Battery monomer and shell and shell bottom structure thereof

Abstract

The utility model relates to a battery monomer, a shell of the battery monomer and a shell bottom structure. The shell bottom structure of the single battery comprises a flat plate part and at least one welding part upwards protruding out of the flat plate part, the upper end face of each welding part is higher than the upper plate face of the flat plate part and forms a welding face used for being connected with the negative electrode lug or the positive electrode lug in a welded mode, and an anti-explosion structure is arranged on the flat plate part. According to the utility model, the welding part and the explosion-proof structure are arranged on the bottom structure of the battery shell, and the welding part is directly welded with the tabs, so that a confluence plate is saved, and the manufacturing cost of the single battery is reduced; when the pressure intensity in the shell is increased, the end part of the shell gradually protrudes outwards along with the increase of the pressure intensity, and when the pressure intensity reaches the withstand pressure intensity of the explosion-proof structure, the explosion-proof structure is broken through, and the pressure in the shell is released, so that the phenomenon that the electrolyte is sprayed out due to overhigh pressure intensity in the shell is avoided, and the safety of the battery is improved. The explosion-proof structure adopts the explosion-proof nick, a series of operations such as explosion-proof sheet welding and detection are not needed, and the production cost is reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of batteries, and particularly relates to a battery cell, its housing, and the bottom structure of the housing. Background Art

[0002] Batteries are widely used in various products such as digital cameras, computers, mobile phones, etc. In the prior art, a battery generally includes a battery housing, a battery top cover, a battery cell, a negative current collector plate, and a positive current collector plate. The battery housing includes a bottom structure and a housing body. The battery cell, the negative current collector plate, and the positive current collector plate are arranged inside the battery housing. The negative electrode tab of the battery cell is welded to the negative current collector plate (or negative transfer sheet), and the positive electrode tab of the battery cell is welded to the positive current collector plate (or positive transfer sheet). When the materials of the battery housing are different, the bottom structure is welded to different current collector plates. For example, when the battery housing is an aluminum shell, the bottom structure is welded to the positive current collector plate (such as the cylindrical battery in the Chinese utility model patent with the authorization announcement number CN220856711U and the authorization announcement date of April 26, 2024); when the battery housing is a steel shell, the bottom structure is welded to the negative current collector plate.

[0003] The battery housing can be a cylindrical housing. For example, the cylindrical battery in the Chinese utility model patent with the authorization announcement number CN220856711U mentioned above. In the cylindrical battery, the bottom structure is a circular cover; the battery housing can also be a regular prismatic housing. For example, the regular prismatic battery disclosed in the Chinese utility model patent with the authorization announcement number CN217134494U and the authorization announcement date of August 5, 2022. In the regular prismatic battery, the bottom structure is a regular polygon cover, and the negative electrode tab of the battery cell is directly led out from the top of the battery cell and connected to the negative terminal, and the positive electrode tab of the battery cell is led out from the bottom of the battery cell and connected to the positive terminal through the battery housing. The positive terminal and the negative terminal are used to connect to the electrical equipment. Since when electrically connecting the bottom structure and the corresponding electrode tab, it is necessary to first weld the corresponding electrode tab to the corresponding current collector plate, and then weld the corresponding current collector plate to the bottom structure, a total of two welds are required, resulting in a low welding yield of the battery.

[0004] In addition, since the battery has a high chemical energy, once a short circuit occurs inside the battery, the pressure of the gas inside the battery housing will rise sharply in a short time, making the battery at risk of explosion. When the battery explodes, the housing of the battery cell will be broken through, and the corrosive electrolyte inside the battery will spray outwards, thus corroding other parts. Summary of the Utility Model

[0005] The purpose of the present utility model is to provide a battery cell, its housing, and the bottom structure of the housing. By providing a welding portion at the bottom of the housing in the present utility model, the tab is directly connected to the welding portion, saving the bottom bus bar and reducing the manufacturing cost of the battery. By providing an explosion-proof notch at the bottom of the housing, a series of operations such as welding and detecting an explosion-proof sheet are not required, reducing the assembly process, simplifying the production process, reducing the production cost, reducing the risk of liquid leakage, and improving the stability of explosion-proof pressure relief of the battery.

