A battery

Abstract

This application provides a battery including a casing, an explosion-proof valve, and a battery cell. The casing includes two opposing first large surfaces and a second large surface. Each of the first and second large surfaces includes two opposing long sides and two opposing short sides. Two opposing first side surfaces and two opposing second side surfaces are disposed between the first and second large surfaces. The connection between the first large surface and the first side surfaces is recessed towards the second large surface to form a recess. The electrode lead-out end is disposed opposite to the recess. A transition surface is formed between the second side surface and the recess. The explosion-proof valve is disposed on the second side surface. The maximum distance between the explosion-proof valve and the transition surface is in the range of 0.1mm-10mm. The wall thickness of the transition surface is less than the wall thickness of the second side surface and also less than the wall thickness of the recess. The wall thickness of the explosion-proof valve is less than or equal to the wall thickness of the transition surface. The explosion-proof valve is an arc-shaped explosion-proof valve extending along the transition surface. This battery results in a more concentrated explosion location during thermal runaway, which is more conducive to directional venting.

Description

[0001] This application is a divisional application based on the original invention patent application number 2024115254057, filed on October 30, 2024, entitled "A Battery". Technical Field

[0002] This application relates to the field of battery technology, and in particular to a battery. Background Technology

[0003] Some batteries with irregularly shaped casings may explode at locations other than the explosion-proof valve during thermal runaway, preventing directional venting. Therefore, ensuring that batteries with irregularly shaped casings can explode at the explosion-proof valve location to achieve directional venting during thermal runaway is a technical problem that needs to be solved by those skilled in the art. Summary of the Invention

[0004] To solve the above-mentioned technical problems, this application provides a battery, the battery including a casing, an explosion-proof valve, and a battery cell located within the casing. The battery cell includes a cell body and electrodes, the electrodes extending from opposite ends of the cell body. The casing includes two large surfaces arranged opposite each other, namely a first large surface and a second large surface. Each of the first and second large surfaces includes two long sides and two short sides arranged opposite each other. Four small surfaces are arranged between the first and second large surfaces, namely two first side surfaces and two second side surfaces arranged opposite each other. The first side surfaces are connected to the short sides, and the second side surfaces are connected to the long sides. The connection between the first large surface and the first side surfaces faces the first long side surface. Two large surfaces are recessed to form a concave portion, which extends through the entire first large surface along the extension direction of the short side. The lead-out end of the electrode body of the battery cell is disposed opposite to the concave portion. The concave portion, together with the first side surface and part of the second large surface, forms a protrusion. The electrode is at least partially accommodated in the protrusion. A transition surface is formed between the second side surface and the concave portion. The explosion-proof valve is disposed on the second side surface. The maximum distance between the explosion-proof valve and the transition surface is 'a', 0.1mm≤a≤10mm. The wall thickness of the transition surface is less than the wall thickness of the second side surface and also less than the wall thickness of the concave portion. The wall thickness of the explosion-proof valve is less than or equal to the wall thickness of the transition surface. The explosion-proof valve is an arc-shaped explosion-proof valve extending along the transition surface.

[0005] The battery provided in this application has an explosion-proof valve positioned near the transition surface of the casing. This transition surface is a weak area of ​​the casing, and in the event of thermal runaway, the explosion point is concentrated near the explosion-proof valve and the transition surface, achieving directional venting. Since the recess faces the second large side surface, the transition surface between the recess and the second side surface is a weak area of ​​the casing. To position the explosion-proof valve closer to this weak transition surface, it can be located in the recess or on the second side surface. Because the electrode lead-out end of the cell body is positioned opposite the recess, and the electrode is at least partially accommodated within the protrusion formed by the recess, the first side surface, and the second large surface, deformation of the electrode (which is thin and easily deformed) can easily cause it to come into contact with the recess. Therefore, if the explosion-proof valve is located in the recess, it is easily interfered with by the electrode, affecting its explosion-proof opening. Therefore, this application places the explosion-proof valve on the second side and controls the maximum distance between the explosion-proof valve and the transition surface to be less than or equal to 10mm, so that the explosion-proof valve is close to the transition surface. Furthermore, by controlling the maximum distance between the explosion-proof valve and the transition surface to be greater than or equal to 0.1mm, a certain distance is maintained between the explosion-proof valve and the transition surface, ensuring it is not on the transition surface. If the explosion-proof valve were on the transition surface, it would further weaken the strength of the transition surface, causing the casing to easily deform and affecting the normal use of the battery. In the battery provided by this application, when the internal pressure reaches a specific level, both the explosion-proof valve and the transition surface burst open, allowing the thermal runaway gas to be rapidly discharged. Attached Figure Description

