Battery cell shell assembly, battery cell and battery pack

Abstract

The utility model relates to the technical field of batteries, and discloses a battery cell shell assembly, a battery cell and a battery pack. The battery cell shell assembly comprises a shell and an anti-explosion valve. The shell is defined by two first side walls which are oppositely arranged and two second side walls which are oppositely arranged, the area of the first side walls is smaller than that of the second side walls, one side of any first side wall sinks towards the other side to form a sinking table, and a mounting hole is formed in the sinking table; the anti-explosion valve is arranged in the mounting hole and located on one side of the sinking table. The wall thickness of the first side wall is equal to that of the second side wall, the wall thickness a of the shell, the thickness f of the shell, the width b of the anti-explosion valve in the thickness direction of the shell and the value range of the distance c between the anti-explosion valve and any side edge of the sinking table are limited, and f-b-2c-6a is larger than or equal to 4 mm and smaller than or equal to 49.8 mm. According to the explosion-proof valve, the technical problem of thin-wall welding of the explosion-proof valve is solved, the internal space of the battery cell is not occupied, the explosion-proof valve does not protrude out of the outer wall of the shell, and the failure risk is low.

Description

Technical Field

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

[0002] With the continuous development of technology, users' requirements for new energy batteries are becoming increasingly higher. To improve the safety performance of battery cells, pressure relief mechanisms are often installed on the cells. When the battery cell is operating abnormally and gas is generated inside, the pressure relief mechanism can be used to discharge the gas, thus preventing major safety accidents.

[0003] Currently, the pressure relief mechanism, or explosion-proof valve, of battery cells is located on the cover plate, which also contains the terminal for electrical connection. As a safety measure, the explosion-proof valve needs to open in the event of thermal runaway, venting gases, which can cause electrolyte spray and potentially sparks that could cause fire. To maximize cell capacity and ensure safer packing, thinning the cell casing to increase internal space and relocating the pressure relief structure from the cover plate to the sidewall of the casing to achieve thermal and electrical separation are very effective methods.

[0004] In the related art, welding an explosion-proof valve on the side wall of the shell requires that the shell have sufficient wall thickness to form a step, and the explosion-proof valve is welded to the outer wall of the shell. Therefore, the shell with a bottom-out explosion-proof valve is mostly welded on one side of the explosion-proof valve. The wall thickness is thicker than the other three sides, which increases the weight of the shell. In addition, it is difficult to weld the thin-walled explosion-proof valve. The explosion-proof valve occupies the internal space of the battery cell and has a high risk of failure. Utility Model Content

[0005] In view of this, the present invention provides a battery cell shell assembly, a battery cell and a battery pack to solve the problems of difficulty in welding thin-wall explosion-proof valves, the explosion-proof valves occupying the internal space of the battery cell and the high risk of failure.

[0006] In a first aspect, the present invention provides a battery cell housing assembly, comprising a housing and an explosion-proof valve. The housing is enclosed by two opposing first side walls and two opposing second side walls, the area of the first side wall being smaller than the area of the second side wall, one side of any first side wall being recessed toward the other side to form a sunken platform, and the sunken platform being provided with a mounting hole; the explosion-proof valve is provided in the mounting hole and is located on one side of the sunken platform; the wall thickness of the first side wall is equal to the wall thickness of the second side wall, the wall thickness of the housing is a, 0.2mm≤a≤0.8mm; the thickness of the housing is f, 14.2mm≤f≤60mm; the width of the explosion-proof valve along the thickness direction of the housing is b, 8mm≤b≤30mm, the spacing between the explosion-proof valve and either side edge of the sunken platform is c, 0.5mm≤c≤1mm; and 4mm≤fb-2c-6a≤49.8mm.

[0007] Beneficial Effects: The battery cell housing assembly provided by the present invention is designed with a uniform wall thickness. Compared to related technical solutions in which the side wall where the explosion-proof valve is located is set to a thicker wall, the present invention does not increase the weight of the housing. By providing a sink on the housing, a mounting hole is provided on the sink, and the explosion-proof valve is positioned at the mounting hole and located within the sink, and is fixed and sealed by welding, the technical difficulties of thin-walled welding explosion-proof valves are solved. The explosion-proof valve does not occupy the internal space of the battery cell, and the explosion-proof valve does not protrude from the outer wall of the housing, reducing the risk of failure.

