Single cell and battery pack

Abstract

This application discloses a single-cell battery and a battery pack, belonging to the field of battery technology, including a housing, an explosion-proof valve, a plate, and a connector. The housing includes multiple sidewalls that are interconnected and form a receiving cavity. At least one sidewall has an explosion-proof hole communicating with the receiving cavity. The explosion-proof valve seals the explosion-proof hole. The plate is disposed within the receiving cavity and has an exhaust hole corresponding to the explosion-proof valve, ensuring communication between the explosion-proof valve and the receiving cavity to form an exhaust channel and reduce the risk of thermal runaway. The connector is disposed on the side of the plate facing the explosion-proof valve and is connected to the plate. The connector, the explosion-proof valve, and the sidewalls are welded together. By using the plate and connector, the sidewall thickness can be reduced while ensuring effective welding of the explosion-proof valve and the sidewalls, preventing the explosion-proof valve from scratching the electrode assembly. Furthermore, the connector being disposed on the side of the plate facing the explosion-proof valve prevents welding slag from falling into the receiving cavity, thereby effectively improving the safety and reliability of the single-cell battery.

Description

Technical Field

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

[0002] With the continuous development of technology, users have increasingly higher requirements for new energy batteries. To improve the safety performance of individual battery cells, explosion-proof valves are usually installed on them. When gas is generated inside a battery cell due to abnormal operation, the gas can be released through the explosion-proof valve to prevent major safety accidents.

[0003] To maximize cell capacity and battery pack safety, thinner casings are typically used to increase internal space within the cells. Explosion-proof valves are moved from the cover plate to the casing sidewall to achieve thermal-electric separation. Currently, welding explosion-proof valves to the casing sidewall requires sufficient wall thickness to create a step for valve installation, increasing casing wall thickness. Alternatively, an outward protrusion in the casing creates mounting holes for the valve, occupying external space and increasing the risk of bottom ball strikes. Utility Model Content

[0004] The purpose of this utility model is to provide a single battery cell to solve the technical problem of increased risk of bottom impact caused by excessively thick casing walls or casing protrusions occupying external space; another purpose of this application is to provide a battery pack.

[0005] Technical solution: This application provides a single-cell battery, including:

[0006] The housing includes multiple sidewalls that are interconnected and form a receiving cavity, and at least one sidewall is provided with an explosion-proof hole communicating with the receiving cavity;

[0007] Explosion-proof valve, with sealed explosion-proof orifice;

[0008] The plate is set inside the receiving cavity, and the plate is provided with an exhaust hole corresponding to the explosion-proof valve;

[0009] A connector is located on the side of the plate facing the explosion-proof valve and is connected to the plate. The connector, the explosion-proof valve, and the side wall are welded together.

[0010] In some embodiments, the plate has an annular groove surrounding the vent hole, the annular groove being formed on the side of the plate facing the explosion-proof valve, and at least a portion of the connector being located within the annular groove.

[0011] In some embodiments, the connector is located within an annular groove and has a connecting surface that is attached to at least a portion of the sidewall and the plate.

[0012] In some embodiments, the connector includes a first body and a first stepped portion, with a sidewall connected to at least a portion of the first body, the first stepped portion connected to the first body and protruding toward the explosion-proof valve relative to the first body, and the first stepped portion connected to the explosion-proof valve.

[0013] In some embodiments, the connector includes a second body and a second step portion, the explosion-proof valve is at least partially connected to the second body, the second step portion is connected to the second body and protrudes toward the sidewall relative to the second body, and the second step portion is connected to the sidewall.

[0014] In some embodiments, the weld depth formed by the connector, the explosion-proof valve, and the sidewall welded onto the connector is A mm, and the maximum dimension of the connector in the first direction is B mm, satisfying: The first direction is the thickness direction of the sidewall.

[0015] In some embodiments, the sidewall has a first side away from the plate, and the explosion-proof valve has a second side away from the plate, with the first and second sides flush.

