Battery case assembly and battery cell

Abstract

The invention 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] The present invention relates to the technical field of batteries, and in particular to a battery shell assembly and a battery cell. Background Art

[0002] Generally, a battery includes a shell, a battery cell and a pole assembly, and the battery cell is located in the shell. The shell includes a bottom plate and a cover plate on both sides along the thickness direction of the battery, and a peripheral side plate surrounding and connecting the bottom plate and the cover plate; the pole passes through the peripheral side plate and is electrically connected to the battery cell installed in the shell. However, with the increasing requirements for lightweight batteries, the thickness of the battery is becoming thinner and thinner, and the size of the peripheral side plate of the shell in the thickness direction of the battery is becoming smaller and smaller, resulting in a smaller and smaller installation space for the pole at the position of the peripheral side plate, making it difficult to install the pole; and as the size of the peripheral side plate of the shell in the thickness direction of the battery becomes smaller and smaller, the volume of the electrolyte contained in the shell becomes smaller, which ultimately leads to a reduction in the electrolyte capacity and reduces the energy density of the battery. Summary of the invention

[0003] An object of an embodiment of the present invention is to provide a battery housing assembly which reduces the difficulty of installing a first pole and has a large electrolyte capacity.

[0004] To achieve this object, the present invention adopts the following technical solutions:

[0005] A battery housing assembly, comprising:

[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, the shell side plate is arranged around the outer periphery of the shell bottom plate and connected with the shell bottom plate to form a receiving cavity, and the opening of the receiving cavity is arranged opposite to the shell bottom plate along the thickness direction of the battery core;

[0008] A first pole, the first pole is passed through the second bottom plate;

[0009] The protrusion is arranged on a side of the second bottom plate away from the accommodating cavity, and the protrusion is formed with an accommodating groove on a side of the second bottom plate facing the accommodating cavity, and the accommodating groove is communicated with the accommodating cavity.

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

[0011] As an alternative technical solution of the battery case assembly, the battery case assembly further includes a second pole column, the second pole column having a polarity opposite to that of the first pole column, the second pole column passing through the second bottom plate, and at least one of the first pole column and the second pole column being insulatedly connected to the second bottom plate.

[0012] As an alternative technical solution of the battery case assembly, the first pole column is a positive pole column, the second pole column is a negative pole column, the first pole column is insulatedly connected to the second bottom plate, and the second pole column is insulatedly connected to the second bottom plate; or,

[0013] The first pole column is a positive pole column, the second pole column is a negative pole column, the first pole column is insulatedly connected to the second bottom plate, the second pole column is electrically connected to the second bottom plate, and the second bottom plate is electrically connected to the battery cell.

[0014] As an alternative technical solution of the battery case assembly, the battery case assembly further includes a second pole column, the second pole column having a polarity opposite to that of the first pole column, the second pole column passing through the protruding portion; the first pole column is insulatedly connected to the second bottom plate; and / or, the second pole column is insulatedly connected to the protruding portion.

[0015] As an alternative technical solution of the battery case assembly, the accommodating cavity includes a first accommodating cavity and a second accommodating cavity, the first accommodating cavity faces the first bottom plate, the second accommodating cavity faces the second bottom plate, along the thickness direction of the battery cell, the distance between the surface of the first bottom plate facing away from the accommodating cavity and the surface of the second bottom plate facing away from the accommodating cavity is a, the distance between the surface of the second bottom plate facing away from the accommodating cavity and the opening is b, and 0.5 ≤ a / b ≤ 1.5.

[0016] As an alternative technical solution of the battery case assembly, along the thickness direction of the battery cell, the height by which the first pole column protrudes from the second bottom plate is h1, and the height by which the protruding portion protrudes from the second bottom plate is h2, where h1 ≤ a; h2 ≤ a.

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

[0018] As an alternative technical solution of the battery case assembly, explosion-proof notches are provided on the first bottom plate, and the explosion-proof notches are provided on the surface of the first bottom plate facing away from the accommodating cavity.

[0019] As an alternative technical solution of the battery case assembly, the shape of the explosion-proof notch is a straight groove, and two such straight grooves are arranged at intervals on the first bottom plate, and the two straight grooves are respectively arranged at two opposite corners of the first bottom plate.

[0020] As an alternative technical solution of the battery case assembly, along a direction perpendicular to the arrangement direction of the first bottom plate and the second bottom plate, the protruding part and the first pole column are arranged at intervals.

[0021] As an alternative technical solution of the battery case assembly, a liquid injection hole is arranged between the protruding part and the first pole column, or a liquid injection hole is arranged on the protruding part;

[0022] The liquid injection hole is blocked by a blocking member.

