Single battery, battery pack and power utilization device

Abstract

The invention discloses a single battery, a battery pack and a power utilization device, and belongs to the technical field of batteries, the single battery comprises a cover plate assembly and a shell, and one of the cover plate assembly and the shell is provided with an anti-explosion hole; the explosion-proof valve covers the explosion-proof hole, the explosion-proof valve comprises a base part and a weak part, the base part is arranged around the weak part, the base part is connected with the cover plate assembly, the weak part is provided with a first surface and a second surface which are oppositely arranged in the first direction, and the first surface is provided with a first groove sunken towards one side close to the electrode assembly; the first surface is provided with a first groove which is recessed towards one side far away from the electrode assembly, the second surface is provided with a second groove which is recessed towards one side far away from the electrode assembly, the first groove surrounds the second groove, the size of the weak part in the first direction is H, the size of the first groove in the first direction is H1mm, the size of the second groove in the first direction is H2mm, and H1 / H is larger than or equal to 0.35 and smaller than or equal to 0.75, and H2 / H is larger than or equal to 0.2 and smaller than or equal to 0.55. Through the arrangement, the problems that the anti-explosion valve deforms or is opened in advance and the like due to stress concentration are avoided, and the opening pressure precision, the deformation resistance and the explosion stability of the anti-explosion valve can be improved.

Description

Technical Field

[0001] The present application belongs to the field of battery technology, and specifically relates to a single cell, a battery pack, and an electrical device. Background Art

[0002] Current batteries often feature explosion-proof valves to relieve pressure in the event of internal battery failure and gas production. To meet the required opening pressure, indentations are often stamped into the valve to regulate the valve's opening pressure. However, these indentations are notoriously inaccurate in regulating the valve's opening pressure. Summary of the Invention

[0003] Purpose of the invention: The embodiments of the present application provide a single cell, a battery pack, and an electrical device, aiming to solve the technical problem of low precision of the notched structure when regulating the opening pressure of the explosion-proof valve.

[0004] Technical solution: This embodiment of the present application provides a single battery, including:

[0005] A housing having a receiving cavity;

[0006] an electrode assembly, located in the accommodating cavity;

[0007] a cover assembly connected to the shell and covering the accommodating cavity, wherein one of the cover assembly and the shell has an explosion-proof hole;

[0008] An explosion-proof valve, covering an explosion-proof hole, the explosion-proof valve includes a base and a weak portion connected to each other, the base is arranged around the weak portion, one of the cover assembly and the shell is connected to the base, the weak portion is configured to be destroyed when impacted by a preset pressure, the weak portion has a first surface and a second surface arranged opposite to each other along a first direction, the first surface has a first groove recessed toward a side close to the electrode assembly, the second surface has a second groove recessed toward a side away from the electrode assembly, the first groove surrounds the second groove, the dimension of the weak portion in the first direction is H, the dimension of the first groove in the first direction is H1 mm, the dimension of the second groove in the first direction is H2 mm, and the following conditions are met: 0.35≤H1 / H≤0.75, 0.2≤H2 / H≤0.55.

[0009] In some embodiments, the single battery cell satisfies: 0.15≤H≤0.45.

[0010] In some embodiments, the residual thickness between the first groove and the second groove is H3 μm, satisfying: H3 ≥ 40.

[0011] In some embodiments, along the second direction, the distance between the side of the base away from the weak portion and the middle of the bottom of the first groove is L mm, satisfying: L≥3, and the second direction intersects the first direction.

[0012] In some embodiments, the first groove has an included angle α°, and the second groove has an included angle β°, satisfying: 55≤α≤75, 55≤β≤75.

[0013] In some embodiments, the cover plate assembly has a limiting groove, which is arranged on a side of the cover plate assembly close to the electrode assembly. The limiting groove surrounds the explosion-proof hole, and the explosion-proof valve is arranged in the limiting groove.

[0014] In some embodiments, the shell has a limiting groove, which is arranged on a side of the shell close to the electrode assembly. The limiting groove surrounds the explosion-proof hole, and the explosion-proof valve is arranged in the limiting groove.

[0015] In some embodiments, the cross-sectional shape of the first groove and the second groove is triangular.

[0016] Accordingly, an embodiment of the present application provides a battery pack including the above-mentioned single battery.

[0017] Accordingly, an embodiment of the present application provides an electrical device, including the above-mentioned single battery, or the above-mentioned battery pack.

