A battery

Abstract

The present application relates to a battery. The battery comprises: a housing having a receiving cavity and a bottom plate serving as a side wall of the receiving cavity, the bottom plate having multiple first weak areas; multiple battery cells, each mounted within the receiving cavity, each battery cell comprising a housing and a cell assembly, the housing having an inner cavity and an exhaust passage communicating with the inner cavity, the cell assembly being housed within the inner cavity of the housing; one end of each housing having an exhaust passage correspondingly facing each first weak area on the bottom plate; wherein, when a battery cell experiences thermal runaway, high-pressure gas generated by the battery cell passes through the exhaust passage and breaks through the corresponding first weak area, causing the battery cell experiencing thermal runaway to be ejected from the corresponding first weak area out of the housing.

Description

Technical Field

[0001] The present application relates to the field of battery manufacturing technology, and specifically to a battery. Background Art

[0002] Lithium-ion batteries have high energy density, long cycle life, excellent rate performance and safety, and are environmentally friendly, making them an important energy product for modern electronic products and electric vehicles. To increase the output voltage or current, batteries typically include multiple battery cells connected in series, parallel, or mixed, and each battery cell is integrated into a battery box. During use, if one of the battery cells experiences thermal runaway due to an abnormality, it will emit a large amount of high-temperature smoke and other substances. Without effective blocking measures, the thermal runaway of a battery cell will quickly spread to other battery cells, causing thermal runaway in other battery cells as well, and then triggering thermal runaway of the entire battery, posing a serious threat to personal and property safety. Summary of the Invention

[0003] Based on this, it is necessary to address the above problems and provide a battery that can prevent thermal runaway from spreading to other battery cells and improve battery safety.

[0004] In one aspect, the present application provides a battery, comprising:

[0005] The box body has a receiving cavity and a bottom plate serving as a side wall of the receiving cavity, wherein the bottom plate has a plurality of first weak areas;

[0006] A plurality of battery cells are installed in the receiving cavity, each of the battery cells comprising a housing and a cell assembly, the housing having an inner cavity and an exhaust passage communicating with the inner cavity, the cell assembly being accommodated in the inner cavity; an end of each housing having the exhaust passage facing each of the first weak areas on the bottom plate in a one-to-one correspondence;

[0007] The high-pressure gas generated when the battery cell experiences thermal runaway passes through the exhaust channel and breaks through the corresponding first weak area, so that the battery cell experiencing thermal runaway is ejected from the corresponding first weak area to the outside of the box.

[0008] In some embodiments, the housing includes a shell and a cover plate, the shell has an opening on a side facing the bottom plate, the cover plate covers the opening of the shell, and the shell and the cover plate together enclose the inner cavity;

[0009] The cover plate is provided with the exhaust channel and a second weak area for sealing the exhaust channel. High-pressure gas generated when thermal runaway occurs in the battery cell can break through the second weak area and the corresponding first weak area on the cover plate.

[0010] In some embodiments, the cover plate further has an annular area arranged around the first weak area;

[0011] In the radial direction from the outer edge to the inner edge of the annular area, the distance between the side surface of the annular area facing the inner cavity and the side surface of the annular area facing the bottom plate decreases gradually or in a step-like manner.

[0012] In some embodiments, the cover plate includes a first annular plate, a second annular plate, and a burst-proof disk, wherein the inner edge of the first annular plate is fixedly connected to the inner edge of the second annular plate and encloses the exhaust passage; the outer edge of the first annular plate and the outer edge of the second annular plate are spaced apart from each other, and the second annular plate is located between the first annular plate and the bottom plate;

[0013] The explosion-proof disk is fixedly connected to the first annular plate and / or the second annular plate to close the exhaust channel, and the second weak area is located on the explosion-proof disk.

[0014] In some embodiments, one end of the shell facing the bottom plate has an annular end surface surrounding the opening, and the annular end surface connects the inner wall and the outer wall of the shell;

[0015] The outer edge of the second annular plate has an annular connecting portion, and the annular connecting portion is attached to and fixed to the annular end surface by welding.

[0016] In some embodiments, an annular ridge is provided on a side of the annular connecting portion facing away from the bottom plate, and the annular ridge rests against the inner wall of the shell.

[0017] In some embodiments, each of the battery cells further includes an adhesive block, and the adhesive block is adhesively fixed between the annular connecting portion and the bottom plate.

[0018] In some embodiments, each of the battery cells further includes a current collecting plate disposed between the first annular plate and the battery cell assembly, wherein the outer peripheral edge of the current collecting plate is folded toward the cover plate to form a flange, and the flange is fixedly connected between the outer edge of the first annular plate and the inner wall of the shell.

[0019] In some embodiments, the first annular plate encloses a first sub-channel on the side facing the inner cavity, the second annular plate encloses a second sub-channel on the side facing the bottom plate, and the exhaust channel includes the first sub-channel and the second sub-channel;

[0020] The maximum flow area and the minimum flow area of ​​the first sub-channel are S1 and S2 respectively, and 0.1≤S2 / S1≤0.7.

