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. The battery includes: a housing having a receiving cavity; a cover plate connected to the housing and sealing the receiving cavity, the cover plate having an explosion-proof hole; and an explosion-proof valve covering the explosion-proof hole. The explosion-proof valve includes a support portion, a weak portion, and a protrusion. The support portion is connected around the weak portion, and the weak portion is connected around the protrusion. The support portion is connected to the cover plate. The weak portion is configured to be destroyed upon impact by a preset pressure. The protrusion protrudes towards the side away from the electrode assembly, and has a recessed portion towards the side closer to the electrode assembly. The area of ​​the explosion-proof valve is S mm. 2 The area of ​​the protrusion is S1mm. 2 The area of ​​the concave part is S2mm 2 The following conditions must be met: 0.6 ≤ S1 / S ≤ 0.85, 0.15 ≤ S2 / S1 ≤ 0.2. By limiting the proportion of the protruding part to the area of ​​the explosion-proof valve and the proportion of the concave part to the area of ​​the protruding part, it can be ensured that the explosion-proof valve absorbs and disperses stress, avoiding problems such as deformation cracking or premature valve opening.

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, the repeated positive and negative pressure differences between the battery's internal environment and the external environment cause problems such as deformation, cracking, and premature opening of the explosion-proof valve, seriously affecting the battery manufacturing 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 part, a weak part, and a protrusion. The support part is connected around the weak part, and the weak part is connected around the protrusion. The support part is connected to a cover plate. The weak part is configured to be destroyed when subjected to a preset pressure impact. The protrusion protrudes from the connection point with the weak part toward the side away from the electrode assembly. The protrusion has a recess that is recessed toward the side closer to the electrode assembly.

[0009] The area of ​​the explosion-proof valve is S mm. 2 The area of ​​the protrusion is S1 mm. 2 The area of ​​the concave part is S2mm 2 The following conditions must be met: 0.6≤S1 / S≤0.85, 0.15≤S2 / S1≤0.2.

[0010] In some embodiments, the protrusion includes a first sub-protrusion and a second sub-protrusion, the first sub-protrusion being disposed around the second sub-protrusion, and the recess being disposed between the first sub-protrusion and the second sub-protrusion and connected to the first sub-protrusion and the second sub-protrusion respectively.

[0011] In some embodiments, the area of ​​the first sub-protrusion is S3 mm. 2 The area of ​​the second sub-protrusion is S4 mm. 2 The following conditions must be met: 0.45≤S3 / S≤0.65, 0.05≤S4 / S≤0.08.

[0012] In some embodiments, there are multiple recesses arranged on the protrusion, with one of two adjacent recesses surrounding the other.

[0013] In some embodiments, the area S2 of the recess satisfies: 0.1≤S2 / S≤0.15.

[0014] 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.

[0015] 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.

[0016] In some embodiments, along the thickness direction of the cover plate, the bottom wall of the limiting groove and the side of the cover plate near the electrode assembly have a minimum dimension L1, and the bearing portion has a maximum dimension L2, satisfying: L1≥L2.

[0017] In some embodiments, along the thickness direction of the cover plate, the cover plate has a maximum dimension L3, and the side of the protrusion away from the electrode assembly has a maximum dimension L4 between the side of the cover plate close to the electrode assembly, satisfying: L3≥L4.

[0018] Accordingly, this application provides a battery pack including the aforementioned single battery cell.

[0019] Accordingly, embodiments of this application provide an electrical device, including the aforementioned single battery cell, or including the aforementioned battery pack.

[0020] 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 within the receiving cavity; the cover plate is connected to the casing and seals the receiving cavity, and the cover plate has 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, and a protrusion. The support portion is connected around the weak portion, and the weak portion is connected around the protrusion. 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 its connection with the weak portion toward the side away from the electrode assembly, and the protrusion has a recess that is recessed toward the side closer to the electrode assembly. The area of ​​the explosion-proof valve is S mm. 2 The area of ​​the protrusion is S1 mm. 2 The area of ​​the concave part is S2 mm 2 The following conditions must be met: 0.6≤S1 / S≤0.85, 0.15≤S2 / S1≤0.2. By limiting the proportion of the protrusion to the area of ​​the explosion-proof valve and the proportion of the recess to the area of ​​the protrusion, the design of the protrusion and recess can effectively 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 deformation of the explosion-proof valve due to pressure difference, which could lead to 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.

[0021] 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.

[0022] 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

[0023] 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.

[0024] Figure 1 This is an exploded view of a single battery cell according to an embodiment of this application;

[0025] Figure 2 This is a cross-sectional view of a cover plate according to an embodiment of this application;

[0026] Figure 3 This is a top view of an explosion-proof valve according to an embodiment of this application;

[0027] Figure 4 This is a bottom view of an explosion-proof valve according to an embodiment of this application;

[0028] Figure 5 This is a top view of an explosion-proof valve according to another embodiment of this application;

[0029] Figure 6 This is a bottom view of an explosion-proof valve according to another embodiment of this application;

[0030] Figure 7 This is a cross-sectional view of an explosion-proof valve according to an embodiment of this application.

