Battery and battery pack

Abstract

Disclosed in the present application are a battery and a battery pack. The battery comprises a case, a top cover sheet and a pressure relief member, wherein the case is provided with an accommodating cavity for accommodating battery cells; the top cover sheet is connected to the case and covers the accommodating cavity, and the top cover sheet is provided with a through hole extending in the direction of thickness of the top cover sheet; the pressure relief member is connected to the top cover sheet and covers the through hole; the pressure relief member comprises a pressure relief body and a first connecting portion; the pressure relief body is located in the accommodating cavity; the first connecting portion is connected to the pressure relief body and is arranged around the pressure relief body; the first connecting portion extends in the direction of thickness; the end of the first connecting portion away from the pressure relief body is connected to the top cover sheet; in the direction of thickness, at least part of the first connecting portion is located between the pressure relief body and the top cover sheet; and in the direction of thickness, the dimensions of the first connecting portion are H2 mm, and the dimensions of the pressure relief body are H3 mm, where H2 and H3 satisfy: 0.2≤H2 / H3≤100. The present application effectively prevents corrosion and cracking of the pressure relief body, thereby prolonging the service life of the pressure relief member.

Description

Batteries and battery packs

[0001] Cross-references to related applications

[0002] This application claims priority to Chinese Patent Application No. 202410685074.7, filed on May 29, 2024, entitled "Battery and Battery Pack", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application belongs to the field of battery technology, specifically relating to a battery and a battery pack. Background Technology

[0004] Explosion-proof valves are an important component of batteries, used to release internal pressure in a timely manner when the battery abnormally produces gas. However, when the battery is used upside down, the explosion-proof valve is completely immersed in the electrolyte, which can easily lead to corrosion and cracking. Summary of the Invention

[0005] Purpose of this application: This application provides a battery designed to solve the problem that the explosion-proof valve of existing batteries is easily corroded by electrolyte when used upside down; another purpose of this application is to provide a battery pack.

[0006] Technical solution: A battery according to an embodiment of this application includes:

[0007] A housing having a receiving cavity for accommodating the battery cell;

[0008] A top cover plate, which is connected to the housing and seals the receiving cavity, the top cover plate having a through hole extending along the thickness direction of the top cover plate;

[0009] A pressure relief component, which is connected to the top cover plate and seals the through hole;

[0010] The pressure relief component includes:

[0011] A pressure relief body is located in the receiving cavity;

[0012] A first connecting portion is connected to and surrounds the pressure relief body; the first connecting portion extends along the thickness direction, and one end of the first connecting portion away from the pressure relief body is connected to the top cover plate; in the thickness direction, at least a portion of the first connecting portion is located between the pressure relief body and the top cover plate.

[0013] Along the thickness direction, the size of the first connecting part is H2 mm, and the size of the pressure relief body is H3 mm, where H2 and H3 satisfy: 0.2≤H2 / H3≤100.

[0014] In some embodiments, the pressure relief element includes pressure relief grooves, which are disposed on the side of the pressure relief body opposite to the battery cell.

[0015] In some embodiments, the area surrounding the pressure relief groove is an open area, and the ratio of the area of ​​the open area to the area of ​​the side of the pressure relief body away from the battery cell is 0.4 to 0.9.

[0016] In some embodiments, the top cover includes a step located within the through hole, and the step is circumferentially disposed along the hole wall of the through hole;

[0017] The pressure relief component includes a mounting boss, which is arranged around the first connecting portion and is connected to the step.

[0018] In some embodiments, the size of the mounting boss along the thickness direction is H1 mm, and H1 and H2 satisfy: 0.1≤H2 / H1≤50.

[0019] In some embodiments, along the thickness direction, the step is disposed on the side of the hole wall of the through hole close to or away from the receiving cavity, the size of the step is H4 mm, the size of the top cover plate is H5 mm, and H1, H4 and H5 satisfy: 0.1≤H1 / (H5-H4)≤10.

[0020] In some embodiments, the pressure relief component further includes a second connecting portion, which is disposed around and connected to the first connecting portion, and the end of the second connecting portion away from the first connecting portion is connected to the mounting boss.

[0021] In some embodiments, the connection between the second connecting portion and the first connecting portion has a rounded corner with a radius of 0.1 to 0.5 mm.

[0022] In some embodiments, the pressure relief component is an integral structure.

[0023] In some embodiments,

[0024] The step includes a platform facing the receiving cavity;

[0025] The mounting boss includes a first surface facing away from the receiving cavity, at least a portion of the first surface being in contact with the platform.

[0026] In some embodiments, the step includes a platform facing away from the receiving cavity, and the first connecting portion passes through the through hole;

[0027] The mounting boss includes a second surface facing the receiving cavity, the second connecting portion includes a third surface facing the receiving cavity, the second surface and the third surface are coplanar, and the second surface and at least a portion of the third surface are in contact with the table surface.

[0028] In some embodiments, a weld is formed between the sidewall of the mounting boss and the through hole, the weld extending circumferentially along the mounting boss and extending along the extension direction of the through hole.

