Battery

Abstract

The battery provided by the embodiment of the invention comprises a shell, an anti-explosion valve and a battery cell, the shell comprises a first large surface and a second large surface which are oppositely arranged, and the first large surface and the second large surface respectively comprise two oppositely arranged long edges and two oppositely arranged short edges; two oppositely-arranged first side faces and two oppositely-arranged second side faces are arranged between the first large face and the second large face, the connecting positions of the first large face and the first side faces are sunken towards the second large face to form a concave part, the tab leading-out end and the concave part are oppositely arranged, a transition face is formed between the second side faces and the concave part, and the anti-explosion valve is arranged on the second side faces. The maximum distance between the anti-explosion valve and the transition face ranges from 0.1 mm to 10 mm, the wall thickness of the transition face is smaller than the wall thickness of the second side face and is also smaller than the wall thickness of the concave part, and the wall thickness of the anti-explosion valve is smaller than or equal to the wall thickness of the transition face. And the anti-explosion valve is an arc-shaped anti-explosion valve extending along the transition surface. When the battery is in thermal runaway, the explosion position is more concentrated, and directional exhaust is more facilitated.

Description

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

[0002] The present application relates to the field of battery technology, and in particular to a battery. Background Art

[0003] For some batteries with irregular shell shapes, when thermal runaway occurs, the explosion position is not where the explosion-proof valve is located, resulting in the problem that directional exhaust cannot be achieved. In view of this, how to ensure that batteries with irregular shell shapes can explode at the explosion-proof valve position to achieve directional exhaust when thermal runaway occurs is a technical problem that needs to be solved by those skilled in the art. Summary of the invention

[0004] In order to solve the above technical problems, the present application provides a battery, the battery comprising a shell, an explosion-proof valve, and a battery cell located in the shell, the battery cell comprising a battery cell body and a pole ear, the pole ear is led out from opposite ends of the battery cell body, the shell comprises two relatively large surfaces, namely a first large surface and a second large surface, the first large surface and the second large surface each comprise two relatively long sides and two relatively short sides, four small surfaces are arranged between the first large surface and the second large surface, namely two relatively first side surfaces and two relatively second side surfaces, the first side surface is connected to the short side, the second side surface is connected to the long side, and the connection between the first large surface and the first side surface faces the first large surface The two large surfaces are sunken to form a recessed portion, and the recessed portion runs through the entire first large surface along the extension direction of the short side. The pole ear lead-out end of the battery cell body is arranged opposite to the recessed portion, and the recessed portion, the first side surface and part of the second large surface form a raised portion, and the pole ear is at least partially accommodated in the raised portion. A transition surface is formed between the second side surface and the recessed portion, and the explosion-proof valve is arranged 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 smaller than the wall thickness of the second side surface and also smaller than the wall thickness of the recessed portion, and 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] In the battery provided by the present application, the explosion-proof valve is arranged near the transition surface of the shell, and the transition surface is a weak area of ​​the shell. When thermal runaway occurs, the explosion position is concentrated near the explosion-proof valve and the transition surface, so that directional exhaust is achieved. Since the recess is recessed toward the second large surface, the transition surface between the recess and the second side surface is a weak area of ​​the shell. In order to arrange the explosion-proof valve close to the weak transition surface, the explosion-proof valve can be arranged in the recess or the second side surface. Since the lead-out end of the pole ear of the battery body is arranged relative to the recess, the pole ear is at least partially accommodated in the raised portion formed by the recess and the first side surface and the second large surface, so if the pole ear is deformed (the pole ear is thin and easier to deform), it is easy to conflict with the recess. Therefore, if the explosion-proof valve is arranged in the recess, the explosion-proof valve is easily interfered by the pole ear, which affects the explosion of the explosion-proof valve. Therefore, the present application sets the explosion-proof valve on the second side surface, and controls the maximum distance between the explosion-proof valve and the transition surface to be less than or equal to 10 mm, so that the explosion-proof valve is close to the transition surface, and controls the maximum distance between the explosion-proof valve and the transition surface to be greater than or equal to 0.1 mm, so that the explosion-proof valve and the transition surface have a certain distance, and are not on the transition surface. If the explosion-proof valve is on the transition surface, the strength of the transition surface will be further weakened, causing the shell to be easily deformed, affecting the normal use of the battery. The battery provided by the present application, when a specific pressure is reached in the shell, the explosion-proof valve and the transition surface will explode, so that the thermal runaway airflow can be quickly discharged. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 A three-dimensional diagram of an embodiment of a battery provided by the present application, in which components inside the housing are indicated by dotted lines;

