Single cells, battery packs and electrical devices

Abstract

This application discloses a single-cell battery, a battery pack, and an electrical device, belonging to the field of battery technology. It includes a cover plate connected to a housing and sealing a cavity. The cover plate has an explosion-proof hole, which is sealed by an explosion-proof valve. The explosion-proof valve includes a supporting portion, a weak portion, a protrusion, and a recess connected sequentially from the outside to the inside. The supporting portion is connected to the cover plate. The protrusion protrudes from its connection with the weak portion toward the side away from the electrode assembly, and the recess is recessed toward the side closer to the electrode assembly. The weak portion includes a first surface of the cover plate close to the electrode assembly in the thickness direction. In the thickness direction, the maximum dimension between the protrusion and the first surface is B mm, and the minimum dimension between the recess and the first surface is C mm, satisfying: 0.15 ≤ B - C ≤ 0.5. By limiting the difference range in the thickness direction between the protrusion and the recess, the protrusion and the recess can fully absorb and disperse stress, avoiding deformation cracking or premature opening of the explosion-proof valve.

Description

Technical Field

[0001] This application belongs to the field of battery technology, specifically relating to a single cell, a battery pack, and an electrical device. Background Technology

[0002] Lithium-ion batteries are widely used in various fields such as transportation power supplies, power storage, new energy storage power supplies, and aerospace and military industries due to their advantages such as large capacity, high operating voltage, strong charge retention, and long cycle life. The cover plate of the battery typically integrates structures such as terminals and explosion-proof valves. The explosion-proof valve's main function is to relieve pressure and vent gas, allowing the directional release of high-temperature, high-pressure gas inside the cell when thermal runaway occurs due to mechanical impact, internal abnormal short circuits, or other reasons, thereby improving the safety performance of the battery pack. However, during the individual cell manufacturing process, such as electrolyte injection, pre-charge formation, and capacity testing, repeated positive and negative pressure differences exist between the battery's internal environment and the external environment, leading to problems such as deformation, cracking, and premature opening of the explosion-proof valve, severely impacting battery process yield and safety performance. Summary of the Invention

[0003] Purpose of the invention: This application provides a single cell, a battery pack, and an electrical device, aiming to solve the technical problems of deformation, cracking, and premature opening of the explosion-proof valve due to pressure difference during battery manufacturing.

[0004] Technical solution: This application provides a single-cell battery, including:

[0005] The housing has a receiving cavity;

[0006] Electrode assembly, the electrode assembly is located within the receiving cavity;

[0007] A cover plate is connected to the housing and seals the receiving cavity; the cover plate is provided with explosion-proof holes.

[0008] An explosion-proof valve, with an explosion-proof valve cover sealing the explosion-proof hole, includes a support portion, a weak portion, a protrusion and a recess connected in sequence from the outside to the inside. The support portion is connected to the cover plate. The weak portion is configured to be destroyed when subjected to a preset pressure impact. The protrusion protrudes from the connection with the weak portion toward the side away from the electrode assembly, and the recess is recessed toward the side closer to the electrode assembly.

[0009] The weak part includes the first surface of the cover plate close to the electrode assembly in the thickness direction. In the thickness direction, the maximum dimension between the protrusion and the first surface is B mm, and the minimum dimension between the concave part and the first surface is C mm, satisfying: 0.15≤BC≤0.5.

[0010] In some embodiments, the bearing portion has a maximum dimension A mm in the thickness direction, satisfying: C > A, 0.4 ≤ A ≤ 0.6.

[0011] In some embodiments, the recess has a first dimension W1 mm ​​in the width direction of the cover plate, satisfying: 10≤W1 / (BC)≤15, and the width direction intersects the thickness direction.

[0012] In some embodiments, the maximum dimension A of the bearing portion in the thickness direction satisfies: 0.25≤BA≤1.1.

[0013] In some embodiments, the bearing portion has a maximum dimension W mm in the width direction of the cover plate, satisfying: 15≤W / A≤70.

[0014] In some embodiments, the protrusion has a second dimension W2 mm in the width direction of the cover plate, satisfying: 4≤W2 / B≤7.

[0015] In some embodiments, the support portion is connected to the side of the cover plate near the electrode assembly, and the protrusion extends into the explosion-proof hole.