[0021] In some embodiments, the first annular plate encloses a first sub-channel on the side facing the inner cavity, the second annular plate encloses a second sub-channel on the side facing the bottom plate, and the exhaust channel includes the first sub-channel and the second sub-channel;

[0022] The maximum flow area and the minimum flow area of ​​the second sub-channel are S3 and S4 respectively, and 0.2≤S4 / S3≤0.8.

[0023] In some embodiments, the orthographic projection of the shell on the base plate does not exceed the range of the corresponding first weak area.

[0024] In some embodiments, the battery further includes a busbar disposed in the receiving cavity, the busbar being arranged on a side of each battery cell facing away from the bottom plate, and each battery cell further includes a pole, the pole being disposed on an end of the housing facing away from the bottom plate;

[0025] One of the pole and the busbar is provided with a plug-in hole, and the other is provided with a plug-in protrusion, and the plug-in protrusion is plugged into and matched with the plug-in hole.

[0026] In some embodiments, elastic contact fingers are provided on the inner wall of the peripheral side of the plug hole, and when the plug protrusion is inserted into the plug hole, the elastic contact fingers elastically abut against the plug protrusion.

[0027] In some embodiments, a plurality of first annular notched grooves are formed on the bottom plate, and each of the first annular notched grooves encloses and forms the first weak area.

[0028] In some embodiments, the distance between two adjacent first annular scoring grooves is 1 mm to 5 mm.

[0029] Compared with the prior art, this application has the following beneficial effects:

[0030] During actual use of the above-mentioned battery, if a battery cell experiences thermal runaway, a large amount of high-pressure gas is generated within the battery cell. This high-pressure gas flows through the exhaust duct in the outer casing to the corresponding first weak area on the bottom plate, breaking through the first weak area. After the first weak area corresponding to the battery cell experiencing thermal runaway ruptures, the battery cell experiencing thermal runaway is driven by the high-pressure airflow and ejected from the first weak area on the bottom plate (i.e., the battery cell experiencing thermal runaway is expelled from the outer casing). This prevents the thermal runaway from spreading to other battery cells within the casing, and consequently, prevents thermal runaway of the entire battery, significantly reducing the threat to personal and property safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a schematic diagram of the structure of a battery in one embodiment of the present application (the side panels and top panel of the box are omitted);

[0032] Figure 2 for Figure 1 A schematic structural diagram of the bottom plate of the battery shown;

[0033] Figure 3 for Figure 2 A schematic structural diagram of the bottom plate shown in another perspective;

[0034] Figure 4 for Figure 1 a cross-sectional view of a battery cell of the battery shown;

[0035] Figure 5 for Figure 4 The battery cell is shown as a partial enlarged view at the cover plate (i.e., position E);

[0036] Figure 6 for Figure 4 The shown partial enlarged view of the battery cell at the pole (i.e., position F);

[0037] Figure 7 for Figure 4 A schematic structural diagram of a cover plate of a battery cell shown;

[0038] Figure 8 for Figure 7 a cross-sectional view of the cover plate shown;

[0039] Figure 9 This is a schematic structural diagram of a cover plate in another embodiment of the present application;

[0040] Figure 10 for Figure 9 A cross-sectional view of the cover is shown. DETAILED DESCRIPTION

[0041] To make the above-mentioned objects, features, and advantages of the present application more clearly understood, the specific embodiments of the present application are described in detail below with reference to the accompanying drawings. The following description sets forth many specific details to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways than those described herein, and those skilled in the art can make similar improvements without violating the scope of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0042] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply 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 understood as a limitation on the present application.

[0043] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of such features. Throughout the description of this application, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0044] In this application, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0045] In this application, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0046] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only implementation methods.

[0047] See also Figures 1 to 4 The present application provides a battery comprising a housing and a plurality of battery cells 20. The housing has a receiving cavity and a bottom plate 11 serving as a side wall of the receiving cavity. The bottom plate 11 has a plurality of first weak areas A1, each of which can rupture under high pressure. Each battery cell 20 is mounted in the receiving cavity of the housing. Each battery cell 20 comprises a housing 21 and a cell assembly 22. The housing 21 has an inner cavity 2110 and an exhaust channel B communicating with the inner cavity 2110, and the cell assembly 22 is accommodated in the inner cavity 2110 of the housing 21. One end of the exhaust channel B of the housing 21 of each battery cell 20 corresponds one-to-one to each first weak area A1 on the bottom plate 11, and one end of the exhaust channel B of the housing 21 of each battery cell 20 faces the corresponding first weak area A1, so that high-pressure gas discharged from the exhaust channel B on the housing 21 can flow to the corresponding first weak area A1, thereby breaking through the first weak area A1. When the battery cell 20 experiences thermal runaway, a large amount of high-pressure gas is generated. The generated high-pressure gas passes through the exhaust channel B and breaks through the corresponding first weak area A1, so that the entire battery cell 20 experiencing thermal runaway is ejected from the corresponding first weak area A1 to the outside of the box.