[0008] Moreover, by controlling parameters such as the wall thickness a of the first side wall, the thickness f of the shell, the width b of the explosion-proof valve along the thickness direction of the shell, and the spacing c between the explosion-proof valve and any side edge of the sink within the above-mentioned corresponding ranges, the strength of the shell can be ensured, and manufacturing can be facilitated. The production yield of the battery cell shell assembly is high and the efficiency is fast, which is conducive to cost control.

[0009] Controlling the width b of the explosion-proof valve within the range of 8mm to 30mm can adapt to process manufacturing and product performance requirements. Controlling the distance c between the explosion-proof valve and either side edge of the sink to a range greater than 0.5mm can meet tooling positioning requirements. At the same time, controlling c to a range less than 1mm can save space. The thickness f of the shell is at least b+2×(c+d+e+r), that is, f≥14.2mm, and due to the process requirements of the shell.

[0010] In an optional embodiment, the first side wall and the second side wall are transitionally connected via an arc segment, and the radius of the arc segment is r, 1.2 mm ≤ r ≤ 1.8 mm.

[0011] In an optional embodiment, along the thickness direction of the shell, the first side wall and the sink are connected by a limiting section, and the width of the limiting section is d, where d=2a.

[0012] In an optional embodiment, along the thickness direction of the shell, the distance between the limiting segment and the arc segment is e, 1mm≤e≤23.9mm.

[0013] In an optional embodiment, along the thickness direction of the shell, the width of the sink is j, j=b+2c+2d, and 8.9 mm≤j≤32.6 mm.

[0014] In an optional embodiment, along the length direction of the shell, the distance between the explosion-proof valve and any side edge of the sink is g, 2.5mm≤g≤6mm.

[0015] In an optional embodiment, along the length direction of the shell, the length of the explosion-proof valve is h, b≤h≤4b, and 8mm≤h≤120mm.

[0016] In an optional embodiment, along the length direction of the shell, the length of the sink is k, k = h + 2 × (g + d), and 13.8 mm ≤ k ≤ 133.6 mm.

[0017] In a second aspect, the present invention further provides a battery cell comprising the battery cell housing assembly of any one of the above technical solutions, as well as an electrode group and a battery cell cover assembly. The electrode group is disposed within the battery cell housing assembly, and the battery cell cover assembly is connected to the battery cell housing assembly to encapsulate the electrode group within the battery cell housing assembly.

[0018] Beneficial effect: Since the battery cell includes the battery cell shell assembly, it has the same effect as the battery cell shell assembly and will not be described in detail here.

[0019] In a third aspect, the present invention further provides a battery pack comprising the battery cell in the above technical solution.

[0020] Beneficial effects: Since the battery pack includes battery cells, it has the same effects as the battery cells and will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0022] Figure 1 This is a structural schematic diagram of a battery cell housing assembly according to an embodiment of the present utility model;

[0023] Figure 2 for Figure 1 A top view of the cell housing assembly is shown;

[0024] Figure 3 For the Figure 2 Partial cross-sectional view at AA in the middle;

[0025] Figure 4 For the Figure 2 Partial cross-sectional view at the middle BB.

[0026] Description of reference numerals:

[0027] 1. Shell; 101. First side wall; 1011. Sink; 1012. Mounting hole; 1013. Limiting section; 102. Second side wall; 103. Arc section; 2. Explosion-proof valve. DETAILED DESCRIPTION

[0028] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative efforts shall fall within the scope of protection of the present invention.

[0029] The following combination Figures 1 to 4 , describing the embodiments of the present utility model.