[0016] In some embodiments, a limiting groove is provided on the side of the cover plate near the electrode assembly. The limiting groove surrounds the explosion-proof hole and is provided on the side of the cover plate near the electrode assembly. The supporting part is provided in the limiting groove.

[0017] Accordingly, this application provides a battery pack including the aforementioned single battery cell.

[0018] Accordingly, embodiments of this application provide an electrical device, including the aforementioned single battery cell, or including the aforementioned battery pack.

[0019] Beneficial Effects: The single-cell battery of this application embodiment includes a casing, an electrode assembly, a cover plate, and an explosion-proof valve. The casing has a receiving cavity; the electrode assembly is located in the receiving cavity; the cover plate is connected to the casing and seals the receiving cavity, and the cover plate is provided with an explosion-proof hole; the explosion-proof valve seals the explosion-proof hole, and the explosion-proof valve includes a support portion, a weak portion, a protrusion, and a recess that are connected in sequence from the outside to the inside. The support portion is connected to the cover plate, the weak portion is configured to be destroyed when subjected to a preset pressure impact, the protrusion protrudes from the connection with the weak portion toward the side away from the electrode assembly, and the recess is recessed toward the side closer to the electrode assembly; wherein, the weak portion includes a first surface close to the electrode assembly in the thickness direction of the cover plate, and in the thickness direction, the maximum dimension between the protrusion and the first surface is B mm, and the minimum dimension between the recess and the first surface is C mm, satisfying: 0.15≤BC≤0.5. By limiting the range of thickness difference between the protrusions and recesses, it is ensured that the protrusions and recesses can fully absorb and disperse the stress on the explosion-proof valve caused by the pressure difference between the cavity and the outside of the casing during the production of a single cell. This avoids local stress concentration that could lead to deformation of the explosion-proof valve, which could then cause cracking or premature opening of the valve. As a result, the production yield of single cells can be effectively improved, as well as the safety and reliability of single cells.

[0020] The battery pack of this application embodiment includes the above-described single battery cell, and therefore the battery pack can have all the technical features and beneficial effects of the above-described single battery cell, which will not be repeated here.

[0021] The electrical device in this application includes the above-mentioned single battery or battery pack. Therefore, the electrical device can have all the technical features and beneficial effects of the above-mentioned single battery or battery pack, which will not be repeated here. Attached Figure Description

[0022] 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.

[0023] Figure 1 This is an exploded view of a single battery cell according to an embodiment of this application;

[0024] Figure 2 This is a cross-sectional view of a cover plate according to an embodiment of this application;

[0025] Figure 3 This is a top view of an explosion-proof valve according to an embodiment of this application;

[0026] Figure 4 This is a bottom view of an explosion-proof valve according to an embodiment of this application;

[0027] Figure 5 This is a cross-sectional view of a cover plate according to an embodiment of this application;

[0028] Figure 6 This is a cross-sectional view of a cover plate according to another embodiment of this application.

[0029] Reference numerals: 1. Housing; 2. Electrode assembly; 3. Cover plate; 4. Explosion-proof valve; 10. Receiving cavity; 30. Explosion-proof hole; 31. Limiting groove; 40. Bearing part; 41. Weak part; 42. Protrusion; 43. Recess; 310. Bottom wall; 410. First surface; 411. Score; X, Thickness direction. Detailed Implementation

[0030] 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.

[0031] 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.

[0032] The applicant notes that lithium-ion batteries, due to their advantages such as large capacity, high operating voltage, strong charge retention, and long cycle life, are currently widely used in various fields including transportation power supplies, power storage, new energy storage power supplies, and aerospace and military industries. The cover plate in a battery typically integrates structures such as terminals and explosion-proof valves. The explosion-proof valve's main function is to release pressure and vent gas, allowing the directional release of high-temperature, high-pressure gas inside the cell when thermal runaway occurs due to mechanical impact, internal abnormal short circuits, or other reasons, thereby improving the safety performance of the battery pack. However, during the individual cell manufacturing process, such as electrolyte injection, pre-charge formation, and capacity testing, repeated positive and negative pressure differences exist between the battery's internal environment and the external environment, leading to problems such as deformation, cracking, and premature opening of the explosion-proof valve, severely impacting battery process yield and safety performance.

