Battery shell, battery monomer and battery pack

Abstract

The utility model relates to the technical field of batteries, and discloses a battery shell, a battery monomer and a battery pack, the battery shell comprises a peripheral side wall and a bottom wall, the bottom wall is provided with a groove, the bottom surface of the groove is provided with an explosion-proof wire, the groove and the explosion-proof wire form an explosion-proof valve, and the outer edge of the bottom surface of the groove encloses a first area; the part, except the first area, of the wall surface, provided with the groove, of the bottom wall is a second area; the second area comprises a first sub-area and a second sub-area, the bottom wall is provided with a protrusion, a first projection of the protrusion in the axial direction of the peripheral side wall forms the first sub-area, and the part, except the first sub-area, in the second area is the second sub-area; the maximum thickness of the bottom wall in the first area is H1mm, the maximum thickness of the bottom wall in the first sub-area is H2mm, and H1 is smaller than H2. The protrusions are arranged on the bottom wall and can be used for secondary welding when the battery is assembled into a battery pack or electric equipment, a good welding effect can be guaranteed, and the problem that the battery is easy to weld through when the battery is thin is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, and in particular to a battery shell, a battery cell and a battery pack. Background Art

[0002] In the related art, the main measure to prevent explosions when batteries fail is to set explosion-proof wires at the bottom of the battery casing. When the battery fails and produces gas, the explosion-proof wires rupture and discharge the gas in the battery casing to reduce the pressure inside the battery casing, thereby preventing the battery from exploding. In order to ensure the blasting effect, the thickness of the explosion-proof wires is relatively thin. In order to ensure sufficient structural strength, the bottom where the explosion-proof wires are located is generally thicker. This will cause the difference between the thickness of the explosion-proof wires and the thickness of the bottom of the battery casing to be too large, making it difficult to form the shell. At the same time, in order to ensure the secondary welding effect of the battery when assembled into the battery pack or electrical equipment, the secondary welding area at the bottom of the battery needs to be further thickened, which further increases the thickness difference between the bottom of the battery and the explosion-proof wires, making it more difficult to form the shell.

[0003] Furthermore, the winding core and current collecting tray in current battery cells are currently placed inside the battery casing, closely attached to the bottom inner side of the casing. This interferes with gas flow during pressure relief, affecting the pressure relief effect. Furthermore, the large contact area between the current collecting tray and the bottom wall of the battery casing can easily lead to poor adhesion, which in turn causes poor welding between the current collecting tray and the bottom wall. Utility Model Content

[0004] The purpose of the utility model is to provide a battery shell, which is designed with gradient thickness in different regions, so as to facilitate the forming of the explosion-proof valve and have a good welding effect, thereby avoiding the problem of easy welding through. In addition, it also improves the gas flow when the battery is depressurized.

[0005] In a first aspect, the present application provides a battery housing, comprising a peripheral side wall and a bottom wall, wherein the bottom wall is connected to one end of the peripheral side wall to form a receiving cavity with one end open;

[0006] The bottom wall is provided with a groove, the depth direction of the groove is the same as the axial direction of the peripheral side wall, the bottom surface of the groove is provided with an explosion-proof line, and the outer edge of the bottom surface of the groove forms a first area;

[0007] The portion of the bottom wall where the groove is provided except the first area is the second area;

[0008] The bottom wall has a protrusion, the protrusion direction of the protrusion is the same as the axial direction of the peripheral side wall, and the first projection of the protrusion in the axial direction of the peripheral side wall falls within the second area;

[0009] The second area includes a first sub-area and a second sub-area, the first projection forms the first sub-area, and a portion of the second area other than the first sub-area is the second sub-area;

[0010] The maximum thickness of the bottom wall in the first region is H1 mm, and the maximum thickness of the bottom wall in the first sub-region is H2 mm, wherein H1<H2.

[0011] In one embodiment, the maximum thickness of the bottom wall in the second sub-region is H3 mm, wherein H1 < H3 < H2.

[0012] In one embodiment, there are multiple grooves, and all of the grooves are distributed at equal angles around the center of the bottom wall.

[0013] In one embodiment, the bottom wall has a first surface and a second surface opposite to each other, wherein the surface of the bottom wall facing the peripheral side wall is the first surface;

[0014] The protrusions are located on the first surface and / or the second surface.