[0030] According to an embodiment of the present utility model, in a first aspect, a battery cell housing assembly is provided, comprising a housing 1 and an explosion-proof valve 2 . The shell 1 is enclosed by two oppositely arranged first side walls 101 and two oppositely arranged second side walls 102. The area of the first side wall 101 is smaller than the area of the second side wall 102. One side of any first side wall 101 is recessed toward the other side to form a sink 1011, and the sink 1011 is provided with a mounting hole 1012; the explosion-proof valve 2 is arranged in the mounting hole 1012 and is located on one side of the sink 1011; the wall thickness of the first side wall 101 and the wall thickness of the second side wall 102 are equal, the wall thickness of the shell 1 is a, 0.2mm≤a≤0.8mm; the thickness of the shell 1 is f, 14.2mm≤f≤60mm; along the thickness direction of the shell 1, the width of the explosion-proof valve 2 is b, 8mm≤b≤30mm, and the distance between the explosion-proof valve 2 and any side edge of the sink 1011 is c, 0.5mm≤c≤1mm; and, 4mm≤fb-2c-6a≤49.8mm.

[0031] Specifically, in this embodiment, the sunken platform 1011 is formed by the inner side of the first side wall 101 being recessed toward the outer side. The explosion-proof valve 2 is provided in the mounting hole 1012 and located on one side of the sunken platform 1011, that is, the explosion-proof valve 2 is provided in the mounting hole 1012 and located on the inner wall of the sunken platform 1011 facing the inner cavity of the housing 1.

[0032] Specifically, the housing 1 of the housing 1 assembly provided in the embodiment of the present invention has four side walls. Since the area of the first side wall 101 is smaller than the area of the second side wall 102, the first side wall 101 is the narrower side, and the second side wall 102 is the wider side. The four side walls of the housing 1 have the same thickness, that is, the housing 1 has a uniform wall thickness structure.

[0033] The explosion-proof valve 2 is provided on the first sidewall 101, resulting in a design where the explosion-proof valve 2 is located at the bottom of the housing 1. The central portion of the housing 1 is hollow, accommodating the electrode assembly. In this embodiment, the housing 1 is open at both ends. Subsequently, a cell cover assembly is installed and connected to the housing 1, encapsulating the electrode assembly within the housing 1. The cell cover assembly is provided with poles to achieve thermal and electrical separation, improving the safety performance of the battery cell.

[0034] The thickness f of the housing 1 , for the first side wall 101 , is also the width of the first side wall 101 .

[0035] By designing the housing 1 to have a uniform wall thickness, the present invention does not increase the weight of the housing 1, compared to related technical solutions in which the side walls where the explosion-proof valve 2 is located are designed to have a thicker wall thickness. By providing a sunken platform 1011 on the housing 1, with a mounting hole 1012 provided on the sunken platform 1011, the explosion-proof valve 2 is positioned at the mounting hole 1012 and within the sunken platform 1011, and secured and sealed by welding, thus solving the technical difficulties of welding the thin-walled explosion-proof valve 2. Furthermore, the explosion-proof valve 2 does not occupy the internal space of the battery cell, and the explosion-proof valve 2 does not protrude from the outer wall of the housing 1, thereby reducing the risk of failure.

[0036] Moreover, by controlling parameters such as the wall thickness a of the first side wall 101, the thickness f of the shell 1, the width b of the explosion-proof valve 2 along the thickness direction of the shell 1, and the spacing c between the explosion-proof valve 2 and any side edge of the sink 1011 within the above-mentioned corresponding ranges, the strength of the shell 1 can be ensured, and the manufacturing is facilitated, the production yield of the battery cell shell assembly is high, the efficiency is fast, and it is beneficial to control costs.

[0037] Specifically, the width b of the explosion-proof valve 2 is controlled within a range of 8 mm to 30 mm, which can adapt to process manufacturing and product performance requirements.

[0038] Specifically, controlling the distance c between the explosion-proof valve 2 and any side edge of the sink 1011 to be greater than 0.5 mm can meet the tooling positioning requirements. At the same time, controlling c to be less than 1 mm can save space.