[0029] In some embodiments, the battery further includes a lower insulating member connected to the top cover sheet on the side facing the receiving cavity, and the distance between the lower insulating member and the pressure relief body along the thickness direction is H6 mm, satisfying: H6≥0.5mm.

[0030] In some embodiments, the thickness of the pressure relief body is 0.15 mm to 0.25 mm.

[0031] In some embodiments, the size of the pressure relief groove in the thickness direction is 30 μm to 120 μm.

[0032] Accordingly, a battery pack according to the embodiments of this application includes the battery as described in any of the foregoing embodiments.

[0033] Beneficial effects: Compared with the prior art, a battery according to an embodiment of this application includes a casing, a top cover, and a pressure relief component; the casing has a receiving cavity for accommodating a battery cell; the top cover is connected to the casing and seals the receiving cavity, and the top cover has a through hole extending along the thickness direction of the top cover; the pressure relief component is connected to the top cover and seals the through hole; the pressure relief component includes a pressure relief body and a first connecting portion; the pressure relief body is located in the receiving cavity; the first connecting portion is connected to the pressure relief body and is disposed around the pressure relief body; the first connecting portion extends along the thickness direction, and one end of the first connecting portion away from the pressure relief body is connected to the top cover; in the thickness direction, at least a portion of the first connecting portion is located between the pressure relief body and the top cover; in the thickness direction, the size of the first connecting portion is H2 mm, and the size of the pressure relief body is H3 mm, where H2 and H3 satisfy: 0.2≤H2 / H3≤100. The pressure relief component of this application includes a first connecting part and a pressure relief body. The first connecting part connects the top cover plate and the pressure relief body and is spaced between the two, thereby achieving a height difference between the pressure relief body and the top cover plate. Furthermore, H2 and H3 satisfy: 0.2≤H2 / H3≤100. When the battery is inverted, the first connecting part supports the pressure relief body, preventing the pressure relief body from being immersed in the electrolyte, thereby effectively preventing the pressure relief body from being corroded by the electrolyte and extending the service life of the pressure relief component.

[0034] Compared with the prior art, a battery pack according to an embodiment of this application includes the battery as described in any of the foregoing embodiments. It is understood that this battery pack possesses all the technical features and beneficial effects of the aforementioned batteries, which will not be repeated here. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1 is a schematic diagram of the structure of a battery according to an embodiment of this application;

[0037] Figure 2 is a structural schematic diagram of the pressure relief component according to an embodiment of this application;

[0038] Figure 3 is a top view of the pressure relief component according to an embodiment of this application;

[0039] Figure 4 is a cross-sectional view of the pressure relief component according to an embodiment of this application;

[0040] Figure 5 is an enlarged view of part B in Figure 4;

[0041] Figure 6 is a schematic diagram of an embodiment of the connection between the top cover plate and the pressure relief component of this application;

[0042] Figure 7 is a top view of Figure 6;

[0043] Figure 8 is a cross-sectional view of Figure 6;

[0044] Figure 9 is an enlarged view of part A in Figure 8;

[0045] Figure 10 is a cross-sectional view of the top cover plate in Figure 8;

[0046] Figure 11 is an enlarged view of part C in Figure 10;

[0047] Figure 12 is a schematic diagram of another embodiment of the connection between the top cover plate and the pressure relief component of this application;

[0048] Figure 13 is a cross-sectional view of Figure 12;

[0049] Figure 14 is an enlarged view of part D in Figure 13.

[0050] Reference numerals: 1-shell, 11-receiving cavity, 2-top cover plate, 21-through hole, 22-step, 221-platform, 3-battery cell, 4-pressure relief component, 41-pressure relief body, 42-first connecting part, 43-mounting boss, 431-first surface, 432-second surface, 44-second connecting part, 441-third surface, 45-pressure relief groove, 5-weld, 6-lower insulating component; 61-clearance groove; 611-bottom of groove; X-thickness direction. Detailed Implementation

[0051] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0052] In the description of this application, it should be understood that the terms "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. 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 indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more features. In the description of this application, "multiple" means two or more, and "at least one" can mean one, two, or more, unless otherwise explicitly specified. In the description of this application, "perpendicular" means completely perpendicular to 90° or almost completely perpendicular, for example, the range of included angles from 80° to 100° is considered perpendicular. Similarly, "parallel" means completely parallel or almost completely parallel, for example, the range of completely parallel angles from 10° is considered parallel.

[0053] It should also be noted that the arrows labeled X in the accompanying drawings of this application represent the thickness direction X of the top cover plate 2, that is, the direction in which the cell 3 faces the top cover plate 2. The thickness direction X is introduced to facilitate the description of the structural positional relationship of the various components of the battery, thereby making it easier to understand its structure.