[0015] In one embodiment, the protrusion is located on the first surface and in the accommodating cavity, and the protrusion includes a first protrusion portion, which is located at the center of the bottom wall.

[0016] In one embodiment, the protrusion further includes a plurality of second protrusions evenly distributed around the periphery of the first protrusion, one end of the second protrusion is connected to the first protrusion, and the other end extends to the peripheral side wall and is connected to the peripheral side wall.

[0017] In one embodiment, a plurality of the second protrusions are distributed at equal angular intervals on the periphery of the first protrusion.

[0018] In one embodiment, the height of the second protrusion is the same as the height of the first protrusion.

[0019] In one embodiment, the number of the second protrusions is three, and the three second protrusions are distributed at equal angular intervals on the periphery of the first protrusion, and the angle between two adjacent second protrusions is 120°.

[0020] In one embodiment, the groove is provided on the second surface and is formed by the second surface being concave toward the first surface.

[0021] In one embodiment, the groove is provided on the first surface and is formed by the first surface being concave toward the second surface.

[0022] In one embodiment, the groove is provided in plurality, and the plurality of second protrusions and the plurality of grooves are staggered and distributed at equal angles.

[0023] In one embodiment, the groove is elliptical, and the major axis of the ellipse is arranged along the radial direction of the peripheral side wall.

[0024] In one embodiment, in the radial direction of the peripheral side wall, the distance from one end of the explosion-proof wire close to the peripheral side wall to the outer wall surface of the peripheral side wall is L mm, and L≤5.0.

[0025] In a second aspect, the present application also provides a battery cell comprising the battery housing as described above.

[0026] In a third aspect, the present application also provides a battery pack comprising a plurality of battery cells as described above.

[0027] The above technical solution provided by the embodiment of the present application has the following advantages compared with the prior art:

[0028] (1) By setting a protrusion on the bottom wall, the protrusion can be used for secondary welding of the battery assembly into the battery pack or electrical equipment. The thickness here is relatively thick, which can ensure a good welding effect and avoid the problem of easy welding through when it is thin. At the same time, the area of ​​the battery bottom wall used for secondary welding is separated from other areas. The area outside the protrusion can be made thinner, which is convenient for the formation of the groove and the explosion-proof line, ensuring that when the battery is depressurized, the first area surrounded by the outer edge of the bottom surface of the groove can be partially or completely broken through by the gas in time, allowing the gas generated in the battery to escape quickly.

[0029] (2) When the second protrusion of the protrusion is connected to the peripheral side wall, the protrusion plays a major supporting role for the bottom wall, and the area outside the protrusion in the second area of ​​the bottom wall can be further thinned, making it easier to form the explosion-proof valve.

[0030] (3) When the protrusion of the bottom wall is provided on the first surface, the battery core and the current collecting tray are supported by the protrusion, thereby forming a gap between the battery core and the current collecting tray and the bottom wall, thereby preventing the battery core and the current collecting tray from being pressed against the bottom wall. This ensures that the gas inside the housing can pass smoothly when the battery is depressurized, which is conducive to the rapid discharge of the gas. At the same time, the presence of the protrusion can make the current collecting tray and the first surface of the bottom wall fit more tightly during welding, that is, the welding between the current collecting tray and the protrusion of the bottom wall, thereby significantly reducing the welding defect rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The accompanying drawings are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present invention, and together with the description, serve to explain the principles of the present invention.

[0032] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0033] In the attached figure:

[0034] Figure 1 This is a cross-sectional view of a battery casing of the present application;

[0035] Figure 2 This is a structural diagram of a battery shell in this application

[0036] Figure 3 This is a structural schematic diagram of the bottom wall of a battery housing of the present application;

[0037] Figure 4 This is a schematic diagram of the interior of a battery housing of the present application;

[0038] Figure 5 This is a schematic diagram of a battery housing of the present application in which a protrusion is provided on a first surface;

[0039] Figure 6 This is a schematic diagram of a battery housing of the present application having a protrusion provided on the second surface;

[0040] Figure 7 This is a schematic structural diagram of a protrusion on a battery casing of the present application.