[0033] In view of this, the single-cell battery of this application embodiment includes a casing, an electrode assembly, a cover plate, and an explosion-proof valve. The casing has a receiving cavity; the electrode assembly is located in the receiving cavity; the cover plate is connected to the casing and seals the receiving cavity, and the cover plate is provided with an explosion-proof hole; the explosion-proof valve seals the explosion-proof hole, and the explosion-proof valve includes a support portion, a weak portion, a protrusion, and a recess that are connected in sequence from the outside to the inside. The support portion is connected to the cover plate, the weak portion is configured to be destroyed when subjected to a preset pressure impact, the protrusion protrudes from the connection with the weak portion toward the side away from the electrode assembly, and the recess is recessed toward the side closer to the electrode assembly; wherein, the weak portion includes a first surface of the cover plate close to the electrode assembly in the thickness direction, and in the thickness direction, the maximum dimension between the protrusion and the first surface is B mm, and the minimum dimension between the recess and the first surface is C mm, satisfying: 0.15≤BC≤0.5. By limiting the range of thickness difference between the protrusions and recesses, it is ensured that the protrusions and recesses can fully absorb and disperse the stress on the explosion-proof valve caused by the pressure difference between the cavity and the outside of the casing during the production of a single cell. This avoids local stress concentration that could lead to deformation of the explosion-proof valve, which could then cause cracking or premature opening of the valve. As a result, the production yield of single cells can be effectively improved, as well as the safety and reliability of single cells.

[0034] In this application, a single battery cell may include lithium-ion secondary batteries, lithium-ion primary batteries, lithium-sulfur batteries, sodium-lithium-ion batteries, sodium-ion batteries, or magnesium-ion batteries, etc., and the embodiments of this application are not limited to this. A single battery cell may be cylindrical, flat, cuboid, or other shapes, etc., and the embodiments of this application are not limited to this either. Single batteries are generally classified into three types according to their packaging method: cylindrical single batteries, square single batteries, and pouch single batteries, and the embodiments of this application are not limited to this either.

[0035] The single-cell battery, battery pack, and power-consuming device of this application will be described in detail below with reference to the accompanying drawings. Unless otherwise specified, the features of the following embodiments and implementations can be combined with each other.

[0036] Figure 1 This is an exploded view of a single battery cell according to an embodiment of this application; Figure 2 This is a cross-sectional view of a cover plate 3 according to an embodiment of this application; Figure 3 This is a top view of an explosion-proof valve 4 according to an embodiment of this application; Figure 4 This is a bottom view of an explosion-proof valve 4 according to an embodiment of this application; Figure 5 This is a cross-sectional view of a cover plate according to an embodiment of this application; Figure 6 This is a cross-sectional view of a cover plate according to another embodiment of this application.

[0037] refer to Figures 1 to 6This application provides a single-cell battery, a battery pack, and an electrical device, including a housing 1, an electrode assembly 2, a cover plate 3, and an explosion-proof valve 4. The housing 1 has a receiving cavity 10; the electrode assembly 2 is located within the receiving cavity 10; the cover plate 3 is connected to the housing 1 and seals the receiving cavity 10. The cover plate 3 has an explosion-proof hole 30, which is sealed by the explosion-proof valve 4. The explosion-proof valve 4 includes a support portion 40, a weak portion 41, a protrusion 42, and a recess 43, which are sequentially connected from the outside to the inside. Specifically, the support portion 40 is connected to the weak portion 41, the weak portion 41 is connected to the protrusion 42, and the protrusion 42 is connected to the recess 43. The weak portion 41 is configured to be destroyed when subjected to a preset pressure impact. When the internal pressure of the single-cell battery is too high (e.g., due to overcharging), the weak portion 41 of the explosion-proof valve 4 is destroyed by the preset pressure to release the gas inside the single-cell battery, thereby reducing the internal pressure of the single-cell battery and preventing the battery from exploding due to excessively rapid internal pressurization. The protrusion 42 protrudes from the connection point with the weak portion 41 towards the side away from the electrode assembly 2, while the recess 43 is recessed towards the side closer to the electrode assembly 2. The arrangement of the protrusion 42 and the recess 43 can avoid stress concentration. The weak portion 41 includes a first surface 410 of the cover plate 3 in the thickness direction X, close to the electrode assembly 2. In the thickness direction X, the maximum dimension between the protrusion 42 and the first surface 410 is B mm, and the minimum dimension between the recess 43 and the first surface 410 is C mm, satisfying: 0.15 ≤ BC ≤ 0.5. By limiting the range of the difference between the protrusion 42 and the recess 43 in the thickness direction X, it is ensured that the arrangement of the protrusion 42 and the recess 43 can fully absorb and disperse the stress on the explosion-proof valve 4 caused by the pressure difference between the cavity 10 and the shell 1 during the production of the single cell. This avoids local stress concentration that could lead to deformation of the explosion-proof valve 4, resulting in cracking or premature opening of the valve. Therefore, it can effectively improve the production yield of the single cell and enhance its safety and reliability.