[0023] As an alternative technical solution of the battery case assembly, along a direction perpendicular to the arrangement direction of the first bottom plate and the second bottom plate, the size of the protruding part is larger than the size of the first pole column.

[0024] Another object of the embodiments of the present invention is to provide a battery cell, which is simple to assemble, has a large electrolyte capacity, and a large energy density of the battery cell.

[0025] To achieve this purpose, the present invention adopts the following technical solutions:

[0026] A battery cell, comprising a battery core and the above-mentioned battery case assembly, the battery core is located in the accommodation cavity of the battery case assembly, and the battery core is connected to the first pole column of the battery case assembly.

[0027] The beneficial effects of the present invention:

[0028] The battery case assembly provided by the present invention includes a case bottom plate, a case side plate, a first pole column, and a protruding portion. The case side plate surrounds the outer periphery of the case bottom plate and is connected to the case bottom plate to form a receiving cavity. The opening of the receiving cavity is disposed opposite to the case bottom plate in the thickness direction of the battery cell, and the battery cell can be placed in the receiving cavity from the opening along the thickness direction of the battery cell. The case bottom plate includes a first bottom plate and a second bottom plate arranged in sequence. The first pole column passes through the second bottom plate and is connected to the battery cell, that is, the first pole column is disposed on the case bottom plate on one side in the thickness direction of the battery cell. Since the size of the case bottom plate is larger than that of the case side plate, while meeting the lightweight requirements of the battery cell, the installation of the first pole column is not affected by the small thickness of the battery cell. Moreover, a dedicated installation area (the second bottom plate) is provided for the first pole column, avoiding the influence of other components on the installation of the first pole column and reducing the installation difficulty of the first pole column. A receiving groove is formed on the side of the second bottom plate facing the receiving cavity of the protruding portion. The receiving groove communicates with the receiving cavity and can store the electrolyte, thereby increasing the electrolyte capacity of the battery case assembly. The setting position of the protruding portion also takes into account the remaining space after the first pole column is arranged on the second bottom plate. Therefore, this space is reasonably utilized to set the protruding portion, which not only does not occupy the space of other positions of the battery case assembly but also can increase the electrolyte capacity as much as possible. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is the first structural schematic diagram of the battery case assembly provided by the first embodiment of the present invention;

[0030] Figure 2 is the exploded view of the battery case assembly provided by the first embodiment of the present invention;

[0031] Figure 3 is Figure 2 the partial enlarged view at E;

[0032] Figure 4 is the second structural schematic diagram of the battery case assembly provided by the first embodiment of the present invention;

[0033] Figure 5 is Figure 4 the sectional view taken along A-A;

[0034] Figure 6 is the structural schematic diagram of the battery case assembly provided by the second embodiment of the present invention;

[0035] Figure 7 is the structural schematic diagram of the battery case assembly provided by the third embodiment of the present invention.

[0036] In the figure:

[0037] 100, bottom shell plate; 110, first bottom plate; 111, explosion-proof notch; 120, second bottom plate; 200, shell side plate; 210, outwardly expanding boss; 201, opening; 300, first pole assembly; 310, first pole; 311, cylinder; 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 assembly; 510, second pole; 600, protruding part; 610, receiving groove; 700, sealing member. Detailed implementation mode

[0038] The present invention will be further described in detail below with reference to the drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present invention, rather than limiting the present invention. In addition, it should be noted that for the sake of description, only parts related to the present invention are shown in the drawings, rather than all the structures.

[0039] In the description of the present invention, unless otherwise clearly defined and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0040] In the present invention, unless otherwise clearly defined and limited, the first feature being "above" or "below" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but through other features between them. Moreover, the first feature being "above", "above", and "on" the second feature includes that the first feature is directly above and obliquely above the second feature, or simply means that the first feature has a higher horizontal height than the second feature. The first feature being "below", "below", and "under" the second feature includes that the first feature is directly below and obliquely below the second feature, or simply means that the first feature has a lower horizontal height than the second feature.

[0041] In the description of this embodiment, the orientation or positional relationships such as "above", "below", "right", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of description and simplifying the operation, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be understood as a limitation of the present invention. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.