[0006] Figure 1 A perspective view of one embodiment of the battery provided in this application, wherein components inside the housing are indicated by dashed lines;

[0007] Figure 2 for Figure 1 A 3D view of the middle battery cell and the second largest surface;

[0008] Figure 3 for Figure 1 A bottom view;

[0009] Figure 4 for Figure 1 Top view;

[0010] Figure 5 for Figure 1 A magnified view of a portion of the image;

[0011] Figure 6 for Figure 5 Side view;

[0012] Figure 7 for Figure 5 Top sectional view;

[0013] Figure 8 for Figure 5 Side sectional view.

[0014] The annotations in the attached figures are explained as follows:

[0015] 1. Shell, 11. First large surface, 12. Second large surface, 13. First side surface, 14. Second side surface, 15. Recess, 16. Liquid injection hole, 17. Plane, 18. Arc surface, 19. Transition surface;

[0016] 2 cells, 21 cell body, 22 tabs;

[0017] 3. Insulating support frame;

[0018] 4 poles;

[0019] 5. Explosion-proof valve. Detailed Implementation

[0020] This application provides a battery. To enable those skilled in the art to better understand the technical solution of this application, the following detailed description is provided in conjunction with the accompanying drawings and specific embodiments.

[0021] like Figure 1 and Figure 2 As shown, the battery provided in this application includes a casing 1, a battery cell 2, and an explosion-proof valve 5.

[0022] The housing 1 includes two large surfaces arranged opposite each other, namely a first large surface 11 and a second large surface 12. Each of the first large surface 11 and the second large surface 12 includes two oppositely arranged long sides and two oppositely arranged short sides. Four small surfaces are arranged between the first large surface 11 and the second large surface 12, namely two oppositely arranged first side surfaces 13 and two oppositely arranged second side surfaces 14. The first side surfaces 13 are connected to the short sides, and the second side surfaces 14 are connected to the long sides.

[0023] The junction of the first large surface 11 and the first side surface 13 is recessed towards the second large surface 12 to form a recess 15. The recess 15 extends through the entire first large surface 11 along the direction of its short side. The recess 15 is used to accommodate insulating components when the battery is assembled.

[0024] The recess 15 forms a protrusion with the first side surface 13 and a portion of the second large surface 12. In the illustrated embodiment, the second large surface 12 is provided with a pole post 4, and the pole lug 22 is electrically connected to the pole post 4. In the illustrated embodiment, the recess 15 has a plane 17 and an arc surface 18. The plane 17 is connected to the first side surface 13. One side of the arc surface 18 is connected to the plane 17, and the other side is connected to the first large surface 11. The plane 17 is parallel to the first large surface 11 or has a small angle with the first large surface 11. The plane 17, the first side surface 13, and a portion of the second side surface 14 form a first portion of the protrusion, and the arc surface 18 and a portion of the second side surface 14 form a second portion of the protrusion. The height of the first portion in the direction of the arrangement of the first large surface 11 and the second large surface 12 is less than the height of the second portion in the direction of the arrangement of the first large surface 11 and the second large surface 12.

[0025] The battery cell 2 is located inside the casing 1. The battery cell 2 includes a cell body 21 and tabs 22, with the tabs 22 extending from opposite ends of the cell body 21. Specifically, the cell body 21 includes a positive electrode and a negative electrode, arranged alternately, with a separator between adjacent positive and negative electrodes. The positive and negative electrodes have similar structures, both including a conductive layer and an active material layer coated on the conductive layer. The uncoated portion of the conductive layer of the positive electrode protrudes beyond the coated portion, forming a single positive electrode tab; multiple single positive electrode tabs are stacked to form a single positive electrode tab. Similarly, the uncoated portion of the conductive layer of the negative electrode protrudes beyond the coated portion, forming a single negative electrode tab; multiple single negative electrode tabs are stacked to form a single negative electrode tab.

