Battery case assembly and battery cell

Abstract

The utility model belongs to the technical field of batteries, and discloses a battery shell assembly and a battery monomer. The battery shell assembly comprises a shell bottom plate, a shell side plate, a first pole and a protruding part. The shell bottom plate comprises a first bottom plate and a second bottom plate which are arranged in sequence; the shell side plate surrounds the periphery of the shell bottom plate and is connected with the shell bottom plate to form a containing cavity, and an opening of the containing cavity and the shell bottom plate are oppositely arranged in the thickness direction of the battery cell; the first pole penetrates through the second bottom plate; the protruding part is arranged on the side, away from the containing cavity, of the second bottom plate and forms a containing groove in the side, facing the containing cavity, of the second bottom plate, and the containing groove communicates with the containing cavity. According to the battery shell assembly, the installation difficulty of the first pole column is reduced, and the electrolyte capacity is large. The single battery comprises a battery cell and the battery shell assembly, the battery cell is located in the containing cavity of the battery shell assembly and connected with the first pole of the battery shell assembly, the single battery is easy to assemble, the capacity of the electrolyte is large, and the energy density of the single battery is large.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, and in particular to a battery casing assembly and a battery cell. Background Technology

[0002] Typically, a battery consists of a casing, battery cells, and terminal blocks, with the battery cells located inside the casing. The casing includes a base plate and a cover plate along both sides of the battery's thickness, as well as peripheral plates connecting the base plate and the cover plate. The terminal blocks pass through the peripheral plates and are electrically connected to the battery cells installed inside the casing. However, with increasing demands for battery lightweighting, batteries are becoming thinner, and the dimensions of the peripheral plates in the battery's thickness direction are also decreasing. This results in less space for the terminal blocks at the peripheral plate locations, making installation difficult. Furthermore, as the dimensions of the peripheral plates in the battery's thickness direction decrease, the volume of electrolyte that the casing can hold also decreases, ultimately reducing the electrolyte capacity and lowering the battery's energy density. Utility Model Content

[0003] One objective of this utility model is to provide a battery housing assembly that reduces the difficulty of installing the first electrode post and has a large electrolyte capacity.

[0004] To achieve this objective, the present invention adopts the following technical solution:

[0005] Battery casing assembly, including:

[0006] A shell bottom plate, the shell bottom plate comprising a first bottom plate and a second bottom plate arranged in sequence;

[0007] A shell side plate surrounds the outer periphery of the shell bottom plate and is connected to the shell bottom plate to form a receiving cavity. The opening of the receiving cavity is arranged opposite to the shell bottom plate along the thickness direction of the cell.

[0008] The first pole post is inserted through the second base plate;

[0009] The protrusion is disposed on the side of the second base plate away from the receiving cavity, and the protrusion forms a receiving groove on the side of the second base plate facing the receiving cavity, the receiving groove communicating with the receiving cavity.

[0010] As an optional technical solution for the battery casing assembly, the first electrode post is a positive electrode post, forming the positive electrode of the battery cell; the inner wall of the receiving groove is electrically connected to the battery cell, forming the negative electrode of the battery cell.

[0011] As an optional technical solution for the battery casing assembly, the battery casing assembly further includes a second terminal post, the second terminal post having the opposite polarity to the first terminal post, the second terminal post passing through the second base plate, and at least one of the first terminal post and the second terminal post being insulated from the second base plate.

[0012] As one optional technical solution for the battery casing assembly, the first terminal is a positive terminal, the second terminal is a negative terminal, the first terminal is insulated from the second base plate, and the second terminal is insulated from the second base plate; or...

[0013] The first terminal is a positive terminal, the second terminal is a negative terminal, the first terminal is insulated from the second base plate, the second terminal is electrically connected to the second base plate, and the second base plate is electrically connected to the battery cell.

[0014] As an optional technical solution for the battery casing assembly, the battery casing assembly further includes a second terminal post, the second terminal post having the opposite polarity to the first terminal post, the second terminal post passing through the protrusion; the first terminal post being insulated from the second base plate; and / or, the second terminal post being insulated from the protrusion.

[0015] As an optional technical solution for the battery casing assembly, the receiving cavity includes a first receiving cavity and a second receiving cavity. The first receiving cavity is opposite to the first base plate, and the second receiving cavity is opposite to the second base plate. Along the thickness direction of the battery cell, the distance between the side surface of the first base plate away from the receiving cavity and the side surface of the second base plate away from the receiving cavity is a, and the distance between the side surface of the second base plate away from the receiving cavity and the opening is b, and 0.5≤a / b≤1.5.

[0016] As an optional technical solution for the battery casing assembly, along the thickness direction of the battery cell, the first electrode protrudes from the second base plate by a height of h1, and the protrusion protrudes from the second base plate by a height of h2, wherein h1≤a; h2≤a.

[0017] As an optional technical solution for the battery casing assembly, along the arrangement direction of the first base plate and the second base plate, the ratio of the length l2 of the second base plate to the length l2 of the first base plate is n, and 0.1≤n≤0.2.

[0018] As an optional technical solution for the battery casing assembly, the first base plate is provided with explosion-proof grooves, which are provided on the side surface of the first base plate opposite to the receiving cavity.