[0042] Refer to the attached Figure 1To the appendix Figure 5 , this embodiment provides a battery case assembly, which includes a case bottom plate 100, a case side plate 200, a first pole 310, and a protruding portion 600. The case bottom plate 100 includes a first bottom plate 110 and a second bottom plate 120 arranged in sequence. The first bottom plate 110 and the second bottom plate 120 can be arranged along the length direction of the battery cell (the x direction in the figure) or along the width direction of the battery cell (the 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 shapes of the first bottom plate 110 and the second bottom plate 120 are not limited and can be rectangular, circular, trapezoidal, etc. In this embodiment, they are rectangular; the first bottom plate 110 and the second bottom plate 120 can be on the same horizontal plane or not on the same horizontal plane. For example, there is a height difference between the first bottom plate 110 and the second bottom plate 120 along the thickness direction of the battery cell (the z direction in the figure), and the two can be parallel or not parallel. For example, the second bottom plate 120 is inclined relative to the first bottom plate 110. In this embodiment, the first bottom plate 110 and the second bottom plate 120 are parallel; the first bottom plate 110 and the second bottom plate 120 can be directly connected in contact or connected through a transition plate. The transition plate can be a flat plate or an arc plate. The case side plate 200 surrounds the outer periphery of the case bottom plate 100 and is connected to the case bottom plate 100 to form a receiving cavity. The opening 201 of the receiving cavity is arranged opposite to the case bottom plate 100 along the thickness direction of the battery cell; the first pole 310 penetrates through the second bottom plate 120, so that at least part of the first pole 310 is located in the receiving cavity, and at least part of the first pole 310 located in the receiving cavity is connected to the battery cell located in the receiving cavity. The protruding portion 600 is arranged on the side of the second bottom plate 120 facing away from the receiving cavity. The protruding portion 600 can be arranged at any position on the second bottom plate 120 as long as it does not interfere with the function of the first pole 310, and the protruding portion 600 can be any regular shape such as square, circular or triangular, etc.; and a receiving groove 610 is formed on the side of the protruding portion 600 facing the receiving cavity of the second bottom plate 120. The receiving groove 610 communicates with the receiving cavity, and the receiving groove 610 can be any regular shape such as square, circular or triangular, etc.

[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 disposed opposite to the shell bottom plate 100 along the thickness direction of the battery cell, and the battery cell can be placed in the receiving cavity from 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 pole column 310 penetrates through the second bottom plate 120 and is connected to the battery cell, that is, the first pole column 310 is disposed on the shell bottom plate 100 on one side of the battery cell in the thickness direction. Since the size of the shell bottom plate 100 is larger than that of the shell side plate 200, while ensuring the lightweight of the battery cell, the installation of the first pole column 310 is not affected by the small thickness of the battery cell (battery cell), and a dedicated installation area (the second bottom plate 120) is provided for the first pole column 310, avoiding the installation of the first pole column 310 being affected by other components and reducing the installation difficulty of the first pole column 310. A receiving groove 610 is formed on the side of the second bottom plate 120 facing the receiving cavity by the protruding portion 600. The receiving groove 610 communicates with the receiving cavity and can store the electrolyte, thereby improving the electrolyte capacity of the battery shell assembly. The setting position of the protruding portion 600 also takes into account the remaining space after the first pole column 310 is provided on the second bottom plate 120. Therefore, the protruding portion 600 is reasonably set in this space, which not only does not occupy the space of other positions of the battery shell assembly, but also can increase the electrolyte capacity as much as possible.

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

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

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

[0047] In this embodiment, by stamping the case bottom plate 100, the case bottom plate 100 is recessed toward the receiving cavity to form a recessed groove, and the bottom of the recessed groove is the second bottom plate 120.

[0048] Specifically, the first bottom plate 110 is parallel to the second bottom plate 120. Along the thickness direction of the battery cell, the distance between the surface of the first bottom plate 110 facing away from the receiving cavity and the surface of the second bottom plate 120 facing away from the receiving cavity is a, that is, the depth of the recessed groove is a, and the distance between the surface of the second bottom plate 120 facing away from the receiving cavity and the opening 201 is b, that is, the height of the part of the case side plate 200 connected to the second bottom plate 120 is b, and 0.5 ≤ a / b ≤ 1.5. Exemplarily, a / b can be 0.5, 1.0 or 1.5, etc. If a / b is less than 0.5, when the first pole 310 does not exceed the requirement of the first bottom plate 110 along the thickness direction of the battery cell, the installation space of the first pole 310 will be limited. If a / b is greater than 1.5, the depth dimension of the second receiving cavity is too small, resulting in limited installation space of the first pole 310 in the second receiving cavity. For example, there is not enough space in the second receiving cavity to accommodate the welding of the first pole 310 and the battery cell tab and the insulating component between the first pole 310 and the second bottom plate 120, etc.