[0031] 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; 310. Bottom wall; 410. Score; 420. Recess; 421. First sub-protrusion; 422. Second sub-protrusion; X, Thickness direction. Detailed Implementation

[0032] 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.

[0033] 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.

[0034] 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.

[0035] 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 has an explosion-proof hole; the explosion-proof valve seals the explosion-proof hole, and the explosion-proof valve includes a supporting part, a weak part, and a protruding part. The supporting part is connected to the weak part around the weak part, and the weak part is connected to the protruding part around the protruding part. The supporting part is connected to the cover plate. The weak part is configured to be destroyed when subjected to a preset pressure impact. The protruding part protrudes from the connection with the weak part toward the side away from the electrode assembly, and the protruding part has a recessed part toward the side closer to the electrode assembly. The area of ​​the explosion-proof valve is S mm. 2 The area of ​​the protrusion is S1 mm. 2 The area of ​​the concave part is S2 mm 2 The following conditions must be met: 0.6≤S1 / S≤0.85, 0.15≤S2 / S1≤0.2. By limiting the proportion of the protrusion to the area of ​​the explosion-proof valve and the proportion of the recess to the area of ​​the protrusion, the design of the protrusion and recess can effectively 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 deformation of the explosion-proof valve due to pressure difference, which could lead to 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.

[0036] 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.

[0037] 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.

[0038] 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 top view of an explosion-proof valve 4 according to another embodiment of this application; Figure 6 This is a bottom view of an explosion-proof valve 4 according to another embodiment of this application; Figure 7 This is a cross-sectional view of an explosion-proof valve 4 according to an embodiment of this application.

[0039] refer to Figures 1 to 7 This application provides a single 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 supporting portion 40, a weak portion 41, and a protruding portion 42. The supporting portion 40 is connected to the weak portion 41, and the weak portion 41 is connected to the protruding portion 42. The supporting portion 40 is connected to the cover plate 3, and the weak portion 41 is configured to be destroyed when subjected to a preset pressure impact. When the internal pressure of the single 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 battery, thereby reducing the internal pressure of the single battery and preventing the single battery from exploding due to excessively rapid internal pressurization. The protrusion 42 protrudes from the connection point with the weak part 41 towards the side away from the electrode assembly 2. The protrusion 42 has a recess 420 that is recessed towards the side closer to the electrode assembly 2. The arrangement of the protrusion 42 and the recess 420 helps to avoid stress concentration. The area of ​​the explosion-proof valve 4 is S mm. 2 The area of ​​the protrusion 42 is S1 mm. 2 The area of ​​the recess 420 is S2 mm. 2 The following conditions must be met: 0.8≤S1 / S≤0.85, 0.15≤S2 / S1≤0.2. By setting the protrusion 42 and the recess 420, 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 can be absorbed and dispersed. This avoids the weak part 41 from deforming due to the pressure difference, which could lead to cracking of the weak part 41 or premature opening of the explosion-proof valve 4. This can effectively improve the production yield of the single cell and improve the safety and reliability of the single cell.

[0040] In some embodiments, the area of ​​the protrusion 42 is S1 mm. 2 The area of ​​explosion-proof valve 4 is S mm. 2 The following condition must be met: 0.6 ≤ S1 / S ≤ 0.85. When the ratio of the area S1 of the protrusion 42 to the area S of the explosion-proof valve 4 is too large, it is understandable that the area occupied by the protrusion 42 in the explosion-proof valve 4 is too large, thus encroaching on the space of the weak part 41. This may cause the weak part 41 to fail to be properly destroyed under the preset pressure, affecting the function of the explosion-proof valve 4 in releasing internal gas. When the ratio of the area S1 of the protrusion 42 to the area S of the explosion-proof valve 4 is too small, the area of ​​the protrusion 42 is too small, and it cannot fully absorb and disperse the pressure difference stress from the production process of the single cell. This may easily cause the weak part 41 to crack due to stress concentration or cause the explosion-proof valve 4 to open prematurely, reducing the safety and reliability of the single cell. By limiting the range of the ratio of the area S1 of the protrusion 42 to the area S of the explosion-proof valve 4, the area of ​​the protrusion 42 and the area of ​​the explosion-proof valve 4 can be controlled within a certain ratio range, ensuring that the protrusion 42 achieves a more ideal state when playing its role in absorbing and dispersing stress. The design ensures that the protrusion 42 is neither too small to effectively distribute stress nor too large to impair the pressure relief function of the explosion-proof valve 4. This optimal area ratio allows the explosion-proof valve 4 to quickly release internal gas and reduce internal pressure when the internal pressure of a single battery cell is excessive, thereby improving the safety and reliability of the battery cell.