[0019] As an optional technical solution for the battery casing assembly, the explosion-proof groove is in the shape of a straight groove, and two straight grooves are provided at intervals on the first base plate, with the two straight grooves respectively located at two opposite corners of the first base plate.

[0020] As an optional technical solution for battery casing assembly, the protrusion is spaced apart from the first electrode post in a direction perpendicular to the arrangement direction of the first base plate and the second base plate.

[0021] As an optional technical solution for the battery casing assembly, a liquid injection hole is provided between the protrusion and the first electrode post, or a liquid injection hole is provided on the protrusion.

[0022] The injection hole is sealed by a plugging component.

[0023] As an optional technical solution for battery casing assembly, the size of the protrusion is larger than the size of the first electrode post in a direction perpendicular to the arrangement direction of the first base plate and the second base plate.

[0024] Another objective of this utility model embodiment is to provide a battery cell that is simple to assemble, has a large electrolyte capacity, and a high energy density.

[0025] To achieve this objective, the present invention adopts the following technical solution:

[0026] A battery cell includes a battery cell and the aforementioned battery casing assembly. The battery cell is located within the receiving cavity of the battery casing assembly, and the battery cell is connected to the first terminal of the battery casing assembly.

[0027] The beneficial effects of this utility model are:

[0028] The battery casing assembly provided by this utility model includes a bottom casing plate, a side casing plate, a first terminal post, and a protrusion. The side casing plate surrounds the outer periphery of the bottom casing plate and connects to the bottom casing plate to form a receiving cavity. The opening of the receiving cavity is positioned opposite to the bottom casing plate along the thickness direction of the battery cell, allowing the battery cell to be placed into the receiving cavity through the opening along the thickness direction of the battery cell. The bottom casing plate includes a first base plate and a second base plate arranged in sequence. The first terminal post passes through the second base plate and connects to the battery cell. That is, the first terminal post is set on the bottom casing plate on one side of the battery cell thickness direction. Since the size of the bottom casing plate is larger than that of the side casing plate, it can ensure the lightweight requirements of the battery cell while ensuring that the installation of the first terminal post is not affected by the small thickness of the battery cell. Furthermore, a dedicated installation area (second base plate) is provided for the first terminal post to avoid the installation of the first terminal post being affected by other components and to reduce the installation difficulty of the first terminal post. The protrusion forms a receiving groove on the side of the second base plate facing the receiving cavity. The receiving groove is connected to the receiving cavity and can store electrolyte, thereby increasing the electrolyte capacity of the battery case assembly. The position of the protrusion also takes into account the remaining space after the first pole is installed on the second base plate. Therefore, the protrusion is set in a reasonable way to make use of this space, so as not to occupy the space of other positions of the battery case assembly, and to maximize the electrolyte capacity. Attached Figure Description

[0029] Figure 1 This is a first structural schematic diagram of the battery casing assembly provided in the first embodiment of this utility model;

[0030] Figure 2 This is an exploded view of the battery housing assembly provided in the first embodiment of the present invention;

[0031] Figure 3 yes Figure 2 A magnified view of the area at point E;

[0032] Figure 4 This is a schematic diagram of the second structure of the battery casing assembly provided in the first embodiment of this utility model;

[0033] Figure 5 yes Figure 4 Cross-sectional view at point AA;

[0034] Figure 6 This is a schematic diagram of the battery casing assembly provided in the second embodiment of this utility model;

[0035] Figure 7 This is a structural schematic diagram of the battery casing assembly provided in the third embodiment of this utility model.

[0036] In the picture:

[0037] 100. Shell bottom plate; 110. First bottom plate; 111. Explosion-proof groove; 120. Second bottom plate; 200. Shell side plate; 210. Outwardly expanding boss; 201. Opening; 300. First pole post assembly; 310. First pole post; 311. Column; 312. Chassis; 3121. Third annular platform; 320. Upper plastic; 321. First annular platform; 330. Aluminum block; 340. Lower plastic; 341. Second annular platform; 400. Cover plate; 500. Second pole post assembly; 510. Second pole post; 600. Protrusion; 610. Receiving groove; 700. Sealing component. Detailed Implementation

[0038] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, not the entire structure.

[0039] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0040] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0041] In the description of this embodiment, the terms "upper," "lower," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, 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. Therefore, they should not be construed as limitations on this utility model. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.