[0038] exist Figure 6In the illustrated embodiment, the maximum dimension between the protrusion 42 and the first surface 410 in the thickness direction X is B mm, and the minimum dimension between the recess 43 and the first surface 410 is C mm, satisfying: 0.15 ≤ BC ≤ 0.5. It is understandable that when the difference between the maximum dimension B between the protrusion 42 and the first surface 410 and the minimum dimension C between the recess 43 and the first surface 410 is too large, the protrusion 42 protrudes relatively high, resulting in a small distance between the protrusion 42 and the side of the cover plate 3 away from the electrode assembly 2. This poses a risk of damage to the explosion-proof valve 4 during the single-cell manufacturing process. On the other hand, the recessed portion of the recess 43 is relatively high, and may deform during production due to localized stress concentration, increasing the risk of abnormal deformation or even cracking of the explosion-proof valve 4. When the difference between the maximum dimension B between the protrusion 42 and the first surface 410 and the minimum dimension C between the recess 43 and the first surface 410 is too small, the protrusion 42 and the recess 43 may not be able to absorb and disperse the pressure in a timely and effective manner, thereby increasing the risk of the explosion-proof valve 4 becoming concave or convex, leading to cracking or premature valve opening. This application, by reasonably controlling the range of the difference between the maximum dimension B between the protrusion 42 and the first surface 410 and the minimum dimension C between the recess 43 and the first surface 410, fully absorbs and disperses the stress brought to the explosion-proof valve 4 by the pressure difference between the cavity 10 and the shell 1 during the production of a single cell, avoids the problem of concave or convex deformation of the explosion-proof valve 4 due to local stress concentration, which could lead to cracking or premature valve opening. This can effectively improve the production yield of single cells and improve the safety and reliability of single cells.

[0039] exist Figure 6 In the illustrated embodiment, the maximum dimension A of the support portion 40 in the thickness direction X satisfies: 0.4 ≤ A ≤ 0.6. Exemplarily, the maximum dimension A of the support portion 40 can be any one of 0.4, 0.42, 0.44, 0.46, 0.48, 0.5, 0.52, 0.54, 0.56, 0.58, and 0.6, or a range between any two. This configuration ensures the connection stability between the support portion 40 and the cover plate 3, preventing the explosion-proof valve 4 from loosening or falling off due to unstable connection during the single-cell manufacturing process or normal use, thus improving the safety and reliability of the single-cell battery.

[0040] exist Figure 6In the illustrated embodiment, in the thickness direction X, the maximum dimension A of the support portion 40 and the minimum dimension C between the recess 43 and the first surface 410 satisfy: C > A. By limiting the minimum dimension C between the recess 43 and the first surface 410 to be greater than the maximum dimension A of the support portion 40 in the thickness direction X, it can be ensured that the concave height of the recess 43 is within a reasonable range, avoiding the concave problem of the explosion-proof valve 4, thereby avoiding the problem of the explosion-proof valve 4 cracking or premature opening, thus effectively improving the production yield of the single cell and improving the safety and reliability of the single cell.

[0041] exist Figure 6 In the illustrated embodiment, in the thickness direction X, the maximum dimension A of the supporting portion 40 and the maximum dimension B between the protrusion 42 and the first surface 410 satisfy: 0.25 ≤ BA ≤ 1.1. If the difference between BA and B is too large, the protrusion height of the protrusion 42 relative to the supporting portion 40 is large, and the overall outward protrusion height of the protrusion 42 is too high, posing a risk of damage to the explosion-proof valve 4. If the difference between BA and B is too small, the protrusion height of the protrusion 42 relative to the supporting portion 40 is small, and the overall outward protrusion height of the protrusion 42 is too low. During the liquid injection and sealing processes in the single-cell manufacturing process, the explosion-proof valve 4 may be subjected to inward pressure due to external pressure, leading to inward deformation.