[0016] In some embodiments, in the first direction, the maximum dimension of the connector is B mm, the maximum dimension of the sidewall is C mm, and the single cell satisfies at least one of the following characteristics:

[0017] 0.3≤B≤0.5;

[0018] 0.1≤C≤0.6.

[0019] In some embodiments, the plate has a plurality of through holes, which are disposed on both sides of the connector along a second direction and are spaced apart, wherein the second direction is the length direction of the plate.

[0020] In some embodiments, the sheet metal is an injection molded part.

[0021] In some embodiments, the connector is a metal component.

[0022] Accordingly, this application provides a battery pack including the aforementioned single battery cell.

[0023] Beneficial Effects: The single-cell battery of this application embodiment includes a casing, an explosion-proof valve, a plate, and a connector. The casing includes multiple sidewalls that are interconnected and form a receiving cavity. At least one sidewall has an explosion-proof hole communicating with the receiving cavity. The explosion-proof valve seals the explosion-proof hole. The plate is disposed within the receiving cavity and has an exhaust hole corresponding to the explosion-proof valve, ensuring communication between the explosion-proof valve and the receiving cavity to form an exhaust channel and reduce the risk of thermal runaway. The connector is disposed on the side of the plate facing the explosion-proof valve and is connected to the plate. The connector, the explosion-proof valve, and the sidewalls are welded together. By setting the plate and connector, the thickness of the sidewalls can be reduced while ensuring effective welding of the explosion-proof valve and the sidewalls, preventing the explosion-proof valve from contacting or even scratching the electrode components inside the single-cell battery, thus affecting the safety of the single-cell battery. Furthermore, the connector being disposed on the side of the plate facing the explosion-proof valve prevents welding slag from falling into the receiving cavity, thereby effectively improving the safety and reliability of the single-cell battery.

[0024] 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. Attached Figure Description

[0025] 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.

[0026] Figure 1 This is a schematic diagram of the structure of a single battery cell according to an embodiment of this application;

[0027] Figure 2 This is a schematic diagram of the structure of a single battery cell according to another embodiment of this application;

[0028] Figure 3 This is an exploded view of a plate and connector according to an embodiment of this application;

[0029] Figure 4 This is a partial cross-sectional view of a single cell according to the first embodiment of this application;

[0030] Figure 5 This is a partial cross-sectional view of a single cell according to the second embodiment of this application;

[0031] Figure 6 This is a partial cross-sectional view of a single cell according to the third embodiment of this application;

[0032] Figure 7 This is a partial cross-sectional view of a single cell according to the fourth embodiment of this application.

[0033] Reference numerals: 1. Housing; 2. Explosion-proof valve; 3. Plate; 4. Connector; 10. Side wall; 11. Receiving cavity; 12. Explosion-proof hole; 30. Vent hole; 31. Annular groove; 32. Through hole; 40. Connecting surface; 41. First body; 42. First step; 43. Second body; 44. Second step; X, First direction; Y, Second direction. Detailed Implementation

[0034] 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.

[0035] 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 between 80° and 100° is considered perpendicular. Similarly, "parallel" means completely parallel or almost completely parallel, for example, the range of completely parallel angles between 10° is considered parallel.

[0036] The applicant notes that with continuous technological advancements, users have increasingly higher demands for new energy batteries. To improve the safety performance of individual battery cells, explosion-proof valves are typically installed. When a battery cell malfunctions and generates internal gas, the explosion-proof valve can release the gas, preventing major safety accidents. To maximize cell capacity and battery pack safety, thinner casings are often used to increase internal space, and the explosion-proof valve is moved from the cover plate to the side wall of the casing to achieve thermal-electric separation. Currently, welding the explosion-proof valve to the side wall of the casing requires sufficient wall thickness to form a step for valve installation, increasing the casing wall thickness; alternatively, the casing protrudes outwards to create mounting holes for the valve, resulting in the casing occupying external space and increasing the risk of bottom impact.