[0042] See attached document Figure 1 To be continued Figure 5 This embodiment provides a battery casing assembly, which includes a bottom casing plate 100, a side casing plate 200, a first terminal post 310, and a protrusion 600. The bottom casing plate 100 includes a first bottom plate 110 and a second bottom plate 120 arranged sequentially. The first bottom plate 110 and the second bottom plate 120 can be arranged along the length direction of the battery cell (x direction in the figure) or along the width direction of the battery cell (y direction in the figure). In this embodiment, the first bottom plate 110 and the second bottom plate 120 are arranged along the length direction of the battery cell. The planar shape of the first bottom plate 110 and the second bottom plate 120 is not limited and can be rectangular, circular, or trapezoidal, etc. In this embodiment, it is rectangular. The first base plate 110 and the second base plate 120 may or may not be on the same horizontal plane. For example, there is a height difference between the first base plate 110 and the second base plate 120 along the thickness direction of the battery cell (the z-direction in the figure), and they may be parallel or non-parallel. For example, the second base plate 120 may be inclined relative to the first base plate 110. In this embodiment, the first base plate 110 and the second base plate 120 are arranged in parallel. The first base plate 110 and the second base plate 120 may be directly connected or connected through a transition plate. The transition plate may be a flat plate or an arc plate. The shell side plate 200 surrounds the outer periphery of the shell bottom plate 100 and is connected to the shell bottom plate 100 to form a receiving cavity. The opening 201 of the receiving cavity is arranged opposite to the shell bottom plate 100 along the thickness direction of the battery cell. The first electrode post 310 passes through the second base plate 120, such that at least a portion of the first electrode post 310 is located in the receiving cavity, and at least a portion of the first electrode post 310 located in the receiving cavity is connected to the battery cell located in the receiving cavity. The protrusion 600 is disposed on the side of the second base plate 120 away from the receiving cavity. The protrusion 600 can be disposed at any position on the second base plate 120, as long as it does not interfere with the function of the first pole post 310. The protrusion 600 can be any regular shape such as square, circle or triangle. The protrusion 600 forms a receiving groove 610 on the side of the second base plate 120 facing the receiving cavity. The receiving groove 610 communicates with the receiving cavity. The receiving groove 610 can be any regular shape such as square, circle or triangle.

[0043] Based on the above design, the shell side plate 200 surrounds the outer periphery of the shell bottom plate 100 and is connected to the shell bottom plate 100 to form a receiving cavity. The opening 201 of the receiving cavity is arranged opposite to the shell bottom plate 100 along the thickness direction of the battery cell, so that the battery cell can be placed into the receiving cavity through the opening 201 along the thickness direction of the battery cell. The shell bottom plate 100 includes a first bottom plate 110 and a second bottom plate 120 arranged in sequence. The first terminal post 310 passes through the second bottom plate 120 and is connected to the battery cell. That is, the first terminal post 310 is set on the shell bottom plate 100 on one side of the battery cell thickness direction. Since the size of the shell bottom plate 100 is larger than that of the shell side plate 200, it can ensure the lightweight of the battery cell while ensuring that the installation of the first terminal post 310 is not affected by the small thickness of the battery cell. In addition, a special installation area (second bottom plate 120) is set for the first terminal post 310 to avoid the installation of the first terminal post 310 being affected by other components and reduce the installation difficulty of the first terminal post 310. The protrusion 600 forms a receiving groove 610 on the side of the second base plate 120 facing the receiving cavity. The receiving groove 610 is connected to the receiving cavity and can store electrolyte, thereby increasing the electrolyte capacity of the battery case assembly. The position of the protrusion 600 also takes into account that there is still space left after the first pole post 310 is installed on the second base plate 120. Therefore, the protrusion 600 is set in a reasonable way to make use of this space, so as not to occupy the space of other positions of the battery case assembly, and to maximize the electrolyte capacity.

[0044] It should be noted that the first terminal 310 can be either a positive or negative terminal. In this embodiment, the first terminal 310 is a positive terminal. The first terminal 310 is welded to the positive tab of the battery cell to form the positive electrode of the battery cell. There is no limitation on the negative electrode of the battery cell. The specific welding process is prior art in this field and will not be described in detail here.

[0045] As can be seen from the above, the receiving cavity includes a space for accommodating the battery cell and a space for accommodating the first terminal 310. Specifically, the receiving cavity includes a first receiving cavity and a second receiving cavity. The first receiving cavity is opposite to the first base plate 110, and the second receiving cavity is opposite to the second base plate 120. In principle, the depths of the first receiving cavity and the second receiving cavity in the battery cell thickness direction can be the same or different. That is, the heights of the first base plate 110 and the second base plate 120 from the cover plate 400 in the battery cell thickness direction can be the same or different. When they are different, the first base plate 110 can be higher or lower than the second base plate 120, as long as a dedicated area is left on the bottom plate 100 (on the side of the battery cell thickness direction) to install the first terminal 310.

[0046] Preferably, along the thickness direction of the battery cell, the depth dimension of the first receiving cavity is greater than the depth dimension of the second receiving cavity, that is, the height of the first base plate 110 is higher than the height of the second base plate 120 (here the shell wall thickness of the first base plate 110 and the second base plate 120 is the same). The space between the two heights is used to avoid the first pole post 310 on the side of the second base plate 120 away from the second receiving cavity, so as to save the space occupied by the entire battery case assembly and improve the space utilization rate.

[0047] In this embodiment, the bottom plate 100 is stamped to form a recessed groove in the direction of the receiving cavity, and the bottom of the recessed groove is the second bottom plate 120.