[0039] Specifically, the shell 1 can be formed by extrusion, stamping, or high-frequency welding. The thickness f of the shell 1 is at least b + 2 × (c + d + e + r), that is, f ≥ 14.2 mm. Due to the manufacturing process requirements of the shell 1, the maximum thickness f of the shell 1 is 60 mm.

[0040] There is at least one explosion-proof valve 2 . When two or more explosion-proof valves 2 are provided, the explosion-proof valves 2 can be spaced apart on one first side wall 101 or dispersedly provided on two first side walls 101 .

[0041] In some embodiments, the first side wall 101 and the second side wall 102 are transitionally connected via an arc segment 103 , and the radius of the arc segment 103 is r, where 1.2 mm ≤ r ≤ 1.8 mm.

[0042] Specifically, r=a+1, and since 0.2 mm≤a≤0.8 mm, 1.2 mm≤r≤1.8 mm.

[0043] In some embodiments, along the thickness direction of the shell 1 , the first side wall 101 and the sink 1011 are connected by a limiting section 1013 , and the width of the limiting section 1013 is d, where d=2a.

[0044] Specifically, in some embodiments, the shell 1 is formed into a sink 1011 by stamping. Since the stamping process cannot form a right angle between the sink 1011 and the first side wall 101, the limiting section 1013 is mostly a bevel in actual production. Then, a through hole, i.e., a mounting hole 1012, is formed in the middle of the sink 1011 by stamping. The mounting hole 1012 cooperates with the explosion-proof valve 2. The explosion-proof valve 2 is located inside the shell 1 and is installed on the sink 1011. Welding is performed from the outside of the shell 1. The explosion-proof valve 2 is fixed to the sink 1011 by welding to achieve fixation and sealing. The middle area of the explosion-proof valve 2 is lower than the outer wall of the sink 1011.

[0045] Limiting the width d of the limiting section 1013 to twice the wall thickness a of the housing 1 can meet the requirements of the stamping process.

[0046] In some embodiments, along the thickness direction of the housing 1 , the distance between the limiting segment 1013 and the arc segment 103 is e, 1 mm ≤ e ≤ 23.9 mm.

[0047] By controlling the spacing e between the limiting segment 1013 and the arc segment 103 to be greater than 1 mm, the airtightness test requirements can be met. At the same time, the thickness f of the housing 1 is limited to e≤(fb-2×(c+d+r)) / 2, that is, e≤(60-8-2×(1.2+0.5+0.4)) / 2, resulting in e≤23.9 mm.

[0048] In some embodiments, along the thickness direction of the housing 1 , the width of the sink 1011 is j, j=b+2c+2d, and 8.9 mm≤j≤32.6 mm.

[0049] In some embodiments, along the length direction of the shell 1 , the distance between the explosion-proof valve 2 and any side edge of the sink 1011 is g, and 2.5 mm ≤ g ≤ 6 mm.

[0050] Along the length direction of the shell 1, by controlling the distance g between the explosion-proof valve 2 and any side edge of the sink 1011 within the range of 2.5 mm to 6 mm, the tooling positioning requirements can be met.

[0051] In some embodiments, along the length direction of the housing 1 , the length of the explosion-proof valve 2 is h, b≤h≤4b, and 8mm≤h≤120mm.

[0052] In some embodiments, along the length direction of the housing 1 , the length of the sink 1011 is k, k=h+2×(g+d), and 13.8 mm≤k≤133.6 mm.

[0053] The following provides specific examples and comparative examples to further illustrate the technical solutions and effects of the present invention. The results are shown in Table 1.