[0006] To achieve the above object, the technical solution of the bottom structure of the housing of the battery cell provided by the present utility model is:

[0007] A bottom structure of the housing of a battery cell, including a flat plate portion and at least one welding portion protruding upward from the flat plate portion. The upper end surfaces of the welding portions are all higher than the upper plate surface of the flat plate portion and form welding surfaces for welding and connecting with a negative tab or a positive tab. An explosion-proof notch is provided on the flat plate portion.

[0008] Further, the bottom of the housing is circular, and there are at least two welding portions, and the welding portions are evenly distributed at intervals on the same circumference with the center of the bottom of the housing as the center of the circle.

[0009] Further, the bottom of the housing is a regular polygon, and there are at least two welding portions, and the welding portions are evenly distributed at intervals on the same circumference with the center of the bottom structure as the center of the circle.

[0010] Further, the welding portion is in a straight strip shape, and the welding portion extends along the radial direction of the bottom of the housing.

[0011] Further, the welding portion is in a curved strip shape, and the welding portion includes a straight line segment and an arc segment. The straight line segment extends along the radial direction of the bottom of the housing, and the arc segment is located at one end of the straight line segment close to the center of the bottom of the housing.

[0012] Further, the explosion-proof structure is at least one of an explosion-proof sheet and an explosion-proof notch.

[0013] Further, the explosion-proof structure is an explosion-proof notch, the explosion-proof notch is in a superior arc shape or a circular shape, the central angle corresponding to the superior arc-shaped explosion-proof notch is not less than 180°, and all the welding portions are located inside the circle where the explosion-proof notch is located.

[0014] Further, the cross-sectional shape of the explosion-proof notch is at least one of a trapezoid, a triangle, a semi-circle, and a square.

[0015] The technical solution of the housing of the battery cell provided by the present utility model is:

[0016] A housing of a battery cell, including a body and a bottom structure of the housing located at the bottom of the body. The bottom structure of the housing is the bottom structure of the housing in the technical solution of the bottom structure of the housing of the above battery cell.

[0017] The technical solution of the battery cell provided by the present utility model is as follows:

[0018] A battery cell includes a battery housing and an electrode core installed in the battery housing. The negative electrode tab or the positive electrode tab of the electrode core is directly welded to the bottom structure of the battery housing, and the battery housing is the battery housing in the above technical solution of the battery housing.

[0019] The present utility model provides a battery cell, its housing, and the bottom structure of the housing. Compared with the prior art, the beneficial effects are as follows:

[0020] By providing a welding part on the bottom structure of the battery housing in the present utility model, the tab is directly connected to the welding part, saving the bottom bus bar and reducing the manufacturing cost of the battery. By providing an explosion-proof structure on the bottom structure of the battery housing in the present utility model, when the pressure inside the housing increases, the end of the housing gradually protrudes outwards with the increase of the pressure. When the pressure reaches the tolerance pressure of the explosion-proof structure, the explosion-proof structure is broken through, and the internal pressure of the housing is relieved, avoiding the phenomenon that the electrolyte sprays out due to too high pressure inside the housing and increasing the battery safety. In addition, by using an explosion-proof notch in the structure, a series of operations such as welding and detecting the explosion-proof sheet are not required, reducing the assembly process, simplifying the production process, reducing the production cost, reducing the risk of liquid leakage, and improving the stability of battery explosion-proof pressure relief. Description of the Drawings

[0021] Figure 1 It is a schematic structural view of the bottom structure of the battery cell of the present utility model from an angle in Specific Embodiment 1;

[0022] Figure 2 It is a schematic structural view of the bottom structure of the battery cell of the present utility model from another angle in Specific Embodiment 1;

[0023] Figure 3 It is a bottom view of the bottom structure of the battery cell of the present utility model in Specific Embodiment 1;

[0024] Figure 4 It is Figure 3 the view in the direction of B-B in

[0025] Figure 5 It is Figure 4 the enlarged view of the structure at C in

[0026] Figure 6 It is an exploded view of the structure of the battery housing of the battery cell of the present utility model in Specific Embodiment 1;

[0027] Figure 7 It is a top view of the battery housing of the battery cell of the present utility model in Specific Embodiment 1;

[0028] Figure 8 It isFigure 7 View A-A thereof;