[0007] Figure 2 for Figure 1 A three-dimensional view of the middle cell and the second largest surface;

[0008] Figure 3 for Figure 1 Bottom view of

[0009] Figure 4 for Figure 1 A top view of

[0010] Figure 5 for Figure 1 A partial enlarged view of

[0011] Figure 6 for Figure 5 Side view of

[0012] Figure 7 for Figure 5 A top sectional view of

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

[0014] The following are the descriptions of the reference numerals:

[0015] 1 housing, 11 first large surface, 12 second large surface, 13 first side surface, 14 second side surface, 15 recess, 16 injection hole, 17 plane, 18 curved surface, 19 transition surface;

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

[0017] 3. Insulation support frame;

[0018] 4 poles;

[0019] 5. Explosion-proof valve. DETAILED DESCRIPTION

[0020] The present application provides a battery. In order to enable those skilled in the art to better understand the technical solution of the present application, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

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

[0022] The housing 1 includes two relatively large surfaces, which are respectively a first large surface 11 and a second large surface 12. The first large surface 11 and the second large surface 12 each include two relatively long sides and two relatively short sides. Four small surfaces are arranged between the first large surface 11 and the second large surface 12, which are respectively two relatively first side surfaces 13 and two relatively second side surfaces 14. The first side surface 13 is connected to the short side, and the second side surface 14 is connected to the long side.

[0023] The connection between the first large surface 11 and the first side surface 13 is recessed toward the second large surface 12 to form a recess 15. The recess 15 runs through the entire first large surface 11 along the extension direction of the short side. The recess 15 is used to accommodate an insulating member when the batteries are grouped.

[0024] The concave portion 15 forms a convex portion with the first side surface 13 and part of the second large surface 12. In the illustrated embodiment, a pole 4 is provided on the second large surface 12, and the pole ear 22 is electrically connected to the pole 4. In the illustrated embodiment, the concave portion 15 has a plane 17 and an arc surface 18, the plane 17 is connected to the first side surface 13, one of the two sides 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 forms a first subdivision of the convex portion with the first side surface 13 and part of the second side surface 14, and the arc surface 18 forms a second subdivision of the convex portion with part of the second side surface 14. The height of the first subdivision in the arrangement direction of the first large surface 11 and the second large surface 12 is less than the height of the second subdivision in the arrangement direction of the first large surface 11 and the second large surface 12.

[0025] The battery cell 2 is located in the shell 1, and the battery cell 2 includes a battery cell body 21 and a tab 22, and the tab 22 is led out from the opposite ends of the battery cell body 21. Specifically, the battery cell body 21 includes a positive electrode sheet and a negative electrode sheet, and the positive electrode sheets and the negative electrode sheets are arranged alternately one by one, and a diaphragm is provided between adjacent positive electrode sheets and negative electrode sheets. The structures of the positive electrode sheets and the negative electrode sheets are similar, and both include a conductive layer and an active material layer coated on the conductive layer. The portion of the conductive layer of the positive electrode sheet that is not coated with the active material protrudes from the portion that is coated with the active material to form a positive electrode tab monolithic sheet, and multiple layers of positive electrode tab monolithic sheets are stacked to form a positive electrode tab. The portion of the conductive layer of the negative electrode sheet that is not coated with the active material protrudes from the portion that is coated with the active material to form a negative electrode tab monolithic sheet, and multiple layers of negative electrode tab monolithic sheets are stacked to form a negative electrode tab.

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

[0027] A transition surface 19 is formed between the second side surface 14 and the recess 15. The 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, 0.1mm≤a≤10mm. Exemplarily, a can be equal to 0.1mm, 0.2mm, 0.4mm, 1mm, 2mm, 4mm, 6mm, 8mm, 10mm. Specifically, the explosion-proof valve 5 can be an integral structure with the shell 1. For example, a thinning area can be formed by stamping the shell 1, and the thinning area is used as the explosion-proof valve 5, or a notch can be provided on the shell 1, and the notch is used as the explosion-proof valve 5. The explosion-proof valve 5 can also be a non-integrated structure with the shell 1. For example, an explosion-proof opening can be provided on the shell 1, and the explosion-proof valve 5 can be a patch attached to the explosion-proof opening.