[0018] Beneficial effects: The single battery of the embodiment of the present application includes a shell, an electrode assembly, a cover assembly and an explosion-proof valve: the shell has a accommodating cavity; the electrode assembly is located in the accommodating cavity; the cover assembly is connected to the shell and covers the accommodating cavity, one of the cover assembly and the shell has an explosion-proof hole; the explosion-proof valve covers the explosion-proof hole, the explosion-proof valve includes a base and a weak portion connected to each other, the base is arranged around the weak portion, one of the cover assembly and the shell is connected to the base, the weak portion is configured to be destroyed when impacted by a preset pressure, the weak portion has a first surface and a second surface arranged opposite to each other along a first direction, the first surface has a first groove recessed toward a side close to the electrode assembly, the second surface has a second groove recessed toward a side away from the electrode assembly, the first groove surrounds the second groove, the dimension of the weak portion in the first direction is H, the dimension of the first groove in the first direction is H1 mm, the dimension of the second groove in the first direction is H2 mm, and the following conditions are satisfied: 0.35≤H1 / H≤0.75, 0.2≤H2 / H≤0.55. The first direction is the thickness direction of the explosion-proof valve. The present application sets a first groove and a second groove. When gas is produced inside the single cell, the high-temperature and high-pressure gas breaks through the residual thickness between the first groove and the second groove to open the explosion-proof valve, thereby realizing the pressure relief function of the single cell. The present application limits the ratio range of H1 / H and H2 / H, so that the stress of the weak part is uniform when subjected to external force, avoiding stress concentration and resulting deformation of the explosion-proof valve or premature opening of the valve, and can improve the opening pressure accuracy, anti-deformation ability and blasting stability of the explosion-proof valve.

[0019] The battery pack of the embodiment of the present application includes the above-mentioned single battery, so the battery pack can have all the technical features and beneficial effects of the above-mentioned single battery, which will not be repeated here.

[0020] The electrical device of the embodiment of the present application includes the above-mentioned single battery or the above-mentioned battery pack, so the electrical device can have all the technical features and beneficial effects of the above-mentioned single battery or the above-mentioned battery pack, which will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0022] Figure 1 This is a schematic structural diagram of a single cell according to an embodiment of the present application;

[0023] Figure 2 This is a partial schematic diagram of an explosion-proof valve according to an embodiment of the present application;

[0024] Figure 3 yes Figure 2 A magnified view of part A;

[0025] Figure 4 is a cross-sectional view of an explosion-proof valve according to an embodiment of the present application;

[0026] Figure 5 yes Figure 4 A magnified view of part B;

[0027] Figure 6 yes Figure 4 A magnified view of part B;

[0028] Figure 7 is a cross-sectional view of a single cell according to an embodiment of the present application;

[0029] Figure 8 yes Figure 7 Enlarged view of part C.

[0030] Description of reference numerals:

[0031] 1. Shell; 2. Electrode assembly; 3. Cover assembly; 4. Explosion-proof valve; 30. Explosion-proof hole; 31. Limiting groove; 40. Base; 41. Weak part; 410. First surface; 411. Second surface; 412. First groove; 413. Second groove; X, first direction; Y, second direction. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the embodiments described are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative efforts are within the scope of protection of this application.

[0033] In the description of the present application, it should be understood that the terms "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more features. In the description of the present application, "multiple" means two or more, and at least one means one, two or more, unless otherwise clearly and specifically defined. In the description of this application, "vertical" means completely vertical at 90° or almost completely vertical, for example, an angle within the range of 80° to 100° is considered vertical. Similarly, "parallel" means completely parallel or almost completely parallel, for example, an angle within 10° of completely parallel is considered parallel.

[0034] The applicant noted that current batteries often have explosion-proof valves to relieve pressure in the event of internal battery failure and gas production. To meet the required opening pressure for the explosion-proof valve, a notched structure is often stamped into the valve to regulate the opening pressure. However, these notched structures exhibit low precision in regulating the opening pressure of the explosion-proof valve.