[0048] During actual use of the above-described battery, if a battery cell 20 experiences thermal runaway, a large amount of high-pressure gas is generated within that battery cell 20. This high-pressure gas flows through the exhaust channel B in the outer casing 21 toward the corresponding first weak area A1 on the bottom plate 11, rupturing that first weak area A1. After the first weak area A1 corresponding to the battery cell 20 experiencing thermal runaway ruptures, the battery cell 20 experiencing thermal runaway, driven by the high-pressure gas flow, is ejected from the corresponding first weak area A1 on the bottom plate 11 (i.e., the battery cell 20 experiencing thermal runaway is expelled from the battery cell 20). This prevents the thermal runaway from spreading to other battery cells 20 within the battery cell, and consequently, prevents thermal runaway of the entire battery, significantly reducing the threat to personal and property safety. Furthermore, since the battery cell 20 experiencing thermal runaway is directly ejected from the battery cell 20, the high-pressure gas does not circulate within the battery cell, resulting in a very short exhaust path and highly efficient exhaust and pressure relief.

[0049] Specifically, in this embodiment, the base plate 11 is provided with a plurality of first annular scored grooves 111, each of which encloses a first weak area A1. This allows a battery cell 20 to generate a large amount of high-pressure gas when thermal runaway occurs, which is then discharged through the exhaust channel B. Under the impact of the high-pressure gas discharged from the exhaust channel B, the corresponding first weak area A1 on the base plate 11 ruptures along the first annular scored grooves 111. Driven by the high-pressure gas, the battery cell 20 experiencing thermal runaway is ejected from the ruptured first weak area A1 out of the box. Optionally, each first annular scored groove 111 on the base plate 11 is located on the side of the base plate 11 facing away from the battery cell 20 (i.e., the outer surface). Of course, in other embodiments, each first annular scored groove 111 on the base plate 11 may also be located on the side of the base plate 11 facing the battery cell 20 (i.e., the inner surface).

[0050] Optionally, the spacing between two adjacent first annular scored grooves 111 on the bottom plate 11 is 1 mm to 5 mm. It should be noted that, based on extensive experiments, the inventors have creatively discovered that if the spacing between two adjacent first annular scored grooves 111 on the bottom plate 11 is less than 1 mm, on the one hand, the strength of the portion of the bottom plate 11 between the two adjacent first annular scored grooves 111 is weak, resulting in weak rigidity and strength of the entire bottom plate 11 and prone to deformation; on the other hand, there is a risk that a battery cell 20 experiencing thermal runaway may affect adjacent battery cells 20 when discharged. If the spacing between two adjacent first annular scored grooves 111 on the bottom plate 11 is greater than 5 mm, space is wasted, significantly reducing the volumetric energy density of the battery. In this embodiment, the spacing between two adjacent first annular scored grooves 111 on the bottom plate 11 is designed to be 1 mm to 5 mm to minimize the adverse effects on the rigidity and strength of the bottom plate 11, the adverse effects on adjacent battery cells 20 when a battery cell 20 experiencing thermal runaway is discharged from the box, and the adverse effects on the volumetric energy density of the battery. Specifically, the spacing is 1mm, 1.4mm, 1.7mm, 2.0mm, 2.2mm, 2.4mm, 2.6mm, 2.8mm, 3.0mm, 3.3mm, 3.5mm, 3.7mm, 4.0mm, 4.4mm, 4.7mm or 5.0mm, including but not limited to the values ​​listed above, and other values ​​within the range are also applicable.

[0051] Specifically in the embodiment, a plurality of positioning blocks 112 are provided on one side (i.e., the inner surface) of the base plate 11 facing each battery cell 20. The plurality of positioning blocks 112 are arranged around each first weak area A1 and are used to position each battery cell 20 one by one at each first weak area A1 on the base plate 11, that is, to limit each battery cell 20 at the corresponding first weak area A1.

[0052] See Figure 4 and Figure 5 In the embodiment of the present application, the housing 21 includes a shell 211 and a cover plate 213. The shell 211 has an opening on the side facing the bottom plate 11, and the cover plate 213 covers the opening of the shell 211 to close the opening of the shell 211. The shell 211 and the cover plate 213 together enclose the above-mentioned inner cavity 2110. The cover plate 213 has an exhaust channel B and a second weak area A2 for closing the exhaust channel B. The high-pressure gas generated when the battery cell 20 undergoes thermal runaway can break through the second weak area A2 on the cover plate 213 and the corresponding first weak area A1 on the bottom plate 11. In this way, by providing the second weak area A2 on the cover plate 213, it is ensured that the second weak area A2 will not start to rupture until the air pressure in the inner cavity 2110 of the shell 211 reaches a preset value, and then the corresponding first weak area A1 on the bottom plate 11 will start to rupture, which greatly reduces the risk of false activation or delayed activation of the first weak area A1 on the bottom plate 11.