[0041] In some embodiments, the area of ​​the protrusion 42 is S1 mm. 2 The area of ​​the recess 420 is S2 mm. 2 The following condition must be met: 0.15 ≤ S2 / S1 ≤ 0.2. If the area of ​​the recess 420 relative to the area of ​​the protrusion 42 is too small, the recess 420 cannot fully absorb and disperse the internal pressure of the single cell, which restricts the explosion-proof valve 4 from opening and releasing pressure in a timely and effective manner. This may prevent the internal pressure of the single cell from being released in time, increasing the risk of danger to the single cell. If the area of ​​the recess 420 relative to the area of ​​the protrusion 42 is too large, it may cause abnormal deformation and cracking of the protrusion 42 during the single cell manufacturing process. By limiting the range of the ratio of the area S2 of the recess 420 to the area S1 of the protrusion 42, the problems of restricted valve opening and abnormal deformation and cracking of the protrusion 42 can be avoided. During the single cell manufacturing process, the explosion-proof valve 4 can more effectively disperse the pressure from the inside and outside of the single cell, making the stress distribution on the explosion-proof valve 4 more uniform, reducing the risk of local stress concentration, and enabling the explosion-proof valve 4 to open in a timely and accurate manner when subjected to a preset pressure impact, preventing the single cell from catching fire or exploding, and improving the safety performance of the single cell.

[0042] exist Figures 2 to 7In the illustrated embodiment, the protrusion 42 includes a first sub-protrusion 421 and a second sub-protrusion 422. The first sub-protrusion 421 surrounds the second sub-protrusion 422, and a recess 420 is disposed between the first sub-protrusion 421 and the second sub-protrusion 422 and connected to both. The explosion-proof valve 4 can be circular or elliptical in shape. Correspondingly, the shapes of the protrusion 42 and the recess 420 can be configured to correspond to the shape of the explosion-proof valve 4, thereby helping to distribute stress more evenly on the explosion-proof valve 4. (Reference) Figure 7 The cross-sectional shapes of the first sub-protrusion 421, the second sub-protrusion 422, and the recess 420 can be arc-shaped, circular arc-shaped, etc. The cross-sectional shapes of the first sub-protrusion 421, the recess 420, and the second sub-protrusion 422, which are arranged sequentially from the outside to the inside, can be wavy. This arrangement avoids stress concentration on the one hand; on the other hand, by setting the first sub-protrusion 421, the second sub-protrusion 422, and the recess 420, a larger range of elastic deformation can be achieved, thereby more effectively absorbing and dispersing 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 a single cell, further reducing the risk of the weak part 41 cracking due to stress or the explosion-proof valve 4 opening prematurely.

[0043] In some embodiments, there are multiple recesses 420 arranged on the protrusion 42, with one of two adjacent recesses 420 surrounding the other. In some embodiments, the multiple recesses 420 may be interconnected. In other embodiments, multiple protrusions may be spaced apart on the protrusion 42.

[0044] In some embodiments, the area of ​​the first sub-protrusion 421 is S3 mm. 2The following condition must be met: 0.45 ≤ S3 / S ≤ 0.65. That is, the area of ​​the first sub-protrusion 421 on the explosion-proof valve 4 should be between 45% and 65%. When the area of ​​the first sub-protrusion 421 is too large, it may undergo excessive elastic deformation due to the stress caused by the internal and external pressure difference during production. This could exceed the material's tolerance limit, leading to abnormal outward deformation or even cracking of the explosion-proof valve 4, affecting the safety and reliability of the individual battery. When the area of ​​the first sub-protrusion 421 is too small, it cannot fully perform its stress absorption and dispersion function, causing more stress to concentrate on the weak part 41 and other areas. This increases the risk of cracking in the weak part 41 due to stress concentration or premature opening of the explosion-proof valve 4, and also poses a risk of abnormal inward deformation and cracking of the explosion-proof valve 4. By rationally designing the ratio range of the area S3 of the first sub-protrusion 421 to the area S of the explosion-proof valve 4, on the one hand, stress can be effectively dispersed and absorbed, ensuring the structural stability of the explosion-proof valve 4 and reducing the risk of deformation and cracking of the explosion-proof valve 4; on the other hand, it can prevent the explosion-proof valve 4 from opening prematurely, and can open normally when the internal pressure of the battery reaches the preset value, releasing the pressure in time, thus improving the safety and reliability of the single battery.