[0035] In view of this, a single cell battery in an embodiment of the present application includes a shell, an electrode assembly, a cover assembly and an explosion-proof valve: the shell has a accommodating cavity; the electrode assembly is located in the accommodating cavity; the cover assembly is connected to the shell and covers the accommodating cavity, one of the cover assembly and the shell has an explosion-proof hole; the explosion-proof valve covers the explosion-proof hole, the explosion-proof valve includes a base and a weak portion connected to each other, the base is arranged around the weak portion, one of the cover assembly and the shell is connected to the base, the weak portion is configured to be destroyed when subjected to a preset pressure impact, the weak portion has a first surface and a second surface arranged opposite to each other along a first direction, the first surface has a first groove recessed toward a side close to the electrode assembly, the second surface has a second groove recessed toward a side away from the electrode assembly, the first groove surrounds the second groove, the dimension of the weak portion in the first direction is H, the dimension of the first groove in the first direction is H1 mm, the dimension of the second groove in the first direction is H2 mm, and the following conditions are satisfied: 0.35≤H1 / H≤0.75, 0.2≤H2 / H≤0.55. The first direction is the thickness direction of the explosion-proof valve. The present application sets a first groove and a second groove. When gas is produced inside the single cell, the high-temperature and high-pressure gas breaks through the residual thickness between the first groove and the second groove to open the explosion-proof valve, thereby realizing the pressure relief function of the single cell. The present application limits the ratio range of H1 / H and H2 / H, so that the stress of the weak part is uniform when subjected to external force, avoiding stress concentration and resulting deformation of the explosion-proof valve or premature opening of the valve, and can improve the opening pressure accuracy, anti-deformation ability and blasting stability of the explosion-proof valve.

[0036] The following is a detailed description of the single cell, battery pack and electrical device of the present application in conjunction with the accompanying drawings. The features of the following embodiments and implementations can be combined with each other unless there is any conflict.

[0037] Figure 1 This is a schematic structural diagram of a single cell according to an embodiment of the present application; Figure 2 This is a partial schematic diagram of an explosion-proof valve 4 according to an embodiment of the present application; Figure 3 yes Figure 2 A magnified view of part A; Figure 4 is a cross-sectional view of an explosion-proof valve 4 according to an embodiment of the present application; Figure 5 yes Figure 4 A magnified view of part B; Figure 6 yes Figure 4 A magnified view of part B; Figure 7 is a cross-sectional view of a single cell according to an embodiment of the present application; Figure 8 yes Figure 7 Enlarged view of part C.

[0038] refer to Figures 1 to 8The single battery of the embodiment of the present application includes a shell 1, an electrode assembly 2, a cover assembly 3 and an explosion-proof valve 4: the shell 1 has a receiving cavity; the electrode assembly 2 is located in the receiving cavity; the cover assembly 3 is connected to the shell 1 and covers the receiving cavity, and one of the cover assembly 3 and the shell 1 has an explosion-proof hole 30; the explosion-proof valve 4 covers the explosion-proof hole 30, and the explosion-proof valve 4 includes a base 40 and a weak portion 41 connected to each other, the base 40 is arranged around the weak portion 41, and one of the cover assembly 3 and the shell 1 is connected to the base 40. The weak portion 41 is configured to be destroyed when subjected to a preset pressure impact. The weak portion 41 has a first surface 410 and a second surface 411 arranged opposite to each other along the first direction X. The first surface 410 has a first groove 412 that is recessed toward the side close to the electrode assembly 2, and the second surface 411 has a second groove 413 that is recessed toward the side away from the electrode assembly 2. The first groove 412 surrounds the second groove 413. The dimension of the weak portion 41 in the first direction X is H, the dimension of the first groove 412 in the first direction X is H1 mm, and the dimension of the second groove 413 in the first direction X is H2 mm, satisfying the following: 0.35≤H1 / H≤0.75, 0.2≤H2 / H≤0.55. Figure 4 and Figure 5 The first direction X is the thickness direction of the explosion-proof valve 4. In the present application, by providing the first groove 412 and the second groove 413, when gas is generated inside the single cell, the high-temperature and high-pressure gas breaks through the residual thickness between the first groove 412 and the second groove 413 to open the explosion-proof valve 4, thereby realizing the pressure relief function of the single cell. In the present application, by limiting the ratio ranges of H1 / H and H2 / H, the stress of the weak portion 41 is uniform when subjected to external force, thereby avoiding stress concentration that may cause deformation of the explosion-proof valve 4 or premature opening of the valve, thereby improving the opening pressure accuracy, anti-deformation capability, and blasting stability of the explosion-proof valve 4.