[0054] In related technologies, the top cover structure of a power battery, as a key component, has a significant impact on the battery's energy density, economy, and safety. The purpose of installing an explosion-proof valve in the top cover is to release internal pressure promptly when abnormal gas generation occurs in the battery cell, preventing cell explosion. The connection between the explosion-proof valve and the top cover involves a through-hole in the top cover, with the explosion-proof valve sealing the through-hole. The current mainstream solution is to have a groove in the top cover, with the explosion-proof valve welded into the groove, making the surface of the explosion-proof valve inside the battery coplanar with the inner surface of the top cover. This structure is easy to manufacture. However, current technological trends in the power battery industry are shifting towards inverted cell applications. In this case, when the battery using the above-mentioned top cover structure is inverted, the explosion-proof valve is completely immersed in the electrolyte. When a short circuit occurs between the negative electrode and the casing, the thin grooves on the explosion-proof valve are at risk of corrosion and cracking, leading to a reduced lifespan of the explosion-proof valve.

[0055] In view of this, this application provides a battery that aims to solve the problem that when the battery is used upside down, the explosion-proof valve is completely immersed in the electrolyte, which makes the explosion-proof valve prone to corrosion and cracking.

[0056] Referring to Figures 1-5, a battery according to an embodiment of this application includes a housing 1, a top cover 2, and a pressure relief component 4. The housing 1 has a receiving cavity 11 for accommodating a battery cell 3. The top cover 2 is connected to the housing 1 and covers the receiving cavity 11. The top cover 2 has a through hole 21 extending along the thickness direction of the top cover. The pressure relief component 4 is connected to the top cover 2 and covers the through hole 21. The pressure relief component 4 includes a pressure relief body 41 and a first connecting portion 42. The pressure relief body 41 is located in the receiving cavity 11. The first connecting portion 42 is connected to the pressure relief body 41 and is disposed around the pressure relief body 41. The first connecting portion 42 extends along the thickness direction X. One end of the first connecting portion 42 away from the pressure relief body 41 is connected to the top cover 2. In the thickness direction X, at least a portion of the first connecting portion 42 is located between the pressure relief body 41 and the top cover 2.

[0057] In this embodiment, the pressure relief component 4 covers the through hole 21. Furthermore, one end of the first connecting part 42 surrounds the pressure relief body 41 and is sealed to the pressure relief body 41. The end of the first connecting part 42 away from the pressure relief body 41 can be directly connected to the top cover plate 2 or connected to the top cover plate 2 through other structures (such as the mounting boss 43 below). At this time, the pressure relief body 41 is directly opposite the through hole 21. When pressure relief is required, the pressure relief body 41 bursts open and the thermal runaway gas is discharged through the through hole 21.

[0058] In this embodiment, the pressure relief component 4 includes a first connecting part 42 and a pressure relief body 41 connected to each other. The first connecting part 42 connects the top cover plate 2 and the pressure relief body 41 and is spaced between them, thereby achieving a height difference between the pressure relief body 41 and the top cover plate 2. When the battery is inverted, the first connecting part 42 supports the pressure relief body 41, preventing the pressure relief body 41 from contacting the electrolyte, thus isolating the ion pathway, eliminating the risk of corrosion of the pressure relief body 41, extending the service life of the pressure relief component 4, and significantly improving the safety and reliability of the battery.

[0059] It should be noted that, in this embodiment, along the thickness direction X, at least a portion of the pressure relief component 4 is located between the pressure relief body 41 and the top cover plate 2. Specifically, at least a portion of the first connecting portion 42 is located between the side of the pressure relief body 41 away from the battery cell 3 and the side of the top cover plate 2 facing the battery cell 3. This ensures that the first connecting portion 42 can support the pressure relief body 41 and keep it a certain distance away from the top cover plate 2. At this time, when the battery is used in an inverted position, the electrolyte accumulates on the top cover plate 2 under the action of gravity. With the support of the first connecting portion 42, the pressure relief body 41 keeps the electrolyte away from the top cover plate 2 and away from the electrolyte surface, thereby effectively preventing the pressure relief body 41 from being corroded by the electrolyte, improving the service life of the pressure relief component 4, and thus improving the safety of the pressure relief component 4.

[0060] It should also be noted that this application, through its uniquely structured pressure relief component, can, on the one hand, support the pressure relief body through the first connecting part to reduce the risk of corrosion of the pressure relief body and ensure its service life; on the other hand, it can effectively reduce the manufacturing difficulty of the top cover plate, and can manufacture pressure relief components with different heights of the first connecting part according to different height requirements. By selecting pressure relief components of different heights according to different needs, the flexibility of battery assembly can be improved, and the adaptability of the pressure relief component can also be improved.

[0061] As shown in Figures 2, 3, 5, 9, 12 and 14, in some embodiments, the pressure relief component 4 includes a pressure relief groove 45, which is disposed on the side of the pressure relief body 41 away from the battery cell 3.

[0062] In this embodiment, the pressure relief groove 45 is provided on the pressure relief body 41. The pressure relief groove 45 is thinner in the thickness direction X compared with other parts of the pressure relief body 41. When there is a lot of thermal runaway gas inside the battery and the gas pressure is high, the pressure relief body 41 will burst first from the pressure relief groove 45 to realize the timely release of thermal runaway gas and avoid battery explosion.