[0053] See Figure 5 、 Figure 7 and Figure 8 Specifically, in this embodiment, the cover plate 213 further includes an annular area A3 surrounding the first weak area A1. The side of the annular area A3 facing the inner cavity 2110 is a first side A31, and the side facing the bottom plate 11 is a second side A32. In the radial direction from the outer edge to the inner edge of the annular area A3, the distance between the first side A31 and the second side A32 of the annular area A3 gradually decreases, so that the first side A31 encloses a first sub-channel B1 for the passage of high-pressure gas, and the second side A32 encloses a second sub-channel B2 for the passage of high-pressure gas. The first sub-channel B1 and the second sub-channel B2 constitute the exhaust channel B described above. In this way, after the second weak area A2 on the cover plate 213 is ruptured under the action of the high-pressure gas, in the discharge direction of the high-pressure airflow discharged from the second weak area A2, the flow area of ​​the first sub-channel B1 gradually increases, and the flow area of ​​the second sub-channel B2 gradually decreases. The first sub-channel B1 and the second sub-channel B2 form a Laval structure, so that the flow rate of the high-pressure airflow flowing through the first sub-channel B1 and the second sub-channel B2 increases rapidly and reaches supersonic speed. The supersonic airflow generates huge thrust, breaking through the corresponding first weak area A1 on the bottom plate 11, and driving the battery cell 20 as a whole to be ejected from the ruptured first weak area A1 on the bottom plate 11 to the outside of the box, thereby preventing thermal runaway from spreading to other battery cells 20 in the box.

[0054] The following describes the process of airflow acceleration. When a battery cell 20 experiences thermal runaway due to an abnormality, a large amount of high-pressure gas is generated. When the air pressure within the inner cavity 2110 of the housing 211 reaches a preset value, the second weak area A2 on the cover plate 213 ruptures, and the high-pressure airflow is discharged from the inner cavity 2110 through the exhaust channel B and reaches the space between the cover plate 213 and the corresponding first weak area A1 on the base plate 11. During the discharge of the high-pressure airflow from the exhaust channel B, it first passes through the first subchannel B1. Because the flow area of ​​the first subchannel B1 gradually decreases, the airflow follows the principle that the smaller the flow area, the greater the flow velocity, and the larger the flow area, the lower the flow velocity. Therefore, the flow velocity of the airflow through the first subchannel B1 continuously increases and reaches the speed of sound. Due to transonic airflow, the principle of smaller flow area, smaller flow velocity is no longer followed, but the principle of larger flow area, larger flow velocity is followed. As the flow area of ​​the second sub-channel B2 becomes larger and larger, the airflow entering the second sub-channel B2 after being accelerated through the first sub-channel B1 continues to accelerate and becomes a supersonic airflow, thereby generating a huge thrust, ensuring that the corresponding first weak area A1 on the bottom plate 11 can be broken through, and the battery cell 20 as a whole is driven to be ejected from the broken first weak area A1 on the bottom plate 11 to the outside of the box.

[0055] It should be noted that, in the radial direction from the outer edge to the inner edge of the annular area A3, the distance between the first side surface A31 and the second side surface A32 is not limited to a gradual decrease, but can also be a step-by-step decrease, as long as a Laval structure can be formed to accelerate the airflow passing through, and no special limitation is made here.

[0056] Specifically, in this embodiment, the cover plate 213 includes a first annular plate 2131, a second annular plate 2133, and a burst-proof disk 2135. The second annular plate 2133 is positioned between the first annular plate 2131 and the base plate 11. In other words, the first annular plate 2131, the second annular plate 2133, and the base plate 11 are stacked in sequence. The inner edge of the first annular plate 2131 is fixedly connected to the inner edge of the second annular plate 2133, and the outer edge of the first annular plate 2131 and the outer edge of the second annular plate 2133 are spaced apart from each other. This causes the distance between the first annular plate 2131 and the second annular plate 2133 to gradually decrease in the radial direction from the outer edge to the inner edge. This results in the first annular plate 2131 having a side surface facing away from the second annular plate 2133 as the first side surface A31, enclosing the first sub-channel B1. The second annular plate 2133 having a side surface facing away from the first annular plate 2131 as the second side surface A32, enclosing the second sub-channel B2.

[0057] The explosion-proof disc 2135 is fixedly connected to the inner edges of the first annular plate 2131 and the second annular plate 2133 to seal the exhaust channel B (i.e., to isolate the first sub-channel B1 from the second sub-channel B2). The second weak area A2 is located on the explosion-proof disc 2135. When the battery cell 20 experiences thermal runaway and the air pressure within the housing 211 reaches a preset value, the second weak area A2 on the explosion-proof disc 2135 ruptures, connecting the first sub-channel B1 with the second sub-channel B2. This accelerates the airflow within the housing 211 to supersonic speeds within the first and second sub-channels B1 and B2. The accelerated airflow generates a tremendous thrust that breaks through the corresponding first weak area A1 on the bottom plate 11, driving the entire battery cell 20 experiencing thermal runaway to be ejected from the ruptured first weak area A1 and out of the housing.