[0048] Specifically, the first base plate 110 and the second base plate 120 are parallel. Along the thickness direction of the battery cell, the distance between the surface of the first base plate 110 away from the receiving cavity and the surface of the second base plate 120 away from the receiving cavity is 'a', i.e., the depth of the recessed groove is 'a'. The distance between the surface of the second base plate 120 away from the receiving cavity and the opening 201 is 'b', i.e., the height of the portion of the shell side plate 200 connected to the second base plate 120 is 'b'. Furthermore, 0.5 ≤ a / b ≤ 1.5. For example, a / b can be 0.5, 1.0, or 1.5, etc. If a / b is less than 0.5, the installation space of the first electrode post 310 will be limited if the thickness direction of the first electrode post 310 does not exceed the requirements of the first base plate 110. If a / b is greater than 1.5, the depth of the second receiving cavity is too small, which limits the installation space of the first pole post 310 in the second receiving cavity. For example, the second receiving cavity does not have enough space to accommodate the welding of the first pole post 310 to the battery cell tab and the insulation components of the first pole post 310 and the second base plate 120.

[0049] More preferably, along the thickness direction of the cell, the first electrode post 310 protrudes from the second base plate 120 at a height of h1, and the protrusion 600 protrudes from the second base plate 120 at a height of h2, where h1≤a; h2≤a. That is to say, along the thickness direction of the cell, the tops of the first electrode post 310 and the protrusion 600 are not higher than the first base plate 110, so that the battery cell with the battery housing assembly can be assembled into a receiving space with the same thickness dimension as the battery cell (here referring to the thickness of the battery cell at the cell position). However, if the top of the first terminal post 310 and the protrusion 600 extends beyond the first base plate 110, when the battery cell is installed in a terminal (e.g., a watch), additional space is needed in the thickness direction of the cell to accommodate the excess portion of the first terminal post 310 and the protrusion 600, which will increase the space occupied by the battery cell. Furthermore, since the first terminal post 310 extends beyond the first base plate 110, the first terminal post 310 may be scratched when the battery cell is installed in a terminal (e.g., a watch). Therefore, the above design can both protect the first terminal post 310 and reduce the space occupied by the battery case assembly.

[0050] Typically, the height h2 of the protrusion 600 protruding from the second base plate 120 ranges from 0.3mm to 2.5mm. For example, h2 can be 0.3mm, 0.6mm, 1.2mm, 2.4mm, or 2.5mm, etc.

[0051] Optionally, along the arrangement direction (x direction) of the first base plate 110 and the second base plate 120, the length of the first base plate 110 is l1, the length of the second base plate 120 is l2, and the ratio of the length l2 of the second base plate 120 to the length l1 of the first base plate 110 is n, and 0.1≤n≤0.2. For example, n can be 0.1, 0.15, or 0.2, etc. Since the portion of the receiving cavity opposite to the first base plate 110 is used to place the battery cell, and the portion of the receiving cavity opposite to the second base plate 120 is used to install the first terminal post 310, if n is less than 0.1, the size of the second base plate 120 in the arrangement direction of the first base plate 110 and the second base plate 120 will be too small, thus limiting the installation space of the first terminal post 310. However, for the sake of space utilization, the value of n should not be too large either. If n is greater than 0.2, the size of the second base plate 120 in the arrangement direction of the first base plate 110 and the second base plate 120 will be too large, resulting in wasted space. Therefore, the installation area of ​​the first terminal post 310 is controlled within the range of 0.1-0.2, so that it can meet the area occupied by the installation of the first terminal post 310 while avoiding wasted space, making the battery case assembly structure compact and space utilization efficient.

[0052] Optionally, along the direction perpendicular to the arrangement direction of the first base plate 110 and the second base plate 120 (the y-direction in the figure), which in this embodiment is the width direction of the battery cell, the width of the first base plate 110 is equal to the width of the second base plate 120, that is, the recessed groove is through the width direction of the battery cell, which is convenient to process and can maximize the installation space of the first electrode post 310 while improving the space utilization of the entire battery case assembly.

[0053] In this embodiment, the first bottom plate 110, the second bottom plate 120, and the shell side plate 200 of the shell bottom plate 100 are formed by stamping and bending of a flat plate.

[0054] Of course, in some other embodiments, the width of the first base plate 110 may be smaller than the width of the second base plate 120 in a direction perpendicular to the arrangement direction of the first base plate 110 and the second base plate 120; that is, in a direction perpendicular to the arrangement direction of the first base plate 110 and the second base plate 120, the two ends of the second base plate 120 extend beyond the two ends of the first base plate 110. In still other embodiments, the width of the first base plate 110 may be larger than the width of the second base plate 120 in a direction perpendicular to the arrangement direction of the first base plate 110 and the second base plate 120; that is, the two ends of the first base plate 110 extend beyond the two ends of the second base plate 120.

[0055] Optionally, the protrusion 600 and the first pole post 310 are spaced apart in a direction perpendicular to the arrangement direction of the first base plate 110 and the second base plate 120, so as to facilitate the processing of the first pole post 310 and the protrusion 600.