[0049] Further preferably, along the thickness direction of the battery cell, the height of the first pole 310 protruding from the second bottom plate 120 is h1, and the height of the protruding part 600 protruding from the second bottom plate 120 is h2, where h1 ≤ a; h2 ≤ a. That is to say, along the thickness direction of the battery cell, the tops of the first pole 310 and the protruding part 600 are not higher than the first bottom plate 110, so that the battery cell having this battery case assembly can be assembled into a receiving space with the same thickness dimension as the battery cell (here, the thickness of the battery cell at the position of the battery cell). However, if the tops of the first pole 310 and the protruding part 600 exceed the first bottom plate 110, when the battery cell is installed in a terminal (such as a watch), an additional receiving space is required in the thickness direction of the battery cell to accommodate the exceeding parts of the first pole 310 and the protruding part 600, that is, it will cause an increase in the occupied space of the battery cell; and since the first pole 310 exceeds the first bottom plate 110, when the battery cell is installed in a terminal (such as a watch, etc.), the first pole 310 may be scratched. Therefore, the above design can not only protect the first pole 310 but also reduce the space occupied by the battery case assembly.

[0050] Under normal circumstances, the height h2 by which the protrusion 600 protrudes from the second bottom plate 120 ranges from 0.3 mm to 2.5 mm. Exemplarily, h2 can be 0.3 mm, 0.6 mm, 1.2 mm, 2.4 mm, 2.5 mm, etc.

[0051] Optionally, along the arrangement direction (x-direction) of the first bottom plate 110 and the second bottom plate 120, the length of the first bottom plate 110 is l1, the length of the second bottom plate 120 is l2, the ratio of the length l2 of the second bottom plate 120 to the length l1 of the first bottom plate 110 is n, and 0.1 ≤ n ≤ 0.2. Exemplarily, n can be 0.1, 0.15, 0.2, etc. Since the part of the accommodation cavity opposite to the first bottom plate 110 is used to place the battery cell, and the part of the accommodation cavity opposite to the second bottom plate 120 is used to pass through and install the first pole 310, if n is less than 0.1, the size of the second bottom plate 120 in the arrangement direction of the first bottom plate 110 and the second bottom plate 120 is too small, restricting the installation space of the first pole 310; however, considering space utilization, the value of n should not be too large either. If n is greater than 0.2, the size of the second bottom plate 120 in the arrangement direction of the first bottom plate 110 and the second bottom plate 120 is too large, resulting in space waste. Therefore, the installation area of the first pole 310 is controlled within the range of 0.1 - 0.2, enabling it to satisfy both the area occupied by the installation of the first pole 310 and avoid space waste, making the battery case assembly structure compact and having high space utilization.

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

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

[0054] Of course, in some other embodiments, along the direction perpendicular to the arrangement direction of the first bottom plate 110 and the second bottom plate 120, the width of the first bottom plate 110 can be less than the width of the second bottom plate 120, that is, along the direction perpendicular to the arrangement direction of the first bottom plate 110 and the second bottom plate 120, both ends of the second bottom plate 120 extend beyond both ends of the first bottom plate 110. In still other embodiments, along the direction perpendicular to the arrangement direction of the first bottom plate 110 and the second bottom plate 120, the width of the first bottom plate 110 can also be greater than the width of the second bottom plate 120, that is, both ends of the first bottom plate 110 extend beyond both ends of the second bottom plate 120.

[0055] Optionally, along a direction perpendicular to the arrangement direction of the first bottom plate 110 and the second bottom plate 120, the protruding portion 600 and the first pole column 310 are arranged at intervals, which is convenient for the processing of the first pole column 310 and the protruding portion 600.

[0056] Furthermore, a liquid injection hole is provided between the protruding portion 600 and the first pole column 310, or a liquid injection hole is provided on the protruding portion 600; the liquid injection hole is blocked by a blocking member 700. Setting the liquid injection hole between the protruding portion 600 and the first pole column 310 makes the liquid injection hole roughly located at the middle position of the second bottom plate 120 in the arrangement direction of the first bottom plate 110 and the second bottom plate 120. When injecting liquid into the battery cell, it is beneficial for the liquid to flow down, that is, injecting the electrolyte from the middle position can fill the accommodation cavity more evenly and shorten the standing time after liquid injection; while setting the liquid injection hole on the protruding portion 600 can save the space occupied by the liquid injection hole on the second bottom plate 120. Optionally, along a direction perpendicular to the arrangement direction of the first bottom plate 110 and the second bottom plate 120, the size of the protruding portion 600 is larger than the size of the first pole column 310, making full use of the space of the second bottom plate 120 in the direction perpendicular to the arrangement direction of the first bottom plate 110 and the second bottom plate 120, increasing the volume of the accommodation groove 610 of the protruding portion 600, and further increasing the volume of the electrolyte accommodated in the housing.