[0026] The tab lead-out end of the battery cell body 21 is disposed opposite to the recess 15, and the tab 22 is at least partially accommodated in the protrusion of the housing 1. In the illustrated embodiment, a portion of the tab 22 is accommodated in the first portion of the protrusion, and a portion of the tab 22 is accommodated in the second portion of the protrusion.

[0027] A transition surface 19 is formed between the second side surface 14 and the recess 15. An explosion-proof valve 5 is disposed on the second side surface 14. The maximum distance between the explosion-proof valve 5 and the transition surface 19 is 'a', where 0.1mm ≤ a ≤ 10mm. For example, 'a' can be equal to 0.1mm, 0.2mm, 0.4mm, 1mm, 2mm, 4mm, 6mm, 8mm, or 10mm. Specifically, the explosion-proof valve 5 can be integrally formed with the housing 1. For example, a thinning area can be formed by stamping the housing 1, and this thinning area can serve as the explosion-proof valve 5. Alternatively, a notch can be provided on the housing 1, and this notch can serve as the explosion-proof valve 5. The explosion-proof valve 5 can also be non-integrated with the housing 1. For example, an explosion-proof opening can be provided on the housing 1, and the explosion-proof valve 5 can be a patch attached to the explosion-proof opening.

[0028] In the aforementioned battery, the explosion-proof valve 5 is positioned near the transition surface 19 of the housing 1. The transition surface 19 is a weak area of ​​the housing 1. In the event of thermal runaway, the explosion point is concentrated near the explosion-proof valve 5 and the transition surface 19, achieving directional venting. Since the recess 15 is recessed towards the second large surface 12, the transition surface 19 between the recess 15 and the second side surface 14 is a weak area of ​​the housing 1. To position the explosion-proof valve 5 close to the weak transition surface 19, it can be positioned in either the recess 15 or the second side surface 14. Since the electrode lead-out end of the cell body 21 is positioned opposite the recess 15, and the electrode 22 is at least partially accommodated within the protrusion formed by the recess 15, the first side surface 13, and the second large surface 12, if the electrode 22 deforms (the electrode 22 is relatively thin and easily deformed), it is likely to come into contact with the recess 15. Therefore, if the explosion-proof valve 5 is positioned in the recess 15, the explosion-proof valve 5 is easily interfered with by the electrode 22, affecting its explosion-proof opening. Therefore, this application places the explosion-proof valve 5 on the second side 14, and controls the maximum distance between the explosion-proof valve 5 and the transition surface 19 to be less than or equal to 10 mm, so that the explosion-proof valve 5 is close to the transition surface 19. By controlling the maximum distance between the explosion-proof valve 5 and the transition surface 19 to be greater than or equal to 0.1 mm, the explosion-proof valve 5 has a certain distance from the transition surface 19 and is not on the transition surface 19. If the explosion-proof valve 5 is on the transition surface 19, it will further weaken the strength of the transition surface 19, causing the shell 1 to be easily deformed, which will affect the normal use of the battery.

[0029] In some embodiments, such as Figure 8 As shown, the battery includes an insulating support frame 3. The insulating support frame 3 is at least partially located within the protrusion. The insulating support frame 3 is used to fix the bundled electrode tabs 22. At least part of the insulating support frame 3 is located between the recess 15 and the electrode tabs 22. When the insulating support frame 3 is set, 0.1mm ≤ a ≤ 7mm. The insulating support frame 3 reduces the force of the thermal runaway airflow impacting the explosion-proof valve 5, which is not conducive to the explosion-proof valve 5 opening. Therefore, in order to make the explosion-proof valve 5 easier to open, the explosion-proof valve 5 needs to be closer to the weak transition surface 19. Therefore, the value of a can be slightly smaller. Therefore, in this embodiment, the upper limit of a is controlled to be reduced to 7mm.