[0028] In the above-mentioned battery, the explosion-proof valve 5 is arranged near the transition surface 19 of the shell 1, and the transition surface 19 is a weak area of ​​the shell 1. When thermal runaway occurs, the explosion position is concentrated near the explosion-proof valve 5 and the transition surface 19, so that directional exhaust is achieved. Since the recess 15 is recessed toward 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 shell 1. In order to arrange the explosion-proof valve 5 close to the weak transition surface 19, the explosion-proof valve 5 can be arranged in the recess 15 or the second side surface 14. Since the pole ear lead-out end of the battery body 21 is arranged opposite to the recess 15, the pole ear 22 is at least partially accommodated in the convex portion formed by the recess 15, the first side surface 13 and the second large surface 12, so if the pole ear 22 is deformed (the pole ear 22 is thin and easy to deform), it is easy to conflict with the recess 15. Therefore, if the explosion-proof valve 5 is arranged in the recess 15, the explosion-proof valve 5 is easily interfered by the pole ear 22, which affects the explosion of the explosion-proof valve 5. Therefore, the present application arranges the explosion-proof valve 5 on the second side surface 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, and controls the maximum distance between the explosion-proof valve 5 and the transition surface 19 to be greater than or equal to 0.1 mm, so that there is a certain distance between the explosion-proof valve 5 and the transition surface 19, and the explosion-proof valve 5 is not on the transition surface 19. If the explosion-proof valve 5 is on the transition surface 19, the strength of the transition surface 19 will be further weakened, causing the shell 1 to be easily deformed, affecting 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 in the raised portion. The insulating support frame 3 is used to fix the convergent pole ear 22. At least part of the insulating support frame 3 is located between the recess 15 and the pole ear 22. When the insulating support frame 3 is set, 0.1mm≤a≤7mm. The insulating support frame 3 causes the force of the thermal runaway airflow to impact the explosion-proof valve 5 to be reduced, which is not conducive to the explosion-proof valve 5 to burst. Therefore, in order to make the explosion-proof valve 5 easy to burst, it is necessary to make the explosion-proof valve 5 closer to the weak transition surface 19. Therefore, the value of a can be slightly smaller. Therefore, this embodiment controls the upper limit value of a to be reduced to 7mm.

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

[0031] When the length of the recess 15 is constant, the greater the ratio of the length of the explosion-proof valve 5 to the length of the recess 15, the greater the length of the explosion-proof valve 5, the easier it is for the explosion-proof valve 5 to explode. At this time, the value of a can be slightly larger to prevent the explosion-proof valve 5 from exploding when the specific pressure is not reached. On the contrary, when the length of the recess 15 is constant, the smaller the ratio of the length of the explosion-proof valve 5 to the length of the recess 15, the smaller the length of the explosion-proof valve 5, the more difficult it is for the explosion-proof valve 5 to explode. At this time, the value of a can be slightly smaller to facilitate the explosion of the explosion-proof valve 5. Therefore, the range of a can be adjusted by controlling the ratio range of the length of the explosion-proof valve 5 to the length of the recess 15, so that the range of a is convenient for the formation of the explosion-proof valve 5 in the process manufacturing. In this embodiment, the range of a is adjusted to 0.2mm-8mm by controlling the ratio range of the length of the explosion-proof valve 5 to the length of the recess 15 to 50%-70%. When a is 0.2mm-8mm, it is convenient for the formation of the explosion-proof valve 5 in the process manufacturing.

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

[0033] If the end of the explosion-proof valve 5 close to the first side surface 13 is too close to the first side surface 13, that is, b is too small, the strength of the edge of the shell 1 (especially the intersection of the plane 17, the first side surface 13 and the second side surface 14) will be too low, causing the shell 1 to be easily deformed and damaged, affecting the normal use of the battery. If the end of the explosion-proof valve 5 close to the first side surface 13 is too far from the first side surface 13, that is, b is too large, the length of the explosion-proof valve 5 will be insufficient, which is not conducive to the explosion of the explosion-proof valve 5. The present application controls b to 5mm-20mm, so that it can ensure that the strength at the edge of the shell 1 meets the requirements and the explosion of the explosion-proof valve 5 can be ensured.