[0058] It should be noted that the cover plate 213 uses a first annular plate 2131 and a second annular plate 2133 to form a Laval structure. The cover plate 213 has a simple structure, and a weight-reducing cavity is formed between the first annular plate 2131 and the second annular plate 2133, which reduces the weight of the cover plate 213, is beneficial to improving the energy density of the battery and reducing processing costs.

[0059] It should also be noted that the explosion-proof disc 2135 is not limited to being fixedly connected to the inner edges of the first annular plate 2131 and the second annular plate 2133. In other embodiments, the explosion-proof disc 2135 can also be fixedly connected to the first side surface A31 of the first annular plate 2131, or fixedly connected to the second side surface A32 of the second annular plate 2133, as long as it can seal the exhaust channel B. This is not limited here. The inner edges of the first annular plate 2131 and the inner edges of the second annular plate 2133 can be fixedly connected by welding, and the explosion-proof disc 2135 can also be fixedly connected to the first annular plate 2131 and / or the second annular plate 2133 by welding. This not only achieves a mechanical connection between the first annular plate 2131, the second annular plate 2133, and the explosion-proof disc 2135, but also achieves a seal between the three.

[0060] Specifically, in this embodiment, the rupture-proof disk 2135 is provided with a second annular notch L2. The area surrounded by the second annular notch L2 is the aforementioned second weakened area A2. Of course, the second weakened area A2 of the rupture-proof disk 2135 can also be formed using notches of other shapes, as long as they can achieve rupture and pressure relief when the air pressure within the housing 211 reaches a predetermined value. This is not a limitation herein.

[0061] In some embodiments, the circumferential edges of the explosion-proof disc 2135 are welded to the inner edges of the first and second annular plates 2131, 2133, so that the explosion-proof disc 2135 seals the central hole formed by the inner edges of the first and second annular plates 2131, 2133, thereby sealing the exhaust passage B. Thus, compared to arrangements of the explosion-proof disc 2135 in other locations, the fixed connection of the explosion-proof disc 2135 to the inner edges of the first and second annular plates 2131, 2133 minimizes the area of ​​the second weak region A2, thereby reducing the difficulty of rupturing the second weak region A2 and facilitating improved accuracy and sensitivity of explosion-proof pressure relief for the battery cells 20.

[0062] Specifically, the maximum flow area of ​​the first sub-channel B1 is S1, and the minimum flow area is S2, with S1 and S2 satisfying the following relationship: 0.1 ≤ S2 / S1 ≤ 0.7. It should be noted that, in the direction perpendicular to the base plate 11 (i.e., the axial direction of the first annular plate 2131 and the second annular plate 2133), the height dimension from the outer edge to the inner edge of the first annular plate 2131 is H1. If S2 / S1 < 0.1, S1 is significantly greater than S2. With the inclination angle of the first annular plate 2131 unchanged, the required height H1 is large, significantly reducing the volumetric energy density of the battery cell 20. If S2 / S1 > 0.7, the difference between S1 and S2 is minimal, making it difficult for the airflow to reach the speed of sound after accelerating through the first sub-channel B1. Therefore, designing the first annular plate 2131 so that S1 and S2 satisfy the following relationship: 0.1 ≤ S2 / S1 ≤ 0.7 helps improve the volumetric energy density of the battery cell 20 and ensures that the airflow can reach the speed of sound after accelerating through the first sub-channel B1. In some embodiments, S1 and S2 satisfy: 0.2≤S2 / S1≤0.6.

[0063] Specifically, the second subchannel B2 has a maximum flow area of ​​S3 and a minimum flow area of ​​S4, with S3 and S4 satisfying the following relationship: 0.2 ≤ S4 / S3 ≤ 0.8. It should be noted that, in the direction perpendicular to the base plate 11 (i.e., the axial direction of the first annular plate 2131 and the second annular plate 2133), the height dimension from the outer edge to the inner edge of the second annular plate 2133 is H2. If S4 / S3 < 0.2, S3 is much greater than S4. With the inclination angle of the second annular plate 2133 unchanged, a larger required height H2 significantly reduces the volumetric energy density of the battery cells 20. When S4 / S3 > 0.8, the difference between S3 and S4 is minimal, resulting in a negligible acceleration effect on the airflow flowing through the second subchannel B2, resulting in insufficient thrust to expel the battery cells 20 from the box. In some embodiments, S4 and S3 satisfy the following relationship: 0.3 ≤ S4 / S3 ≤ 0.7.