[0030] In some embodiments, the length of the explosion-proof valve 5 accounts for 50%-70% of the length of the recess 15; for example, it can be equal to 50%, 55%, 60%, 65%, or 70%. The length of the explosion-proof valve 5 refers to the length from the end of the explosion-proof valve 5 near the first large surface 11 to the end of the explosion-proof valve 5 near the first side surface 13. The length of the explosion-proof valve 5 ranges from 10mm to 30mm; for example, it can be equal to 10mm, 15mm, 20mm, 20.4mm, 25mm, or 30mm. The length of the recess 15 refers to the length from the end of the recess 15 connected to the first large surface 11 to the end of the recess 15 connected to the first side surface 13. Specifically, the length of the recess 15 ranges from 20mm to 40mm; for example, it can be equal to 20mm, 25mm, 30mm, 31mm, 35mm, or 40mm. When the length of the explosion-proof valve 5 accounts for 50%-70% of the length of the recess 15, 0.2mm ≤ a ≤ 8mm.

[0031] When the length of the recess 15 is constant, the larger the proportion of the length of the explosion-proof valve 5 to the length of the recess 15, the longer the explosion-proof valve 5 is, and the easier it is for the explosion-proof valve 5 to burst open. In this case, the value of 'a' can be slightly larger to prevent the explosion-proof valve 5 from bursting before reaching a specific pressure. Conversely, when the length of the recess 15 is constant, the smaller the proportion of the length of the explosion-proof valve 5 to the length of the recess 15, the shorter the length of the explosion-proof valve 5 is, and the more difficult it is for the explosion-proof valve 5 to burst open. In this case, the value of 'a' can be slightly smaller to facilitate the bursting of the explosion-proof valve 5. Therefore, the range of 'a' can be adjusted by controlling the ratio of the length of the explosion-proof valve 5 to the length of the recess 15, making the range of 'a' convenient for the formation of the explosion-proof valve 5 during manufacturing. In this embodiment, by controlling the proportion of the length of the explosion-proof valve 5 to the length of the recess 15 to be 50%-70%, the range of 'a' is adjusted to 0.2mm-8mm. When 'a' is between 0.2mm and 8mm, it is convenient for the formation of the explosion-proof valve 5 during manufacturing.

[0032] In some embodiments, the minimum distance between the end of the explosion-proof valve 5 near the first side 13 and the first side 13 is b, where 5mm ≤ b ≤ 20mm. For example, b can be equal to 5mm, 6mm, 8mm, 9mm, 9.3mm, 10mm, 15mm, or 20mm.

[0033] If the end of the explosion-proof valve 5 closest to the first side 13 is too close to the first side 13 (i.e., b is too small), the strength at the edge of the housing 1 (especially at the junction of plane 17, the first side 13, and the second side 14) will be too low, making the housing 1 prone to deformation and damage, affecting the normal use of the battery. If the end of the explosion-proof valve 5 closest to the first side 13 is too far from the first side 13 (i.e., b is too large), the length of the explosion-proof valve 5 will be insufficient, which is not conducive to the explosion-proof valve 5 opening. This application controls b to be between 5mm and 20mm, which can ensure that the strength at the edge of the housing 1 meets the requirements and that the explosion-proof valve 5 can open smoothly.

[0034] In some embodiments, the second side surface 14 and the second large surface 12 are fixed by welding. The minimum distance between the end of the explosion-proof valve 5 near the second large surface 12 and the second large surface 12 (c in the figure) is 5%-35% of the distance between the first large surface 11 and the second large surface 12 (d in the figure). For example, it can be equal to 5%, 10%, 15%, 20%, 25%, 30%, or 35%. Specifically, the minimum distance between the end of the explosion-proof valve 5 near the second large surface 12 and the second large surface 12 is 0.5mm-10mm. For example, it can be equal to 0.5mm, 1mm, 2mm, 2.5mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, or 10mm. Specifically, the distance between the first large surface 11 and the second large surface 12 is 15mm-45mm. For example, it can be equal to 15mm, 16mm, 18.8mm, 20mm, 25mm, 30mm, 35mm, 40mm, or 45mm.

[0035] If the explosion-proof valve 5 is too close to the solder mark, the solder mark will weaken the strength of the explosion-proof valve 5, making it prone to deformation and hindering its opening. If the explosion-proof valve 5 is too far from the solder mark, its length will be too short, also hindering its opening. This application ensures that the explosion-proof valve 5 can open smoothly in the event of battery thermal runaway by controlling the minimum distance between the end of the explosion-proof valve 5 closest to the second large surface 12 and the second large surface 12 to be 5%-35% of the distance between the first large surface 11 and the second large surface 12.