[0041] Figure Number:

[0042] 10. Battery casing; 11. Side wall; 12. Bottom wall; 12a. First surface; 12b. Second surface; 20. Groove; 30. Accommodation cavity; 40. Explosion-proof line; 50. Protrusion; 51. First protrusion; 52. Second protrusion; A. First sub-region; B. Second sub-region; C. First region. DETAILED DESCRIPTION

[0043] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, the specific embodiments of the present invention are now described in detail with reference to the accompanying drawings. In the following description, it should be understood that the directions or positional relationships indicated by "front", "back", "up", "down", "left", "right", "longitudinal", "horizontal", "vertical", "horizontal", "top", "bottom", "inside", "outside", "head", "tail", etc. are based on the directions or positional relationships shown in the accompanying drawings and are constructed and operated in specific directions. They are only for the convenience of describing the present technical solution and do not indicate that the devices or components referred to must have specific directions. Therefore, they should not be understood as limiting the present invention.

[0044] It should also be noted that, unless otherwise clearly specified and limited, terms such as "installed", "connected", "connected", "fixed", and "set" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; 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 internal connection of two elements or the interaction relationship between two elements. When an element is referred to as being "on" or "under" another element, the element can be "directly" or "indirectly" located on the other element, or there may be one or more intervening elements. The terms "first", "second", and "third" are only for the convenience of describing the present technical solution, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first", "second", and "third" can explicitly or implicitly include one or more of the features. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to the specific circumstances.

[0045] In the following description, specific details such as specific system structures and techniques are provided for purposes of illustration, not limitation, to facilitate a thorough understanding of the embodiments of the present invention. However, it will be apparent to those skilled in the art that the present invention may be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to avoid obscuring the description of the present invention with unnecessary detail.

[0046] In the present application, the explosion-proof line 40 described below is an indentation formed by pressing during the manufacturing process. Its function is to break through the bottom of the groove 20 to release the gas inside the battery when an abnormal situation occurs in the battery (such as overcharging, short circuit, continuous heating to thermal runaway, etc.), thereby helping to relieve the internal pressure of the battery and prevent the battery from exploding or catching fire.

[0047] Example 1

[0048] Please refer to Figure 1 and Figure 2The present application provides a battery housing 10, which includes a peripheral side wall 11 and a bottom wall 12. The bottom wall 12 is connected to one end of the peripheral side wall 11 to form a receiving cavity 30 with an open end. The bottom wall 12 is provided with a groove 20, the depth direction of the groove 20 is the same as the axial direction of the peripheral side wall 11, the bottom surface of the groove 20 is provided with an explosion-proof line 40, the outer edge of the bottom surface of the groove 20 forms a first area C, the wall surface of the bottom wall 12 provided with the groove 20, except for the first area, is a second area, the bottom wall 12 has a protrusion 50, the protrusion 50 direction is the same as the axial direction of the peripheral side wall 11, and the first projection of the protrusion 50 in the axial direction of the peripheral side wall 11 falls into the second area. The second area includes a first sub-area A and a second sub-area B. The first projection forms the first sub-area A, and the part of the second area except the first sub-area A is the second sub-area B. The maximum thickness of the bottom wall 12 in the first region C is H1 mm, and the maximum thickness of the bottom wall 12 in the first sub-region A is H2 mm, where H1<H2.

[0049] It should be noted that the second region includes the plane where the notch of the groove 20 is located on the bottom wall 12, the outer surface of the protrusion 50, and the groove wall surface of the groove 20 away from its center. The second region does not serve as a pressure relief explosion function. An explosion-proof wire 40 is provided on the bottom surface of the groove 20. The outer edge of the bottom surface of the groove 20 forms the first region C. The provision of the explosion-proof wire 40 weakens the strength of the bottom wall 12 at this location, so that when the gas generated inside the battery housing 10 increases to a certain level, the pressure of the gas inside will break through the explosion-proof wire 40, thereby partially or completely breaking open the first region C, allowing the gas to quickly escape from the housing, thereby preventing the single battery from exploding and catching fire. That is, the provision of the explosion-proof wire 40 enables the first region C to serve as a pressure relief explosion function. When the battery experiences an abnormal condition (such as overcharging, short circuiting, continuous heating to runaway, etc.), the first region C is breached by the gas generated in the battery, allowing the gas generated in the battery to quickly escape, while the second region is not breached by the gas generated in the battery to relieve pressure.