[0029] Figure 9 is Figure 8 Enlarged view of the structure at D in

[0030] Figure 10 Schematic diagram of a bottom structure in Specific Embodiment 2 of the battery cell of the present utility model;

[0031] Figure 11 Schematic diagram of a bottom structure in Specific Embodiment 4 of the battery cell of the present utility model;

[0032] Figure 12 Schematic diagram of another bottom structure in Specific Embodiment 4 of the battery cell of the present utility model;

[0033] Figure 13 Schematic diagram of yet another bottom structure in Specific Embodiment 4 of the battery cell of the present utility model;

[0034] Figure 14 Schematic diagram of the bottom structure in Specific Embodiment 5 of the battery cell of the present utility model.

[0035] Explanation of reference numerals:

[0036] 1. Bottom structure; 2. Welding part; 3. Reinforcing part; 4. Welding reference part; 5. Explosion-proof notch; 6. Assembly step; 61. Support surface; 62. Limiting surface; 7. Shell body; 8. Weld seam; 9. Explosion-proof part. Specific embodiments

[0037] Specific Embodiment 1 of the battery cell provided by the present utility model:

[0038] Referring to Figure 1-9 as shown, the battery cell includes a battery shell and an electric core installed in the battery shell. The battery shell includes a shell body 7 and a bottom structure 1 welded to the shell body 7. The upper end of the battery shell is open, so as to facilitate putting the electric core assembly into the battery shell. After that, the battery shell is hermetically connected to the battery top cover, thereby realizing the sealing of the battery cell; of course, in other specific embodiments, the shell body 7 and the bottom structure 1 may also be integrally formed.

[0039] As Figure 1-4As shown, the bottom structure 1 includes a flat plate portion and at least one welding portion 2 protruding upward from the flat plate portion. The upper end surfaces of the welding portions 2 are all higher than the upper plate surface of the flat plate portion and form welding surfaces for welding connection with the negative electrode tab. The thickness H of each welding portion 2 is less than the thickness h of the flat plate portion. The negative electrode tab of the battery cell is directly welded to the bottom structure 1 of the battery case through the welding surface. Of course, according to different materials of the battery case, in other specific embodiments, the welding surface of the bottom structure 1 can be directly welded to the positive electrode tab of the battery cell.

[0040] Specifically, in Figure 1-3 , there are four welding portions 2. However, in other specific embodiments, as shown in Figure 1-3 , the number of welding portions 2 can be 2, 3 or more.

[0041] In different specific embodiments, the positive terminal and the negative terminal for electrically connecting the battery cell to the electrical device can both be provided on the battery top cover of the battery cell; or, one of the positive terminal and the negative terminal for electrically connecting the battery cell to the electrical device is provided on the battery top cover of the battery cell, and the other is provided on the bottom structure of the battery cell.

[0042] Since the thickness of the welding portion 2 is less than that of the flat plate portion, when welding the welding portion 2 and the negative electrode tab from the bottom of the bottom structure 1, the welding power can be reduced, and the electrode tab of the electrode assembly can be prevented from being welded through; at the same time, the flat plate portion is thicker to ensure the structural strength of the bottom structure 1, and the welding portion 2 protruding upward from the flat plate portion can also enhance the structural strength of the bottom structure 1, thereby preventing the bottom structure 1 from deforming during welding and improving the welding yield and product quality.

[0043] In order to reduce costs, as a specific embodiment, as shown in Figure 1-3 , the bottom structure 1 is formed by stamping a sheet metal, or the bottom structure 1 is formed by cold extrusion processing of a blank metal, or the bottom structure 1 is formed by cold extrusion of a blank metal followed by stamping processing, with relatively low costs. Of course, in other specific embodiments, the bottom structure 1 can also be integrally injection molded.