[0042] In the embodiments of this application, explosion-proof valves 4 of different sizes (A, B, and C) were set and welded to the cover plate 3 for actual testing and verification. The results were shown in Table 1.

[0043] Table 1:

[0044]

[0045]

[0046] Referring to Examples 1 to 9, the individual cells all meet the following conditions: 0.15≤BC≤0.5, C>A, 0.4≤A≤0.6, and 0.25≤BA≤1.1. The verification results show that no abnormal problems such as internal or external deformation, damage, or premature opening of the explosion-proof valve 4 occurred during the manufacturing process of the individual cells.

[0047] Referring to Comparative Example 1, BC = 0.45, BA = 0.4, and the single cell satisfies: 0.15 ≤ BC ≤ 0.5, 0.25 ≤ BA ≤ 1.1, and 0.4 ≤ A ≤ 0.6, but does not satisfy C > A. The verification result is that the height of the concave portion of recess 43 is insufficient, and the explosion-proof valve 4 has a concave deformation problem. It is understandable that when the minimum dimension C between recess 43 and the first surface 410 is relatively small, due to the insufficient height of the concave portion of recess 43, when subjected to stress, recess 43 may not be able to effectively deform to disperse the stress, resulting in stress concentration in recess 43, which in turn causes the explosion-proof valve 4 to have a concave deformation problem.

[0048] Referring to Comparative Example 2, BC = 0.1, BA = 0.2, the single cell satisfies: C > A, 0.4 ≤ A ≤ 0.6, but does not satisfy 0.15 ≤ BC ≤ 0.5, 0.25 ≤ BA ≤ 1.1. The verification result is that the overall outward convex height of the protrusion 42 is too low. During the negative pressure extraction processes such as liquid injection and sealing pin installation in the single cell manufacturing process, the explosion-proof valve 4 has an inward deformation problem. It is understandable that the protrusion height of the protrusion 42 is smaller than that of the supporting part 40 and the recess 43. During the negative pressure extraction processes such as liquid injection and sealing pin installation in the single cell manufacturing process, external pressure will act on the explosion-proof valve 4, making the explosion-proof valve 4 prone to inward deformation.

[0049] Referring to Comparative Example 3, BC = 0.55, BA = 0.65, the single cell satisfies: C > A, 0.4 ≤ A ≤ 0.6, and 0.25 ≤ BA ≤ 1.1, but does not satisfy 0.15 ≤ BC ≤ 0.5. The verification result is that the height of the concave portion of recess 43 is insufficient, and the explosion-proof valve 4 has a concave deformation problem. It is understandable that the distance between the highest point of protrusion 42 and the lowest point of recess 43 is relatively large, and the insufficient height of the concave portion of recess 43 will cause external pressure to act on the explosion-proof valve 4, making it prone to inward deformation.

[0050] Referring to Comparative Example 4, BC = 1.06, BA = 1.11. The single cell satisfies: C > A, 0.4 ≤ A ≤ 0.6, and 0.25 ≤ BA ≤ 1.1, but does not satisfy 0.15 ≤ BC ≤ 0.5. The verification result is that the overall protrusion height of the protrusion 42 is too high, and the distance between the explosion-proof valve 4 and the upper surface of the cover plate 3 is too small. There is a risk of the explosion-proof valve 4 being damaged during the single cell manufacturing process. It is understandable that the distance between the highest point of the protrusion 42 and the lowest point of the recess 43 is too large, and the protrusion height of the protrusion 42 is too high, resulting in a small distance between the protrusion 42 and the side of the cover plate 3 away from the electrode assembly 2. This poses a risk of the explosion-proof valve 4 being damaged during the single cell manufacturing process.