[0050] The battery casing 10 based on the above technology is provided with a protrusion 50 on the bottom wall 12. The protrusion 50 is used for secondary welding of the battery assembly into the battery pack or electrical equipment. The thickness here is relatively thick, which can ensure a good welding effect and avoid the problem of easy welding through when it is thin. At the same time, the area of ​​the battery bottom wall 12 used for secondary welding is separated from other areas. The area outside the protrusion 50 can be made thinner, which is convenient for the formation of the groove 20 and the explosion-proof line 40, ensuring that when the battery is depressurized, the first area C enclosed by the outer edge of the bottom surface of the groove 20 can be broken through by the gas in time, allowing the gas generated in the battery to quickly leak out.

[0051] In one embodiment, the maximum thickness of the bottom wall 12 in the second sub-region B is H3 mm, wherein H1 < H3 < H2.

[0052] For example, the thickness of the bottom wall 12 in the second sub-region B is relatively small relative to the thickness of the first sub-region A. That is, when the battery shell is stamped or stretched, a first region C with a thickness smaller than that of the second sub-region B is formed, and an explosion-proof line 40 is formed in the groove 20. This makes it easier to form the explosion-proof valve and ensures that the first region C can be more easily broken through by gas when the battery is depressurized.

[0053] In this embodiment, the shape of the groove 20 can also be annular. For example, the groove 20 is an annular shape connected end to end, in which case the bottom surface of the groove 20 is annular; or the groove 20 is C-shaped, in which case the bottom surface of the groove 20 is C-shaped. If the outer edge of the notch of the explosion-proof wire 40 coincides with the outer edge of the bottom surface of the groove 20, the boundary of the first area is the intersection of the outer edge of the bottom surface of the groove 20 and the outer edge of the bottom surface of the explosion-proof wire 40. In this regard, this application does not limit the specific shape of the groove 20.

[0054] In one embodiment, the bottom wall 12 and the peripheral side walls 11 may be an integral piece or separate pieces. That is, the bottom wall 12 and the peripheral side walls 11 may be formed using an integral molding process, or the bottom wall 12 and the peripheral side walls 11 may form two separate structures, that is, the bottom wall 12 and the peripheral side walls 11 may be formed separately and then connected to form the battery housing 10.

[0055] Specifically, in this embodiment, the battery housing 10 is formed by a stamping process so that the bottom wall 12 and the peripheral side wall 11 are integrally formed, and the connection between the peripheral side wall 11 and the bottom wall 12 can be omitted, thereby ensuring the structural strength of the battery housing 10. In addition, the battery housing of this embodiment is made of aluminum, but is not limited thereto.

[0056] In one embodiment, there are multiple grooves 20, all of which are distributed at equal angles around the center of the bottom wall 12. In this way, multiple explosion-proof valves can be formed on the bottom wall 12, which facilitates the rapid release of gas generated in the battery housing 10 and achieves a better pressure relief effect. At the same time, it can also make the force and material flow more uniform during the molding process, thereby making the dimensions of each part more uniform, making the explosion value of the explosion-proof valve formed by the grooves 20 and the explosion-proof line 40 more stable.

[0057] Reference Figure 3In one embodiment, the bottom wall 12 has opposing first and second surfaces 12a, 12b. The surface of the bottom wall 12 facing the peripheral sidewall 11 is the first surface 12a, and the surface of the bottom wall 12 facing away from the peripheral sidewall 11 is the second surface 12b. In other words, defining the two opposing surfaces of the bottom wall 12 as the first surface 12a and the second surface 12b, respectively, is intended to facilitate description of the connection between the bottom wall 12 and the peripheral sidewall 11, as well as the location of the groove 20 on the bottom wall 12, in this embodiment. Specifically, after the bottom wall 12 and the peripheral sidewall 11 are connected to form a housing, the first surface 12a of the bottom wall 12 is specifically the bottom surface of the housing's accommodating cavity 30, and the second surface 12b of the bottom wall 12 is specifically the outer bottom surface of the housing.

