Single battery and battery pack

Abstract

The invention discloses a single battery and a battery pack, and belongs to the technical field of batteries, and the single battery comprises a shell, an anti-explosion valve, a plate and a connecting piece, the shell comprises a plurality of side walls, the side walls are connected with one another and define a containing cavity, and at least one side wall is provided with an anti-explosion hole communicating with the containing cavity. The explosion-proof valve seals the explosion-proof hole; the plate is arranged in the containing cavity, the plate is provided with the exhaust hole corresponding to the anti-explosion valve, it can be ensured that the anti-explosion valve communicates with the containing cavity to form an exhaust channel, and the risk of thermal runaway is reduced. The connecting piece is arranged on the side, facing the anti-explosion valve, of the plate and connected with the plate, and the connecting piece, the anti-explosion valve and the side wall are connected in a welded mode. By arranging the plate and the connecting piece, effective welding of the anti-explosion valve and the side wall can be ensured while the thickness of the side wall is reduced, the anti-explosion valve is prevented from scraping the electrode assembly, the connecting piece is arranged on the side, facing the anti-explosion valve, of the plate, welding slag generated by welding can be prevented from falling into the containing cavity, and therefore the safety and reliability of the single battery can be effectively improved.

Description

Technical Field

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

[0002] With the continuous development of technology, users have higher and higher requirements for new energy batteries. In order to improve the safety performance of battery cells, explosion-proof valves are usually installed on battery cells. When the battery cell operates abnormally and produces gas inside, the gas can be discharged through the explosion-proof valve to avoid major safety accidents.

[0003] In order to maximize the capacity of the battery cell and the safety of the battery pack, the shell is usually thinned to increase the internal space of the battery cell, and the explosion-proof valve is adjusted from the cover plate to the side wall of the shell to achieve the effect of thermal and electrical separation. At present, welding the explosion-proof valve on the side wall of the shell requires that the shell has sufficient wall thickness to form a step to install the explosion-proof valve, resulting in an increase in the shell wall thickness; or, the shell is formed outwardly to form a bulge to form a mounting hole to install the explosion-proof valve, resulting in the shell occupying external space and increasing the risk of bottom ball hit. Summary of the invention

[0004] Purpose of the invention: An embodiment of the present application provides a single cell battery, aiming to solve the technical problem of increased risk of bottom ball hitting caused by excessive shell wall thickness or shell protrusion occupying external space; another purpose of the embodiment of the present application is to provide a battery pack.

[0005] Technical solution: The present application embodiment provides a single battery, including:

[0006] The shell comprises a plurality of side walls, the plurality of side walls are connected to each other and enclose a receiving cavity, and at least one side wall is provided with an explosion-proof hole communicating with the receiving cavity;

[0007] Explosion-proof valve, sealing explosion-proof hole;

[0008] A plate is arranged in the accommodating cavity, and the plate is provided with an exhaust hole corresponding to the explosion-proof valve;

[0009] The connecting piece is arranged on a side of the plate member facing the explosion-proof valve and is connected to the plate member. The connecting piece, the explosion-proof valve and the side wall are connected by welding.

[0010] In some embodiments, the plate has an annular groove, which is arranged around the exhaust hole. The annular groove is opened on a side of the plate facing the explosion-proof valve, and at least a part of the connector is located in the annular groove.

[0011] In some embodiments, the connecting member is located in the annular groove, and the connecting member has a connecting surface, and the connecting surface is attached to at least a portion of the side wall and the plate.

[0012] In some embodiments, the connecting member includes a first body and a first step portion, the side wall is connected to at least a portion of the first body, the first step portion is connected to the first body and protrudes toward the explosion-proof valve relative to the first body, and the first step portion is connected to the explosion-proof valve.

[0013] In some embodiments, the connecting piece includes a second body and a second step portion, the explosion-proof valve is connected to at least a portion of the second body, the second step portion is connected to the second body and protrudes toward the side wall relative to the second body, and the second step portion is connected to the side wall.