[0037] In view of this, embodiments of this application provide a single-cell battery, including a housing, an explosion-proof valve, a plate, and a connector. The housing includes multiple sidewalls that are interconnected and form a receiving cavity. At least one sidewall has an explosion-proof hole communicating with the receiving cavity. The explosion-proof valve seals the explosion-proof hole. The plate is disposed within the receiving cavity and has an exhaust hole corresponding to the explosion-proof valve, ensuring communication between the explosion-proof valve and the receiving cavity to form an exhaust channel and reduce the risk of thermal runaway. The connector is disposed on the side of the plate facing the explosion-proof valve and is connected to the plate. The connector, the explosion-proof valve, and the sidewalls are welded together. By providing the plate and connector, the sidewall thickness can be reduced while ensuring effective welding of the explosion-proof valve and the sidewalls. Furthermore, the connector's placement on the side of the plate facing the explosion-proof valve prevents welding slag from falling into the receiving cavity, thereby effectively improving the safety and reliability of the single-cell battery.

[0038] The single-cell battery and battery pack 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.

[0039] Figure 1 This is a schematic diagram of the structure of a single battery cell according to an embodiment of this application; Figure 2 This is a schematic diagram of the structure of a single battery cell according to another embodiment of this application; Figure 3 This is a schematic diagram of the structure of a plate 3 and a connector 4 according to an embodiment of this application; Figure 4 This is a partial cross-sectional view of a single cell according to the first embodiment of this application; Figure 5 This is a partial cross-sectional view of a single cell according to the second embodiment of this application; Figure 6 This is a partial cross-sectional view of a single cell according to the third embodiment of this application; Figure 7 This is a partial cross-sectional view of a single cell according to the fourth embodiment of this application.

[0040] refer to Figures 1 to 7This application provides a single-cell battery, including a housing 1, an explosion-proof valve 2, a plate 3, and a connector 4. The housing 1 includes multiple sidewalls 10, which are interconnected and form a receiving cavity 11. At least one sidewall 10 has an explosion-proof hole 12 communicating with the receiving cavity 11. The explosion-proof valve 2 seals the explosion-proof hole 12. The explosion-proof valve 2 includes a support portion and a weak portion connected to each other. The support portion is arranged around the weak portion, which is configured to be destroyed when subjected to a preset pressure impact, thereby forming a venting channel to prevent the battery from exploding due to excessive internal pressure and other dangerous situations, playing a key role in safety protection. The explosion-proof valve 2 is disposed on the sidewall 10 of the housing 1, which can achieve the effect of thermoelectric separation, preventing the accumulation of heat inside the battery from affecting electrical components such as terminals and cells, reducing the risk of electrical short circuits caused by overheating, and enhancing the safety and stability of the single-cell battery.

[0041] Plate 3 is disposed within the receiving cavity 11. Plate 3 has an exhaust port 30 corresponding to the explosion-proof valve 2, ensuring that the explosion-proof valve 2 is connected to the receiving cavity 11 to form an exhaust channel, reducing the risk of thermal runaway. Connector 4 is disposed on the side of plate 3 facing the explosion-proof valve 2 and is connected to plate 3. Connector 4, explosion-proof valve 2, and side wall 10 are welded together. By setting plate 3 and connector 4, the thickness of side wall 10 can be reduced while ensuring effective welding of explosion-proof valve 2 and side wall 10, preventing explosion-proof valve 2 from contacting or even scratching the electrode components inside the single cell, thus affecting the safety of the single cell. Furthermore, the fact that connector 4 is disposed on the side of plate 3 facing the explosion-proof valve 2 can prevent welding slag from falling into the receiving cavity 11, thereby effectively improving the safety and reliability of the single cell.