[0058] In practical applications, the battery housing, the winding core, and the current collecting disk constitute part of the battery structure. The winding core is conductively connected to the battery housing through the current collecting disk, and the current collecting disk is located between the winding core and the bottom wall. Specifically, refer to Figure 4 and Figure 5 The protrusion 50 is located on the first surface 12a and in the accommodating cavity 30. That is to say, at this time, the protrusion 50 plays a role in supporting the winding core and the current collecting disk placed in the accommodating cavity 30, so that the winding core and the current collecting disk are propped up and there is a gap between them and the bottom wall 12, preventing the winding core and the current collecting disk from being tightly attached to the first surface 12a of the bottom wall 12, ensuring that when the battery encounters an extreme situation (such as thermal runaway), the gas inside the shell 10 can pass smoothly, which is conducive to the rapid discharge of the gas. At the same time, the protrusion 50 can also be used for secondary welding when the battery is assembled into a battery pack or an electrical device, which can ensure a good welding effect and avoid the problem of easy penetration when it is thin. In addition, the bottom wall 12 is connected to the current collecting disk through the protrusion, and the contact area between the two is relatively small. Therefore, the force area of ​​the protrusion 50 is small, and the pressure it is subjected to is greater, which can make the current collecting disk and the protrusion 50 fit more closely, further improving the contact between the current collecting disk and the battery shell 10, making it more conducive to welding and reducing the defective rate of welding.

[0059] Reference Figure 6 In another embodiment, the protrusion 50 is located on the second surface 12b. In other words, the protrusion 50 in this case only serves to prevent welding penetration. That is, during secondary welding in a battery pack or electrical device, the welding tab is brought into contact with the protrusion 50 and welded using welding equipment at the contact point to prevent penetration due to the thinness of the second sub-region B.

[0060] In other embodiments, both the first surface 12a and the second surface 12b are provided with protrusions 50. In this case, the battery housing has both of the above-mentioned effects when used.

[0061] Reference Figure 7In one embodiment, the protrusion 50 includes a first protrusion 51, which is located in the middle of the bottom wall 12. Specifically, the protrusion 50 may consist solely of the first protrusion 51, and the first protrusion 51 is located in the middle of the bottom wall 12 to better support the collecting plate. It should be noted that the shape of the first protrusion 51 can be circular or other shapes, without limitation.

[0062] Reference Figure 7 In one embodiment, the protrusion 50 further includes a plurality of second protrusions 52 evenly distributed around the periphery of the first protrusion 51. One end of the second protrusion 52 is connected to the first protrusion 51, and the other end extends to and is connected to the peripheral sidewall 11. In other words, the winding core and the current collecting tray are primarily supported by the first protrusion 51 and its second protrusions 52. This ensures that in extreme situations (such as thermal runaway), the winding core and the current collecting tray can be supported over a larger area. This prevents the winding core from moving toward the bottom wall 12 outside the first protrusion during battery deflation, interfering with gas flow and affecting the rapid release of gas from the battery housing 10. Furthermore, because the second protrusions 52 are connected to the peripheral sidewall, the first and second protrusions 51, 52 can now support the bottom wall, weakening the supporting role of the second sub-region B. Consequently, the thickness of the second sub-region B can be further reduced, making the formation of the explosion-proof valve easier.

[0063] In one embodiment, a plurality of second protrusions 52 are distributed on the periphery of the first protrusion 51 at equal angular intervals.

[0064] The above-mentioned multiple refers to two or more, which can be determined according to actual conditions. Specifically in this application, the number of second protrusions 52 is three, and the three second protrusions 52 are spaced apart on the outside of the center of the first protrusion 51, and the angle between two adjacent second protrusions 52 is 120°. In other words, the three second protrusions 52 are spaced apart at an angle of 120° on the outside of the center of the first protrusion 51 to divide the second sub-area B at the bottom into three areas, which makes it easier to select the desired area to form the explosion-proof valve according to needs. At the same time, the three second protrusions 52 spaced apart at an angle of 120° can also better support the winding core and the collecting plate.

[0065] In one embodiment, the second protrusion 52 and the first protrusion 51 are in a strip shape, and the height of the second protrusion 52 is the same as that of the first protrusion 51. That is, the heights of the first protrusion 51 and the second protrusion 52 are set to be the same to provide a more stable support function; in other embodiments, the second protrusion 52 and the first protrusion 51 can also have other shapes, such as a stepped structure, which is not limited in this application.