[0014] In some embodiments, the depth of penetration formed by welding the connector, explosion-proof valve and side wall on the connector is A mm, the maximum dimension of the connector in the first direction is B mm, and it satisfies: 1 / 3≤A / B≤1, and the first direction is the thickness direction of the side wall.

[0015] In some embodiments, the side wall has a first surface away from the plate, the explosion-proof valve has a second surface away from the plate, and the first surface and the second surface are flush.

[0016] In some embodiments, in the first direction, the maximum dimension of the connector is B mm, the maximum dimension of the side wall is C mm, and the single battery meets 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, the plurality of through holes are disposed on both sides of the connecting member along the second direction, and the plurality of through holes are disposed at intervals, and the second direction is the length direction of the plate.

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

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

[0022] Accordingly, an embodiment of the present application provides a battery pack, comprising the above-mentioned single battery.

[0023] Beneficial effects: The single cell of the embodiment of the present application includes a shell, an explosion-proof valve, a plate and a connector. The shell includes a plurality of side walls, which are interconnected and enclose a receiving chamber, and at least one side wall is provided with an explosion-proof hole connected to the receiving chamber; the explosion-proof valve seals the explosion-proof hole; the plate is arranged in the receiving chamber, and the plate is provided with an exhaust hole corresponding to the explosion-proof valve, which can ensure that the explosion-proof valve is connected to the receiving chamber to form an exhaust channel, thereby reducing the risk of thermal runaway. The connector is arranged on the side of the plate facing the explosion-proof valve and connected to the plate, and the connector, the explosion-proof valve and the side wall are welded. By arranging the plate and the connector, the effective welding of the explosion-proof valve and the side wall can be ensured while the thickness of the side wall is thinned, so as to prevent the explosion-proof valve from contacting or even scratching the electrode assembly inside the single cell to affect the safety of the single cell, and the connector is arranged on the side of the plate facing the explosion-proof valve to prevent welding slag from falling into the receiving chamber, thereby effectively improving the safety and reliability of the single cell.

[0024] 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. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. 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.

[0026] Figure 1 is a schematic structural diagram of a single cell according to an embodiment of the present application;

[0027] Figure 2 is a schematic structural diagram of a single cell according to another embodiment of the present application;

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

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

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

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

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

[0033] Figure numerals: 1, shell; 2, explosion-proof valve; 3, plate; 4, connecting piece; 10, side wall; 11, accommodating chamber; 12, explosion-proof hole; 20, second surface; 30, exhaust hole; 31, annular groove; 32, through hole; 40, connecting surface; 41, first body; 42, first step portion; 43, second body; 44, second step portion; 100, first surface; X, first direction; Y, second direction. DETAILED DESCRIPTION

[0034] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0035] 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 positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying 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. Thus, 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.

[0036] The applicant has noticed that with the continuous development of technology, users have higher and higher requirements for new energy batteries. In order to improve the safety performance of battery cells, explosion-proof valves are usually installed on battery cells. When the battery cell operates abnormally and generates gas inside, the gas can be discharged through the explosion-proof valve to avoid major safety accidents. In order to maximize the capacity of the battery cell and the safety of the battery pack, it is usually necessary to thin the shell to increase the internal space of the battery cell, and adjust the explosion-proof valve from the cover plate to the side wall of the shell to achieve the effect of thermal and electrical separation. At present, welding an explosion-proof valve on the side wall of the shell requires that the shell have sufficient wall thickness to form a step to install the explosion-proof valve, resulting in an increase in the wall thickness of the shell; or, the shell forms a bulge outward to form a mounting hole to install the explosion-proof valve, resulting in the shell occupying external space and increasing the risk of bottom ball hits.