[0051] exist Figure 6In the illustrated embodiment, in the thickness direction X, the maximum dimension between the protrusion 42 and the first surface 410 is B mm, and the minimum dimension between the recess 43 and the first surface 410 is C mm. In the width direction Y of the cover plate 3, the recess 43 has a first dimension W1 mm, satisfying: 10≤W1 / (BC)≤15. The width direction Y intersects the thickness direction X. By limiting the range of the ratio between the first dimension of the recess 43 in the width direction Y and the height difference between the protrusion 42 and the recess 43 in the thickness direction X, it is ensured that the protrusion 42 and the recess 43 can fully absorb and disperse the stress brought to the explosion-proof valve 4 by the pressure difference between the cavity 10 and the shell 1 during the production of the single cell. This avoids the problem of the explosion-proof valve 4 becoming concave and convex due to local stress concentration, which could lead to cracking or premature opening of the explosion-proof valve 4. This effectively improves the production yield of the single cell and enhances its safety and reliability.

[0052] exist Figure 6 In the illustrated embodiment, the protrusion 42 has a second dimension W2 mm in the width direction Y, and the maximum dimension B between the protrusion 42 and the first surface 410 in the thickness direction X satisfies: 4 ≤ W2 / B ≤ 7. It is understood that if the ratio of W2 / B is too large, the overall protrusion height of the protrusion 42 is too low. During the negative pressure extraction processes such as electrolyte injection and sealing pin installation in the single-cell manufacturing process, the explosion-proof valve 4 may be subjected to inward pressure due to external pressure, leading to inward deformation. If the ratio of W2 / B is too small, the overall protrusion height of the protrusion 42 is too high, the distance between the explosion-proof valve 4 and the upper surface of the cover plate 3 is small, and the explosion-proof valve 4 may be damaged. This embodiment of the application, by limiting the range of the ratio of the second dimension W2 of the protrusion 42 in the width direction Y to the maximum dimension B between the protrusion 42 and the first surface 410 in the thickness direction X, can avoid the problems of inward deformation and damage to the explosion-proof valve 4, ensuring the safety and reliability in the single-cell manufacturing process.

[0053] exist Figure 6In the illustrated embodiment, the support portion 40 has a maximum dimension A mm in the thickness direction X and a maximum dimension W mm in the width direction Y, satisfying: 15 ≤ W / A ≤ 70. If the ratio of W / A is too small, the maximum dimension A of the support portion 40 in the thickness direction X is too large, resulting in a higher overall protrusion height of the protrusion 42, a smaller distance between the explosion-proof valve 4 and the upper surface of the cover plate 3, and a problem of the explosion-proof valve 4 being crushed. If the ratio of W / A is too large, the maximum dimension A of the support portion 40 in the thickness direction X is too small, the size design of the explosion-proof valve 4 is unreasonable, resulting in insufficient overall strength of the explosion-proof valve 4, and a problem of abnormal external convex and internal concave deformation during the single-cell manufacturing process. By limiting the range of the ratio of the maximum dimension W of the support portion 40 in the width direction Y to the maximum dimension A of the support portion 40 in the thickness direction X, this embodiment of the application can ensure the structural stability of the explosion-proof valve 4, avoid the problem of the explosion-proof valve 4 being crushed and abnormal external convex and internal concave deformation, ensure the safety and reliability in the single-cell manufacturing process, and improve the production yield of the single-cell.

[0054] In some embodiments, a notch 411 is provided in the weak portion 41, and the notch 411 surrounds the protrusion 42. By providing the notch 411, the weak portion 41 can more accurately rupture at the notch 411 when subjected to a preset pressure, ensuring that the explosion-proof valve 4 releases the gas inside the single cell in a timely manner under appropriate pressure, thereby effectively reducing the internal pressure and preventing the single cell from becoming dangerous.

[0055] In some embodiments, the notch 411 may be provided on the side of the weak portion 41 away from the electrode assembly 2 and recessed towards the electrode assembly 2. In other embodiments, the notch 411 may be provided on the side of the weak portion 41 close to the electrode assembly 2 and recessed away from the electrode assembly 2. Specifically, in Figure 3 In the illustrated embodiment, the groove 411 is provided on the side of the weak portion 41 away from the electrode assembly 2 and recessed towards the electrode assembly 2. The groove 411 can be formed by laser etching or by machining or other methods, and this application does not limit this.

[0056] exist Figure 2 and Figure 5 In the illustrated embodiment, the support portion 40 is connected to the side of the cover plate 3 near the electrode assembly 2, and the protrusion 42 protrudes into the explosion-proof hole 30. Placing the explosion-proof valve 4 on the side of the cover plate 3 near the electrode assembly 2 avoids the problem of easy failure due to scratching that occurs when welding the explosion-proof valve 4 to the outer wall of the cover plate 3, thus ensuring the stability of the connection between the explosion-proof valve 4 and the cover plate 3.