[0066] In one embodiment, a plurality of grooves 20 are provided, and the plurality of second protrusions 52 and the plurality of grooves 20 are staggered and distributed at equal angles. This facilitates the processing and forming of the explosion-proof valve structure, and ensures that when the battery pressure is released, the gas generated in the battery housing 10 can more easily break through the first area C.

[0067] In one embodiment, the groove 20 is provided on the second surface 12 b of the bottom wall 12 and is formed by the second surface 12 b of the bottom wall 12 being concave inward toward the first surface 12 a .

[0068] In this embodiment, the groove 20 is disposed on the second surface 12b of the bottom wall 12, which is the outer surface of the battery housing. An explosion-proof wire 40 is disposed on the bottom surface of the groove 20, and the outer edge of the bottom surface of the groove 20 forms a first region C. In other words, the first region C is recessed inward relative to the second surface 12b of the bottom wall 12. As a result, when the battery is bumped, it will first strike the higher portion of the second surface 12b of the bottom wall 12 and is less likely to strike the first region C where the explosion-proof wire is disposed, thereby ensuring the high reliability of the battery explosion-proof valve.

[0069] In other embodiments, the groove 20 can also be provided on the first surface 12a of the bottom wall 12, and formed by the first surface 12a of the bottom wall 12 being concave toward the second surface 12b. That is, a groove 20 is provided on the bottom wall 12, and an explosion-proof line 40 is provided on the bottom surface of the groove 20, so that the outer edge of the bottom surface of the groove 20 forms a first area C. Since the surface of the first area C is lower than the highest point of the first surface 12a of the bottom wall 12, there is a gap between the winding core, the collecting plate and the first area C. When the pressure is released, it can be ensured that the flow of the gas will not be interfered with, which is conducive to the rapid discharge of the gas, and at the same time, it can prevent the collecting plate from hitting the explosion-proof valve and damaging the explosion-proof valve. In addition, the explosion-proof valve formed by the groove 20 and the explosion-proof line 40 is provided on the first surface 12a of the bottom wall 12, which can be easier to form and can also be secondary molded.

[0070] In one embodiment, the groove 20 is elliptical, with the major axis of the ellipse arranged radially along the peripheral sidewall 11. In actual use, since the material is moved radially (radially) from the center of the bottom wall 12 during the molding process along the peripheral sidewall 11, the explosion-proof valve formed by this structure is easier to mold and can achieve a more uniform size distribution after molding. In addition, it is understood that during the machining process of the groove 20, due to machining errors, the groove 20 is not an absolute ellipse, and the situation where the groove 20 is elliptical also falls within the scope of protection of this application.

[0071] Reference Figure 6In one embodiment, in the radial direction of the peripheral sidewall 11, the distance L between the end of the explosion-proof wire 40 closest to the peripheral sidewall 11 and the peripheral sidewall 11 is 5.0 mm or less. This ensures that the explosion-proof wire 40 is relatively close to the peripheral sidewall 11. When the battery pressure is released, the pressure on the peripheral sidewall 11 is relatively small, effectively preventing the peripheral sidewall 11 or its associated locations from cracking.

[0072] Example 2

[0073] Based on the above-mentioned battery housing 10 , the present invention further provides a single battery, which includes the battery housing 10 of the above-mentioned embodiment 1.

[0074] It is understandable that the battery cell of the embodiment of the present application includes the technical features and technical effects of the aforementioned battery housing 10, which will not be repeated here.

[0075] Example 3

[0076] Based on the above-mentioned single battery, the present invention also provides a battery pack, which includes a plurality of the above-mentioned single batteries, wherein the plurality of single batteries can be connected in series or in parallel, without limitation.

[0077] It can be understood that the battery pack of the embodiment of the present application includes the technical features and technical effects of the aforementioned single battery, which will not be repeated here.

[0078] It can be understood that the above embodiments only express the preferred implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the patent scope of the present invention. It should be pointed out that for ordinary technicians in this field, without departing from the concept of the present invention, the above technical features can be freely combined, and several deformations and improvements can be made, all of which fall within the scope of protection of the present invention. Therefore, all equivalent changes and modifications made to the scope of the claims of the present invention should fall within the scope of coverage of the claims of the present invention.