[0056] Furthermore, an injection hole is provided between the protrusion 600 and the first electrode post 310, or an injection hole is provided on the protrusion 600; the injection hole is sealed by a sealing member 700. Positioning the injection hole between the protrusion 600 and the first electrode post 310, so that the injection hole is approximately located in the middle of the second base plate 120 in the arrangement direction of the first base plate 110 and the second base plate 120, facilitates electrolyte injection into the battery cell. In other words, injecting electrolyte from the middle position allows for more even filling of the cavity and shortens the settling time after injection. Furthermore, positioning the injection hole on the protrusion 600 saves space occupied by the injection hole on the second base plate 120. Optionally, the size of the protrusion 600 is larger than the size of the first electrode post 310 in a direction perpendicular to the arrangement direction of the first base plate 110 and the second base plate 120. This makes full use of the space of the second base plate 120 in the direction perpendicular to the arrangement direction of the first base plate 110 and the second base plate 120, increases the volume of the receiving groove 610 of the protrusion 600, and thus increases the volume of electrolyte contained in the housing.

[0057] Preferably, the ratio of the size of the protrusion 600 to the size of the second base plate 120 in the direction perpendicular to the arrangement direction of the first base plate 110 and the second base plate 120 is in the range of 0.1-0.5. For example, it can be 0.1, 0.3 or 0.5, etc. If the ratio of the size of the protrusion 600 to the size of the second base plate 120 is less than 0.1, the size of the protrusion 600 is too small, the capacity of the receiving groove 610 is small, and the space of the second base plate 120 in the y direction is not fully utilized. If the ratio of the size of the protrusion 600 to the size of the second base plate 120 is greater than 0.5, the space occupied by the protrusion 600 is too large, and the distances between the protrusion 600 and the first electrode post 310 and the injection hole in the y direction will be too small, which will hinder the injection operation of the injection hole. In addition, the electrolyte leakage during injection is likely to flow to components such as the first electrode post 310. Therefore, controlling the ratio between 0.1 and 0.5 can fully utilize the space of the second base plate 120 while also ensuring a safe distance between the first electrode post 310 and the injection hole.

[0058] Optionally, the side panel 200 is provided with an outwardly expanding boss 210 at its edge opposite to the bottom panel 100. The outwardly expanding boss 210 extends along the outer circumference of the side panel 200 and forms a closed loop. The battery housing assembly also includes a cover plate 400, which is fastened to the opening 201 and is fitted and connected to the outwardly expanding boss 210. In this embodiment, the cover plate 400 is located inside the opening 201, and the periphery of the cover plate 400 is sealed to the inner wall of the outwardly expanding boss 210. That is, the cover plate 400 is used to seal the opening 201 of the receiving cavity. The bottom panel 100, the side panel 200, and the cover plate 400 form the housing of the battery cell. Providing the outwardly expanding boss 210 can increase the contact area between the cover plate 400 and the side panel 200, and improve the connection strength and sealing performance of the cover plate 400 and the side panel 200.

[0059] In this embodiment, the distance between the side wall of the outwardly expanding boss 210 and the shell side plate 200 is 0.05mm-0.20mm. For example, it can be 0.05mm, 0.10mm, 0.15mm or 0.20mm.

[0060] Optionally, the bottom plate 100 and the cover plate 400 are made of the same material, preferably a conductive material, such as stainless steel or aluminum plate.

[0061] In this embodiment, the wall thickness k1 of the bottom plate 100 and the wall thickness k2 of the cover plate 400 are both in the range of 0.05mm-0.25mm. For example, they can be 0.05mm, 0.10mm, 0.15mm, 0.20mm or 0.25mm.

[0062] The ratio of the wall thickness k2 of the cover plate 400 to the wall thickness k1 of the shell bottom plate 100, k2 / k1, ranges from 0.5 to 1.5. For example, k2 / k1 can be 0.5, 0.6, 0.9, 1.2 or 1.5, etc.

[0063] In order to meet the pressure relief requirements of the battery casing assembly, the first base plate 110 is provided with explosion-proof grooves 111. The explosion-proof grooves 111 are provided on the side surface of the first base plate 110 away from the receiving cavity. By providing the explosion-proof grooves 111 on the relatively large surface of the casing, when the battery cell explodes, the gas can be quickly ejected to achieve the explosion.

[0064] It should be noted that when the wall thickness k1 of the bottom plate 100 is less than the wall thickness k2 of the cover plate 400, the explosion-proof groove 111 is set on the side with thinner wall thickness, that is, on the bottom plate 100, which makes it easier to open the valve to release pressure and prevent explosion.

[0065] In this embodiment, the explosion-proof groove 111 is a straight groove. Two straight grooves are spaced apart on the first base plate 110. The two straight grooves are respectively located at two opposite corners of the first base plate 110. The depth of the straight groove is 30%-80% of the wall thickness of the shell base plate 100. For example, it can be 30%, 60% or 80%. If the ratio of the depth of the straight groove to the wall thickness of the shell base plate 100 is less than 30%, the depth of the straight groove is too shallow, which will prevent the battery cell from exploding when it needs to, and will not meet the explosion requirements. If the ratio of the depth of the straight groove to the wall thickness of the shell base plate 100 is greater than 80%, the depth of the straight groove is too deep, which will result in the shell strength being too low and the battery cell being prone to premature explosion.

[0066] By setting two straight grooves at two opposite corners of the first base plate 110, the stress at this corner is more concentrated than the stress at other locations of the first base plate 110. Therefore, setting the explosion-proof groove 111 at the corner can improve the overall explosion-proof sensitivity of the battery cell and enhance safety.