[0063] It should be noted that in this embodiment, the pressure relief mark 45 is located on the side of the pressure relief body 41 facing away from the battery cell 3. When the battery is used upside down, the electrolyte first falls onto the pressure relief body 41 and then continues to fall onto the top cover plate 2. If the pressure relief mark 45 were located on the side of the pressure relief body 41 facing the battery cell 3, the electrolyte would fall directly into the pressure relief mark 45 and accumulate there, causing corrosion of the weak areas at the pressure relief mark 45. However, in this embodiment, the pressure relief mark 45 is located on the side of the pressure relief body 41 facing away from the battery cell 3, so the electrolyte cannot fall directly into the pressure relief mark 45, and there is no accumulation of electrolyte within the pressure relief mark 45, effectively reducing the possibility of corrosion of the pressure relief mark 45.

[0064] As shown in Figure 5, in some embodiments, along the thickness direction X, the size of the first connecting part 42 is H2 mm, and the size of the pressure relief body 41 is H3 mm, where H2 and H3 satisfy: 0.2≤H2 / H3≤100.

[0065] In this embodiment, the ratio of the size of the first connecting part 42 to the size of the pressure relief body 41 is in the range of 0.2 to 100. This allows the first connecting part 42 to effectively support the pressure relief body 41 and raise it to a certain height, thus preventing corrosion. If the ratio is too small, the first connecting part 42 cannot prevent the electrolyte from corroding the pressure relief body 41. If the ratio is too large, the pressure relief component 4 becomes difficult to process, prone to cracking, and has a low yield.

[0066] It should be noted that, in the embodiments of this application, the numerical range of H2 / H3 is 0.2≤H2 / H3≤100, that is, the value can be any value among 0.2, 0.3, 0.4, 0.5, 0.1, 2, 3, 5, 10, 15, 20, 30, 40, 50, and 100, or a range between any two values.

[0067] Optionally, in this embodiment, 0.2≤H2≤25, 0.15≤H3≤1; within this range, on the one hand, the first connecting part 42 can maintain sufficient height to support the pressure relief body 41, preventing the pressure relief body 41 from contacting the electrolyte, while also avoiding the waste of internal battery space caused by an excessively large size of the first connecting part 42, effectively ensuring the energy volume density of the battery. Furthermore, within this range, the thickness of the pressure relief body 41 can meet the requirements for etching the pressure relief groove 45, and on the other hand, allow the overall thickness of the pressure relief body 41 to be relatively thin, facilitating the complete explosion of the pressure relief body 41 portion in the middle of the pressure relief groove 45 after it bursts open, achieving timely and effective rapid pressure relief.

[0068] It should be noted that the function of the first connecting part 42 is to support the pressure relief body 41, thereby preventing the pressure relief body 41 from being submerged in the electrolyte when the battery is inverted. Simultaneously, the pressure relief groove 45 is located on the side of the pressure relief body 41 facing away from the battery cell 3. In this case, only the bottom of the pressure relief groove 45 needs to be above the electrolyte surface; even if at least a portion of the pressure relief body 41 is submerged in the electrolyte, the pressure relief groove 45 will not be corroded. Therefore, the dimension of the first connecting part 42 in the thickness direction X does not need to be very large. This effectively reduces the processing difficulty, ensures the yield of the pressure relief component 4, and prevents the pressure relief component 4 from cracking during processing.

[0069] It should be noted that, in this embodiment, the numerical range of H2 is 0.2 ≤ H2 ≤ 25, that is, the value can be any value among 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, and 25, or a range between any two values. The numerical range of H3 is 0.15 ≤ H3 ≤ 1, that is, the value can be any value among 0.15, 0.16, 0.17, 0.18, 0.19, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, and 1, or a range between any two values.

[0070] It should also be noted that, in the embodiments of this application, the dimensions of H2 and H3 can be directly measured using length measuring tools such as vernier calipers.

[0071] It should also be noted that since the pressure relief component 4 is relatively thin, it can be directly stamped using a stamping process. Therefore, ensuring that the ratio of the dimensions of the first connecting part 42 and the pressure relief body 41 in the thickness direction X is 0.2≤H2 / H3≤100, and 0.2≤H2≤25, 0.15≤H3≤1, can facilitate the integral stamping forming of the pressure relief component 4.

[0072] As shown in Figures 8-11 and 14, in some embodiments, the top cover plate 2 includes a step 22, which is located inside the through hole 21 and is arranged circumferentially along the hole wall of the through hole 21; the pressure relief component 4 includes a mounting boss 43, which is arranged around the first connecting portion 42 and is connected to the step 22.

[0073] In this embodiment, the pressure relief component 4 is connected to the step 22 of the top cover plate 2 via the mounting boss 43, thereby achieving the connection between the pressure relief component 4 and the top cover plate 2. Furthermore, by placing the step 22 within the through hole 21, the mounting boss 43 is at least partially located within the through hole 21. This allows the gap between the sidewall of the mounting boss 43 and the through hole 21 to be filled and welded to form a weld 5. Compared to directly welding the pressure relief component 4 to the inner surface of the top cover plate 2 facing the battery, this structure's weld 5 extends not only circumferentially along the mounting boss 43 but also along the extension direction of the through hole 21, forming a deeper and thicker weld 5, resulting in a better welding connection.