[0045] In some embodiments, the area of ​​the second sub-protrusion 422 is S4 mm. 2 The following condition must be met: 0.05 ≤ S4 / S ≤ 0.08, meaning the area of ​​the second sub-protrusion 422 on the explosion-proof valve 4 is between 5% and 8%. When the area of ​​the second sub-protrusion 422 is too large, it typically possesses a certain elastic deformation capacity to absorb and disperse stress. However, if the area of ​​the second sub-protrusion 422 is too large, its elastic deformation may exceed the material's tolerance limit, leading to abnormal overall outward deformation of the explosion-proof valve 4, or even cracking, affecting the safety and reliability of the individual battery. When the area of ​​the second sub-protrusion 422 is too small, during the individual battery manufacturing process, the explosion-proof valve 4 will be subjected to pressure from the internal battery reaction and the influence of the external environment. If the area of ​​the second sub-protrusion is too small, it cannot effectively resist the pressure from the internal and external pressure difference, leading to an inward concavity in the middle of the explosion-proof valve 4, where the second sub-protrusion 422 is located. By rationally designing the ratio range of the area S4 of the second sub-protrusion 422 to the area S of the explosion-proof valve 4, it is possible to effectively prevent the explosion-proof valve 4 from having an inward concavity in the middle or an abnormal outward deformation and cracking, thus ensuring the structural integrity and normal function of the explosion-proof valve 4 and improving the safety and reliability of the single battery.

[0046] In some embodiments, the area of ​​the recess 420 is S2 mm. 2The condition is satisfied: 0.1 ≤ S² / S ≤ 0.15. That is, the area of ​​the recess 420 on the explosion-proof valve 4 is between 10% and 15%. If the area of ​​the recess 420 is too small, it may cause the valve to open restrictively after gas is generated inside the individual battery during the capacity grading process. The capacity grading process involves sorting individual batteries by capacity, measuring their actual capacity by charging and discharging them, and grouping batteries with similar capacities together. During charging and discharging, gas may be generated inside the individual battery due to chemical reactions, putting pressure on the explosion-proof valve. Insufficient area of ​​the recess 420 prevents it from fully absorbing and dispersing the internal pressure of the individual battery, thus restricting the explosion-proof valve 4 from opening and releasing pressure effectively and in a timely manner. This may prevent the internal pressure of the individual battery from being released in time, increasing the risk of danger to the individual battery. When the area of ​​the recess 420 is too large, it will occupy the area of ​​the first sub-protrusion 421 and the second sub-protrusion 422, which may lead to abnormal internal deformation and cracking of the explosion-proof valve 4 during the single-cell manufacturing process. By reasonably designing the ratio range of the area S2 of the recess 420 to the area S of the explosion-proof valve 4, the problem of valve opening restriction caused by the area of ​​the recess 420 being too small and the abnormal internal deformation and cracking of the explosion-proof valve 4 caused by the area being too large can be effectively prevented. This ensures the stable performance of the explosion-proof valve 4, enabling it to open normally when the internal pressure of the battery reaches the preset value, release pressure in a timely manner, and improve the safety and reliability of the single-cell battery.

[0047] In the embodiments of this application, explosion-proof valves 4 with different S2, S3 and S4 are set and welded to the cover plate 3 for actual testing and verification. The abnormal situation of explosion-proof valves 4 during the single cell manufacturing process is tracked. The verification results are shown in Table 1.

[0048] Table 1:

[0049]

[0050]

[0051] As shown in Table 1, Example 1, the area S of the explosion-proof valve 4 is 110 mm². 2 The area of ​​the protrusion 42 is 93 mm². 2 The area S2 of the recess 420 is 16 mm. 2 The area S3 of the first sub-protrusion 421 is 71 mm. 2 The area S4 of the second sub-protrusion 422 is 6 mm. 2The values ​​are: S1 / S = 0.85, S2 / S = 0.15, S3 / S = 0.65, S4 / S = 0.05, and S2 / S1 = 0.17. This satisfies the requirements: 0.6 ≤ S1 / S ≤ 0.85, 0.1 ≤ S2 / S ≤ 0.15, 0.45 ≤ S3 / S ≤ 0.65, 0.05 ≤ S4 / S ≤ 0.08, and 0.15 ≤ S2 / S1 ≤ 0.2. By rationally setting the area ratio of the first sub-protrusion 421, the second sub-protrusion 422, and the concave portion 420 on the explosion-proof valve 4, stress can be effectively absorbed and dispersed, avoiding problems such as abnormal cracking due to outward convex deformation, inward concavity, or constrained valve opening.

[0052] As shown in Table 1, Example 2, the area S of the explosion-proof valve 4 is 110 mm². 2 The area S1 of the protrusion 42 is 91 mm. 2 The area S2 of the recess 420 is 15mm. 2 The area S3 of the first sub-protrusion 421 is 68 mm. 2 The area S4 of the second sub-protrusion 422 is 8mm. 2 The values ​​are: S1 / S = 0.83, S2 / S = 0.14, S3 / S = 0.62, S4 / S = 0.07, and S2 / S1 = 0.16. This satisfies the requirements: 0.6 ≤ S1 / S ≤ 0.85, 0.1 ≤ S2 / S ≤ 0.15, 0.45 ≤ S3 / S ≤ 0.65, 0.05 ≤ S4 / S ≤ 0.08, and 0.15 ≤ S2 / S1 ≤ 0.2. By rationally setting the area ratio of the first sub-protrusion 421, the second sub-protrusion 422, and the concave portion 420 on the explosion-proof valve 4, stress can be effectively absorbed and dispersed, avoiding problems such as abnormal cracking due to outward convex deformation, inward concavity, or constrained valve opening.