[0067] In this embodiment, one of the straight grooves is adjacent to the first pole post 310. Optionally, explosion-proof grooves 111 can also be provided at all four corners of the first base plate 110.

[0068] In this embodiment, the first base plate 110 is a rectangular plate, and the angle between the straight groove and the two sides of the first base plate 110 along the y-direction is α, where 30°≤α≤70°. For example, α can be 30°, 50°, or 70°, etc., and can be set according to specific needs. By limiting the angle range of α to between 30° and 70°, the line connecting the straight groove and the two opposite corners (where the straight groove is provided) of the first base plate 110 is approximately perpendicular, so that the straight groove is approximately orthogonal to the corner in the direction of the connecting line, thereby making the blasting intensity on the straight groove the same.

[0069] Furthermore, the intersection of the lines connecting the straight groove and the two opposite corners (corners where the straight groove is provided) of the first base plate 11 is the midpoint of the straight groove.

[0070] For ease of distinction, the two corners mentioned above will be referred to as the first corner and the second corner, respectively. The two straight grooves will be referred to as the first straight groove and the second straight groove, respectively. The first straight groove corresponds to the first corner, and the second straight groove corresponds to the second corner.

[0071] Furthermore, the distance from the intersection of the first straight groove and the aforementioned connecting line to the first corner is s1, and the dimension of the line connecting the first corner and the second corner is s2, where 0.1 ≤ s1 / s2 ≤ 0.25. For example, s1 / s2 can be 0.1, 0.2, or 0.25. The value of s1 / s2 should not be too large. If the value of s1 / s2 is greater than 0.25, the distance between the first straight groove and the first corner will be too large, and the position of the first straight groove will exceed the corner stress concentration range of the first base plate 110. However, the value of s1 / s2 should not be too small either. For example, if the value of s1 / s2 is less than 0.1, the distance between the first straight groove and the first corner will be too small, and the first straight groove will exceed the bulge range of the shell (the strength at the corner of the shell is high, and bulging hardly occurs).

[0072] Typically, the battery casing assembly also includes an upper plastic 320, an aluminum block 330, and a lower plastic 340, forming the first terminal post assembly 300. Specifically, as shown... Figure 1 , Figure 2 and Figure 5 As shown, the first pole post 310 includes a column 311 and a base plate 312 connected to each other. A first mounting hole is provided on the second base plate 120. A lower plastic 340 is attached to the side of the second base plate 120 facing the receiving cavity, and a second mounting hole is provided on the lower plastic 340, directly opposite the first mounting hole. The column 311 passes through the second mounting hole and the first mounting hole in sequence. The base plate 312 abuts against the side of the lower plastic 340 away from the second base plate 120. An aluminum block 330 is located on the side of the second base plate 120 away from the receiving cavity and is riveted to the column 311. An upper plastic 320 is fitted onto the column 311 and sandwiched between the aluminum block 330 and the second base plate 120. The upper plastic 320 serves to insulate and isolate the aluminum block 330 and the second base plate 120, while the lower plastic 340 serves to insulate and isolate the second base plate 120 from the base plate 312. The upper plastic 320 and the lower plastic 340 also serve a sealing function.

[0073] In this embodiment, a first annular platform 321 is provided on the side of the upper plastic 320 facing the aluminum block 330. The first annular platform 321 extends circumferentially along the side wall of the column 311 and is arranged in a closed loop, which increases the sealing of the connection between the aluminum block 330 and the column 311, and acts as a sealing ring to further improve the sealing performance of the battery case assembly.

[0074] Similarly, a second annular platform 341 is provided on the side of the lower plastic 340 facing the second base plate 120. The second annular platform 341 extends circumferentially along the second mounting hole and is arranged in a closed loop. The second annular platform 341 is sandwiched between the hole wall of the first mounting hole and the side wall of the column 311, insulating and isolating the second base plate 120 and the column 311, and sealing the gap between the first mounting hole and the column 311, thus acting as a sealing ring and further improving the sealing performance of the battery case assembly.

[0075] Similarly, a third annular platform 3121 is provided on the side of the chassis 312 facing the lower plastic 340, and an annular groove is provided on the side of the lower plastic 340 facing the chassis 312. The shape of the annular groove is adapted to the shape of the third annular platform 3121, and the third annular platform 3121 can be engaged in the annular groove, improving the sealing performance between the lower plastic 340 and the chassis 312. Of course, in other embodiments, the annular groove can also be provided on the chassis 312, and the third annular platform 3121 can be provided on the lower plastic 340, as long as the third annular platform 3121 can be engaged in the annular groove to achieve tight contact between the lower plastic 340 and the chassis 312, thereby improving the sealing performance of the battery casing assembly.

[0076] See attached document Figure 6 As shown, in other embodiments of this utility model, the battery casing assembly may have both a positive and a negative terminal. Specifically, the battery casing assembly further includes a second terminal 510, which has the opposite polarity to the first terminal 310. The second terminal 510 passes through the second base plate 120, and at least one of the first terminal 310 and the second terminal 510 is insulated from the second base plate 120. The second terminal 510 can be either a positive or a negative terminal. When the second terminal 510 is a positive terminal, the first terminal 310 is a negative terminal; when the second terminal 510 is a negative terminal, the first terminal 310 is a positive terminal.