[0064] It should be noted that the explosion-proof disk 2135 is not necessary. In other embodiments, see Figure 9 and Figure 10 As shown, the cover plate 213 may also not include the explosion-proof disc 2135, ensuring that the first sub-channel B1 and the second sub-channel B2 remain connected. The high-pressure airflow generated when a battery cell 20 experiences thermal runaway is discharged directly through the first sub-channel B1 and the second sub-channel B2. For ease of understanding, the following description uses the embodiment in which the cover plate 213 includes the explosion-proof disc 2135 as an example.

[0065] Please continue to see Figure 5 、 Figure 7 and Figure 8 Specifically, in this embodiment, each battery cell 20 further includes a current collecting tray 23 disposed between the first annular plate 2131 and the battery cell assembly 22. The outer peripheral edge of the current collecting tray 23 is folded toward the cover plate 213 to form a flange 231. The flange 231 of the current collecting tray 23 is fixedly connected between the outer edge of the first annular plate 2131 and the inner wall of the housing 211, thereby achieving a fixed connection between the first annular plate 2131 and the current collecting tray 23 and the housing 211, and preventing high-pressure air in the housing 211 from entering the space between the first annular plate 2131 and the inner wall of the housing 211 from the space between the first annular plate 2131 and the inner wall of the housing 211. Furthermore, the shell 211, the flange 231 of the collecting plate 23 and the outer edge of the first annular plate 2131 can be fixedly connected by welding, which on the one hand realizes the mechanical connection between the shell 211, the collecting plate 23 and the first annular plate 2131; on the other hand, it realizes the sealing of the gap between the inner wall of the shell 211 and the flange 231 of the collecting plate 23 and the gap between the flange 231 of the collecting plate 23 and the first annular plate 2131.

[0066] Specifically in the embodiment, the end of the shell 211 facing the base plate 11 has an annular end face 2112 arranged around the opening. The annular end face 2112 connects the inner wall and the outer wall of the shell 211. The outer edge of the second annular plate 2133 has an annular connecting portion 2136, and the annular connecting portion 2136 is attached to the annular end face 2112 and fixed by welding. Furthermore, the side of the annular connecting portion 2136 facing away from the base plate 11 has an annular welding surface that is roughly parallel to the annular end face 2112. The annular connecting portion 2136 is attached to the annular end face 2112 on the shell 211 through the annular welding surface, and the annular welding surface of the annular connecting portion 2136 is fixed to the annular end face 2112 of the shell 211 by welding.

[0067] It should be noted that the outer edges of the first annular plate 2131 and the second annular plate 2133 are spaced apart and fixedly connected to the housing 211, while the inner edges of the first annular plate 2131 and the second annular plate 2133 are fixedly connected to each other. This creates a triangular structure among the first annular plate 2131, the second annular plate 2133, and the housing 211, significantly improving the stability of the three structures and preventing deformation of the first annular plate 2131 and the second annular plate 2133. Because the first annular plate 2131 is less susceptible to deformation, it can better guide airflow sequentially through the first sub-channel B1 and the second sub-channel B2, preventing it from flowing into the gap between the first annular plate 2131 and the inner wall of the housing 211. This reduces the impact of the air pressure within the housing 211 on the connection between the second annular plate 2133 and the inner wall of the housing 211, preventing the connection between the second annular plate 2133 and the housing 211 from failing before the second weak area A2.

[0068] Furthermore, an annular ridge 2137 is provided on the side of the annular connecting portion 2136 facing away from the base plate 11. The annular ridge 2137 abuts against the inner wall of the housing 211. The provision of the annular ridge 2137 not only facilitates positioning of the second annular plate 2133 and the housing 211 prior to welding, but also facilitates assembly of the housing 211 and the cover plate 213, thereby improving welding quality. Furthermore, the annular ridge 2137 reinforces the second annular plate 2133, thereby improving structural strength and stability.

[0069] The battery further includes an adhesive block 40, which is bonded and fixed between the annular connecting portion 2136 and the base plate 11. Specifically, the second annular plate 2133 of the cover plate 213 is bonded and fixed to the base plate 11 via the adhesive block 40, thereby securing the battery cell 20 to the base plate 11. Specifically, the side of the annular connecting portion 2136 facing the base plate 11 has an annular bonding surface that is substantially parallel to the surface of the base plate 11. The adhesive block 40 is disposed between this annular bonding surface of the annular connecting portion 2136 and the base plate 11, thereby bonding and fixing the second annular plate 2133 to the base plate 11. Optionally, the adhesive block 40 may be made of structural adhesive.

[0070] It is understood that the bonding block 40 may be annular in shape to match the annular bonding surface of the annular connecting portion 2136. Of course, the bonding block 40 may also include multiple bonding blocks 40, which are arranged at intervals along the circumference of the annular bonding surface of the annular connecting portion 2136, as long as the second annular plate 2133 can be bonded and fixed to the bottom plate 11. This is not limited here.