[0057] Preferably, along the direction (y direction) perpendicular to the arrangement direction of the first bottom plate 110 and the second bottom plate 120, the ratio range of the size of the protruding portion 600 to the size of the second bottom plate 120 is 0.1 - 0.5. Exemplarily, it can be 0.1, 0.3, or 0.5, etc. If the ratio of the size of the protruding portion 600 to the size of the second bottom plate 120 is less than 0.1, the size of the protruding portion 600 is too small and the accommodation volume of the accommodation groove 610 is small, without making full use of the space of the second bottom plate 120 in the y direction; if the ratio of the size of the protruding portion 600 to the size of the second bottom plate 120 is greater than 0.5, the space occupied by the protruding portion 600 is too large, and the distances between the protruding portion 600, the first pole column 310, and the liquid injection hole in the y direction will be too small, which will interfere with the liquid injection operation of the liquid injection hole, and the electrolyte leaked during liquid injection is also likely to flow to components such as the first pole column 310. Therefore, controlling the ratio within 0.1 - 0.5 can make full use of the space of the second bottom plate 120 while ensuring a safe distance between the first pole column 310 and the liquid injection hole.

[0058] Optionally, an outwardly expanding boss 210 is provided at the edge of the housing side plate 200 facing away from the housing bottom plate 100. The outwardly expanding boss 210 extends circumferentially along the outer periphery of the housing side plate 200 and is arranged in a closed loop. The battery housing assembly further includes a cover plate 400, which is fastened to the opening 201 and is in fitting connection with the outwardly expanding boss 210. In this embodiment, the cover plate 400 is located within the opening 201, and the periphery of the cover plate 400 is sealingly connected to the inner wall of the outwardly expanding boss 210. That is, the cover plate 400 is used to block the opening 201 of the accommodating cavity, and the housing bottom plate 100, the housing side plate 200, and the cover plate 400 form the housing of the battery cell. The provision of the outwardly expanding boss 210 can increase the contact area between the cover plate 400 and the housing side plate 200, and improve the connection strength and sealing performance between the cover plate 400 and the housing side plate 200.

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

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

[0061] In this embodiment, the wall thickness k1 of the housing bottom plate 100 and the wall thickness k2 of the cover plate 400 both have a value range of 0.05 mm - 0.25 mm. Exemplarily, it can be 0.05 mm, 0.10 mm, 0.15 mm, 0.20 mm, or 0.25 mm.

[0062] Among them, the ratio k2 / k1 of the wall thickness k2 of the cover plate 400 to the wall thickness k1 of the housing bottom plate 100 ranges from 0.5 to 1.5. Exemplarily, k2 / k1 can be 0.5, 0.6, 0.9, 1.2, or 1.5, etc.

[0063] To meet the pressure relief requirement of the battery housing assembly, an explosion-proof notch 111 is provided on the first bottom plate 110. The explosion-proof notch 111 is provided on the surface of the first bottom plate 110 facing away from the accommodating cavity. By arranging the explosion-proof notch 111 on the relatively larger surface of the housing, when the battery cell explodes, the gas can be quickly ejected to achieve explosion.

[0064] It should be noted that when the wall thickness k1 of the housing bottom plate 100 is less than the wall thickness k2 of the cover plate 400, the explosion-proof notch 111 is provided on the thinner side, that is, on the housing bottom plate 100, which is more likely to open the valve for pressure relief and explosion protection.

[0065] In this embodiment, the shape of the explosion-proof notch 111 is a straight groove. Two straight grooves are arranged at intervals on the first bottom plate 110. The two straight grooves are respectively arranged at two opposite corners of the first bottom plate 110, and the groove depth of the straight groove is 30%-80% of the wall thickness of the shell bottom plate 100. Exemplarily, it can be 30%, 60% or 80%. When the ratio of the groove depth of the straight groove to the wall thickness of the shell bottom plate 100 is less than 30%, the groove depth of the straight groove is too shallow, resulting in the inability to explode when the battery cell needs to explode, and the explosion requirement cannot be met. When the ratio of the groove depth of the straight groove to the wall thickness of the shell bottom plate 100 is greater than 80%, the groove depth of the straight groove is too deep, resulting in too low shell strength, and the battery cell is prone to explode prematurely.

[0066] By arranging the two straight grooves at two opposite corners of the first bottom plate 110 respectively, the stress at this corner position is more concentrated than that at other positions of the first bottom plate 110. Therefore, setting the explosion-proof notch 111 at the corner position 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 310. Optionally, explosion-proof notches 111 can also be arranged at the four corner positions of the first bottom plate 110.