[0036] In some embodiments, the minimum height of the protrusion in the direction of the arrangement of the first large surface 11 and the second large surface 12 (e in the figure) is 30%-55% of the distance between the first large surface 11 and the second large surface 12 (d in the figure). For example, it can be equal to 30%, 35%, 40%, 45%, 50%, or 55%. Specifically, the minimum height of the protrusion in the direction of the arrangement of the first large surface 11 and the second large surface 12 is 7mm-13.8mm. For example, it can be equal to 7.0mm, 7.8mm, 8.8mm, 9.8mm, 10.8mm, 11.8mm, or 13.8mm. Specifically, the distance between the first large surface 11 and the second large surface 12 is 15mm-45mm. For example, it can be equal to 15mm, 16mm, 18.8mm, 20mm, 25mm, 30mm, 35mm, 40mm, or 45mm. When the minimum height of the protrusion in the direction of the arrangement of the first large surface 11 and the second large surface 12 is 30%-55% of the distance between the first large surface 11 and the second large surface 12, 0.1mm≤a≤6mm.

[0037] The greater the proportion of the minimum height of the protrusion in the direction of the arrangement of the first large surface 11 and the second large surface 12 to the distance between the first large surface 11 and the second large surface 12, the smaller the length of the recess 15, the smaller the length of the transition surface 19, and the greater the strength of the transition surface 19. Conversely, the smaller the proportion of the minimum height of the protrusion in the direction of the arrangement of the first large surface 11 and the second large surface 12 to the distance between the first large surface 11 and the second large surface 12, the larger the length of the recess 15, the larger the length of the transition surface 19, and the smaller the strength of the transition surface 19. When the strength of the transition surface 19 is greater, the value of 'a' can be slightly smaller to facilitate the opening of the explosion-proof valve 5. When the strength of the transition surface 19 is less, the value of 'a' can be slightly larger to prevent the explosion-proof valve 5 from opening before reaching a specific pressure. When the proportion of the minimum height of the protrusion in the direction of the arrangement of the first large surface 11 and the second large surface 12 to the distance between the first large surface 11 and the second large surface 12 is in the range of 30%-55%, controlling the value of 'a' between 0.1mm and 6mm provides the best valve opening stability.

[0038] In some embodiments, the wall thickness of the transition surface 19 ( Figure 7 The wall thickness of the middle g is less than that of the second side 14. Figure 7 The middle part (i) is also smaller than the concave part by 15 ( Figure 7 The wall thickness of the explosion-proof valve 5 (h). Figure 7 f) is less than or equal to the wall thickness of the transition surface 19. With this design, when a certain pressure is reached inside the housing 1, both the explosion-proof valve 5 and the transition surface 19 will burst open, allowing the thermal runaway gas to be discharged rapidly.

[0039] In some embodiments, the wall thickness of the explosion-proof valve 5 ( Figure 7 The wall thickness of the second side (f) accounts for 14% of the total wall thickness. Figure 7The proportion of i) is in the range of 35%-68%, and for example, it can be equal to 35%, 40%, 45%, 50%, 55%, 60%, 65%, or 68%. When the proportion of the wall thickness of the explosion-proof valve 5 to the wall thickness of the second side 14 is in the range of 35%-68%, 0.2mm≤a≤5mm.

[0040] When the wall thickness of the second side 14 is constant, the larger the proportion of the explosion-proof valve 5's wall thickness to the wall thickness of the second side 14, the larger the wall thickness of the explosion-proof valve 5. In this case, the value of 'a' can be slightly smaller to facilitate the explosion-proof valve 5's opening. Conversely, when the wall thickness of the second side 14 is constant, the smaller the proportion of the explosion-proof valve 5's wall thickness to the wall thickness of the second side 14, the smaller the wall thickness of the explosion-proof valve 5. In this case, the value of 'a' can be slightly larger to avoid the explosion-proof valve 5 from opening too close to the transition surface 19 before reaching a specific pressure. When the proportion of the explosion-proof valve 5's wall thickness to the wall thickness of the second side 14 is in the range of 35%-68%, controlling the value of 'a' between 0.2mm and 5mm provides the best valve opening stability.

