 / 10. The effective reaction area of ​​the electrode 210 is typically concentrated in the middle, while there may be uncoated areas at the top and bottom. Therefore, setting the height of the heating element 300 to 70%-90% of the height of the electrode 210 precisely covers the main area of ​​the electrode coating, ensuring that heat directly acts on the core reaction area of ​​the battery 1 during charging and discharging, efficiently triggering thermal runaway reactions.

[0065] If the height of the heating element 300 is too high, it may cause overheating of the inactive areas at the top or bottom of the electrode 210, leading to local thermal runaway rather than overall failure, causing the test results to deviate from the actual situation. If the height of the heating element 300 is too low, it may cause the heating element 300 to be too short and only trigger a local reaction. Therefore, by setting reasonable parameters to match the height of the heating element 300 with that of the electrode 210, the heat of the heating element 300 can be evenly diffused along the plane of the electrode 210, avoiding abnormal temperature gradients caused by excessive or insufficient height difference, and ensuring that thermal runaway occurs throughout the main body area of ​​the cell 200.

[0066] In some embodiments, the electrode 210 includes a positive electrode 211 and a negative electrode 212; along the radial direction of the battery 1, at least one of the positive electrode 211 and the negative electrode 212 is attached with a heating element 300. The positive electrode 211 and the negative electrode 212 are the core areas where electrochemical reactions occur inside the battery 1. Therefore, by providing a heating element 300 on the positive electrode 211 or the negative electrode 212, the electrode material can be directly heated, thereby triggering the thermal runaway reaction of the cell 200 more precisely.

[0067] In some embodiments, refer to Figure 4 As shown, the battery cell 200 includes at least a separator 220, which is disposed between the positive electrode 211 and the negative electrode 212. One end of the heating wire 400 passes through the separator 220 to connect with the heating element. It should be noted that, in the specific configuration, in order to ensure the insulation effect between the positive electrode 211 and the negative electrode 212, the area of ​​the separator 220 is larger than that of the positive electrode 211 and the negative electrode 212. Therefore, in this embodiment, the heating wire 400 passes through the separator 220 without damaging the positive electrode 211 or the negative electrode 212, while achieving the purpose of leading out the heating wire 400, thereby ensuring the smooth conduct of the thermal runaway test.

[0068] In some embodiments, refer to Figure 5 As shown, battery 1 includes an explosion-proof valve 500 with an opening through which a heating wire 400 passes. The heating wire 400 located inside the housing 100 is electrically connected to the heating element 300, while the heating wire 400 located outside the housing 100 is used to connect to a power source. The explosion-proof valve 500 is a standard component installed on the housing 100 of battery 1, used to release gas when the internal pressure is too high. By providing an opening in the explosion-proof valve 500 and passing the heating wire 400 through it, additional openings in other locations on the housing 100 can be avoided, reducing the structural complexity of battery 1.

[0069] Furthermore, the heating wire 400 needs to carry a high current, which can easily generate electromagnetic interference. Therefore, by concentrating the heating wire 400 from the explosion-proof valve 500, the exposed length of the heating wire 400 inside the housing 100 can be shortened, and interference with the internal signal of the battery cell 200 can be reduced, thus ensuring the test effect of thermal runaway test.

[0070] Furthermore, the traditional method of leading out the heating wire 400 may require reserving space on the side or bottom of the housing 100, potentially causing conflicts with the installation positions of monitoring devices such as temperature sensors and pressure sensors. In contrast, the explosion-proof valve 500 is located at the top of the battery 1, and the heating guide extends along the height direction, avoiding any impact on the arrangement of side or bottom sensors and improving the accuracy of thermal runaway data acquisition.

[0071] In some embodiments, the heating wire 400 is sealed to the opening by a sealant. This sealed connection prevents electrolyte leakage from the battery 1, avoiding any impact on the thermal runaway test of the battery 1. Furthermore, it effectively prevents external moisture and oxygen from entering the battery 1, thus avoiding the risk of an explosion caused by the reaction of the negative electrode material (such as lithium metal) with moisture to generate hydrogen gas.