[0077] In one specific implementation, the first terminal 310 is the positive terminal, and the second terminal 510 is the negative terminal. The first terminal 310 is insulated from the second base plate 120, and the second terminal 510 is also insulated from the second base plate 120 and electrically connected to the battery cell. The casing base plate 100 is insulated from the battery cell, which can reduce the risk of external short circuits to the battery cell. At the same time, the material of the casing base plate 100 does not need to carry a potential, reducing the requirements for material stability.

[0078] It should be noted that the assembly method of the second pole post 510 can be the same as that of the first pole post 310, that is, the second pole post 510 and other components form the second pole post assembly 500, which will not be described in detail here.

[0079] In another specific implementation, the first terminal 310 is a positive terminal, the second terminal 510 is a negative terminal, the first terminal 310 is insulated from the second base plate 120, and the second terminal 510 is electrically connected to the second base plate 120.

[0080] See attached document Figure 7In another embodiment of this utility model, based on the existing battery casing assembly which has both a positive and a negative terminal, the placement of the negative terminal is optimized. Specifically, the battery casing assembly further includes a second terminal 510, which has the opposite polarity to the first terminal 310, and passes through the protrusion 600. The first terminal 310 is insulated from the second base plate 120; and / or, the second terminal 510 is insulated from the protrusion. That is, in one embodiment, the first terminal 310 is insulated from the second base plate 120, and the second terminal 510 is insulated from the protrusion 600; in another embodiment, the first terminal 310 is insulated from the second base plate 120, and the second terminal 510 is electrically connected to the protrusion 600; in yet another embodiment, the first terminal 310 is electrically connected to the second base plate 120, and the second terminal 510 is insulated from the protrusion 600. The second pole post 510 is positioned on the protrusion 600, which reduces the area occupied by the second base plate 120, and the protrusion 600 also facilitates the fixing of the second pole post 510.

[0081] It should be noted that although at least part of the second electrode post 510 is located in the receiving tank 610 and occupies part of the space of the receiving tank 610, there is still space for electrolyte in the receiving tank 610.

[0082] In this embodiment, the assembly method of the second pole post 510 can still be the same as that of the first pole post 310, that is, the second pole post 510 and other components form the second pole post assembly 500, except that the insertion position of the second pole post 510 becomes the protrusion 600, and the rest remains unchanged.

[0083] In another embodiment of this utility model, the casing can be directly used as the positive or negative electrode of the battery cell, without the need for an additional terminal post. In this embodiment, the first terminal post 310 is the positive terminal post, forming the positive electrode of the battery cell; the second base plate 120 is connected to the cell on the side facing the receiving cavity, forming the negative electrode of the battery cell. Specifically, the second base plate 120 is welded to the negative electrode tab of the cell. Using the casing as the negative electrode is a common structural design, especially widely used in cylindrical lithium-ion batteries (such as 18650, 21700, 26650, etc.) and some button batteries. This design can simplify the battery cell structure and reduce internal resistance.

[0084] Of course, in other embodiments, the negative electrode can also be located on the housing, such as the first base plate 110, the side plate 200, and the cover plate 400. Specifically, the negative electrode connection can be achieved by welding a nickel strip onto the housing to connect to a terminal (e.g., a watch).

[0085] Preferably, the first electrode post 310 is a positive electrode post, forming the positive electrode of the battery cell; the inner wall of the receiving groove 610 (the side of the protrusion 600 facing the receiving cavity) is electrically connected to the battery cell. Specifically, the negative electrode tab of the battery cell is welded to the inner wall of the receiving groove 610 to form the negative electrode of the battery cell. The protrusion 600 can be directly connected to the terminal slot, eliminating the need for nickel strip components and reducing the internal resistance of the battery cell.

[0086] In this embodiment, the protrusion 600 is shaped to resemble the first pole post assembly 300 and is spaced apart from the first pole post assembly 300 on the second base plate 120. This not only makes it aesthetically pleasing and symmetrical but also serves as a positioning structure. When the battery cell is assembled in the terminal, the protrusion 600 can be fitted into the recessed position (slot) of the terminal to position the battery cell. Furthermore, the snap-fit ​​connection between the protrusion 600 and the recessed position of the terminal enhances the fixation of the battery cell in the terminal and avoids poor contact between the battery cell and the terminal.

[0087] In this embodiment, the injection hole is disposed on the second base plate 120 and located between the first pole post assembly 300 and the protrusion 600.

[0088] Similarly to the previous embodiment, the injection hole is set between the protrusion 600 and the first electrode assembly 300, so that the injection hole is approximately located in the middle of the second base plate 120 in the arrangement direction of the first base plate 110 and the second base plate 120. When injecting electrolyte into the battery cell, it is beneficial to inject the electrolyte. In other words, injecting electrolyte from the middle position can fill the cavity more evenly and shorten the standing time after injection.

[0089] This embodiment also provides a battery cell that is simple to assemble, has a large electrolyte capacity, and a high energy density.