[0042] In some embodiments, plate 3 is an injection-molded part, and connector 4 is a metal part. For example, connector 4 can be made of high-strength materials such as aluminum or steel. Plate 3 is injection-molded, and connector 4 is embedded in the annular groove of plate 3. Plastic material has the advantages of relatively low cost, easy processing and molding, low density, and light overall weight. Plate 3 is located on the side of connector 4 away from explosion-proof valve 2, which can prevent welding slag from falling into the receiving cavity 11 during welding, thereby effectively improving the safety of the single battery cell.

[0043] exist Figure 1 and Figure 2In the illustrated embodiment, the housing 1 is formed by four side walls 10, the thickness of which can be the same or differentiated as needed. Exemplarily, an explosion-proof hole 12 is formed on the narrower side wall 10 by punching or machining to position the explosion-proof valve 2. The explosion-proof valve 2 passes through the explosion-proof hole 12 to abut against the plate 3 and connector 4 located in the receiving cavity 11. The explosion-proof valve 2, side wall 10, and connector 4 are connected by welding to complete the fixing and sealing of the explosion-proof valve 2. This configuration eliminates the need to increase the thickness of the side wall 10 where the explosion-proof valve 2 is located, ensuring effective welding of the explosion-proof valve 2 and the side wall 10.

[0044] exist Figure 3 In the illustrated embodiment, the plate 3 has an annular groove 31 surrounding the exhaust port 30. The annular groove 31 is located on the side of the plate 3 facing the explosion-proof valve 2, and at least a portion of the connector 4 is located within the annular groove 31. The connector 4 has an annular structure and is embedded within the annular groove 31 to engage with the annular groove 31 in a first direction X, where the first direction X is the thickness direction of the sidewall 10. This arrangement reduces space occupation and effectively improves energy density.

[0045] exist Figures 1 to 7 In the illustrated embodiment, the sidewall 10 has a first surface away from the plate 3, and the explosion-proof valve 2 has a second surface away from the plate 3. The first and second surfaces are flush. This application uses the plate 3 and connector 4 to position the explosion-proof valve 2, eliminating the need for steps on the sidewall 10 to limit its movement. The outer surface of the explosion-proof valve 2 is flush with the outer surface of the sidewall 10, thus avoiding the need to occupy external space in the housing 1 and reducing the risk of impact and collision to the individual battery cells.

[0046] In some embodiments, a bottom ball impact test is typically used to simulate the impact of a foreign object on the bottom of the battery pack under actual road conditions, serving as a method for testing the safety performance of the battery pack. During the test, a ball or impact head is used as the impact object to strike the bottom of the battery pack at a certain speed and angle. This impact process simulates the impact force that the bottom of the battery pack may experience when a vehicle encounters obstacles such as speed bumps or stones during driving. In the bottom ball impact test, having the first and second surfaces flush effectively reduces the risk of impact damage due to the external protruding structure, improving the safety and reliability of the battery in various complex environments.

[0047] exist Figures 4 to 6In the illustrated embodiment, the maximum dimension of the sidewall 10 in the first direction X is C mm, satisfying: 0.1 ≤ C ≤ 0.6. Exemplarily, the maximum dimension C of the sidewall 10 in the first direction X can be any value from 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, or a range between any two. The material of the housing 1 can be a high-strength material such as aluminum or steel.

[0048] In some embodiments, the casing 1 may be made of aluminum. An aluminum casing 1 is lightweight and strong, providing good protection for the internal components of the battery, while also exhibiting good thermal conductivity, which is beneficial for heat dissipation during battery operation. Exemplarily, the thickness of the thin-walled aluminum casing can be between 0.3 mm and 0.6 mm, and this application does not impose any limitation on this.

[0049] In other embodiments, the casing 1 can be made of steel. A steel casing 1 is high-strength, durable, and can withstand significant external impacts and internal pressure. Furthermore, steel has good corrosion resistance, ensuring that the casing 1 is not damaged by corrosion during long-term battery use. Exemplarily, the thickness of the thin-walled steel casing can be between 0.1 mm and 0.3 mm, and this application does not impose any limitation on this.