[0053] As shown in Table 1, Example 3, the area S of the explosion-proof valve 4 is 110 mm². 2 The area S1 of the protrusion 42 is 82 mm. 2 The area S2 of the recess 420 is 14 mm. 2 The area S3 of the first sub-protrusion 421 is 62 mm. 2 The area S4 of the second sub-protrusion 422 is 6 mm. 2The values ​​are: S1 / S = 0.75, S2 / S = 0.13, S3 / S = 0.56, S4 / S = 0.05, and S2 / S1 = 0.17. This satisfies the requirements: 0.6 ≤ S1 / S ≤ 0.85, 0.1 ≤ S2 / S ≤ 0.15, 0.45 ≤ S3 / S ≤ 0.65, 0.05 ≤ S4 / S ≤ 0.08, and 0.15 ≤ S2 / S1 ≤ 0.2. By rationally setting the area ratio of the first sub-protrusion 421, the second sub-protrusion 422, and the concave portion 420 on the explosion-proof valve 4, stress can be effectively absorbed and dispersed, avoiding problems such as abnormal cracking due to outward convex deformation, inward concavity, or constrained valve opening.

[0054] As shown in Table 1, Example 4, the area S of the explosion-proof valve 4 is 110 mm². 2 The area S1 of the protrusion 42 is 79 mm. 2 The area S2 of the recess 420 is 13mm. 2 The area S3 of the first sub-protrusion 421 is 58 mm. 2 The area S4 of the second sub-protrusion 422 is 8mm. 2 The values ​​are: S1 / S = 0.72, S2 / S = 0.12, S3 / S = 0.53, S4 / S = 0.07, and S2 / S1 = 0.16. This satisfies the requirements: 0.6 ≤ S1 / S ≤ 0.85, 0.1 ≤ S2 / S ≤ 0.15, 0.45 ≤ S3 / S ≤ 0.65, 0.05 ≤ S4 / S ≤ 0.08, and 0.15 ≤ S2 / S1 ≤ 0.2. By rationally setting the area ratio of the first sub-protrusion 421, the second sub-protrusion 422, and the concave portion 420 on the explosion-proof valve 4, stress can be effectively absorbed and dispersed, avoiding problems such as abnormal cracking due to outward convex deformation, inward concavity, or constrained valve opening.

[0055] As shown in Table 1, Example 5, the area S of the explosion-proof valve 4 is 110 mm². 2 The area S1 of the protrusion 42 is 71 mm. 2 The area S2 of the recess 420 is 12mm. 2 The area S3 of the first sub-protrusion 421 is 53 mm. 2 The area S4 of the second sub-protrusion 422 is 6 mm. 2The values ​​are: S1 / S = 0.65, S2 / S = 0.11, S3 / S = 0.48, S4 / S = 0.05, and S2 / S1 = 0.17. This satisfies the requirements: 0.6 ≤ S1 / S ≤ 0.85, 0.1 ≤ S2 / S ≤ 0.15, 0.45 ≤ S3 / S ≤ 0.65, 0.05 ≤ S4 / S ≤ 0.08, and 0.15 ≤ S2 / S1 ≤ 0.2. By rationally setting the area ratio of the first sub-protrusion 421, the second sub-protrusion 422, and the concave portion 420 on the explosion-proof valve 4, stress can be effectively absorbed and dispersed, avoiding problems such as abnormal cracking due to outward convex deformation, inward concavity, or constrained valve opening.

[0056] As shown in Table 1, Example 6, the area S of the explosion-proof valve 4 is 110 mm². 2 The area S1 of the protrusion 42 is 68 mm. 2 The area S2 of the recess 420 is 11 mm. 2 The area S3 of the first sub-protrusion 421 is 49 mm. 2 The area S4 of the second sub-protrusion 422 is 8mm. 2 The values ​​are: S1 / S = 0.62, S2 / S = 0.1, S3 / S = 0.45, S4 / S = 0.07, and S2 / S1 = 0.16. This satisfies the requirements: 0.6 ≤ S1 / S ≤ 0.85, 0.1 ≤ S2 / S ≤ 0.15, 0.45 ≤ S3 / S ≤ 0.65, 0.05 ≤ S4 / S ≤ 0.08, and 0.15 ≤ S2 / S1 ≤ 0.2. By rationally setting the area ratio of the first sub-protrusion 421, the second sub-protrusion 422, and the concave portion 420 on the explosion-proof valve 4, stress can be effectively absorbed and dispersed, avoiding problems such as abnormal cracking due to outward convex deformation, inward concavity, or constrained valve opening.