[0068] In this embodiment, the first bottom plate 110 is a rectangular plate. The included angle between the straight groove and the side edges at both ends of the first bottom plate 110 along the y direction is α, and 30°≤α≤70°. Exemplarily, α can be 30°, 50° or 70°, etc., and it can be set specifically according to needs. Limiting the angle range of α between 30°-70° makes the straight groove approximately perpendicular to the connection line of the two opposite corners (where the straight groove is arranged) of the first bottom plate 110, makes the straight groove approximately in the opposite orientation to the above corners in the direction of the above connection line, and further makes the explosion strength on the straight groove the same.

[0069] Furthermore, the intersection point of the connection line of the two opposite corners (the corners where the straight groove is arranged) of the straight groove and the first bottom plate 11 is the midpoint of the straight groove.

[0070] For the convenience of distinction, the above two corners are respectively called the first corner and the second corner. The two straight grooves are respectively called the first straight groove and the second straight groove. 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 above-mentioned connecting line to the first corner is s1, the size of the connecting line between the first corner and the second corner is s2, and 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 bottom plate 110; however, the value of s1 / s2 should not be too small. For example, if the value of s1 / s2 is less than 0.1, the distance from the first straight groove to the first corner will be too small, and the first straight groove will exceed the bulging range of the shell (the shell corners have high strength and almost no bulging occurs).

[0072] Typically, the battery housing assembly further includes an upper plastic 320, an aluminum block 330, and a lower plastic 340 to form a first pole assembly 300. Figure 1 , Figure 2 and Figure 5 As shown, the first pole 310 includes a column 311 and a chassis 312 connected to each other, a first mounting hole is provided on the second bottom plate 120, a lower plastic 340 is attached to the side of the second bottom plate 120 facing the accommodating cavity, and a second mounting hole is provided on the lower plastic 340, the second mounting hole is directly opposite to the first mounting hole, the column 311 is penetrated with the second mounting hole and the first mounting hole in sequence, the chassis 312 abuts against the side of the lower plastic 340 away from the second bottom plate 120; the aluminum block 330 is located on the side of the second bottom plate 120 away from the accommodating cavity, and is sleeved and riveted with the column 311; the upper plastic 320 is sleeved on the column 311 and sandwiched between the aluminum block 330 and the second bottom plate 120. The upper plastic 320 is used to insulate and isolate the aluminum block 330 and the second bottom plate 120, and the lower plastic 340 is used to insulate and isolate the second bottom plate 120 and the chassis 312, and the upper plastic 320 and the lower plastic 340 also play a sealing role.

[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, thereby increasing the sealing of the connection between the aluminum block 330 and the column 311, acting as a sealing ring, and further improving the sealing performance of the battery shell 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 along the circumference of the second mounting hole and is arranged in a closed loop. The second annular platform 341 is clamped 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, acting as a sealing ring, further improving the sealing performance of the battery shell assembly.

[0075] By the same token, on the side of the chassis 312 facing the lower plastic 340, there is a third annular platform 3121. On the side of the lower plastic 340 facing the chassis 312, there is an annular groove. The shape of the annular groove is adapted to that of the third annular platform 3121. The third annular platform 3121 can be clamped in the annular groove to improve 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 clamped in the annular groove to achieve close contact between the lower plastic 340 and the chassis 312, thereby improving the sealing performance of the battery case assembly.

[0076] Refer to the attached Figure 6 As shown, in other embodiments of the present invention, both a positive terminal and a negative terminal can be provided on the battery case assembly. Specifically, the battery case assembly further includes a second terminal 510. The polarity of the second terminal 510 is opposite to that of the first terminal 310. The second terminal 510 passes through the second bottom plate 120. At least one of the first terminal 310 and the second terminal 510 is insulatingly connected to the second bottom plate 120. The second terminal 510 can be a positive terminal 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 a specific embodiment, the first terminal 310 is a positive terminal, the second terminal 510 is a negative terminal. The first terminal 310 is insulatingly connected to the second bottom plate 120, and the second terminal 510 is insulatingly connected to the second bottom plate 120. Moreover, the second terminal 510 is electrically connected to the battery cell, and the case bottom plate 100 is insulatingly arranged from the battery cell, which can reduce the risk of external short circuit of the battery cell. At the same time, the material of the case bottom plate 100 does not need to be charged, reducing the requirements for the stability of the material.

[0078] It should be noted that the assembly method of the second terminal 510 can be the same as that of the first terminal 310, that is, the second terminal 510 forms a second terminal assembly 500 with other components, which will not be elaborated here in detail.

[0079] In another specific embodiment, the first terminal 310 is a positive terminal, the second terminal 510 is a negative terminal. The first terminal 310 is insulatingly connected to the second bottom plate 120, and the second terminal 510 is electrically connected to the second bottom plate 120.