[0050] exist Figure 4 In the illustrated embodiment, in the first direction X, when the maximum dimension B of the sidewall 10 is the same as the thickness of the explosion-proof valve 2, the connector 4 is located within the annular groove 31. The connector 4 has a connecting surface 40, which is attached to at least a portion of the sidewall 10 and the plate 3. This arrangement, with the surfaces of the plate 3 and the connector 4 aligned with the sides of the explosion-proof valve 2 and the sidewall 10, increases the contact area between the plate 3 and the connector 4 and the explosion-proof valve 2, thereby effectively improving the connection stability and sealing performance of the explosion-proof valve 2.

[0051] exist Figure 5 In the illustrated embodiment, in the first direction X, when the maximum dimension B of the sidewall 10 is greater than the thickness of the explosion-proof valve 2, the connector 4 includes a first body 41 and a first stepped portion 42. The sidewall 10 is at least partially connected to the first body 41, and the first stepped portion 42 is connected to the first body 41 and protrudes towards the explosion-proof valve 2 relative to the first body 41. The first stepped portion 42 is connected to the explosion-proof valve 2. The first stepped portion 42 can accommodate situations where the sidewall 10 has a large dimension. The first stepped portion 42 is connected to both the explosion-proof valve 2 and the sidewall 10 to accommodate the height difference between them. This configuration allows for more precise positioning and fixation of the explosion-proof valve 2.

[0052] exist Figure 6In the illustrated embodiment, in the first direction X, when the maximum dimension B of the sidewall 10 is less than the thickness of the explosion-proof valve 2, the connector 4 includes a second body 43 and a second stepped portion 44. The explosion-proof valve 2 is at least partially connected to the second body 43, and the second stepped portion 44 is connected to the second body 43 and protrudes towards the sidewall 10 relative to the second body 43. The second stepped portion 44 is connected to the sidewall 10. The second stepped portion 44 can accommodate situations where the sidewall 10 is small. The second stepped portion 44 is connected to both the explosion-proof valve 2 and the sidewall 10 to accommodate the height difference between the sidewall 10 and the explosion-proof valve 2. This configuration allows for more precise positioning and fixation of the explosion-proof valve 2.

[0053] exist Figure 7 In the embodiment shown, the weld depth formed by the connector 4, the explosion-proof valve 2, and the sidewall 10 welded onto the connector 4 is A mm. In the first direction X, the maximum dimension of the connector 4 is B mm, satisfying: 1 / 3 The connector 4, explosion-proof valve 2, and side wall 10 are welded together, forming a weld mark with a penetration depth of A on the connector 4. If the ratio of A / B is too small, the weld may not meet the tensile strength requirements, resulting in a weak connection between the explosion-proof valve 2 and the connector 4. Under internal pressure impact, there may be a risk of loosening or detachment, which could lead to the explosion-proof valve 2 failing to rupture in time when needed, thereby increasing the risk of fire or explosion of the single cell. If the ratio of A / B is too large, it may cause the connector 4 to be welded through, which could then cause thermal impact on the plate 3, resulting in deformation or melting of the plate 3. This application limits the ratio of the penetration depth A formed by the connector 4, explosion-proof valve 2, and side wall 10 welded onto the connector 4 to the maximum dimension B of the connector 4. This ensures the connection stability between the explosion-proof valve 2 and the connector 4 while preventing the connector 4 from being welded through during welding, thus affecting the strength of the plate 3 that is attached to the connector 4, and improving the safety and reliability of the single cell.