[0041] In some embodiments, a recess 15 is formed at the connection between the first large surface 11 and the two first side surfaces 13, and the battery includes two of the aforementioned explosion-proof valves 5, such as Figure 4 As shown, Figure 4 Each of the two circled locations has an explosion-proof valve 5. One explosion-proof valve 5 is located on one second side 14 and near the transition surface 19 connected to a recess 15, while the other explosion-proof valve 5 is located on the other second side 14 and near the transition surface 19 connected to another recess 15, so that the two explosion-proof valves 5 are diagonally arranged. This design avoids the problem that if two explosion-proof valves 5 are located on the same second side 14, the explosion of one explosion-proof valve 5 would cause the other explosion-proof valve 5 to deform and fail to explode.

[0042] In the illustrated embodiment, as Figure 5 As shown, the explosion-proof valve 5 is an arc-shaped explosion-proof valve 5 extending along the transition surface 19. Specifically, the width of the arc-shaped explosion-proof valve 5 is j, where 0.05mm ≤ j ≤ 0.5mm. For example, j can be equal to 0.1mm, 0.2mm, 0.3mm, 0.4mm, or 0.5mm. A width that is too wide or too narrow is not conducive to the explosion-proof valve 5 opening. In other embodiments, the explosion-proof valve 5 can also be other shapes, such as straight, triangular, circular, rectangular, cross-shaped, T-shaped, X-shaped, etc.

[0043] In the illustrated embodiment, as Figure 6As shown, the distance (k) between the two ends of the arc-shaped explosion-proof valve 5 (the end closer to the first large surface 11 and the end closer to the second large surface 12) in the direction of the arrangement of the first large surface 11 and the second large surface 12 is in the range of 60%-100% of the distance between the first large surface 11 and the second large surface 12 (d). For example, it can be equal to 60%, 70%, 80%, 90%, or 100%. When the distance between the two ends of the arc-shaped explosion-proof valve 5 in the direction of the arrangement of the first large surface 11 and the second large surface 12 is in the range of 60%-100% of the distance between the first large surface 11 and the second large surface 12, 0.2mm ≤ a ≤ 8mm.

[0044] When the extension direction of the arc-shaped explosion-proof valve 5 is fixed, the greater the proportion of the distance between the two ends of the arc-shaped explosion-proof valve 5 in the direction of the arrangement of the first large surface 11 and the second large surface 12 to the distance between the first large surface 11 and the second large surface 12, the longer the arc-shaped explosion-proof valve 5 is, and the easier it is for the arc-shaped explosion-proof valve 5 to burst open. In this case, the value of 'a' can be slightly larger to prevent the explosion-proof valve 5 from bursting open before reaching a specific pressure. Conversely, when the extension direction of the arc-shaped explosion-proof valve 5 is fixed, the smaller the proportion of the distance between the two ends of the arc-shaped explosion-proof valve 5 in the direction of the arrangement of the first large surface 11 and the second large surface 12 to the distance between the first large surface 11 and the second large surface 12, the shorter the length of the arc-shaped explosion-proof valve 5 is, and the more difficult it is for the arc-shaped explosion-proof valve 5 to burst open. In this case, the value of 'a' can be slightly smaller to facilitate the bursting of the explosion-proof valve 5. Therefore, the range of 'a' can be adjusted by controlling the ratio of the distance between the two ends of the arc-shaped explosion-proof valve 5 in the direction of the arrangement of the first large surface 11 and the second large surface 12 to the distance between the first large surface 11 and the second large surface 12, so that the range of 'a' is convenient for the formation of the explosion-proof valve 5 during the manufacturing process. In this embodiment, by controlling the ratio of the distance between the two ends of the arc-shaped explosion-proof valve 5 in the direction of the arrangement of the first large surface 11 and the second large surface 12 to the distance between the first large surface 11 and the second large surface 12 to be within the range of 60%-100%, the range of 'a' is adjusted to 0.2mm-8mm. When 'a' is within the range of 0.2mm-8mm, it is convenient for the formation of the explosion-proof valve 5 during the manufacturing process.

[0045] The housing 1 is provided with a liquid injection hole 16. In the illustrated embodiment, the liquid injection hole 16 is located on the second large surface 12. The center line of the second large surface 12 parallel to the long side is the first center line ( Figure 3 The center line parallel to the shorter side (L1) is the second center line. Figure 3 In the case of L2), the injection port 16 is located on one side of the first centerline and on the other side of the second centerline. The injection port 16 and the explosion-proof valve 5, which are located on the same side of the second centerline, are located on opposite sides of the first centerline. This design can prevent the explosion-proof valve 5 from being unable to open smoothly in the event of thermal runaway of the battery due to deformation of the explosion-proof valve 5 caused by the pressure exerted on the casing 1 during the injection process of the injection port 16B.