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

[0035] If the explosion-proof valve 5 is too close to the weld mark, the weld mark will weaken the strength of the explosion-proof valve 5, causing the explosion-proof valve 5 to be easily deformed, which is not conducive to the explosion of the explosion-proof valve 5. If the explosion-proof valve 5 is too far from the weld mark, the length of the explosion-proof valve 5 will be too small, which is also not conducive to the explosion of the explosion-proof valve 5. The present application controls the ratio of the minimum distance between the end of the explosion-proof valve 5 close to the second large surface 12 and the second large surface 12 to the distance between the first large surface 11 and the second large surface 12 to 5%-35%, which can ensure that the explosion-proof valve 5 can be smoothly exploded when the battery has thermal runaway.

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

[0037] The greater the ratio of the minimum height of the protrusion in the arrangement direction 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. The smaller the ratio of the minimum height of the protrusion in the arrangement direction 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 greater the length of the recess 15, the greater 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 large, the value of a can be slightly smaller to facilitate the explosion of the explosion-proof valve 5. When the strength of the transition surface 19 is small, the value of a can be slightly larger to prevent the explosion-proof valve 5 from exploding when the specific pressure is not reached. When the ratio of the minimum height of the protrusion in the arrangement direction 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 within the range of 30%-55%, the value of a is controlled within 0.1mm-6mm, and the valve opening stability is best.

[0038] In some embodiments, the wall thickness of the transition surface 19 ( Figure 7 g) is smaller than the wall thickness of the second side surface 14 ( Figure 7 i), which is also smaller than the concave portion 15 ( Figure 7 The wall thickness of explosion-proof valve 5 ( Figure 7 f) is less than or equal to the wall thickness of the transition surface 19. With this design, when a specific pressure is reached in the shell 1, both the explosion-proof valve 5 and the transition surface 19 burst open, so that the thermal runaway airflow can be quickly discharged.

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

[0040] When the wall thickness of the second side surface 14 is constant, the greater the proportion of the wall thickness of the explosion-proof valve 5 to the wall thickness of the second side surface 14, the greater the wall thickness of the explosion-proof valve 5, and the value of a can be slightly smaller at this time, so as to facilitate the explosion of the explosion-proof valve 5. On the contrary, when the wall thickness of the second side surface 14 is constant, the smaller the proportion of the wall thickness of the explosion-proof valve 5 to the wall thickness of the second side surface 14, the smaller the wall thickness of the explosion-proof valve 5, and the value of a can be slightly larger at this time, so as to avoid being too close to the transition surface 19 and causing the explosion of the explosion-proof valve 5 before reaching a specific pressure. When the proportion of the wall thickness of the explosion-proof valve 5 to the wall thickness of the second side surface 14 is within the range of 35%-68%, the value of a is controlled within the range of 0.2mm-5mm, and the valve opening stability is the best.

[0041] In some embodiments, a concave portion 15 is formed at the connection between the first large surface 11 and the two first side surfaces 13, and the battery includes two explosion-proof valves 5, such as Figure 4 As shown, Figure 4 There is one explosion-proof valve 5 at each of the two circled positions, one explosion-proof valve 5 is arranged on one second side surface 14 and close to a transition surface 19 connected to one recess 15, and the other explosion-proof valve 5 is arranged on another second side surface 14 and close to a transition surface 19 connected to another recess 15, so that the two explosion-proof valves 5 are arranged diagonally. This design avoids the problem that when two explosion-proof valves 5 are arranged on the same second side surface 14, the explosion of one explosion-proof valve 5 causes the other explosion-proof valve 5 to deform and thus cannot be exploded.

[0042] In the illustrated embodiment, 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, 0.05mm≤j≤0.5mm, and exemplary, j can be equal to 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm. Too wide or too narrow is not conducive to the explosion of the explosion-proof valve 5. In other embodiments, the explosion-proof valve 5 can also be other shapes, such as, straight line, triangle, round rectangle, "cross", "T", "X" and the like.