[0080] Refer to the attached Figure 7, in yet another embodiment of the present invention, on the basis that both a positive pole column and a negative pole column are provided on the battery case assembly, the setting position of the negative pole column is optimized. Specifically, the battery case assembly further includes a second pole column 510, the polarity of the second pole column 510 is opposite to that of the first pole column 310, and the second pole column 510 penetrates through the protruding portion 600; the first pole column 310 is insulated and connected to the second bottom plate 120; and / or, the second pole column 510 is insulated and connected to the protruding portion. That is, in one implementation, the first pole column 310 is insulated and connected to the second bottom plate 120, and the second pole column 510 is insulated and connected to the protruding portion 600; in another implementation, the first pole column 310 is insulated and connected to the second bottom plate 120, and the second pole column 510 is electrically connected to the protruding portion 600; in yet another implementation, the first pole column 310 is electrically connected to the second bottom plate 120, and the second pole column 510 is insulated and connected to the protruding portion 600. Setting the second pole column 510 on the protruding portion 600 reduces the occupied area of the second bottom plate 120, and the protruding portion 600 can also facilitate the fixing of the second pole column 510.

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

[0082] In this embodiment, the assembly method of the second pole column 510 can still be the same as that of the first pole column 310, that is, the second pole column 510 and other components form a second pole column assembly 500, except that the penetrating position of the second pole column 510 becomes the protruding portion 600 and other parts remain unchanged.

[0083] In yet another embodiment of the present invention, the housing can also be directly used as the positive or negative electrode of the battery cell without additionally providing an extra pole column. In this embodiment, the first pole column 310 is a positive pole column to form the positive electrode of the battery cell; the side of the second bottom plate 120 facing the receiving cavity is connected to the battery core to form the negative electrode of the battery cell. Specifically, the second bottom plate 120 is welded to the negative electrode tab of the battery core. Using the housing 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 structure of the battery cell and reduce the internal resistance.

[0084] Of course, in other implementations, positions on the housing such as the first bottom plate 110, the housing side plate 200, and the cover plate 400 can also be used as the negative electrode. The specific negative electrode connection method can be to weld a nickel strip on the housing to lead out and connect to a terminal (such as a watch, etc.).

[0085] Preferably, the first pole column 310 is a positive pole column, forming the positive pole of the battery cell; the inner wall of the receiving groove 610 (the side where the protruding portion 600 faces the receiving cavity) is electrically connected to the battery core. Specifically, the negative tab of the battery core is welded to the inner wall of the receiving groove 610 to form the negative pole of the battery cell. The protruding portion 600 can be directly connected to the terminal slot, eliminating the nickel strip component and reducing the internal resistance of the battery cell.

[0086] In this embodiment, the protruding portion 600 is arranged in the shape of imitating the first pole column assembly 300 and is spaced from the first pole column assembly 300 on the second bottom plate 120. It is not only beautiful and symmetrical but also can be used as a positioning structure. That is, when the battery cell is assembled to the terminal, the protruding portion 600 can be assembled to the terminal recessed position (slot) to position the battery cell; and the snap connection between the protruding portion 600 and the terminal recessed position enhances the fixation of the battery cell at the terminal and avoids poor contact between the battery cell and the terminal.

[0087] In this embodiment, the liquid injection hole is arranged on the second bottom plate 120 and is located between the first pole column assembly 300 and the protruding portion 600.

[0088] For the same reason as in the previous embodiment, the liquid injection hole is arranged between the protruding portion 600 and the first pole column assembly 300, so that the liquid injection hole is approximately located at the middle position of the second bottom plate 120 in the arrangement direction of the first bottom plate 110 and the second bottom plate 120. When injecting liquid into the battery cell, it is beneficial for the liquid to flow down. That is to say, injecting the electrolyte from the middle position can fill the receiving cavity more evenly and shorten the standing time after liquid injection.

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

[0090] Specifically, the battery cell includes a battery core and the above-mentioned battery case assembly. The battery core is located in the receiving cavity of the battery case assembly, and the battery core is connected to the first pole column 310 of the battery case assembly. Since the first pole column 310 is located on one of the shell bottom plates 100 in the thickness direction of the battery core, the installation difficulty is low; and a protruding portion 600 is provided on the side of the second bottom plate 120 facing away from the receiving cavity. The protruding portion 600 forms a receiving groove 610 on the side of the second bottom plate 120 facing the receiving cavity, and the receiving groove 610 is communicated with the receiving cavity, which can store the electrolyte, thereby increasing the electrolyte capacity of the battery cell.