[0037] In view of this, an embodiment of the present application provides a single cell battery, including a shell, an explosion-proof valve, a plate and a connector. The shell includes a plurality of side walls, which are interconnected and enclose a receiving chamber, and at least one side wall is provided with an explosion-proof hole connected to the receiving chamber; the explosion-proof valve seals the explosion-proof hole; the plate is arranged in the receiving chamber, and the plate is provided with an exhaust hole corresponding to the explosion-proof valve, which can ensure that the explosion-proof valve is connected to the receiving chamber to form an exhaust channel and reduce the risk of thermal runaway. The connector is arranged on the side of the plate facing the explosion-proof valve and is connected to the plate, and the connector, the explosion-proof valve and the side wall are welded. By arranging the plate and the connector, the effective welding of the explosion-proof valve and the side wall can be ensured while the thickness of the side wall is thinned, and the connector is arranged on the side of the plate facing the explosion-proof valve to prevent welding slag from falling into the receiving chamber, thereby effectively improving the safety and reliability of the single cell battery.

[0038] The single cell and battery pack of the present application are described in detail below in conjunction with the accompanying drawings. The features of the following embodiments and implementations can be combined with each other if there is no conflict.

[0039] Figure 1 is a schematic structural diagram of a single cell according to an embodiment of the present application; Figure 2 is a schematic structural diagram of a single cell according to another embodiment of the present application; Figure 3 It is a structural schematic diagram of a plate 3 and a connecting member 4 according to an embodiment of the present application; Figure 4 is a partial cross-sectional view of a single cell according to the first embodiment of the present application;

[0040] Figure 5 is a partial cross-sectional view of a single cell according to the second embodiment of the present application; Figure 6 is a partial cross-sectional view of a single cell according to the third embodiment of the present application; Figure 7 It is a partial cross-sectional view of a single cell according to the fourth embodiment of the present application.

[0041] refer to Figures 1 to 7The embodiment of the present application provides a single cell battery, including a shell 1, an explosion-proof valve 2, a plate 3 and a connector 4. The shell 1 includes a plurality of side walls 10, which are interconnected to form a receiving chamber 11, and at least one side wall 10 is provided with an explosion-proof hole 12 connected to the receiving chamber 11. The explosion-proof valve 2 seals the explosion-proof hole 12. The explosion-proof valve 2 includes a load-bearing portion and a weak portion connected to each other, the load-bearing portion is arranged around the weak portion, and the weak portion is configured to be destroyed when subjected to a preset pressure shock, thereby forming an exhaust channel to avoid dangerous situations such as explosion of the battery due to excessive internal pressure, and plays a key role in safety protection. The explosion-proof valve 2 is arranged on the side wall 10 of the shell 1, which can achieve the effect of thermal and electrical separation, and can prevent the heat accumulation inside the battery from affecting electrical components such as poles and cells, reduce the risk of faults such as electrical short circuits caused by overheating, and enhance the safety and stability of the single cell battery.

[0042] The plate 3 is arranged in the accommodating chamber 11, and the plate 3 is provided with an exhaust hole 30 corresponding to the explosion-proof valve 2, which can ensure that the explosion-proof valve 2 is connected to the accommodating chamber 11 to form an exhaust channel to reduce the risk of thermal runaway. The connector 4 is arranged on the side of the plate 3 facing the explosion-proof valve 2 and is connected to the plate 3. The connector 4, the explosion-proof valve 2 and the side wall 10 are welded and connected. By arranging the plate 3 and the connector 4, the effective welding of the explosion-proof valve 2 and the side wall 10 can be ensured while the thickness of the side wall 10 is thinned, and the explosion-proof valve 2 is prevented from contacting or even scratching the electrode assembly inside the single cell to affect the safety of the single cell. The connector 4 is arranged on the side of the plate 3 facing the explosion-proof valve 2 to prevent welding slag from falling into the accommodating chamber 11, thereby effectively improving the safety and reliability of the single cell.