[0074] As shown in Figure 5, in some embodiments, the size of the mounting boss 43 along the thickness direction X is H1 mm, and H1 and H2 satisfy: 0.1≤H2 / H1≤50.

[0075] In this embodiment, the ratio of the size of the first connecting part 42 to the size of the mounting boss 43 is in the range of 0.1 to 50. This ensures that the first connecting part 42 effectively supports the pressure relief body 41, preventing corrosion of the pressure relief body 41. If this ratio is too small, the first connecting part 42 cannot prevent the electrolyte from corroding the pressure relief body 41; if this ratio is too large, the overall processing of the pressure relief component 4 is difficult, prone to cracking, and the yield rate is low.

[0076] It should be noted that, in the embodiments of this application, the numerical range of H2 / H1 is 0.1≤H2 / H1≤50, that is, the value can be any value among 0.1, 0.2, 0.3, 0.4, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 40, and 50, or a range between any two values.

[0077] Optionally, in this embodiment, 0.5≤H1≤2, 0.2≤H2≤25; within this range, 0.1≤H2 / H1≤50 is also satisfied. On the one hand, this ensures that the first connecting part 42 has sufficient height to support the pressure relief body 41, preventing the pressure relief body 41 from contacting the electrolyte. On the other hand, it avoids wasting internal battery space due to an excessively large size of the first connecting part 42, effectively ensuring the battery's energy volume density. Since the mounting boss 43 needs to be welded to the top cover plate 2, it needs to have a certain thickness. This allows the mounting boss 43 to have a large welding area, enabling effective welding. On the other hand, the mounting boss 43 should have a thickness of at least 0.5 mm to prevent deformation during welding, ensuring the stability of the overall structure of the pressure relief component 4 and the sealing performance when welded to the top cover plate 2. It also ensures the corrosion resistance of the mounting boss. Of course, the thickness of the mounting boss 43 should not be too thick, preferably not exceeding 2 mm, as this would increase production difficulty and the overall weight of the battery.

[0078] It should be noted that, in this embodiment, the numerical range of H1 is 0.5 ≤ H1 ≤ 2, that is, the value can be any value among 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5, and 2, or a range between any two values. The numerical range of H2 is 0.2 ≤ H2 ≤ 25, that is, the value can be any value among 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, and 25, or a range between any two values.

[0079] It should also be noted that, in the embodiments of this application, the dimensions of H1 and H2 can be directly measured using length measuring tools such as vernier calipers.

[0080] Referring to Figures 5 and 11, in some embodiments, along the thickness direction X, a step 22 is disposed on the side of the hole wall of the through hole 21 near or away from the receiving cavity 11. The size of the step 22 is H4 mm, and the size of the top cover plate 2 is H5 mm. H1, H4 and H5 satisfy: 0.1≤H1 / (H5-H4)≤10.

[0081] In this embodiment, the ratio of the size of the mounting boss 43 to the size of the top cover plate 2 excluding the size of the step 22 is between 0.1 and 10. This ratio allows the groove formed by the step 22 and the top cover plate 2 to accommodate at least a portion of the mounting boss 43, facilitating positioning and limiting of the mounting boss 43 when the pressure relief component 4 is connected to the top cover plate 2, thereby achieving the positioning of the pressure relief component 4. Furthermore, limiting the size to this range facilitates welding and fixing the pressure relief component 4 to the top cover plate 2, simplifying the welding process and making it easy to operate.

[0082] It should be noted that, in the embodiments of this application, the numerical range of H1 / (H5-H4) is 0.1≤H1 / (H5-H4)≤10, that is, the value can be any value among 0.1, 0.2, 0.3, 0.4, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or any range between any two values.

[0083] It should also be noted that, in the embodiments of this application, the dimensions of H1, H4 and H5 can be directly measured by length measuring tools such as vernier calipers.

[0084] Optionally, in this embodiment, the following conditions are met: 0.1≤H1 / (H5-H4)≤10, and 0.5≤H1≤2, 0.5≤H4≤4.5, and 1≤H5≤5.5. Within this range, the larger the ratio, the thicker the corresponding mounting boss 43, resulting in a better welding connection and improved corrosion resistance. Furthermore, within this range, it is beneficial to rationally arrange the weld position, facilitating weld extension and further ensuring the welding connection effect.

[0085] As shown in Figures 2-5, 9, 12 and 13, in some embodiments, the pressure relief component 4 further includes a second connecting portion 44, which is disposed around and connected to the first connecting portion 42, and the end of the second connecting portion 44 away from the first connecting portion 42 is connected to the mounting boss 43.

[0086] In this embodiment, a second connecting part 44 is provided so that the second connecting part 44 connects between the first connecting part 42 and the mounting boss 43, thereby achieving a transition function and making it easier to manufacture the pressure relief part 4.