[0044] In order to increase the total area of the welding surface as much as possible while ensuring the structural strength of the bottom structure 1 and reduce the resistance value at the connection between the negative electrode tab and the welding portion 2, as a specific embodiment, as shown in Figure 1-3As shown, the shape of the bottom structure 1 is a centrally symmetric figure. Specifically, the bottom structure 1 is a circular cover. There are at least two welding parts 2, and each welding part 2 is evenly spaced on the same circumference with the center of the bottom structure as the center of the circle. That is, the welding parts 2 (the weak parts of the bottom structure 1) are evenly spaced on the same circumference, so as to ensure the distance between adjacent welding parts 2, and avoid the situation that the distance between any two welding parts 2 is too close, resulting in the structural strength of a certain point on the bottom structure 1 not meeting the requirements. Thus, while ensuring the structural strength of the bottom structure 1, the total area of the welding surface can be increased as much as possible, that is, the total contact area between the welding surface and the negative electrode tab is increased, thereby reducing the resistance value at the connection between the negative electrode tab and the welding part 2 and improving the performance of the battery.

[0045] Specifically, referring to Figure 1-3 As shown, the welding parts 2 are arranged in pairs and grouped. The two welding parts 2 in each group are centrally symmetrically arranged around the center of the bottom structure 1.

[0046] In order to further increase the total area of the welding surface, as a specific implementation manner, as Figure 1-3 shown, each welding surface includes a straight line segment and an arc segment. The straight line segment extends radially, and the arc segment is located at one end of the straight line segment close to the center of the bottom structure (i.e., the center of the bottom structure circle), so as to increase the area of each welding surface, thereby increasing the total contact area between the welding surface and the negative electrode tab, and further reducing the resistance value at the connection between the negative electrode tab and the welding part 2 and improving the performance of the battery.

[0047] However, in other specific implementation manners, referring to Figure 1-3 shown, each welding surface can also only include a straight line segment, and ensure that there is enough distance at the end of the welding surface close to the center of the bottom structure 1, so as to ensure the structural strength of the bottom structure 1. At this time, the total area of the welding surface is smaller.

[0048] In order to improve production efficiency, as a specific implementation manner, the bottom structure 1 further includes a welding reference part 4 for positioning the welding part 2. The welding reference part 4 protrudes upward from the flat part, and the upper end surface of the welding reference part 4 is lower than the upper end surface of the welding part 2. Specifically, referring to Figure 1-2 , the number of the welding reference parts 4 is four, the number of the welding reference parts 4 is the same as the number of the welding parts 2, and the welding reference part 4 is a protrusion protruding upward from the flat part.

[0049] On the one hand, both the welding reference part 4 and the welding part 2 protrude upward from the flat part, which is convenient for processing and manufacturing the bottom structure 1. At the same time, the welding reference part 4 can also play a role in strengthening the structural strength of the bottom structure 1. On the other hand, by photographing the position of the welding reference part 4 with a camera, the controller can control the welding head of the laser welding equipment to quickly align with the welding surface and start welding from one end of the welding surface close to the edge of the bottom structure 1 until the welding surface is completely welded to the negative electrode tab.

[0050] Of course, in other specific embodiments, the welding reference part 4 may not be provided, and the welding head of the laser welding device can be quickly aligned with the welding surface manually; or, the position of the welding part can be directly detected by a camera, and the controller can control the welding head of the laser welding device to be aligned with the welding surface.

[0051] To avoid deformation of the bottom structure 1 during welding, as a specific embodiment, as Figure 1-3 shown, the bottom structure 1 further includes a reinforcing part 3 for strengthening the structural strength of the bottom structure 1. The reinforcing part 3 protrudes upward from the flat plate part. The upper end surface of the reinforcing part 3 is lower than the welding surface, and the lower end surface of the reinforcing part 3 is higher than the lower plate surface of the flat plate part. The reinforcing part 3 can further increase the structural strength of the bottom structure 1, avoid deformation of the bottom structure 1 during welding, and ensure the welding quality; at the same time, the upper end surface of the reinforcing part 3 is lower than the welding surface, which can prevent the reinforcing part 3 from contacting the negative electrode tab, so as to better weld the negative electrode tab and the welding part 2. Of course, in other specific embodiments, the upper end surface of the reinforcing part 3 can also be flush with the welding surface.

[0052] At this time, the reinforcing part 3, the welding part 2, and the welding reference part 4 all protrude upward from the flat plate part, which is convenient for processing and manufacturing the bottom structure 1.