[0043] In some embodiments, the plate 3 is an injection molded part, and the connector 4 is a metal part. For example, the material of the connector 4 can be a material with high strength such as aluminum or steel. The plate 3 is injection molded and the connector 4 is embedded in the annular groove of the plate 3. The plastic material has the characteristics of relatively low cost, easy processing and molding, low density, and overall light weight. The plate 3 is arranged on the side of the connector 4 away from the explosion-proof valve 2, which can prevent the welding slag generated by welding from falling into the accommodating cavity 11 during welding, thereby effectively improving the safety of the single battery.

[0044] exist Figure 1 and Figure 2In the illustrated embodiment, the housing 1 is formed by enclosing four side walls 10, and the thickness of the four side walls 10 can be the same or can be designed differently according to the needs. For example, an explosion-proof hole 12 is formed on a narrower side wall 10 by punching or machining to locate the position of the explosion-proof valve 2. The explosion-proof valve 2 is inserted into the explosion-proof hole 12 to abut against the plate 3 and the connecting member 4 provided in the accommodating chamber 11. The explosion-proof valve 2, the side wall 10 and the connecting member 4 are connected by welding to complete the fixing and sealing of the explosion-proof valve 2. With such a configuration, there is no need to increase the thickness of the side wall 10 provided with the explosion-proof valve 2, thereby ensuring the effective welding of the explosion-proof valve 2 and the side wall 10.

[0045] exist Figure 3 In the illustrated embodiment, the plate 3 has an annular groove 31, which is arranged around the exhaust hole 30, and the annular groove 31 is opened on the side of the plate 3 facing the explosion-proof valve 2, and at least part of the connector 4 is located in the annular groove 31. The connector 4 is an annular structure, and the connector 4 is embedded in the annular groove 31 to cooperate with the annular groove 31 in the first direction X. The first direction X is the thickness direction of the side wall 10. Such a configuration can reduce space occupation and effectively improve energy density.

[0046] exist Figures 1 to 7 In the illustrated embodiment, the side wall 10 has a first surface 100 away from the plate 3, the explosion-proof valve 2 has a second surface 20 away from the plate 3, and the first surface 100 is flush with the second surface 20. In the present application, the plate 3 and the connector 4 are provided to position the explosion-proof valve 2, and there is no need to provide a step on the side wall 10 to limit the explosion-proof valve 2. The outer side surface of the explosion-proof valve 2 is provided flush with the outer side surface of the side wall 10, and there is no need to occupy the external space of the housing 1, which can reduce the risk of collision and impact of the single battery.

[0047] In some embodiments, a battery pack bottom ball impact test is generally used to simulate the situation where the bottom of the battery pack is hit by foreign objects in actual road conditions, as a method for testing the safety performance of the battery pack. During the test, a ball hitting head or an impact head is used as an impact object to impact the bottom of the battery pack at a certain speed and angle. This impact process can simulate the impact force that the bottom of the battery pack may be subjected to when the vehicle encounters obstacles such as speed bumps and stones during driving. In the bottom ball impact test, the flush arrangement of the first surface 100 and the second surface 20 can effectively reduce the risk of damage caused by impact due to external protruding structures, thereby improving the safety and reliability of the battery in various complex environments.

[0048] exist Figures 4 to 6In the illustrated embodiment, in the first direction X, the maximum dimension of the side wall 10 is C mm, satisfying: 0.1≤C≤0.6. Exemplarily, the maximum dimension C of the side wall 10 in the first direction X can be any value among 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 of values ​​between any two of them. The material of the housing 1 can be a material with high strength such as aluminum or steel.

[0049] In some embodiments, the shell 1 may be made of aluminum. The shell 1 made of aluminum has the characteristics of light weight and high strength, which can better protect the internal components of the battery and has good thermal conductivity, which is beneficial to the heat dissipation of the battery during operation. For example, the thickness of the thin-walled aluminum shell may be between 0.3 mm and 0.6 mm, which is not limited in this application.