[0054] exist Figures 4 to 6In the illustrated embodiment, the maximum dimension of the connector 4 in the first direction X is B mm, satisfying: 0.3 ≤ B ≤ 0.5. Exemplarily, the maximum dimension B of the connector 4 in the first direction X can be any value from 0.3, 0.31, 0.32, 0.33, 0.34, 0.35, 0.36, 0.37, 0.38, 0.39, 0.4, 0.41, 0.42, 0.43, 0.44, 0.45, 0.46, 0.47, 0.48, 0.49, 0.5, or a range between any two. If the maximum dimension B of the connector 4 is too small, the connector 4 may not have sufficient depth to weld to the explosion-proof valve 2 and the side wall 10, posing a risk of the connector 4 and plate 3 detaching. If the maximum dimension B of the connector 4 is too large, the connector 4 will occupy too much internal space in the receiving cavity 11, affecting the energy density of the single battery cell. By limiting the maximum size B of connector 4, excessive size B of connector 4 is prevented from occupying too much internal space of cavity 11, thereby reducing the adverse effects on the energy density of individual cells. This helps to achieve a more compact design while ensuring the performance of individual cells. It also avoids the problem of insufficient welding depth caused by the maximum size B of connector 4 being too small, reduces the risk of connector 4 and plate 3 falling off, ensures that explosion-proof valve 2 is firmly connected to side wall 10, and improves the stability and safety of the overall structure of individual cells.

[0055] In the embodiments of this application, the welding strength of the sidewall 10, the explosion-proof valve 2, and the connector 4 is tested by pressure testing. The testing method is as follows: test samples of individual batteries are randomly selected, and the receiving cavity 11 is pressurized with gas using a bursting device. When the internal pressure of the receiving cavity 11 exceeds the welding strength, cracking will occur, releasing the internal pressure of the sealed cavity. Based on the pressure value applied by the bursting device, it can be determined whether the welding strength of the sidewall 10, the explosion-proof valve 2, and the connector 4 meets the requirement of a pressure resistance greater than 0.4 MPa. Here, OK indicates that the welding strength of the explosion-proof valve 2 and the connector 4 meets the requirement, and NG indicates that the welding strength of the explosion-proof valve 2 and the connector 4 does not meet the requirement. The specific test results are shown in Table 1.

[0056] Table 1:

[0057]

[0058] Referring to Comparative Examples 1 and 2, when the weld depth A formed on the connector 4 exceeds the maximum dimension B of the connector 4 in the first direction X, such that A / B > 1, the weld penetrates the connector 4 and is embedded in the plate 3. However, in the embodiments of this application, the plate 3 can be an injection molded part, which is at risk of melting the plastic when subjected to heat, affecting the strength of the plate 3 and failing to meet the design requirements.

[0059] Referring to Comparative Examples 3 and 4, when the weld penetration depth A formed on the connector 4 is too small, resulting in A / B < 1 / 3, the weld joint cannot meet the tensile strength requirement of 0.4 MPa. It is understandable that when the weld strength between the explosion-proof valve 2 and the connector 4 does not meet the requirements, the connection between them will be weak, potentially leading to loosening or detachment under internal pressure impact. This could result in the explosion-proof valve 2 failing to rupture in time when needed, thereby increasing the risk of fire and explosion of the individual battery cells.

[0060] Referring to Examples 1 to 10, when the maximum dimension B of the connector 4 in the first direction X, the maximum dimension C of the sidewall 10 in the first direction X, and the weld penetration A formed on the connector 4 satisfy 0.3≤B≤0.5, 0.1≤C≤0.6, and 1 / 3≤A / B≤1, the risk of cracking or falling off of the connector 4 and the plate 3 can be reduced, and the risk of melting plastic caused by welding through the connector 4 can be avoided, ensuring the effective welding of the connector 4, the explosion-proof valve 2, and the sidewall 10.

[0061] exist Figure 3 In the illustrated embodiment, the plate 3 has multiple through holes 32, which are disposed on both sides of the connector 4 along the second direction Y, and are spaced apart. The second direction Y is the length direction of the plate 3. The second direction Y is perpendicular to the first direction X. By spaced apart multiple through holes 32 on the plate 3, the material required to manufacture the plate 3 can be reduced while ensuring the structural stability of the plate 3, thus lowering production costs.