[0057] As shown in Comparative Example 1 in Table 1, the area S of the explosion-proof valve 4 is 110 mm². 2 The area S1 of the protrusion 42 is 89 mm. 2 The area S2 of the recess 420 is 16 mm. 2 The area S3 of the first sub-protrusion 421 is 69 mm. 2 The area S4 of the second sub-protrusion 422 is 4 mm. 2 The values ​​are: S1 / S = 0.81, S2 / S = 0.15, S3 / S = 0.63, S4 / S = 0.04, and S2 / S1 = 0.18. This satisfies the requirements of 0.6 ≤ S1 / S ≤ 0.85, 0.1 ≤ S2 / S ≤ 0.15, 0.45 ≤ S3 / S ≤ 0.65, and 0.15 ≤ S2 / S1 ≤ 0.2. However, the requirement of 0.05 ≤ S4 / S ≤ 0.08 is not met. This is understandable because the area S4 of the second sub-protrusion 422 is too small to effectively resist the pressure from the internal and external pressure difference, causing an inward concavity in the middle of the explosion-proof valve 4, affecting the structural integrity and normal function of the explosion-proof valve 4.

[0058] As shown in Comparative Example 2 in Table 1, the area S of the explosion-proof valve 4 is 110 mm². 2 The area S1 of the protrusion 42 is 91 mm. 2 The area S2 of the recess 420 is 16 mm. 2 The area S3 of the first sub-protrusion 421 is 65mm². 2 The area S4 of the second sub-protrusion 422 is 10 mm. 2 The values ​​are: S1 / S = 0.83, S2 / S = 0.15, S3 / S = 0.59, S4 / S = 0.09, and S2 / S1 = 0.18. This satisfies the requirements of 0.6 ≤ S1 / S ≤ 0.85, 0.1 ≤ S2 / S ≤ 0.15, 0.45 ≤ S3 / S ≤ 0.65, and 0.15 ≤ S2 / S1 ≤ 0.2. However, the requirement of 0.05 ≤ S4 / S ≤ 0.08 is not met. This is understandable because an excessively large area S4 of the second sub-protrusion 422 would cause excessive elastic deformation when absorbing and dispersing stress, exceeding the material's tolerance limit. This would lead to abnormal overall convex deformation of the explosion-proof valve 4, and even cracking, affecting the safety and reliability of the individual battery.

[0059] As shown in Comparative Example 3 in Table 1, the area S of the explosion-proof valve 4 is 110 mm². 2 The area S1 of the protrusion 42 is 88 mm. 2 The area S2 of the recess 420 is 10 mm. 2 The area S3 of the first sub-protrusion 421 is 70 mm. 2 The area S4 of the second sub-protrusion 422 is 8mm. 2 The values ​​are: S1 / S = 0.80, S2 / S = 0.09, S3 / S = 0.64, S4 / S = 0.07, and S2 / S1 = 0.11. This satisfies the requirements of 0.6 ≤ S1 / S ≤ 0.85, 0.1 ≤ S2 / S ≤ 0.15, 0.45 ≤ S3 / S ≤ 0.65, and 0.05 ≤ S4 / S ≤ 0.08. However, the requirements of 0.1 ≤ S2 / S ≤ 0.15 and 0.15 ≤ S2 / S1 ≤ 0.2 are not met. This is understandable because the area S2 of the recess 420 is too small, preventing it from fully absorbing and dispersing the internal pressure of the individual battery cells. Consequently, the explosion-proof valve 4 is restricted from opening and releasing pressure normally, resulting in a problem of restricted valve opening.

[0060] As shown in Comparative Example 4 in Table 1, the area S of the explosion-proof valve 4 is 110 mm². 2 The area S1 of the protrusion 42 is 96 mm. 2 The area S2 of the recess 420 is 18 mm. 2 The area S3 of the first sub-protrusion 421 is 70 mm.2 The area S4 of the second sub-protrusion 422 is 8mm. 2 The values ​​are: S1 / S = 0.87, S2 / S = 0.16, S3 / S = 0.64, S4 / S = 0.07, and S2 / S1 = 0.19. This satisfies the requirements of 0.45 ≤ S3 / S ≤ 0.65, 0.05 ≤ S4 / S ≤ 0.08, and 0.15 ≤ S2 / S1 ≤ 0.2. However, the requirements of 0.6 ≤ S1 / S ≤ 0.85 and 0.1 ≤ S2 / S ≤ 0.15 are not met. This is understandable because when the area S1 of the protrusion 42 is relatively large and the area S2 of the recess 420 is too large, the recess 420 may undergo excessive elastic deformation during production due to the stress caused by the internal and external pressure difference. This could exceed the bearing limit of the explosion-proof valve material, leading to abnormal internal deformation or even cracking of the explosion-proof valve, affecting the safety and reliability of the individual battery.