[0050] In other embodiments, the shell 1 may be made of steel. The shell 1 made of steel has high strength, is durable, and can withstand large external impacts and internal pressures. In addition, steel has good corrosion resistance, which can ensure that the shell 1 is not corroded during long-term use of the battery. For example, the thickness of the thin-walled steel shell may be between 0.1 mm and 0.3 mm, which is not limited in this application.

[0051] exist Figure 4 In the illustrated embodiment, in the first direction X, when the maximum dimension B of the side wall 10 is the same as the thickness of the explosion-proof valve 2, the connector 4 is located in the annular groove 31, and the connector 4 has a connecting surface 40, which is attached to at least a portion of the side wall 10 and the plate 3. In this way, the surfaces of the plate 3 and the connector 4 facing the explosion-proof valve 2 and the side wall 10 are arranged flush, which can increase 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.

[0052] exist Figure 5 In the illustrated embodiment, in the first direction X, when the maximum dimension B of the side wall 10 is greater than the thickness of the explosion-proof valve 2, the connector 4 includes a first body 41 and a first step portion 42, the side wall 10 is connected to at least part of the first body 41, the first step portion 42 is connected to the first body 41, and is protruded relative to the first body 41 toward the explosion-proof valve 2, and the first step portion 42 is connected to the explosion-proof valve 2. The first step portion 42 can be provided to adapt to the situation where the side wall 10 is larger in size, and the first step portion 42 is respectively connected to the explosion-proof valve 2 and the side wall 10 to adapt to the height difference between the side wall 10 and the explosion-proof valve 2. With such a configuration, the explosion-proof valve 2 can be positioned and fixed more accurately.

[0053] exist Figure 6In the illustrated embodiment, in the first direction X, when the maximum dimension B of the side wall 10 is smaller than the thickness of the explosion-proof valve 2, the connector 4 includes a second body 43 and a second step portion 44, the explosion-proof valve 2 is connected to at least part of the second body 43, the second step portion 44 is connected to the second body 43, and is protruded relative to the second body 43 toward the side wall 10, and the second step portion 44 is connected to the side wall 10. The second step portion 44 can be provided to adapt to the situation where the side wall 10 is smaller in size, and the second step portion 44 is respectively connected to the explosion-proof valve 2 and the side wall 10 to adapt to the height difference between the side wall 10 and the explosion-proof valve 2. With such a configuration, the explosion-proof valve 2 can be positioned and fixed more accurately.

[0054] exist Figure 7 In the illustrated embodiment, the depth of penetration formed by the connection member 4, the explosion-proof valve 2 and the side wall 10 welded on the connection member 4 is A mm, and in the first direction X, the maximum size of the connection member 4 is B mm, satisfying: 1 / 3≤A / B≤1. The connection member 4, the explosion-proof valve 2 and the side wall 10 are welded to form a weld mark, and the depth of penetration formed by the weld mark on the connection member 4 is A. If the ratio of A / B is too small, the weld may not meet the tensile requirements, resulting in a loose connection between the explosion-proof valve 2 and the connection member 4, which may be loose or detached when subjected to internal pressure shock, and further resulting in the explosion-proof valve 2 may not be able to break in time when needed, thereby increasing the risk of fire and explosion of the single battery. If the ratio of A / B is too large, the connection member 4 may be welded through, which may cause thermal impact on the plate 3, causing the plate 3 to deform or melt. The present application limits the ratio of the penetration depth A formed by welding the connector 4, the explosion-proof valve 2 and the side wall 10 on the connector 4 to the maximum size B of the connector 4, so as to ensure the connection stability between the explosion-proof valve 2 and the connector 4 while avoiding welding through the connector 4 and affecting the strength of the plate 3 fitted with the connector 4, thereby improving the safety and reliability of the single battery.