[0062] Accordingly, this application provides a battery pack including the aforementioned single battery cell. The single battery cell of this application includes a housing 1, an explosion-proof valve 2, a plate 3, and a connector 4. The housing 1 includes multiple sidewalls 10, which are interconnected to form a receiving cavity 11. At least one sidewall 10 has an explosion-proof hole 12 communicating with the receiving cavity 11. The explosion-proof valve 2 seals the explosion-proof hole 12. The plate 3 is disposed within the receiving cavity 11 and has an exhaust hole 30 corresponding to the explosion-proof valve 2, ensuring communication between the explosion-proof valve 2 and the receiving cavity 11 to form an exhaust channel and reduce the risk of thermal runaway. The connector 4 is disposed on the side of the plate 3 facing the explosion-proof valve 2 and connected to the plate 3. The connector 4, the explosion-proof valve 2, and the sidewalls 10 are welded together. By setting plate 3 and connector 4, the thickness of side wall 10 can be reduced while ensuring effective welding of explosion-proof valve 2 and side wall 10, preventing explosion-proof valve 2 from contacting or even scratching the electrode components inside the single cell, thus affecting the safety of the single cell. In addition, the connector 4 is set on the side of plate 3 facing explosion-proof valve 2, which can prevent welding slag from falling into the receiving cavity 11, thereby effectively improving the safety and reliability of the single cell.

[0063] 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.

[0064] The present application provides a detailed description of a single battery cell and a battery pack, and uses specific examples to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only for the purpose of helping to understand the technical solutions and core ideas of the present application. Those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A single cell, characterized by, The shell comprises a plurality of side walls connected to each other and surrounding a receiving cavity, at least one of the side walls being provided with an explosion-proof hole communicating with the receiving cavity; The explosion-proof valve seals the explosion-proof hole; The plate member is arranged in the receiving cavity, and is provided with an exhaust hole corresponding to the explosion-proof valve, the plate member has an annular groove opened on a side of the plate member facing the explosion-proof valve; The connecting member is arranged on the side of the plate member facing the explosion-proof valve and connected to the plate member, the connecting member, the explosion-proof valve and the side wall are all welded to each other, and at least part of the connecting member is located in the annular groove; The outer side surface of the explosion-proof valve is flush with the outer side surface of the side wall. The annular groove surrounds the exhaust hole.

2. The cell according to claim 1, wherein The connecting member is located in the annular groove, and has a connecting surface attached to at least part of the side wall and the plate member.

3. The cell according to claim 2, wherein The connecting member comprises a first body and a first step portion, at least part of the side wall is connected to the first body, the first step portion is connected to the first body and protrudes towards the explosion-proof valve relative to the first body, and the first step portion is connected to the explosion-proof valve; or 4. The cell according to claim 2, wherein The connecting member comprises a second body and a second step portion, at least part of the explosion-proof valve is connected to the second body, the second step portion is connected to the second body and protrudes towards the side wall relative to the second body, and the second step portion is connected to the side wall. The side wall has a first surface away from the plate member, the explosion-proof valve has a second surface away from the plate member, and the first surface and the second surface are flush.

5. The cell according to any one of claims 1 to 4, wherein The connecting piece, the explosion-proof valve and the side wall welded on the connecting piece form a penetration depth of A mm, and the maximum dimension of the connecting piece in a first direction is B mm, satisfying: , wherein the first direction is the thickness direction of the side wall.

6. The cell according to claim 1, wherein In a first direction, the maximum size of the connecting member is B mm, and the maximum size of the side wall is C mm, and the single battery satisfies at least one of the following characteristics:

7. The cell according to claim 1, wherein The plate member has a plurality of through holes arranged on both sides of the connecting member in a second direction, and the through holes are arranged at intervals, and the second direction is the length direction of the plate member. 0.3≤B≤0.5； 0.1≤C≤0.6。 8. The cell according to claim 1, wherein The plate member is an injection molded part; and / or 9. The cell of claim 1 wherein, The connecting member is a metal member. The single battery comprises any one of claims 1 to 9.

10. A battery pack, characterized by, ​

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