[0090] Specifically, the battery cell includes a battery cell and the aforementioned battery casing assembly. The battery cell is located within the housing cavity of the battery casing assembly and is connected to the first terminal post 310 of the battery casing assembly. Since the first terminal post 310 is located on the bottom plate 100 of the casing on one side in the thickness direction of the battery cell, the installation is easy. Furthermore, the second bottom plate 120 has a protrusion 600 on the side away from the housing cavity, and the protrusion 600 forms a receiving groove 610 on the side of the second bottom plate 120 facing the housing cavity. The receiving groove 610 communicates with the housing cavity and can store electrolyte, thereby increasing the electrolyte capacity of the battery cell.

[0091] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating the present utility model, and are not intended to limit the implementation of the present utility model. Those skilled in the art can make various obvious changes, readjustments, and substitutions without departing from the protection scope of this utility model. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. A battery case assembly, characterized by, include: Shell bottom plate (100), the shell bottom plate (100) includes a first bottom plate (110) and a second bottom plate (120) arranged in sequence; A shell side plate (200) surrounds the outer periphery of the shell bottom plate (100) and is connected to the shell bottom plate (100) to form a receiving cavity. The opening (201) of the receiving cavity is arranged opposite to the shell bottom plate (100) along the thickness direction of the cell. The first pole post (310) is inserted through the second base plate (120); A protrusion (600) is provided on the side of the second base plate (120) away from the receiving cavity, and the protrusion (600) forms a receiving groove (610) on the side of the second base plate (120) facing the receiving cavity, the receiving groove (610) communicating with the receiving cavity.

2. The battery case assembly according to claim 1, wherein The first electrode post (310) is a positive electrode post, forming the positive electrode of the battery cell; the inner wall of the receiving groove (610) is electrically connected to the battery cell, forming the negative electrode of the battery cell.

3. The battery case assembly according to claim 1, wherein The battery casing assembly further includes a second terminal (510) with the opposite polarity to the first terminal (310). The second terminal (510) passes through the second base plate (120), and at least one of the first terminal (310) and the second terminal (510) is insulated from the second base plate (120).

4. The battery case assembly according to claim 3, wherein The first terminal (310) is a positive terminal, and the second terminal (510) is a negative terminal. The first terminal (310) is insulated from the second base plate (120), and the second terminal (510) is insulated from the second base plate (120); or, The first terminal (310) is a positive terminal, the second terminal (510) is a negative terminal, the first terminal (310) is insulated from the second base plate (120), the second terminal (510) is electrically connected to the second base plate (120), and the second base plate (120) is electrically connected to the battery cell.

5. The battery case assembly according to claim 1, wherein The battery casing assembly further includes a second terminal (510), which has the opposite polarity to the first terminal (310), and the second terminal (510) passes through the protrusion (600). The first pole post (310) is insulated from the second base plate (120); and / or, the second pole post (510) is insulated from the protrusion.

6. The battery case assembly of claim 1, wherein, The receiving cavity includes a first receiving cavity and a second receiving cavity. The first receiving cavity is opposite to the first base plate (110), and the second receiving cavity is opposite to the second base plate (120). Along the thickness direction of the battery cell, the distance between the side surface of the first base plate (110) away from the receiving cavity and the side surface of the second base plate (120) away from the receiving cavity is a, and the distance between the side surface of the second base plate (120) away from the receiving cavity and the opening (201) is b, and 0.5≤a / b≤1.

5.

7. The battery case assembly according to claim 6, wherein Along the thickness direction of the battery cell, the first electrode post (310) protrudes from the second base plate (120) by a height of h1, and the protrusion (600) protrudes from the second base plate (120) by a height of h2, wherein h1≤a; h2≤a.

8. The battery casing assembly according to any one of claims 1 to 7, characterized in that, Along the arrangement direction of the first base plate (110) and the second base plate (120), the ratio of the length l2 of the second base plate (120) to the length l2 of the first base plate (110) is n, and 0.1≤n≤0.

2.

9. The battery case assembly according to any one of claims 1 to 7, wherein The first base plate (110) is provided with explosion-proof grooves (111), which are provided on the side surface of the first base plate (110) away from the receiving cavity.

10. The battery case assembly of claim 9, wherein, The explosion-proof groove (111) is a straight groove. Two straight grooves are provided at intervals on the first base plate (110). The two straight grooves are respectively provided at two opposite corners of the first base plate (110).

11. The battery case assembly according to any one of claims 1 to 7, wherein The protrusion (600) is spaced apart from the first pole post (310) in a direction perpendicular to the arrangement direction of the first base plate (110) and the second base plate (120).

12. The battery casing assembly according to claim 11, characterized in that, A liquid injection hole is provided between the protrusion (600) and the first pole post (310), or a liquid injection hole is provided on the protrusion (600); The injection hole is sealed by a plug (700).

13. The battery case assembly according to any one of claims 1 to 7, wherein The protrusion (600) is larger than the first pole post (310) in a direction perpendicular to the arrangement direction of the first base plate (110) and the second base plate (120).

14. A battery cell, characterized by The battery includes a battery cell and a battery housing assembly as described in any one of claims 1-13, wherein the battery cell is located within a receiving cavity of the battery housing assembly and is connected to the first terminal (310) of the battery housing assembly.

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