[0055] exist Figures 4 to 6In the illustrated embodiment, in the first direction X, the maximum dimension of the connector 4 is B mm, satisfying: 0.3≤B≤0.5. Exemplarily, the maximum dimension B of the connector 4 in the first direction X may be any value among 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 value between any two of them. If the maximum dimension B of the connector 4 is too small, the connector 4 may not have enough depth to be welded with the explosion-proof valve 2 and the side wall 10, and there is a risk of the connector 4 and the plate 3 falling off. If the maximum dimension B of the connector 4 is too large, the connector 4 may occupy too much space inside the accommodating cavity 11, affecting the energy density of the single battery. By limiting the maximum size B of the connector 4, it is prevented that the maximum size B of the connector 4 is too large and occupies too much internal space of the accommodating cavity 11, thereby reducing the adverse effect on the energy density of the single cell, which helps to achieve a more compact design while ensuring the performance of the single cell. It can also avoid the problem of insufficient welding depth caused by the maximum size B of the connector 4 being too small, reduce the risk of the connector 4 and the plate 3 falling off, ensure that the explosion-proof valve 2 is firmly connected to the side wall 10, and improve the stability and safety of the overall structure of the single cell.

[0056] In the embodiment of the present application, the welding strength of the side wall 10, the explosion-proof valve 2 and the connector 4 is tested by a pressure test. The testing method is as follows: randomly select a test sample of a single cell, and use a blasting device to inflate and pressurize the accommodating cavity 11. When the internal pressure of the accommodating cavity 11 exceeds the welding strength, cracking will occur, and the internal pressure of the sealed cavity will be released. According to the pressure value applied by the blasting device, it can be determined whether the welding strength of the side wall 10, the explosion-proof valve 2 and the connector 4 meets the requirement of a pressure resistance greater than 0.4MPa, where OK means that the welding strength of the explosion-proof valve 2 and the connector 4 meets the requirement, and NG means 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.

[0057] Table 1:

[0058]

[0059]

[0060]

[0061] Referring to Comparative Examples 1 and 2, when the penetration depth A formed by welding on the connector 4 exceeds the maximum dimension B of the connector 4 in the first direction X, so that A / B>1, the welding penetrates the connector 4 and is embedded in the plate 3. In the embodiment of the present application, the plate 3 may be an injection molded part, and there is a risk of melting the plastic when affected by heat, thereby affecting the strength of the plate 3 and failing to meet the design requirements.

[0062] Referring to Comparative Examples 3 and 4, when the penetration depth A formed by welding on the connector 4 is too small, so that A / B < 1 / 3, the weld cannot meet the requirement of tensile resistance of 0.4 MPa. It is understandable that when the welding strength of the explosion-proof valve 2 and the connector 4 does not meet the requirements, the connection between the explosion-proof valve 2 and the connector 4 will be loose, and there may be a risk of loosening or detachment when subjected to internal pressure shock, which may cause the explosion-proof valve 2 to fail to rupture in time when needed, thereby increasing the risk of fire and explosion of the single battery.

[0063] With reference 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 side wall 10 in the first direction X, and the penetration A formed by welding 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 the plastic due to welding through the connector 4 can be avoided, thereby ensuring effective welding of the connector 4, the explosion-proof valve 2, and the side wall 10.

[0064] exist Figure 3 In the illustrated embodiment, the plate 3 has a plurality of through holes 32, which are arranged on both sides of the connecting member 4 along the second direction Y, and the plurality of through holes 32 are arranged at intervals, and the second direction Y is the length direction of the plate 3. The second direction Y is perpendicular to the first direction X, and the plurality of through holes 32 are arranged at intervals on the plate 3, which can reduce the materials required for manufacturing the plate 3 and reduce the production cost while ensuring the structural stability of the plate 3.