[0071] Specifically in this embodiment, the orthographic projection of the housing 211 on the base plate 11 does not exceed the range of the corresponding first weak area A1, so that the size of the first weak area A1 on the base plate 11 is larger than the outer dimensions of the housing 211 of the corresponding battery cell 20. This ensures that the battery cell 20 can be ejected from the corresponding first weak area A1 on the base plate 11 and prevents the housing 211 of the battery cell 20 from being stuck in the first weak area A1 on the base plate 11. Preferably, the orthographic projection of the housing 211 on the base plate 11 roughly coincides with the edge of the first weak area A1. This ensures that the battery cell 20 can be ejected smoothly while minimizing the impact on adjacent battery cells 20 and reducing space waste.

[0072] See Figure 4 and Figure 6 In the embodiment of the present application, each battery cell 20 further includes a post 24, which is insulated and disposed on the end of the housing 211 facing away from the base plate 11. Specifically, the end of the battery cell assembly 22 facing the current collecting plate 23 includes a first tab, which is electrically connected to the current collecting plate 23 and, in turn, to the housing 211. The end of the battery cell assembly 22 facing the post 24 includes a second tab of opposite polarity to the first tab, which is electrically connected to the post 24. In this way, the post 24 and the housing 211 serve as the two electrode terminals of the battery cell 20, respectively, jointly enabling the input and output of electrical energy into and out of the battery cell 20. It should be noted that if the first tab is a positive tab and the second tab is a negative tab, the housing 211 serves as the positive terminal and the post 24 serves as the negative terminal. If the first tab is a negative tab and the second tab is a positive tab, the housing 211 serves as the negative terminal and the post 24 serves as the positive terminal. It should be noted that the pole 24 and the second tab may be directly connected, or indirectly connected via a current collecting component, as long as electrical conduction between the pole 24 and the second tab is achieved, and no limitation is imposed here.

[0073] Furthermore, the battery also includes a busbar 30 disposed within the housing cavity. This busbar 30 is located on the side of each battery cell 20 facing away from the base plate 11 and is electrically connected to the terminals 24 of each battery cell 20, enabling series, parallel, or mixed connection of the battery cells 20. Thus, when a battery cell 20 experiences thermal runaway, the high-pressure airflow ruptures the second weak area A2 on the explosion-proof disc 2135, rupturing the corresponding first weak area A1 on the base plate 11. The terminal 24 of the battery cell 20 experiencing thermal runaway detaches from the busbar 30 and is ejected from the first weak area A1 on the base plate 11 out of the housing.

[0074] Specifically, in one embodiment, a plug hole 241 is provided on the pole 24, and a plug protrusion 31 is provided on the busbar 30. The plug protrusion 31 is plugged into the plug hole 241, that is, the plug protrusion 31 and the plug hole 241 are plugged together to achieve electrical connection between the pole 24 and the busbar 30. In this way, the pole 24 and the busbar 30 are connected by plugging and fitting, which ensures electrical connection between the two while minimizing the connection strength between the pole 24 and the busbar 30. This ensures that when a battery cell 20 experiences thermal runaway, the pole 24 can be smoothly separated from the busbar 30 under the action of high-pressure airflow. As a result, when the battery cell 20 experiencing thermal runaway is ejected from the corresponding first weak area A1 on the bottom plate 11, the pole 24 will cause less damage to the busbar 30, thereby minimizing the impact on other battery cells 20.

[0075] Furthermore, elastic contact fingers 2410 are provided on the inner wall of the peripheral side of the insertion hole 241. When the insertion protrusion 31 is inserted into the insertion hole 241, the elastic contact fingers 2410 elastically abut against the insertion protrusion 31, thereby ensuring close contact between the elastic contact fingers 2410 and the insertion protrusion 31 to achieve electrical connection, thereby ensuring that the terminal 24 of the battery cell 20 and the busbar 30 maintain electrical connection.

[0076] It is understood that the elastic contact finger 2410 is able to maintain contact with the insertion protrusion 31 inserted into the insertion hole 241 under the action of a spring or spring. The specific structure can adopt relatively mature existing technologies and is not specifically limited here. The elastic contact finger 2410 on the inner wall of the peripheral side of the insertion hole 241 can be one or more, and is not specifically limited here.

[0077] Specifically in this embodiment, the box body also includes a top plate and multiple side plates. The top plate is located on the side of each battery cell 20 facing away from the bottom plate 11. Each side plate is arranged between the top plate and the bottom plate 11 and is connected end to end in sequence, so that the top plate, the bottom plate 11, and each side plate together enclose the aforementioned receiving cavity. In some embodiments, there are four side plates, and the four side plates, the top plate, and the bottom plate 11 together form the box body in the shape of a rectangular parallelepiped. Of course, the box body can also have other shapes, which are not limited here.

[0078] Based on the above-mentioned battery, the present application also provides an electric device, which uses the battery cell 20 described in any of the above-mentioned embodiments as its power source. Specifically, the electric device can be a vehicle, a mobile phone, a portable device, a laptop computer, a ship, a spacecraft, an electric toy, an electric tool, etc. The vehicle can be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle can be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc.; the spacecraft includes airplanes, rockets, space shuttles and spacecraft, etc.; the electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys and electric airplane toys, etc.; the electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools and railway electric tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators and electric planers, etc. The embodiments of the present application do not impose any special restrictions on the above-mentioned electric devices.