[0043] In the illustrated embodiment, Figure 6As shown, the distance between the two ends of the arc-shaped explosion-proof valve 5 (the end close to the first large surface 11 and the end close to the second large surface 12) in the arrangement direction of the first large surface 11 and the second large surface 12 (k in the figure) accounts for 60%-100% of the distance between the first large surface 11 and the second large surface 12 (d in the figure), and can be equal to 60%, 70%, 80%, 90%, 100%. When the distance between the two ends of the arc-shaped explosion-proof valve 5 in the arrangement direction of the first large surface 11 and the second large surface 12 accounts for 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 explosion-proof valve 5 is constant, the greater the ratio of the distance between the two ends of the arc explosion-proof valve 5 in the arrangement direction 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 greater the length of the arc explosion-proof valve 5, and the easier it is for the arc explosion-proof valve 5 to burst. At this time, the value of a can be slightly larger to prevent the explosion-proof valve 5 from bursting when the specific pressure is not reached. On the contrary, when the extension direction of the arc explosion-proof valve 5 is constant, the smaller the ratio of the distance between the two ends of the arc explosion-proof valve 5 in the arrangement direction 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 arc explosion-proof valve 5, and the more difficult it is for the arc explosion-proof valve 5 to burst. At this time, 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 arrangement direction 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 in the process manufacturing. In this embodiment, by controlling the distance between the two ends of the arc-shaped explosion-proof valve 5 in the arrangement direction of the first large surface 11 and the second large surface 12 to account for the distance between the first large surface 11 and the second large surface 12 The ratio range is 60%-100%, so that the range of a is adjusted to 0.2mm-8mm, and when a is 0.2mm-8mm, it is convenient for the formation of the explosion-proof valve 5 in the process manufacturing.

[0045] The housing 1 is provided with a liquid injection hole 16. In the illustrated embodiment, the liquid injection hole 16 is provided 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 L1), the center line parallel to the short side is the second center line ( Figure 3 In the figure L2, the injection hole 16 is located on one side of the first center line and on one side of the second center line, and the injection hole 16 and the explosion-proof valve 5 located on the same side of the second center line are located on both sides of the first center line. This design can avoid the explosion-proof valve 5 being deformed due to the pressure on the housing 1 during the process of opening the injection hole 16B and the injection process, so that the explosion-proof valve 5 cannot be opened smoothly when the battery has thermal runaway.

[0046] The above specific examples are used to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method and core ideas of the present application. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present application, several improvements and modifications can be made to the present application, and these improvements and modifications also fall within the scope of protection of the claims of the present application.

Claims

1. A battery, characterized in that: The battery comprises a shell, an explosion-proof valve, and a cell in the shell, wherein the cell comprises a cell body and a tab, wherein the tab is led out from opposite ends of the cell body, the shell comprises two relatively large surfaces, namely a first large surface and a second large surface, wherein the first large surface and the second large surface each comprise two relatively long sides and two relatively short sides, wherein four small surfaces are arranged between the first large surface and the second large surface, namely two relatively first side surfaces and two relatively second side surfaces, wherein the first side surface is connected to the short side, and the second side surface is connected to the long side, and the connection between the first large surface and the first side surface is recessed toward the second large surface to form a recessed portion, The recess runs through the entire first large surface along the extension direction of the short side, the pole ear lead-out end of the battery body is arranged opposite to the recess, the recess and the first side surface and part of the second large surface form a protrusion, the pole ear 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 arranged 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 smaller than the wall thickness of the second side surface, and also smaller than the wall thickness of the recess, and 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 comprises an insulating support frame, wherein at least a part of the insulating support frame is located in the protruding portion, and the insulating support frame is used to fix and gather the pole lug, and at least a part of the insulating support frame is located between the recess and the pole lug, and 0.1 mm≤a≤7 mm.

3. The battery according to claim 1, characterized in that The ratio of the length of the explosion-proof valve to the length of the recess is in the range of 50%-70%, and 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 close to the first side surface and the first side surface is b, and 5mm≤b≤20mm.

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

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

7. The battery according to claim 1, characterized in that The ratio of the wall thickness of the explosion-proof valve to the wall thickness of the second side surface is in the range of 35%-68%, and 0.2mm≤a≤5mm.

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

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 arrangement direction of the first large surface and the second large surface accounts for 60%-100% of the distance between the first large surface and the second large surface, and 0.2mm≤a≤8mm.

10. The battery according to any one of claims 1 to 9, characterized in that: The shell is provided with an injection hole, and the injection hole is provided 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 injection hole is located on one side of the first center line and on one side of the second center line. The injection hole and the explosion-proof valve located on the same side of the second center line are respectively located on both sides of the first center line.

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