[0061] As shown in Comparative Example 5 in Table 1, the area S of the explosion-proof valve 4 is 110 mm². 2 The area S1 of the protrusion 42 is 94 mm. 2 The area S2 of the recess 420 is 15mm. 2 The area S3 of the first sub-protrusion 421 is 73 mm. 2 The area S4 of the second sub-protrusion 422 is 6 mm. 2 The values ​​are: S1 / S = 0.85, S2 / S = 0.14, S3 / S = 0.66, S4 / S = 0.05, and S2 / S1 = 0.16. This satisfies the requirements of 0.6 ≤ S1 / S ≤ 0.85, 0.1 ≤ S2 / S ≤ 0.15, 0.05 ≤ S4 / S ≤ 0.08, and 0.15 ≤ S2 / S1 ≤ 0.2. However, the requirement of 0.45 ≤ S3 / S ≤ 0.65 is not met. This is understandable because the area S3 of the first sub-protrusion 421 is too large, causing excessive elastic deformation of the first sub-protrusion 421 during production due to the stress caused by the internal and external pressure difference. This exceeds the bearing limit of the explosion-proof valve 4 material, resulting in abnormal outward deformation of the explosion-proof valve 4, and even cracking, affecting the safety and reliability of the single battery cell.

[0062] As shown in Comparative Example 6 in Table 1, the area S of the explosion-proof valve 4 is 110 mm². 2 The area S1 of the protrusion 42 is 69 mm. 2 The area S2 of the recess 420 is 15mm. 2 The area S3 of the first sub-protrusion 421 is 48 mm. 2 The area S4 of the second sub-protrusion 422 is 6 mm. 2The values ​​are: S1 / S = 0.63, S2 / S = 0.14, S3 / S = 0.44, S4 / S = 0.05, and S2 / S1 = 0.22. This satisfies the requirements of 0.6 ≤ S1 / S ≤ 0.85, 0.1 ≤ S2 / S ≤ 0.15, and 0.05 ≤ S4 / S ≤ 0.08. However, the requirements of 0.45 ≤ S3 / S ≤ 0.65 and 0.15 ≤ S2 / S1 ≤ 0.2 are not met. This is understandable because the area S3 of the first sub-protrusion 421 is too small. A small area of ​​the first sub-protrusion 421 cannot fully utilize its stress absorption and dispersion function, causing more stress to concentrate in the weak part 41 and other areas, leading to abnormal deformation and cracking of the explosion-proof valve 4. Furthermore, the area of ​​the concave part 420 relative to the protruding part 42 is too large, which can also lead to abnormal deformation and cracking of the protruding part 42 during the single-cell manufacturing process.

[0063] As shown in Comparative Example 7 of Table 1, the area S of the explosion-proof valve 4 is 110 mm². 2 The area S1 of the protrusion 42 is 95 mm. 2 The area S2 of the recess 420 is 16 mm. 2 The area S3 of the first sub-protrusion 421 is 70 mm. 2 The area S4 of the second sub-protrusion 422 is 9 mm. 2 The values ​​are: S1 / S = 0.86, S2 / S = 0.15, S3 / S = 0.64, S4 / S = 0.08, and S2 / S1 = 0.17. This satisfies the requirements of 0.1 ≤ S2 / S ≤ 0.15, 0.45 ≤ S3 / S ≤ 0.65, 0.05 ≤ S4 / S ≤ 0.08, and 0.15 ≤ S2 / S1 ≤ 0.2. However, the requirement of 0.6 ≤ S1 / S ≤ 0.85 is not met. This is understandable because the area S1 of the protrusion 42 is too large, encroaching on the space of the weak part 41. This may prevent the weak part 41 from being properly damaged under preset pressure, affecting the function of the explosion-proof valve 4 in releasing internal gas. After gas is generated inside the individual battery during the capacity grading process, there is a problem with the valve opening being restricted.

[0064] As shown in Comparative Example 8 in Table 1, the area S of the explosion-proof valve 4 is 110 mm². 2 The area S1 of the protrusion 42 is 65 mm. 2 The area S2 of the recess 420 is 11 mm. 2 The area S3 of the first sub-protrusion 421 is 48 mm. 2 The area S4 of the second sub-protrusion 422 is 6 mm. 2The values ​​are: S1 / S = 0.59, S2 / S = 0.10, S3 / S = 0.44, S4 / S = 0.05, and S2 / S1 = 0.17. This satisfies the requirements of 0.1 ≤ S2 / S ≤ 0.15, 0.05 ≤ S4 / S ≤ 0.08, and 0.15 ≤ S2 / S1 ≤ 0.2. However, it does not meet the requirements of 0.6 ≤ S1 / S ≤ 0.85 and 0.45 ≤ S3 / S ≤ 0.65. This is understandable because the area S1 of the protrusion 42 is too small to fully absorb and disperse the differential pressure stress from the single-cell production process, making the weak part 41 prone to cracking due to stress concentration or causing the explosion-proof valve 4 to open prematurely. In addition, the area S3 of the first sub-protrusion 421 is too small. The first sub-protrusion 421 with an insufficient area cannot fully perform its stress absorption and dispersion function, which may cause more stress to be concentrated in the weak part 41 and other parts, resulting in the explosion-proof valve 4 having abnormal concave deformation and cracking.