[0039] In some embodiments, reference Figure 4 and Figure 5The dimension H of the weak portion 41 in the first direction X of the battery cell satisfies the following: 0.15 ≤ H ≤ 0.45. For example, the dimension H of the weak portion 41 in the first direction X can be any value among 0.15, 0.17, 0.19, 0.21, 0.23, 0.25, 0.27, 0.29, 0.31, 0.33, 0.35, 0.37, 0.39, 0.41, 0.43, or 0.45, or a range between any two values. With this configuration, if the H value is too small, the overall strength of the explosion-proof valve 4 will be reduced, and problems such as deformation or premature opening of the explosion-proof valve 4 may occur, affecting the performance and safety of the battery cell. Furthermore, an excessively small H value can make the processing of the first groove 412 and the second groove 413 difficult. On the other hand, if the H value is too large, the strength of explosion-proof valve 4 increases, but the opening pressure of explosion-proof valve 4 will also increase accordingly. When abnormal gas production occurs inside the single cell and pressure relief is required, explosion-proof valve 4 may not open in time, posing a safety risk. Excessive thickness also increases material cost and the overall weight of the battery. For example, in the embodiment, different H values ​​are combined with corresponding groove size ratios to ensure that explosion-proof valve 4 can open at the appropriate pressure while maintaining the opening pressure accuracy, maintaining safe and stable operation of the battery.

[0040] In some embodiments, reference Figure 4 and Figure 5 The residual thickness between the first groove 412 and the second groove 413 is H3μm, satisfying: H3≥40. The residual thickness between the first groove 412 and the second groove 413 refers to the thickness of the remaining portion between the first groove 412 and the second groove 413. When gas is generated inside the single cell, the high-temperature and high-pressure gas breaks through the residual thickness between the first groove 412 and the second groove 413 to open the explosion-proof valve 4, thereby achieving the pressure relief function of the single cell. The value of H3 determines the opening pressure required for the gas to break through the weak portion 41. The larger the H3 value, the more difficult it is for the gas to break through the residual thickness to open the explosion-proof valve 4, and the higher the required opening pressure. Conversely, if the H3 value is too low, the opening pressure will be correspondingly reduced. If the H3 value is too low, resulting in too low an opening pressure, the explosion-proof valve 4 may open prematurely when the internal pressure of the single cell fluctuates normally, resulting in the explosion-proof valve 4's anti-deformation ability not meeting the requirements. In the embodiment of the present application, by reasonably limiting the H3 value, the first groove 412 and the second groove 413 can better withstand the pressure inside the single battery acting along the first direction X, ensuring that the anti-deformation ability and explosion stability of the explosion-proof valve 4 meet the requirements, thereby accurately controlling the explosion pressure.

[0041] In some embodiments, by setting the explosion-proof valve 4 with different H, H1, H2, and H3 and testing the anti-deformation ability and explosion stability of the explosion-proof valve 4, the test results are shown in Table 1.

[0042] Table 1:

[0043]

[0044]

[0045]

[0046] In some embodiments, the deformation resistance test of the explosion-proof valve 4 involves fatigue testing the valve 4 using positive and negative pressures of ±0.15 MPa within the specified range of the valve 4, such as the burst pressure of 0.6±0.2 MPa, 0.9±0.2 MPa, etc., with one positive and one negative pressure cycle simulating the pressure changes experienced by the valve 4 under various battery conditions, such as charging and discharging, to test its deformation fatigue resistance. In this embodiment, the valve 4 is considered qualified if it cracks after 3500 cycles or more.

[0047] In some embodiments, the explosion stability test of the explosion-proof valve 4 refers to measuring the explosion stability of the explosion-proof valve 4 through the CPK (Process Capability Index). Specifically, in the explosion stability test of the explosion-proof valve 4, 32 sets of experimental data are taken, and the stability of the data is measured using the upper and lower limits of the design specifications as the qualified range. The larger the CPK value, the more stable the explosion pressure of the explosion-proof valve 4, the less the product quality is affected by accidental factors in the production process, and the more reliable the production process. In the embodiment of the present application, a CPK value greater than or equal to 1.33 is qualified.