[0065] Accordingly, an embodiment of the present application provides a battery pack, including the above-mentioned single cell. The single cell of the embodiment of the present application includes a shell 1, an explosion-proof valve 2, a plate 3 and a connector 4. The shell 1 includes a plurality of side walls 10, which are interconnected and enclose a receiving chamber 11, and at least one side wall 10 is provided with an explosion-proof hole 12 connected to the receiving chamber 11; the explosion-proof valve 2 seals the explosion-proof hole 12; the plate 3 is arranged in the receiving chamber 11, and the plate 3 is provided with an exhaust hole 30 corresponding to the explosion-proof valve 2, which can ensure that the explosion-proof valve 2 is connected to the receiving chamber 11 to form an exhaust channel to reduce the risk of thermal runaway. The connector 4 is arranged on the side of the plate 3 facing the explosion-proof valve 2, and is connected to the plate 3, and the connector 4, the explosion-proof valve 2 and the side wall 10 are welded. By providing the plate 3 and the connector 4, the thickness of the side wall 10 can be reduced while ensuring effective welding of the explosion-proof valve 2 and the side wall 10, preventing the explosion-proof valve 2 from contacting or even scratching the electrode assembly inside the single cell and affecting the safety of the single cell. The connector 4 is provided on the side of the plate 3 facing the explosion-proof valve 2 to prevent welding slag from falling into the accommodating cavity 11, thereby effectively improving the safety and reliability of the single cell.

[0066] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0067] The above is a detailed introduction to a single cell and a battery pack provided in the embodiments of the present application, and the principles and implementation methods of the present application are explained by applying specific examples. The description of the above embodiments is only used to help understand the technical solution and its core idea 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 replace some of the technical features therein with equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A single cell battery, characterized in that: include: The shell comprises a plurality of side walls, the plurality of side walls are connected to each other and enclose a receiving cavity, and at least one of the side walls is provided with an explosion-proof hole communicating with the receiving cavity; An explosion-proof valve, sealing the explosion-proof hole; A plate, disposed in the accommodating cavity, the plate being provided with an exhaust hole corresponding to the explosion-proof valve; A connecting piece is arranged on a side of the plate member facing the explosion-proof valve and connected to the plate member. The connecting piece, the explosion-proof valve and the side wall are connected by welding.

2. The single cell according to claim 1, characterized in that: The plate has an annular groove, which is arranged around the exhaust hole. The annular groove is opened on a side of the plate facing the explosion-proof valve, and at least a part of the connecting member is located in the annular groove.

3. The single cell according to claim 2, characterized in that: The connecting member is located in the annular groove, and the connecting member has a connecting surface, and the connecting surface is attached to at least a portion of the side wall and the plate.

4. The single cell according to claim 2, characterized in that: The connecting member includes a first body and a first step portion, the side wall is connected to at least a portion of the first body, the first step portion is connected to the first body and is protruded relative to the first body toward the explosion-proof valve, and the first step portion is connected to the explosion-proof valve; or The connecting member includes a second body and a second step portion, the explosion-proof valve is connected to at least a portion of the second body, the second step portion is connected to the second body and protrudes toward the side wall relative to the second body, and the second step portion is connected to the side wall.

5. The single cell according to any one of claims 1 to 4, characterized in that: The depth of penetration formed by welding the connecting piece, the explosion-proof valve and the side wall on the connecting piece is A mm, the maximum dimension of the connecting piece in the first direction is B mm, and the following conditions are satisfied: 1 / 3≤A / B≤1, and the first direction is the thickness direction of the side wall.

6. The single cell according to claim 1, characterized in that: The side wall has a first surface away from the plate, the explosion-proof valve has a second surface away from the plate, and the first surface is flush with the second surface.

7. The single cell according to claim 1, characterized in that: In the first direction, the maximum dimension of the connector is B mm, the maximum dimension of the side wall is C mm, and the single battery meets at least one of the following characteristics: 0.3≤B≤0.5； 0.1≤C≤0.6。 8. The single cell according to claim 1, characterized in that: The plate has a plurality of through holes, the plurality of through holes are arranged on both sides of the connecting member along a second direction, and the plurality of through holes are arranged at intervals, and the second direction is the length direction of the plate.

9. The single cell according to claim 1, characterized in that: The panel is an injection molded part; and / or The connecting piece is a metal piece.

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

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