[0087] Optionally, in this embodiment, the length of the second connecting portion 44 is 1 to 5 mm, so as to achieve a smooth transition between the first connecting portion 42 and the mounting boss 43.

[0088] It should be noted that the length of the second connecting part 44 ranges from 1 to 5 millimeters, meaning that this value can be any value among 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, and 5, or a range between any two values. The length of the second connecting part 44 can be directly measured using length measuring tools such as vernier calipers or rulers.

[0089] Furthermore, the connection between the second connecting part 44 and the first connecting part 42 is rounded with a radius of 0.1 to 0.5 mm. This ensures a smooth transition between the connection between the first connecting part 42 and the second connecting part 44, facilitating subsequent production and processing.

[0090] It should be noted that the radius of this fillet is 0.1–0.5 mm, meaning it can be any value from 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, to 0.5, or a range between any two values. It should also be noted that the radius of this fillet can be measured as follows: First, determine a chord at any position on the arc. Then, determine the perpendicular bisector of this chord. Next, determine the perpendicular bisector of another chord on the arc. The intersection of the two perpendicular bisectors is the center of the arc. Then, use calipers or other length measuring tools to measure the straight-line distance from the center to any point on the arc; this is the radius of the arc. Of course, other methods for determining the radius of an arc can also be used, which will not be elaborated here.

[0091] In some embodiments, the pressure relief component 4 is an integral structure.

[0092] In this embodiment, the pressure relief body 41, the first connecting part 42, the second connecting part 44, the mounting protrusion and the pressure relief groove 45 of the pressure relief component 4 are integrally formed, which can be by injection molding or other methods. The integrally formed pressure relief component 4 is easier to manufacture and has a more stable structure, while avoiding connection errors.

[0093] In addition, in this embodiment, the dimension of the pressure relief mark 45 in the thickness direction X, i.e. the depth, is 30μm to 120μm. When the thickness of the pressure relief body 41 is 0.15mm to 0.25mm, the position of the pressure relief body 41 corresponding to the pressure relief mark 45 is a weak area, which is convenient to break apart and relieve pressure in the event of thermal runaway.

[0094] It should be noted that the depth of the pressure relief notch 45 is 30μm to 120μm, meaning this value can be any value from 30, 31, 32, 33, 34, 35, 40, 45, 50, 60, 70, 80, 90, 100, 110, and 120, or a range between any two values. This dimension can be directly measured using a micrometer or other length measuring tools.

[0095] In addition, the area surrounding the pressure relief groove 45 is an open area. The ratio of the area of ​​the open area to the area of ​​the side of the pressure relief body 41 away from the battery cell 3 is 0.4 to 0.9. Setting it in this area will not interfere with the setting of the first connection part 42, and can ensure that the pressure relief body 41 has a sufficient open area to ensure the pressure relief of the pressure relief component 4.

[0096] It should be noted that the ratio of the area of ​​the open area to the area of ​​the side of the pressure relief body 41 away from the battery cell 3 is 0.4 to 0.9. That is, this value can be any value or a range between any two values ​​from 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9.

[0097] It should also be noted that the cross-sectional area of ​​the open area and the area of ​​the side of the pressure relief body 41 facing away from the battery cell 3 can be measured and calculated using conventional area measurement methods. For example, if the open area and the pressure relief body 41 are of regular shape (e.g., square, circular, elliptical, annular, etc.), the area measurement method corresponding to the shape can be used for measurement and calculation. If the open area and the pressure relief body 41 are of irregular shape, the film coating method can be used for measurement and calculation. That is, a uniformly mass film is attached to the open area and the side of the pressure relief body 41 facing away from the battery cell 3, the corresponding portion of the film is removed, and the mass of the film is determined. The quotient of the removed film mass and the pre-determined mass per unit area of ​​the film is determined as the area of ​​the open area and the area of ​​the side of the pressure relief body 41 facing away from the battery cell 3. By quotienting the area of ​​the open area and the area of ​​the side of the pressure relief body 41 facing away from the battery cell 3, the ratio can be obtained. If this ratio falls within the above range, this embodiment can be realized.

[0098] Referring to Figures 9 and 11, in some embodiments, step 22 includes a platform 221 facing the receiving cavity 11; mounting boss 43 includes a first surface 431 facing away from the receiving cavity 11, at least a portion of the first surface 431 being in contact with the platform 221.

[0099] In this embodiment, the mounting boss 43 is located on the side of the top cover plate 2 facing the battery cell 3. The mounting boss 43 is positioned within the groove formed by the platform 221 and the wall of the through hole 21, and is directly welded together. The weld 5 is located on the side of the top cover plate 2 facing the battery cell 3. In this case, the first connecting portion 42 is relatively short, and the overall size of the pressure relief component 4 along the thickness direction X is small. This facilitates the production and molding of the pressure relief component, ensures a high yield rate, reduces material usage, and lowers the overall weight of the battery. Furthermore, in this embodiment, the mounting boss 43 only needs to be directly welded to the platform 221 and the top cover plate 2. Therefore, the area of ​​the pressure relief body 41 is larger, allowing for a larger opening area for rapid pressure relief.