[0072] In addition, by setting the heating wire 400 to a sealed connection with the opening, it is possible to prevent the internal pressure of the battery 1 from being slowly released through the opening during the test, thereby ensuring that the internal pressure of the battery 1 can accumulate to the opening threshold of the explosion-proof valve 500, so that the explosion-proof valve 500 can work normally under preset conditions, accurately simulate the real thermal runaway scenario, and ensure the thermal runaway test effect of the battery 1.

[0073] In some embodiments, the thickness of the heating element 300 is ≤0.1mm. By setting the thickness parameter of the heating element 300 as described above, a thinner heating element 300 can be directly embedded inside the battery 1, avoiding deformation of the internal structure of the battery 1 or changes in the electrode spacing due to excessive thickness of the heating element 300. This can better maintain the original performance and safety of the battery 1 and ensure that the thermal runaway test data can closely reflect real working conditions.

[0074] In addition, the thinner heating element 300 structure can maximize the contact area between the heating element 300 and the internal materials of the battery 1. When the heating element 300 is heated, the heat can be quickly conducted and diffused to the core area of ​​the battery 1 through the heating element 300, shortening the thermal runaway trigger time and achieving a more uniform surface temperature distribution. This avoids test deviations caused by local overheating, improves the test efficiency of thermal runaway, and ensures the test effect of thermal runaway.

[0075] In some embodiments, the battery 1 further includes a sensor disposed within the housing 100 for detecting the temperature of the cell 200. During thermal runaway testing, the sensor can monitor the temperature changes of the cell 200 in real time, providing continuous temperature data to help researchers better understand the propagation process of thermal runaway.

[0076] It should also be noted that the wires connected to the sensor can also pass through the opening 501 on the explosion-proof valve 500 together with the heating wire 400 in this embodiment. Therefore, there is no need to set up a separate channel for the sensor wires, which improves the compactness of the battery structure.

[0077] The embodiments of this utility model have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this utility model. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this utility model. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this utility model. Therefore, the content of this specification should not be construed as a limitation of this utility model.

Claims

1. A battery, characterized by, include: Casing (100); The battery cell (200) is disposed within the housing (100); A heating element (300) is disposed within the housing (100) for heating the battery cell (200); and, A heating wire (400) is connected to the heating element (300) to supply power to the heating element (300).

2. The battery of claim 1, wherein, Along the radial direction of the battery (1), the heating element (300) is attached to the outer surface of the cell (200).

3. The battery of claim 1, wherein, The heating element (300) is disposed inside the battery cell (200).

4. The battery of claim 3, wherein, The cell (200) includes a wound electrode (210). Along the radial direction of the battery (1), a heating element (300) is attached to the electrode (210). The electrode (210) includes a wound end. When the electrode (210) is in an unfolded state, the ratio of the distance between the heating element (300) and the wound end to the length of the electrode (210) is ≥1 / 5.

5. The battery of claim 3, wherein, The cell (200) includes an electrode (210). Along the radial direction of the battery (1), a heating element (300) is attached to the electrode (210). The ratio of the height of the heating element (300) to the height of the electrode (210) is between 7 / 10 and 9 / 10.

6. The battery of any one of claims 4-5, wherein, The electrode (210) includes a positive electrode (211) and a negative electrode (212); Along the radial direction of the battery (1), at least one of the positive electrode (211) and the negative electrode (212) is attached with the heating element (300).

7. The battery of claim 6, wherein, The battery cell (200) also includes a separator (220) disposed between the positive electrode (211) and the negative electrode (212). One end of the heating wire (400) passes through the separator (220) to connect with the heating element (300).

8. The battery of any one of claims 1-5, wherein, The battery (1) includes an explosion-proof valve (500), which has an opening (510). The heating wire (400) passes through the opening (510). The heating wire (400) located inside the housing (100) is electrically connected to the heating element (300), and the heating wire (400) located outside the housing (100) is used to connect to the power supply.

9. The battery of claim 8, wherein, The heating wire (400) and the opening (510) are sealed together by a sealing element.

10. The battery of any one of claims 1-5, wherein, The thickness of the heating element (300) is ≤0.1mm.

11. The battery according to any one of claims 1-5, characterized in that, The battery (1) also includes a sensor disposed within the housing (100) for detecting the temperature of the cell (200).

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