[0053] However, in other specific embodiments, referring to Figure 1-3 shown, reinforcing ribs can also be provided on the upper plate surface of the flat plate part, or reinforcing ribs can be provided on the lower plate surface of the flat plate part. Compared with the technical solution of providing reinforcing ribs on the lower or upper plate surface of the flat plate part, making the reinforcing part 3 protrude upward from the flat plate part can reduce the weight of the flat plate part, thereby reducing the weight of the battery housing and improving the weight energy density of the battery cell.

[0054] In other specific embodiments, referring to Figure 1-3 shown, when the bottom structure 1 is integrally injection-molded or 3D printed, the lower end surface of the reinforcing part 3 can also be lower than the lower plate surface of the flat plate part. At this time, the reinforcing part 3 protrudes downward from the flat plate part.

[0055] To further improve the battery performance, as Figure 1-3 shown, the reinforcing part 3 is at least two arc-shaped reinforcing ribs, and the arc-shaped reinforcing ribs are evenly distributed on the same circumference with the center of the bottom structure as the center. One end of each welding part 2 and each arc-shaped reinforcing rib are arranged alternately on the same circumference.

[0056] Specifically, as Figure 1-3As shown, the strengthening part 3 is at least a pair of arc-shaped stiffeners evenly distributed at intervals on the same circumference. Each pair of arc-shaped stiffeners is arranged in central symmetry with the center of the bottom structure 1 as the symmetry center. One end of the welding part extends between adjacent two arc-shaped stiffeners, so as to utilize the space between adjacent welding parts to increase the total area of the welding surface and improve the battery performance.

[0057] However, in other embodiments, referring to Figure 1-3 As shown, the strengthening part 3 can also be only one annular stiffener, or the strengthening part 3 is two, three or other numbers of arc-shaped, rectangular or other-shaped stiffeners. In this embodiment, the setting form of the strengthening part 3 is not limited, as long as the strengthening part 3 can strengthen the structural strength of the bottom structure 1.

[0058] However, in other specific embodiments, the strengthening part 3 can be not provided, but the structural strength of the bottom structure 1 can be improved by increasing the thickness of the flat part, so as to avoid deformation of the bottom structure 1 during welding.

[0059] To ensure safety, as a specific embodiment, as Figure 1-5 shown in FIGS. 7-9, explosion-proof indentations 5 are provided on the flat part. The shape of the explosion-proof indentations 5 is at least 2 / 3 of a circle, and all welding surfaces are located inside the circle where the explosion-proof indentations 5 are located. When the internal pressure of the battery is too high, the explosion-proof indentations 5 are opened, so as to release the internal pressure of the battery to the outside. To ensure the total area of the welding surface, the diameter of the explosion-proof indentations 5 is greater than 2 / 3 of the diameter of the bottom structure 1.

[0060] Specifically, as Figure 1-5 shown, the explosion-proof indentations 5 are a complete circle, but in other specific embodiments, the explosion-proof indentations 5 can also be 2 / 3 of a circle or 3 / 4 of a circle. In this embodiment, the specific shape of the explosion-proof indentations 5 is not limited, as long as the explosion-proof indentations 5 can normally play an explosion-proof role.

[0061] In other specific embodiments, the explosion-proof indentations 5 can also not be provided on the bottom structure 1, but an explosion-proof valve can be provided on the battery cover; or, an explosion-proof valve is provided on the battery cover, and explosion-proof indentations 5 are provided on the bottom structure 1. At this time, the explosion-proof indentations 5 are used as a secondary explosion-proof device.

[0062] To further ensure safety, as a specific embodiment, as Figure 1-2As shown, an explosion-proof part 9 is provided at the center of the bottom structure 1. When the bottom structure 1 is a circular cover, the explosion-proof part 9 is arranged at the center of the circle of the bottom structure. The explosion-proof part 9 can specifically be a weak part with a relatively thin thickness, or a circle of explosion-proof notches is provided at the edge of the explosion-proof part 9. When the internal pressure of the battery cell is relatively large, the explosion-proof part 9 is damaged, so that the pressure inside the battery cell leaks to the outside of the battery cell. When the pressure inside the battery cell is relatively large, the wound core (i.e., the wound type battery core) will first deform from the outer periphery, and the middle part of the wound core deforms last. Since the explosion-proof part 9 is arranged at the center of the bottom structure 1, the explosion-proof part 9 is directly opposite to the middle part of the wound core. When the wound core just starts to deform, the explosion-proof part 9 will not be blocked by the deformed wound core, and the explosion-proof performance is good. The explosion-proof part 9 is also a kind of explosion-proof structure on the bottom structure.