[0100] As shown in Figure 14, in some embodiments, the step 22 includes a platform 221 facing away from the receiving cavity 11, and the first connecting portion 42 passes through the through hole 21; the mounting boss 43 includes a second surface 432 facing the receiving cavity 11, and the second connecting portion 44 includes a third surface 441 facing the receiving cavity 11. The second surface 432 and the third surface 441 are coplanar, and the second surface 432 and at least part of the third surface 441 are in contact with the platform 221.

[0101] In this embodiment, the first connecting part 42 is partially inserted into the through hole 21, and the mounting boss 43 is located on the side of the step 22 away from the receiving cavity 11 and is connected to the top cover plate 2. When the battery is used in an inverted position, by reasonably setting the size of the first connecting part 42 extending through the through hole 21, the pressure relief body 41 can be made to exceed the liquid level of the electrolyte without contacting the electrolyte, thereby isolating the ion pathway and eliminating the risk of corrosion of the pressure relief body 41. Meanwhile, in this embodiment, the mounting boss 43 is located on the side of the step 22 away from the receiving cavity 11. At this time, the weld 5 between the mounting boss 43 and the top cover plate 2 is located on the side of the top cover plate 2 away from the receiving cavity 11. At least a portion of the second surface 432 of the mounting boss 43 and the third surface 441 of the second connecting part 44 are in contact with the platform 221 of the step 22. For the electrolyte to come into contact with the weld 5, it needs to pass through the contact surfaces of the second surface 432 and the third surface 441 with the platform 221 before reaching the weld 5. Therefore, in this embodiment, the contact path between the electrolyte and the weld 5 is large, which in turn improves the corrosion resistance of the weld 5.

[0102] It should be noted that the bonding in this embodiment can also be welding bonding, which further increases the overall size of weld 5 and further improves the corrosion resistance of weld 5.

[0103] As shown in Figures 9 and 14, in some embodiments, the battery further includes a lower insulating member 6, which is connected to the side of the top cover 2 facing the receiving cavity 11. The lower insulating member 6 has a relief groove 61 for avoiding the pressure relief member 4. Along the thickness direction X, the distance between the bottom 611 of the relief groove 61 and the pressure relief body 41 is H6 mm, satisfying: H6≥0.5mm.

[0104] In this embodiment, the distance between the bottom 611 of the clearance groove 61 and the pressure relief body 41 is greater than or equal to 0.5 mm, which is used to provide deformation space for the lower insulating member 6 and prevent the lower insulating member 6 from deforming and pressing on the pressure relief body 41, thereby causing damage to the pressure relief body 41.

[0105] It should be noted that when the battery is inverted, the lower insulating component 6 is located between the top cover plate 2 and the battery cell 3. The lower insulating component is usually an insulating injection molded part. When the battery is inverted, the battery cell 3 presses on the lower insulating component 6, which makes the lower insulating component 6 locally susceptible to deformation. However, the lower insulating component 6 also has a certain supporting capacity, and other structures on the top cover plate 2, such as electrode terminals, also provide a certain supporting effect for the lower insulating component 6. Therefore, the deformation range of the lower insulating component 6 is also limited. In this embodiment, the distance between the pressure relief body 41 and the lower insulating component 6 is limited to be greater than or equal to 0.5 mm to meet its deformation requirements, while also preventing pressure on the pressure relief body 41.

[0106] Additionally, it should be noted that due to the limited internal space of the battery, the distance between the lower insulating component 6 and the pressure relief body 41 will not be excessively large. Therefore, it is sufficient to maintain a distance of 0.5 mm or greater between the two within the allowable range of the internal space of the battery.

[0107] The following are some specific embodiments of this application to illustrate the technical effects of the above solution.

[0108] In this application embodiment, in conjunction with the above embodiments, it can be determined that the battery of this application, along the thickness direction, when satisfying 0.5≤H1≤2, 0.2≤H2≤25, 0.15≤H3≤1, 0.5≤H4≤4.5, 1≤H5≤5.5, 0.1≤H2 / H1≤50, 0.2≤H2 / H3≤100, 0.1≤H1 / (H5-H4)≤10, the pressure relief component 4 will not crack during the production process, and the weld airtightness test of the pressure relief component 4 and the top cover plate 2 after welding is qualified. At the same time, the pressure relief component 4 will not be corroded when the battery is used upside down.