[0065] In some embodiments, a notch 410 is provided in the weak portion 41, and the notch 410 surrounds the protrusion 42. By providing the notch 410, the weak portion 41 can more accurately rupture at the notch 410 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.

[0066] In some embodiments, the notch 410 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 410 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 , Figure 5 and Figure 7 In the illustrated embodiment, the groove 410 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 410 can be formed by laser etching or by machining or other methods, and this application does not limit this.

[0067] exist Figure 2 and Figure 7 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.

[0068] exist Figure 2 and Figure 7In 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.

[0069] exist Figure 7 In the illustrated embodiment, along the thickness direction X of the cover plate 3, the bottom wall 310 of the limiting groove 31 and the side of the cover plate 3 near the electrode assembly 2 have a minimum dimension L1, and the supporting part 40 has a maximum dimension L2, satisfying: L1 ≥ L2. It can be understood that by limiting the minimum dimension L1 between the bottom wall 310 of the limiting groove 31 and the side of the cover plate 3 near the electrode assembly 2 to be greater than or equal to the maximum dimension L2 of the supporting part 40, the explosion-proof valve 4 can be prevented from protruding from the lower surface of the cover plate 3, thereby preventing the explosion-proof valve 4 from occupying the space of the electrode assembly 2 in the receiving cavity 10, thus improving the energy density and performance of the single battery. Furthermore, it can also prevent the explosion-proof valve 4 from colliding or scratching with other components under vibration conditions, reducing the possibility of the single battery being endangered due to damage to the explosion-proof valve 4.

[0070] exist Figure 7 In the illustrated embodiment, along the thickness direction X of the cover plate 3, the cover plate 3 has a maximum dimension L3, and the side of the protrusion 42 away from the electrode assembly 2 has a maximum dimension L4 between the side of the cover plate 3 closest to the electrode assembly 2, satisfying: L3 ≥ L4. It can be understood that by limiting the maximum dimension L3 of the cover plate to be greater than or equal to the maximum dimension L4 between the side of the protrusion 42 away from the electrode assembly 2 and the side of the cover plate 3 closest to the electrode assembly 2, the protrusion 42 of the explosion-proof valve 4 can be prevented from extending beyond the upper surface of the cover plate 3, thus avoiding external impact or scratches. This reduces the risk of the explosion-proof valve 4 failing due to external force damage and ensures that the explosion-proof valve 4 can function normally when needed.

[0071] 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.

[0072] 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.

[0073] 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.

[0074] 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 cover seals the explosion-proof orifice, the explosion-proof valve includes a support portion, a weak portion, and a protrusion, the support portion is connected to the weak portion around the weak portion, the weak portion is connected to the protrusion around the protrusion, 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 point with the weak portion toward the side away from the electrode assembly, the protrusion has a recessed portion toward the side closer to the electrode assembly; the protrusion includes a first sub-protrusion and a second sub-protrusion, the first sub-protrusion is disposed around the second sub-protrusion, the recess is disposed between the first sub-protrusion and the second sub-protrusion, and is respectively connected to the first sub-protrusion and the second sub-protrusion; The area of ​​the explosion-proof valve is S mm. 2 The area of ​​the protrusion is S1 mm. 2 The area of ​​the recess is S2mm. 2 The area of ​​the first sub-protrusion is S3 mm. 2 The area of ​​the second sub-protrusion is S4 mm. 2 The following conditions must be met: 0.6≤S1 / S≤0.85, 0.15≤S2 / S1≤0.2, 0.1≤S2 / S≤0.15, 0.45≤S3 / S≤0.65, and 0.05≤S4 / S≤0.

08.

2. The single-cell battery according to claim 1, characterized in that, The number of recesses is multiple, and the multiple recesses are arranged on the protrusion, with one of two adjacent recesses surrounding the other.

3. 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.

4. The single-cell battery according to claim 1 or 3, 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.

5. The single-cell battery according to claim 4, characterized in that, Along the thickness direction of the cover plate, the bottom wall of the limiting groove and the side of the cover plate near the electrode assembly have a minimum dimension L1, and the bearing part has a maximum dimension L2, satisfying: L1≥L2.

6. The single-cell battery according to claim 1, characterized in that, Along the thickness direction of the cover plate, the cover plate has a maximum dimension L3, and the side of the protrusion away from the electrode assembly has a maximum dimension L4 with respect to the side of the cover plate near the electrode assembly, satisfying: L3≥L4.

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.

Images