[0054] Table 1:

[0055]

[0056] The battery cell shell assembly provided by the embodiment of the present invention can be applied to thin-walled and uniform-walled shells 1. Since the wall thickness of the four side walls of the shell 1 is the same, the mounting hole 1012 is located at the sink 1011, and the explosion-proof valve 2 is installed on the inner wall of the shell 1, which reduces the weight of the shell 1. In addition, welding the explosion-proof valve 2 on the thin-walled and uniform-walled shell 1 does not occupy the internal space of the pole group. The explosion-proof valve 2 will neither affect the battery cell by internal scratches nor protrude from the outer surface of the shell 1. The failure risk is low, which solves the technical problem of welding the explosion-proof valve 2 on the thin-walled and uniform-walled shell 1. In addition, the present invention limits the parameter ranges of structures such as the sink 1011 and the explosion-proof valve 2, and makes the ultimate use of the various parameters of the shell 1 and the explosion-proof valve 2, ensuring that the various requirements such as process manufacturing, testing, and performance meet the various index requirements of the shell 1 with the bottom-exiting explosion-proof valve 2.

[0057] According to an embodiment of the present invention, in a second aspect, a battery cell is provided, comprising the battery cell housing assembly of any one of the above technical solutions, as well as a pole group and a battery cell cover assembly. The pole group is disposed within the battery cell housing assembly, and the battery cell cover assembly is connected to the battery cell housing assembly, encapsulating the pole group within the battery cell housing assembly.

[0058] Because the battery cell includes a battery cell shell assembly, it has the same effect as the battery cell shell assembly and is not described in detail here.

[0059] According to an embodiment of the present invention, in a third aspect, a battery pack is further provided, comprising the battery cell in the above technical solution.

[0060] Since the battery pack includes battery cells and has the same effect as the battery cells, it will not be described in detail here.

[0061] Although the embodiments of the present invention have been described with reference to the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations shall fall within the scope defined by the appended claims.

Claims

1. A battery cell housing assembly, characterized in that: include: The housing is formed by two oppositely arranged first side walls and two oppositely arranged second side walls, the area of the first side walls is smaller than the area of the second side walls, one side of any of the first side walls is recessed toward the other side to form a sunken platform, and the sunken platform is provided with a mounting hole; An explosion-proof valve is provided in the mounting hole and is located on one side of the sinking platform; The wall thickness of the first side wall is equal to the wall thickness of the second side wall, and the wall thickness of the shell is a, 0.2mm≤a≤0.8mm; The thickness of the shell is f, 14.2 mm ≤ f ≤ 60 mm; Along the thickness direction of the shell, the width of the explosion-proof valve is b, 8mm≤b≤30mm, and the distance between the explosion-proof valve and any side edge of the sink is c, 0.5mm≤c≤1mm; And, 4mm≤fb-2c-6a≤49.8mm.

2. The battery cell housing assembly according to claim 1, characterized in that: The first side wall and the second side wall are transitionally connected via an arc segment, and the radius of the arc segment is r, 1.2 mm ≤ r ≤ 1.8 mm.

3. The battery cell housing assembly according to claim 2, characterized in that: Along the thickness direction of the shell, the first side wall and the sink are connected by a limiting section, and the width of the limiting section is d, where d=2a.

4. The battery cell housing assembly according to claim 3, characterized in that: Along the thickness direction of the shell, the distance between the limiting segment and the arc segment is e, 1mm≤e≤23.9mm.

5. The battery cell housing assembly according to claim 3 or 4, characterized in that: Along the thickness direction of the shell, the width of the sink is j, j=b+2c+2d, and 8.9mm≤j≤32.6mm.

6. The battery cell housing assembly according to claim 3 or 4, characterized in that: Along the length direction of the shell, the distance between the explosion-proof valve and any side edge of the sink is g, 2.5mm≤g≤6mm.

7. The battery cell housing assembly according to claim 6, characterized in that: Along the length direction of the shell, the length of the explosion-proof valve is h, b≤h≤4b, and 8mm≤h≤120mm.

8. The battery cell housing assembly according to claim 7, characterized in that: Along the length direction of the shell, the length of the sink is k, k=h+2×(g+d), and 13.8mm≤k≤133.6mm.

9. A battery cell, characterized in that: include: The battery cell housing assembly according to any one of claims 1 to 8; A pole group, the pole group is arranged in the battery shell assembly, A cell cover assembly is connected to the cell shell assembly to encapsulate the electrode group in the cell shell assembly.

10. A battery pack, characterized in that: Including the battery cell according to claim 9.

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