[0048] With reference to Examples 1 to 12, when the single battery meets 0.35≤H1 / H≤0.75, 0.2≤H2 / H≤0.55, 0.15≤H≤0.45, and H3≥40, the test results show that H1 / H, H2 / H, and H3 are within the value range, the anti-deformation capability of the explosion-proof valve 4 meets the requirements, and the overall burst stability meets the requirements. It can be understood that the number of times N of the anti-deformation fatigue capability of the explosion-proof valve 4 is greater than 3500 times, and the burst stability CPK value is greater than or equal to 1.33, indicating that the opening pressure accuracy, anti-deformation capability, and burst stability of the explosion-proof valve 4 are good, and can meet the use requirements of the single battery.

[0049] Referring to Comparative Examples 1 to 4, when the single cell meets the requirements of 0.2≤H2 / H≤0.55, 0.15≤H≤0.45, and H3≥40, but does not meet the requirements of 0.35≤H1 / H≤0.75, the test results show that the H1 / H value is low, the anti-deformation capacity of the explosion-proof valve 4 meets the requirements, and the overall blasting stability is low. It can be understood that the blasting stability CPK value is less than 1.33, which does not meet the overall blasting stability requirements of the explosion-proof valve 4. The relatively low H1 value results in a shallow first groove 412. When gas is generated inside the single cell and the pressure rises, impacting the weak portion 41 of the explosion-proof valve 4, the process of gas breaking through the weak portion 41 is not stable, which in turn affects the overall blasting stability of the explosion-proof valve 4 and the safety and reliability of the single cell.

[0050] Referring to Comparative Examples 5 to 8, when the single cell meets the requirements of 0.35≤H1 / H≤0.75, 0.15≤H≤0.45, and H3≥40, but does not meet the requirements of 0.2≤H2 / H≤0.55, the test results show that the H2 / H value is low, and the anti-deformation capacity of the explosion-proof valve 4 meets the requirements, but the overall blasting stability is low. It can be understood that the blasting stability CPK value is less than 1.33, which does not meet the overall blasting stability requirements of the explosion-proof valve 4. The relatively low H2 value results in a shallow second groove 413. When gas is generated inside the single cell and the pressure rises, impacting the weak portion 41 of the explosion-proof valve 4, the process of gas breaking through the weak portion 41 is not stable, which in turn affects the overall blasting stability of the explosion-proof valve 4 and the safety and reliability of the single cell.

[0051] Referring to Comparative Examples 9 to 12, when the single cell meets the requirements of 0.2≤H2 / H≤0.55, 0.15≤H≤0.45, and H3≥40, but does not meet the requirements of 0.35≤H1 / H≤0.75, the test results show that the H1 / H value is relatively high, indicating that the anti-deformation capability of the explosion-proof valve 4 does not meet the requirements, while the overall blast stability meets the requirements. It can be understood that the number of times of anti-deformation fatigue capability is less than 3500, which does not meet the anti-deformation requirements of the explosion-proof valve 4. The relatively low H1 value results in a shallow first groove 412. When gas is generated inside the single cell and the pressure rises, impacting the weak portion 41 of the explosion-proof valve 4, the process of gas breaking through the weak portion 41 is not stable, which in turn affects the overall blast stability of the explosion-proof valve 4 and the safety and reliability of the single cell.

[0052] Referring to Comparative Examples 13 to 16, when the single cell meets 0.35≤H1 / H≤0.75, 0.15≤H≤0.45 and H3≥40, but does not meet 0.2≤H2 / H≤0.55, the test result shows that the H2 / H value is high, the anti-deformation ability of the explosion-proof valve 4 does not meet the requirements, and the overall blasting stability meets the requirements; it can be understood that the number of anti-deformation fatigue capabilities is less than 3500, which does not meet the anti-deformation requirements of the explosion-proof valve 4, and the H2 value is relatively high. When gas is produced inside the single cell and the pressure increases to impact the weak part 41 of the explosion-proof valve 4, the depth of the second groove 413 on the weak part 41 is large, so the bottom of the second groove 413 is subjected to greater deformation stress, which is prone to cracking or premature valve opening, thereby affecting the anti-deformation ability of the explosion-proof valve 4 and affecting the safety and reliability of the single cell.

[0053] With reference to Comparative Examples 17 to 20, when the single cell meets 0.35≤H1 / H≤0.75, 0.2≤H2 / H≤0.55, and 0.15≤H≤0.45, but does not meet H3≥40, the test results show that the H3 value is low, the anti-deformation capability of the explosion-proof valve 4 does not meet the requirements, and the overall blast stability meets the requirements. It is understandable that the number of anti-deformation fatigue tests is less than 3500, which does not meet the anti-deformation requirements of the explosion-proof valve 4. If the H3 value is too low, resulting in too low an opening pressure, the explosion-proof valve 4 may open prematurely when the internal pressure of the single cell fluctuates normally, resulting in the explosion-proof valve 4's anti-deformation capability not meeting the requirements, affecting the safety and reliability of the single cell.