[0057] exist Figure 2 and Figure 5In the illustrated embodiment, a limiting groove 31 is formed on the side of the cover plate 3 near the electrode assembly 2. The limiting groove 31 surrounds the explosion-proof hole 30 and is formed on the side of the cover plate 3 near the electrode assembly 2. The supporting part 40 is disposed within the limiting groove 31. The limiting groove 31 can position and fix the explosion-proof valve 4. By providing the limiting groove 31 on the cover plate 3 and placing the explosion-proof valve 4 within the limiting groove 31, the explosion-proof valve 4 will not occupy the space of the electrode assembly 2 in the receiving cavity 10, thereby improving the energy density and performance of the single battery cell.

[0058] This application provides a battery pack including the aforementioned individual battery cells. Therefore, the battery pack can possess all the technical features and beneficial effects of the aforementioned individual battery cells, which will not be repeated here. The battery pack also includes a housing, wherein at least one individual battery cell is housed inside the housing.

[0059] Accordingly, this application also provides an electrical device, including the aforementioned single battery cell, or the aforementioned battery pack. Therefore, the electrical device can possess all the technical features and beneficial effects of the aforementioned single battery cell or battery pack, which will not be elaborated upon here. The electrical device can be a mobile phone, portable device, laptop computer, electric vehicle, electric car, ship, spacecraft, electric toy, and power tool, etc. For example, spacecraft include airplanes, rockets, space shuttles, and spacecraft; electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys; power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc.

[0060] 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.

[0061] The foregoing has provided a detailed description of a single battery, battery pack, and power device provided in the embodiments of this application, and specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the technical solutions and core ideas of this application. Those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and 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 this application.

Claims

1. A single-cell battery, characterized in that, include: A housing having a receiving cavity; An electrode assembly located within the receiving cavity; A cover plate, which is connected to the housing and seals the receiving cavity, and the cover plate is provided with explosion-proof holes; An explosion-proof valve, wherein the explosion-proof valve covers the explosion-proof hole, the explosion-proof valve includes a support portion, a weak portion, a protrusion and a recess connected in sequence from the outside to the inside, the support portion is connected to the cover plate, the weak portion is configured to be destroyed when subjected to a preset pressure impact, the protrusion protrudes from the connection with the weak portion toward the side away from the electrode assembly, and the recess is recessed toward the side closer to the electrode assembly; The weak portion includes a first surface of the cover plate near the electrode assembly in the thickness direction. In the thickness direction, the maximum dimension between the protrusion and the first surface is B mm, and the minimum dimension between the recess and the first surface is C mm, satisfying: 0.15≤BC≤0.

5. In the thickness direction, the bearing portion has a maximum dimension A mm, satisfying: C>A, 0.4≤A≤0.6; In the thickness direction, the maximum dimension A of the bearing portion satisfies: 0.25≤BA≤1.

1.

2. The single-cell battery according to claim 1, characterized in that, In the width direction of the cover plate, the recess has a first dimension W1 mm, satisfying: 10≤W1 / (BC)≤15, and the width direction intersects the thickness direction.

3. The single-cell battery according to claim 1, characterized in that, In the width direction of the cover plate, the bearing portion has a maximum dimension W mm, satisfying: 15≤W / A≤70.

4. The single-cell battery according to claim 1, characterized in that, In the width direction of the cover plate, the protrusion has a second dimension W2 mm, which satisfies: 4≤W2 / B≤7.

5. The single-cell battery according to claim 1, characterized in that, The supporting part is connected to the side of the cover plate near the electrode assembly, and the protrusion protrudes into the explosion-proof hole.

6. The single-cell battery according to claim 1 or 5, characterized in that, A limiting groove is provided on the side of the cover plate near the electrode assembly. The limiting groove surrounds the explosion-proof hole and is provided on the side of the cover plate near the electrode assembly. The supporting part is provided in the limiting groove.

7. A battery pack, characterized in that, Includes the single-cell battery as described in any one of claims 1 to 6.

8. An electrical device, characterized in that, It includes a single cell battery as described in any one of claims 1 to 6, or it includes a battery pack as described in claim 7.

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