[0063] In order to improve the welding yield, as a specific implementation manner, as Figure 5-9 shown, an assembly step 6 for limiting the housing body 7 is provided on the bottom structure 1. The assembly step 6 includes a support surface 61 for supporting the housing body 7 and a limiting surface 62 for limiting cooperation with the inner wall surface of the housing body 7. The position of the housing body 7 is limited by the limiting surface 62 and the support surface 61, and the relative position of the housing body 7 and the bottom structure 1 during welding is fixed, so that a weld seam 8 is formed between the housing body 7 and the area corresponding to the support surface 61 on the bottom structure 1, and the welding yield is improved.

[0064] However, in other specific implementation manners, referring to Figure 5-9 shown, a stop step can also be provided on the housing body 7, so that the outer wall surface of the bottom structure 1 is in limiting cooperation with the inner surface of the housing body 7, and the stop step is in stop cooperation with the upper surface of the bottom structure 1, thereby limiting the relative movement between the housing body 7 and the bottom structure 1 during welding.

[0065] Specific embodiment 2 of the battery cell provided by the present utility model:

[0066] The purpose of this embodiment is to provide a battery cell with a different battery housing structure. The main difference between this embodiment and specific embodiment 1 is that: in specific embodiment 1, the welding part is in a curved strip shape, and in this embodiment, the welding part 2 is in a straight strip shape. There are four welding parts, and the four welding parts are evenly arranged circumferentially around the center of the housing structure. All four welding parts 2 extend radially along the bottom structure of the housing.

[0067] Specific embodiment 3 of the battery cell provided by the present utility model:

[0068] The purpose of this embodiment is to provide a battery cell with a different battery housing structure. The main difference between this embodiment and the specific embodiment 1 is that: in the specific embodiment 1, the battery cell is a cylindrical battery, and in this embodiment, the battery cell is a regular polygonal prism-shaped battery, which is the same as the regular polygonal prism-shaped battery in the authorized publication number CN217134494U.

[0069] The bottom structure 1 is a regular polygon cover, and there are at least two welding parts, and each welding part is evenly distributed at intervals on the same circumference with the center of the bottom structure as the center of the circle, so as to ensure the distance between adjacent welding parts 2, and avoid the structural strength of a certain point on the bottom structure 1 not meeting the requirements due to the proximity of any two welding parts 2. Thus, while ensuring the structural strength of the bottom structure 1, the total area of the welding surface can be increased as much as possible, that is, the total contact area between the welding surface and the negative electrode tab is increased, and further the resistance value at the connection between the negative electrode tab and the welding part 2 is reduced, improving the performance of the battery. Specifically, the shape of the bottom structure can be an equilateral triangle, a square, a regular pentagon, a regular hexagon, etc...

[0070] Preferably, in some specific embodiments, the shape of the bottom structure is a centrally symmetric figure, and the center of the bottom structure is the center of symmetry of the bottom structure. For example, the shape of the bottom structure is a regular hexagon, a regular octagon, etc...

[0071] Specific embodiment 4 of the battery cell provided by the present utility model:

[0072] The purpose of this embodiment is to provide a battery cell with only one welding part. The main difference between this embodiment and the specific embodiment 1 is that: in the specific embodiment 1, there are at least two welding parts, while in this embodiment, there is only one welding part.

[0073] There is only one welding part. In different specific embodiments, as Figure 11 shown, the shape of the welding surface of the welding part 2 can be a circular ring with the center of the bottom structure as the center of the circle; or, as Figure 12 shown, the shape of the welding surface of the welding part 2 is a circle; or, as Figure 13 shown, the shape of the welding surface of the welding part 2 is an ellipse. In this embodiment, the shape of the welding surface is not limited, as long as there is only one welding surface.

[0074] Specific embodiment 5 of the battery cell provided by the present utility model:

[0075] The purpose of this embodiment is to provide a battery cell with a different welding part structure. The main difference between this embodiment and the specific embodiment 1 is that: in the specific embodiment 1, the welding parts are evenly distributed at intervals on the same circumference, while in this embodiment, the welding parts are arranged arbitrarily on the bottom structure 1.