[0054] In some embodiments, reference Figure 4 and Figure 6 Along the second direction Y, the distance between the side of the base 40 away from the weak portion 41 and the middle of the first groove 412 is L mm, satisfying: L ≥ 3, and the second direction Y intersects the first direction X. It can be understood that the second direction Y is perpendicular to the first direction X. The base 40 of the explosion-proof valve 4 is connected to the cover assembly 3 or the housing 1 by welding. If the L value is too small, the first groove 412 is too close to the welding area, and the thermal stress generated during welding acts on the first groove 412 or the second groove 413, which may cause deformation of the first groove 412 or the second groove 413, thereby affecting the bursting pressure accuracy of the explosion-proof valve 4. By limiting the distance L between the side of the base 40 away from the weak portion 41 and the middle of the first groove 412 along the second direction Y, this application can ensure that after the explosion-proof valve 4 is stamped, when the base 40 is welded to the cover assembly 3 or the housing 1, deformation of the first groove 412 or the second groove 413 caused by welding heat can be avoided, thereby ensuring the bursting pressure accuracy and stability of the explosion-proof valve 4.

[0055] In some embodiments, reference Figure 4 and Figure 6, the first groove 412 has an angle α°, satisfying: 55≤α≤75. α is the opening angle of the first groove 412. The first groove 412 is usually realized by a stamping process. If α is less than 55, the mold edge is too sharp, which can easily lead to cracking of the material during stamping or mold wear, affecting production efficiency and yield; if α is greater than 75, the side wall of the first groove 412 is too gentle, which will weaken the stress concentration effect, thereby reducing the explosion stability of the explosion-proof valve 4. By limiting the angle α of the first groove 412, the embodiment of the present application can take into account both process forming and structural stability, while meeting the yield and production efficiency of the stamping process of the explosion-proof valve 4, and improving the explosion stability of the explosion-proof valve 4.

[0056] In some embodiments, reference Figure 4 and Figure 6 , the second groove 413 has an angle β°, satisfying: 55≤β≤75. β is the opening angle of the second groove 413. The second groove 413 is usually realized by a stamping process. If β is less than 55, the mold edge is too sharp, which can easily lead to cracking of the material during stamping or mold wear, affecting production efficiency and yield; if β is greater than 75, the side wall of the second groove 413 is too gentle, which will weaken the stress concentration effect, thereby reducing the explosion stability of the explosion-proof valve 4. By limiting the angle β of the second groove 413, the embodiment of the present application can take into account both process forming and structural stability, while meeting the yield and production efficiency of the stamping process of the explosion-proof valve 4, and improving the explosion stability of the explosion-proof valve 4.

[0057] In some embodiments, reference Figure 7 and Figure 8 The cover plate assembly 3 has a limiting groove 31, which is arranged on the side of the cover plate assembly 3 close to the electrode assembly 2. The limiting groove 31 surrounds the explosion-proof hole 30, and the explosion-proof valve 4 is arranged in the limiting groove 31. The limiting groove 31 is arranged on the side of the cover plate assembly 3 close to the electrode assembly 2. The explosion-proof valve 4 can be accurately positioned through the limiting groove 31. The base 40 of the explosion-proof valve 4 is welded to the bottom wall of the limiting groove 31. On the one hand, it can prevent the explosion-proof valve 4 from rubbing, colliding or being squeezed with the outside of the single battery. On the other hand, it can prevent the explosion-proof valve 4 from being accommodated in the limiting groove 31 and rubbing, colliding or being squeezed with the electrode assembly 2, thereby ensuring the structural integrity of the explosion-proof valve 4 and improving the safety and reliability of the single battery.