[0079] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0080] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. A battery, characterized in that: include: The box body has a receiving cavity and a bottom plate (11) serving as a side wall of the receiving cavity, wherein the bottom plate (11) has a plurality of first weak areas (A1); A plurality of battery cells (20) are installed in the receiving cavity, each of the battery cells (20) comprising a shell (21) and a battery cell assembly (22), the shell (21) having an inner cavity (2110) and an exhaust channel (B) communicating with the inner cavity (2110), the battery cell assembly (22) being accommodated in the inner cavity (2110); one end of each of the shells (21) having the exhaust channel (B) facing each of the first weak areas (A1) on the bottom plate (11) in a one-to-one correspondence; Wherein, the high-pressure gas generated when the battery cell (20) undergoes thermal runaway passes through the exhaust channel (B) and breaks through the corresponding first weak area (A1), so that the battery cell (20) undergoing thermal runaway is directly ejected from the corresponding first weak area (A1) to the outside of the box; The housing (21) comprises a shell (211) and a cover plate (213); the shell (211) has an opening on a side facing the bottom plate (11); the cover plate (213) covers the opening of the shell (211); the shell (211) and the cover plate (213) together enclose the inner cavity (2110); the cover plate (213) has the exhaust channel (B) and a second weak area (A2) for closing the exhaust channel (B); the high-pressure gas generated when the battery cell (20) experiences thermal runaway can break through the second weak area (A2) and the corresponding first weak area (A1) on the cover plate (213); The cover plate (213) further comprises an annular area (A3) arranged around the first weak area (A1); in the radial direction from the outer edge to the inner edge of the annular area (A3), the distance between the side of the annular area (A3) facing the inner cavity (2110) and the side facing the bottom plate (11) gradually decreases or decreases in a step-like manner; The cover plate (213) comprises a first annular plate (2131), a second annular plate (2133) and an explosion-proof disc (2135); the inner edge of the first annular plate (2131) is fixedly connected to the inner edge of the second annular plate (2133), and encloses the exhaust channel (B); the outer edge of the first annular plate (2131) and the outer edge of the second annular plate (2133) are arranged at intervals from each other, and the second annular plate (2133) is located between the first annular plate (2131) and the bottom plate (11); the explosion-proof disc (2135) is fixedly connected to the first annular plate (2131) and / or the second annular plate (2133) to close the exhaust channel (B); the second weak area (A2) is located on the explosion-proof disc (2135); The first annular plate (2131) encloses a first sub-channel (B1) toward the side of the inner cavity (2110), and the second annular plate (2133) encloses a second sub-channel (B2) toward the side of the bottom plate (11). The exhaust channel (B) includes the first sub-channel (B1) and the second sub-channel (B2); the first sub-channel (B1) and the second sub-channel (B2) form a Laval structure.

2. The battery according to claim 1, characterized in that One end of the shell (211) facing the bottom plate (11) has an annular end surface (2112) arranged around the opening, and the annular end surface (2112) connects the inner wall and the outer wall of the shell (211); The outer edge of the second annular plate (2133) has an annular connecting portion (2136), and the annular connecting portion (2136) is attached to and fixed to the annular end surface (2112) by welding.

3. The battery according to claim 2, characterized in that An annular convex strip (2137) is provided on the side of the annular connecting portion (2136) facing away from the bottom plate (11), and the annular convex strip (2137) abuts against the inner wall of the shell (211).

4. The battery according to claim 2, characterized in that Each of the battery cells (20) further includes an adhesive block (40), wherein the adhesive block (40) is adhesively fixed between the annular connecting portion (2136) and the bottom plate (11).

5. The battery according to claim 1, characterized in that Each of the battery cells (20) further comprises a current collecting plate (23) arranged between the first annular plate (2131) and the battery cell assembly (22), wherein the outer peripheral edge of the current collecting plate (23) is folded toward the cover plate (213) to form a flange (231), and the flange (231) is fixedly connected between the outer edge of the first annular plate (2131) and the inner wall of the shell (211).

6. The battery according to claim 1, characterized in that The maximum flow area and the minimum flow area of ​​the first sub-channel (B1) are S1 and S2 respectively, and the maximum flow area and the minimum flow area of ​​the second sub-channel (B2) are S3 and S4 respectively; Among them, 0.1≤S2 / S1≤0.7, and / or, 0.2≤S4 / S3≤0.

8.

7. The battery according to claim 1, characterized in that A plurality of first annular notched grooves (111) are provided on the bottom plate (11), each of the first annular notched grooves (111) encloses the first weak area (A1), and the distance between two adjacent first annular notched grooves (111) is 1 mm to 5 mm.

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