[0076] The welding part 2 may not be arranged in central symmetry. For example, as Figure 14 shown, the welding part 2 only includes a circular welding surface and a rectangular welding surface. At this time, it is necessary to ensure the distance between adjacent welding parts 2.

[0077] Specific embodiment 6 of the battery cell provided by the present utility model:

[0078] The purpose of this embodiment is to provide a battery cell with a different explosion-proof structure. The main difference between this embodiment and specific embodiment 1 is that: an explosion-proof film is provided on the bottom structure in this embodiment, an opening is made on the bottom structure, and an explosion-proof valve is installed in the opening, and no explosion-proof notch is provided. In other embodiments, an explosion-proof valve and an explosion-proof notch may also be provided on the bottom structure at the same time.

[0079] Specific embodiment of the bottom structure of the battery cell housing provided by the present utility model:

[0080] The specific structure of the bottom structure of the housing in this embodiment is the same as the specific structure of the bottom structure in the specific embodiment of the battery cell of the present utility model, and will not be described in detail here.

[0081] Specific embodiment of the battery housing provided by the present utility model:

[0082] The battery housing includes a bottom structure and a housing body adapted to the bottom structure. The specific structure of the battery housing in this embodiment is the same as the specific structure of the battery housing in the specific embodiment of the battery cell of the present utility model, and will not be described in detail here.

[0083] Finally, it should be noted that the above are only the preferred embodiments of the present utility model and are not used to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still make modifications to the technical solutions recorded in the foregoing embodiments without creative labor, or perform equivalent replacements on some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present utility model shall be included in the protection scope of the present utility model.

Claims

1. The bottom structure of the housing of a battery cell, characterized in that, It includes a flat plate portion and at least one welding portion that protrudes upward from the flat plate portion. The upper end surfaces of the welding portions are all higher than the upper end surface of the flat plate portion, forming a welding surface for welding with a negative electrode tab or a positive electrode tab. An explosion-proof structure is provided on the flat plate portion.

2. The bottom structure of the housing of the battery cell according to claim 1, characterized in that The bottom of the housing is circular, and there are at least two welding portions, and the welding portions are evenly distributed at intervals on the same circumference with the center of the bottom of the housing as the center of the circle.

3. The bottom structure of the housing of the battery cell according to claim 1, characterized in that, The bottom of the housing is a regular polygon, and there are at least two welding portions, and the welding portions are evenly distributed at intervals on the same circumference with the center of the bottom structure as the center of the circle.

4. The bottom structure of the housing of the battery cell according to claim 2, characterized in that, The welding portion is in a straight strip shape, and the welding portion extends radially along the bottom of the housing.

5. The bottom structure of the housing of the battery cell according to claim 2, characterized in that, The welding portion is in a curved strip shape, and the welding portion includes a straight line segment and an arc segment. The straight line segment extends radially along the bottom of the housing, and the arc segment is located at one end of the straight line segment close to the center of the bottom of the housing.

6. The bottom structure of the housing of the battery cell according to claim 1, characterized in that The explosion-proof structure is at least one of an explosion-proof film and an explosion-proof notch.

7. The bottom structure of the housing of the battery cell according to claim 6, characterized in that The explosion-proof structure is an explosion-proof notch. The explosion-proof notch is in a superior arc shape or a circular shape. The central angle corresponding to the superior arc-shaped explosion-proof notch is not less than 180°, and all the welding portions are located inside the circle where the explosion-proof notch is located.

8. The bottom structure of the housing of the battery cell according to claim 7, characterized in that, The cross-sectional shape of the explosion-proof notch is at least one of a trapezoid, a triangle, a semi-circle or a square.

9. A housing of a battery cell, comprising a main body and a housing bottom structure located at the bottom of the main body, characterized in that, The bottom structure of the housing is the bottom structure of the housing according to any one of claims 1 to 8.

10. A battery cell includes a housing and an electrode core installed in the battery housing. The negative electrode tab or the positive electrode tab of the electrode core is directly welded to the bottom structure of the battery housing. It is characterized in that, The housing is the housing according to claim 9.

Images