[0058] In other embodiments, the housing 1 has a limiting groove 31, which is provided on a side of the housing 1 close to the electrode assembly 2. The limiting groove 31 surrounds the explosion-proof hole 30, and the explosion-proof valve 4 is provided in the limiting groove 31. The limiting groove 31 is provided on a side of the housing 1 close to the electrode assembly 2, and the explosion-proof valve 4 can be precisely positioned through the limiting groove 31. The base 40 of the explosion-proof valve 4 is welded to the bottom wall of the limiting groove 31. On the one hand, this can prevent the explosion-proof valve 4 from rubbing, colliding, or squeezing against the outside of the single battery cell. On the other hand, this can prevent the explosion-proof valve 4 from being accommodated in the limiting groove 31 and rubbing, colliding, or squeezing against the electrode assembly 2, thereby ensuring the structural integrity of the explosion-proof valve 4 and improving the safety and reliability of the single battery cell.

[0059] In some embodiments, reference Figure 2 and Figure 3 The first and second grooves 412, 413 have triangular cross-sections. This arrangement directs gas pressure to the bottoms of the first and second grooves 412, 413, ensuring that the explosion-proof valve 4 opens precisely at the preset pressure. Furthermore, the triangular cross-section is easily formed through a stamping process, ensuring controllable machining accuracy.

[0060] Accordingly, the embodiment of the present application provides a battery pack including the above-mentioned single battery. Therefore, the battery pack can have all the technical features and technical effects of the above-mentioned single battery, which will not be described in detail here.

[0061] Accordingly, an embodiment of the present application provides an electrical device, including the above-mentioned single cell, or the above-mentioned battery pack, so that the electrical device can have all the technical features and beneficial effects of the above-mentioned single cell or battery pack, which will not be repeated here. The electrical device can be a mobile phone, a portable device, a laptop computer, an electric vehicle, an electric car, a ship, a spacecraft, an electric toy, and an electric tool, etc. For example, spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc.; electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc.; electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools, and railway electric tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc.

[0062] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0063] The above is a detailed introduction to a single cell battery, a battery pack and an electrical device provided in the embodiments of the present application, and specific examples are used to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the technical solutions and core ideas of the present application; ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A single battery, characterized in that: include: A housing having a receiving cavity; an electrode assembly, located in the accommodating cavity; a cover assembly connected to the shell and covering the accommodating cavity, wherein one of the cover assembly and the shell has an explosion-proof hole; An explosion-proof valve, sealing the explosion-proof hole, the explosion-proof valve comprising a connected base and a weak portion, the base being arranged around the weak portion, the cover assembly and one of the shell being connected to the base, the weak portion being configured to be destroyed when impacted by a preset pressure, the weak portion having a first surface and a second surface arranged opposite to each other along a first direction, the first surface having a first groove recessed toward a side close to the electrode assembly, the second surface having a second groove recessed toward a side away from the electrode assembly, the first groove surrounding the second groove, a dimension of the weak portion in the first direction being H, a depth dimension of the first groove in the first direction being H1 mm, a depth dimension of the second groove in the first direction being H2 mm, satisfying the following: 0.35≤H1 / H≤0.75, 0.2≤H2 / H≤0.

55.

2. The single cell according to claim 1, characterized in that: The single cell satisfies: 0.15≤H≤0.

45.

3. The single cell according to claim 1, characterized in that: The residual thickness between the first groove and the second groove is H3 μm, satisfying: H3 ≥ 40.

4. The single cell according to claim 1, characterized in that: Along the second direction, the distance between the side of the base away from the weak portion and the middle of the first groove is L mm, satisfying: L≥3, and the second direction intersects the first direction.

5. The single cell according to claim 1, characterized in that: The first groove has an included angle α°, and the second groove has an included angle β°, satisfying: 55≤α≤75, 55≤β≤75.

6. The single cell according to claim 1, characterized in that: The cover plate assembly has a limiting groove, which is arranged on a side of the cover plate assembly close to or away from the electrode assembly. The limiting groove surrounds the explosion-proof hole, and the explosion-proof valve is arranged in the limiting groove.

7. The single cell according to claim 1, characterized in that: The shell has a limiting groove, which is arranged on a side of the shell close to or away from the electrode assembly. The limiting groove surrounds the explosion-proof hole, and the explosion-proof valve is arranged in the limiting groove.

8. The single cell according to claim 1, characterized in that: The cross-sectional shape of the first groove and the second groove is triangular.

9. A battery pack, characterized in that: The invention comprises a single cell according to any one of claims 1 to 8.

10. An electrical device, characterized in that: The invention comprises a single cell according to any one of claims 1 to 8, or a battery pack according to claim 9.

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