[0046] The above examples illustrate the principles and implementation methods of this application. The descriptions of these embodiments are merely for the purpose of helping to understand the method and core ideas of this application. It should be noted that those skilled in the art can make various improvements and modifications to this application without departing from its principles, and these improvements and modifications also fall within the protection scope of the claims of this application.

Claims

1. A battery, characterized in that, The battery includes a casing, an explosion-proof valve, and a battery cell located within the casing. Each battery cell includes a cell body and tabs, with the tabs extending from opposite ends of the cell body. The casing includes two large, oppositely arranged surfaces, a first large surface and a second large surface. Each of the first and second large surfaces includes two oppositely arranged long sides and two oppositely arranged short sides. Four small surfaces are arranged between the first and second large surfaces: two oppositely arranged first side surfaces and two oppositely arranged second side surfaces. The first side surfaces connect to the short sides, and the second side surfaces connect to the long sides. The connection point between the first large surface and the first side surface is recessed towards the second large surface, forming a concave portion. The recess extends through the entire first large surface along the extension direction of the short side. The lead-out end of the electrode body of the battery cell is disposed opposite to the recess. The recess, the first side surface, and part of the second large surface form a protrusion. The electrode is at least partially accommodated in the protrusion. A transition surface is formed between the second side surface and the recess. The explosion-proof valve is disposed on the second side surface. The maximum distance between the explosion-proof valve and the transition surface is 'a', 0.1mm≤a≤10mm. The wall thickness of the transition surface is less than the wall thickness of the second side surface and also less than the wall thickness of the recess. The wall thickness of the explosion-proof valve is less than or equal to the wall thickness of the transition surface. The explosion-proof valve is an arc-shaped explosion-proof valve extending along the transition surface.

2. The battery according to claim 1, characterized in that, The battery includes an insulating support frame, at least partially located within the protrusion, the insulating support frame being used to fix and gather the tabs, at least partially located between the recess and the tabs, 0.1mm≤a≤7mm.

3. The battery according to claim 1, characterized in that, The length of the explosion-proof valve accounts for 50%-70% of the length of the recess, with 0.2mm≤a≤8mm.

4. The battery according to claim 1, characterized in that, The minimum distance between the end of the explosion-proof valve closest to the first side and the first side is b, where 5mm ≤ b ≤ 20mm.

5. The battery according to claim 1, characterized in that, The second side is fixed to the second large surface by welding, and the minimum distance between the end of the explosion-proof valve near the second large surface and the second large surface is 5%-35% of the distance between the first large surface and the second large surface.

6. The battery according to claim 1, characterized in that, The minimum height of the protrusion in the direction of the arrangement of the first and second large surfaces is 30%-55% of the distance between the first and second large surfaces, and 0.1mm≤a≤6mm.

7. The battery according to claim 1, characterized in that, The wall thickness of the explosion-proof valve accounts for 35%-68% of the wall thickness of the second side, with 0.2mm≤a≤5mm.

8. The battery according to claim 1, characterized in that, A recess is formed at the connection between the first large surface and the two first side surfaces. The battery includes two explosion-proof valves. One explosion-proof valve is located on one of the second side surfaces and is close to the transition surface connected to one of the recesses. The other explosion-proof valve is located on another second side surface and is close to the transition surface connected to the other recess.

9. The battery according to claim 1, characterized in that, The distance between the two ends of the arc-shaped explosion-proof valve in the direction of the arrangement of the first and second large surfaces is in the range of 60%-100% of the distance between the first and second large surfaces, and 0.2mm≤a≤8mm.

10. The battery according to any one of claims 1-9, characterized in that, The housing is provided with a liquid injection hole, which is located on the second large surface. The center line of the second large surface parallel to the long side is the first center line, and the center line parallel to the short side is the second center line. The liquid injection hole is located on one side of the first center line and on one side of the second center line. The liquid injection hole and the explosion-proof valve, which are located on the same side of the second center line, are respectively located on both sides of the first center line.

Images