Claims

1. A battery casing, characterized in that: It comprises a peripheral side wall (11) and a bottom wall (12), wherein the bottom wall (12) is connected to one end of the peripheral side wall (11) to form a receiving cavity (30) with one end open; The bottom wall (12) is provided with a groove (20), the depth direction of the groove (20) is the same as the axial direction of the peripheral side wall (11), the bottom surface of at least one of the grooves (20) is provided with an explosion-proof line (40), and the outer edge of the bottom surface of the groove (20) forms a first area (C); The portion of the wall surface of the bottom wall (12) provided with the groove (20) other than the first area is the second area; The bottom wall (12) has a protrusion (50), the protrusion direction of the protrusion (50) is the same as the axial direction of the peripheral side wall (11), and the first projection of the protrusion (50) in the axial direction of the peripheral side wall (11) falls within the second area; The second area includes a first sub-area (A) and a second sub-area (B), the first projection forms the first sub-area (A), and the portion of the second area other than the first sub-area (A) is the second sub-area (B); The maximum thickness of the bottom wall (12) in the first region (C) is H1 mm, and the maximum thickness of the bottom wall (12) in the first sub-region (A) is H2 mm, wherein H1<H2.

2. The battery housing according to claim 1, wherein: The maximum thickness of the bottom wall (12) in the second sub-region (B) is H3 mm, wherein H1<H3<H2.

3. The battery housing according to claim 1, wherein: There are a plurality of grooves (20), and all of the grooves (20) are distributed at equal angles around the center of the bottom wall (12).

4. The battery housing according to claim 1, wherein: The bottom wall (12) has a first surface (12a) and a second surface (12b) opposite to each other, wherein the surface of the bottom wall (12) facing the peripheral side wall (11) is the first surface (12a); The protrusion (50) is located on the first surface (12a) and / or the second surface (12b).

5. The battery housing according to claim 4, wherein: The protrusion (50) is located on the first surface (12a) and in the accommodating cavity (30), and the protrusion (50) includes a first protrusion portion (51), and the first protrusion portion (51) is located at the center of the bottom wall (12).

6. The battery housing according to claim 5, characterized in that The protrusion (50) further includes a plurality of second protrusions (52) uniformly distributed around the periphery of the first protrusion (51), one end of the second protrusion (52) being connected to the first protrusion (51), and the other end extending to the peripheral side wall (11) and being connected to the peripheral side wall (11).

7. The battery housing according to claim 6, wherein: A plurality of the second protrusions (52) are distributed at equal angular intervals on the periphery of the first protrusion (51).

8. The battery housing according to claim 6, wherein: The height of the second protrusion (52) is the same as the height of the first protrusion (51).

9. The battery housing according to claim 7, wherein: The number of the second protrusions (52) is three, and the three second protrusions (52) are distributed at equal angular intervals on the periphery of the first protrusion (51), and the angle between two adjacent second protrusions (52) is 120°.

10. The battery housing according to claim 4, wherein: The groove (20) is provided on the second surface (12b) and is formed by the second surface (12b) being concave toward the first surface (12a).

11. The battery housing according to claim 4, wherein: The groove (20) is provided on the first surface (12a) and is formed by the first surface (12a) being concave toward the second surface (12b).

12. The battery housing according to claim 7, wherein: The grooves (20) are provided in plurality, and the plurality of second protrusions (52) and the plurality of grooves (20) are staggered and distributed at equal angle intervals.

13. The battery housing according to claim 12, wherein: The groove (20) is elliptical, and the major axis of the ellipse is arranged along the radial direction of the peripheral side wall (11).

14. The battery housing according to claim 13, wherein: In the radial direction of the peripheral side wall (11), the distance from one end of the explosion-proof wire (40) close to the peripheral side wall (11) to the outer wall surface of the peripheral side wall (11) is L mm, and L≤5.

0.

15. A battery cell, characterized in that: The invention comprises a battery housing, wherein the battery housing is the battery housing according to any one of claims 1 to 14.

16. A battery pack, characterized in that: The device comprises a plurality of battery cells as claimed in claim 15 .

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