[0091] Obviously, the above-mentioned embodiments of the present invention are merely examples for clearly illustrating the present invention, rather than limitations on the implementation manners of the present invention. For those of ordinary skill in the art, various obvious changes, re-adjustments and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to enumerate all the implementation manners here. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. A battery housing assembly, characterized in that: include: A shell bottom plate (100), the shell bottom plate (100) comprising a first bottom plate (110) and a second bottom plate (120) arranged in sequence; a shell side plate (200), the shell side plate (200) being arranged around the outer periphery of the shell bottom plate (100) and connected to the shell bottom plate (100) to form a receiving cavity, the opening (201) of the receiving cavity being arranged opposite to the shell bottom plate (100) along the thickness direction of the battery core; A first pole (310), the first pole (310) being disposed through the second bottom plate (120); A protrusion (600), wherein the protrusion (600) is arranged on a side of the second bottom plate (120) facing away from the accommodating cavity, and the protrusion (600) is formed with an accommodating groove (610) on a side of the second bottom plate (120) facing the accommodating cavity, and the accommodating groove (610) is connected to the accommodating cavity.

2. The battery housing assembly according to claim 1, characterized in that: The first pole (310) is a positive pole, forming a positive pole of a battery cell; the inner wall of the receiving groove (610) is electrically connected to the battery core, forming a negative pole of the battery cell.

3. The battery housing assembly according to claim 1, characterized in that: The battery housing assembly also includes a second pole (510), the second pole (510) having a polarity opposite to that of the first pole (310), the second pole (510) being passed through the second bottom plate (120), and at least one of the first pole (310) and the second pole (510) being insulated and connected to the second bottom plate (120).

4. The battery housing assembly according to claim 3, characterized in that: The first pole (310) is a positive pole, the second pole (510) is a negative pole, the first pole (310) is insulated from the second bottom plate (120), and the second pole (510) is insulated from the second bottom plate (120); or, The first pole (310) is a positive pole, the second pole (510) is a negative pole, the first pole (310) is insulated and connected to the second bottom plate (120), the second pole (510) is electrically connected to the second bottom plate (120), and the second bottom plate (120) is electrically connected to the battery cell.

5. The battery housing assembly according to claim 1, characterized in that: The battery housing assembly further includes a second pole (510), the second pole (510) having a polarity opposite to that of the first pole (310), and the second pole (510) is disposed through the protruding portion (600); The first pole (310) is insulated and connected to the second bottom plate (120); and / or the second pole (510) is insulated and connected to the protruding portion.

6. The battery housing assembly according to claim 1, characterized in that: The accommodating cavity comprises a first accommodating cavity and a second accommodating cavity, the first accommodating cavity is opposite to the first bottom plate (110), the second accommodating cavity is opposite to the second bottom plate (120), along the thickness direction of the battery cell, the distance between a side surface of the first bottom plate (110) facing away from the accommodating cavity and a side surface of the second bottom plate (120) facing away from the accommodating cavity is a, the distance between a side surface of the second bottom plate (120) facing away from the accommodating cavity and the opening (201) is b, and 0.5≤a / b≤1.

5.

7. The battery housing assembly according to claim 6, characterized in that: Along the thickness direction of the battery cell, the height of the first pole (310) protruding from the second bottom plate (120) is h1, and the height of the protruding portion (600) protruding from the second bottom plate (120) is h2, wherein h1≤a; h2≤a.

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

2.

9. The battery housing assembly according to any one of claims 1 to 7, characterized in that: An explosion-proof notch (111) is provided on the first bottom plate (110), and the explosion-proof notch (111) is provided on a side surface of the first bottom plate (110) facing away from the accommodating cavity.

10. The battery housing assembly according to claim 9, characterized in that: The explosion-proof notch (111) is in the shape of a linear groove, two linear grooves are arranged on the first bottom plate (110) at intervals, and the two linear grooves are respectively arranged at two opposite corners of the first bottom plate (110).

11. The battery housing assembly according to any one of claims 1 to 7, characterized in that: The protrusion (600) is spaced apart from the first pole (310) along a direction perpendicular to the arrangement direction of the first bottom plate (110) and the second bottom plate (120).

12. The battery housing assembly according to claim 11, characterized in that: A liquid injection hole is provided between the protruding portion (600) and the first pole (310), or a liquid injection hole is provided on the protruding portion (600); The liquid injection hole is blocked by a blocking member (700).

13. The battery housing assembly according to any one of claims 1 to 7, characterized in that: Along a direction perpendicular to the arrangement direction of the first bottom plate (110) and the second bottom plate (120), the size of the protrusion (600) is greater than the size of the first pole (310).

14. A battery cell, characterized in that: It comprises a battery cell and a battery shell assembly as claimed in any one of claims 1 to 13, wherein the battery cell is located in a receiving cavity of the battery shell assembly, and the battery cell is connected to the first pole (310) of the battery shell assembly.

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