[0109] It should be noted that the testing method in the above embodiments is as follows:

[0110] Adjust the parameters of the production mold for pressure relief component 4 to the required range, and produce pressure relief component 4. Confirm that the parameters of pressure relief component 4 meet the values ​​listed in each embodiment using a two-dimensional microscope. Confirm that the appearance of pressure relief component 4 is normal and there are no defects such as cracks or extrusion using a metallographic microscope. Use pressure relief component 4 to produce top cover assembly. Observe the appearance of the weld between pressure relief component 4 and top cover plate 2 using a metallographic microscope to check whether the appearance is good. Test the airtightness function with helium and test the pressure relief value of top cover assembly to check whether it meets the design requirements using a bursting machine. Use the top cover assembly that has passed the above tests to produce battery. After the negative electrode of the battery is connected to the shell, charge and discharge cycle is performed until the battery fails due to electrochemical corrosion. Disassemble the battery and visually inspect whether pressure relief component 4 has a blackened corrosion appearance. Scan the explosion-proof valve with an EDS (Energy Dispersive X-ray Spectroscopy) instrument to confirm whether pressure relief component 4 has lithium ion intercalation corrosion.

[0111] Accordingly, a battery pack according to an embodiment of this application includes the battery as described in any of the foregoing embodiments.

[0112] It is understandable that this battery pack possesses all the technical features and beneficial effects of the aforementioned batteries, which will not be elaborated upon here.

[0113] It should be noted that the battery pack in this application embodiment can be used as a backup power source, electrode, electric vehicle, electric bicycle, electric motorcycle, large storage battery, etc.

[0114] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0115] The present application provides a detailed description of a battery and battery pack, and uses specific examples to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only for the purpose of helping to understand the technical solutions and core ideas of the present application. Those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A battery, wherein, include: A housing having a receiving cavity for accommodating the battery cell; A top cover plate, which is connected to the housing and seals the receiving cavity, the top cover plate having a through hole extending along the thickness direction of the top cover plate; A pressure relief component, which is connected to the top cover and seals the through hole; the pressure relief component includes: a pressure relief body, which is located in the receiving cavity; A first connecting portion is connected to and surrounds the pressure relief body; the first connecting portion extends along the thickness direction, and one end of the first connecting portion away from the pressure relief body is connected to the top cover plate; in the thickness direction, at least a portion of the first connecting portion is located between the pressure relief body and the top cover plate. Along the thickness direction, the size of the first connecting part is H2 mm, and the size of the pressure relief body is H3 mm, where H2 and H3 satisfy: 0.2≤H2 / H3≤100.

2. The battery according to claim 1, wherein, The pressure relief component includes pressure relief grooves, which are located on the side of the pressure relief body opposite to the battery cell.

3. The battery according to claim 2, wherein, The area surrounding the pressure relief groove is an open area, and the ratio of the area of ​​the open area to the area of ​​the side of the pressure relief body away from the battery cell is 0.4 to 0.

9.

4. The battery according to claim 1, wherein, The top cover plate includes a step, the step is located inside the through hole, and the step is arranged circumferentially along the hole wall of the through hole; The pressure relief component includes a mounting boss, which is arranged around the first connecting portion and is connected to the step.

5. The battery according to claim 4, wherein, Along the thickness direction, the size of the mounting boss is H1 mm, and H1 and H2 satisfy: 0.1≤H2 / H1≤50.

6. The battery according to claim 5, wherein, Along the thickness direction, the step is disposed on the side of the hole wall of the through hole close to or away from the receiving cavity. The size of the step is H4 mm, and the size of the top cover plate is H5 mm. H1, H4 and H5 satisfy: 0.1≤H1 / (H5-H4)≤10.

7. The battery according to claim 4, wherein, The pressure relief component further includes a second connecting portion, which is disposed around the first connecting portion and connected to the first connecting portion, and the end of the second connecting portion away from the first connecting portion is connected to the mounting boss.

8. The battery according to claim 7, wherein, The connection between the second connecting part and the first connecting part has a rounded corner with a radius of 0.1 to 0.5 mm.

9. The battery according to claim 7, wherein, The pressure relief component is a one-piece structure.

10. The battery according to claim 4, wherein, The step includes a platform facing the receiving cavity; The mounting boss includes a first surface facing away from the receiving cavity, at least a portion of the first surface being in contact with the platform.

11. The battery according to claim 4, wherein, A weld is formed between the sidewall of the mounting boss and the through hole. The weld extends circumferentially along the mounting boss and extends along the extension direction of the through hole.

12. The battery according to claim 7, wherein, The step includes a platform, which is located on the side of the step away from the receiving cavity, and the first connecting part is disposed in the through hole; The mounting boss includes a second surface facing the receiving cavity, the second connecting portion includes a third surface facing the receiving cavity, the second surface and the third surface are coplanar, and the second surface and at least a portion of the third surface are in contact with the table surface.

13. The battery according to claim 1, wherein, The battery also includes a lower insulating member connected to the side of the top cover plate facing the receiving cavity. The lower insulating member has a relief groove for avoiding the pressure relief member. Along the thickness direction, the distance between the bottom of the relief groove and the pressure relief body is H6 mm, satisfying: H6≥0.5mm.

14. The battery according to claim 1, wherein, The thickness of the pressure relief body is 0.15mm to 0.25mm.

15. The battery according to claim 2, wherein, The pressure relief groove has a size of 30μm to 120μm in the thickness direction.

16. A battery pack, wherein, Includes the battery as described in any one of claims 1-15.

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