Battery cell shell

Abstract

The utility model provides a battery cell shell which comprises a side shell and a cover body, the side shell and the cover body are both made of steel, the side shell comprises at least two shell side walls which are arranged along the circumferential direction and form an angle, the side shell further comprises a shell corner connected between the shell side walls, and the shell corner is connected with the cover body. The cover body comprises a positioning surface and a first boss, the positioning surface is in contact with the edge of the opening of the side shell, the first boss is arranged on the positioning surface of the cover body and faces the side shell, the first boss abuts against the outer surface of the side shell, and at least part of the first boss is arranged corresponding to the corner of the shell. A plurality of first bosses are arranged on the positioning surface of the cover body, and positioning is realized through contact between the first bosses and the outer surface of the side shell. The plurality of first bosses are arranged, and at least part of the first bosses are arranged corresponding to the shell body corners of the side shell, so that the cover body can be reliably positioned relative to the side shell by utilizing the first bosses, and the clamping difficulty in the welding process is further reduced.

Description

Technical Field

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

[0002] The aluminum casing of current battery cells no longer meets the requirements. Higher temperature-resistant and stronger materials are needed as the main material for the outer structural components, namely steel casings and top covers. Because steel has a higher density, and considering the energy density requirements of the battery cell's weight, a thinner thickness is needed in the dimensional design to provide more space for the cell and simultaneously increase its volumetric energy density. The thinner top cover and casing require more precise clamping during laser welding. Utility Model Content

[0003] The technical problem to be solved by this utility model is to overcome the defect that the steel shell of the battery cell is difficult to clamp and position during welding, and to provide a battery cell shell.

[0004] The present invention solves the above-mentioned technical problems through the following technical solution:

[0005] A battery cell housing includes a side shell and a cover, both of which are made of steel. The side shell includes at least two circumferentially angled sidewalls and a housing corner connecting the sidewalls. The cover includes a positioning surface that contacts the opening edge of the side shell and a first protrusion facing the side shell at the positioning surface of the cover. The first protrusion abuts against the outer surface of the side shell, and at least a portion of the first protrusion corresponds to the housing corner.

[0006] By setting multiple first protrusions on the positioning surface of the cover, positioning is achieved through the contact between the first protrusions and the outer surface of the side shell. Furthermore, by setting multiple first protrusions and aligning at least some of them with the shell corners of the side shell, the cover can reliably position itself relative to the side shell using these first protrusions, thereby reducing the clamping difficulty during the welding process.

[0007] Preferably, the side shell includes four shell corners located between the four shell side walls, and the cover is provided with corresponding first protrusions at the positions of the four shell corners.

[0008] By setting a first boss at each corner of the side shell for positioning, all corners of the side shell are utilized, thus improving the positioning effect of the first boss relative to the side shell.

[0009] Preferably, a second protrusion is further provided at the positioning surface of the cover, the second protrusion being in contact with the inner surface of the side shell, and in the thickness direction of the side shell, the contact area of ​​the second protrusion relative to the side shell at least partially overlaps with the contact area of ​​the first protrusion relative to the side shell.

[0010] By further providing a second protrusion, the cover can be positioned by contacting the inner surface of the side shell. At the same time, along the thickness direction of the side shell, the contact area of ​​the first protrusion relative to the side shell and the thickness area of ​​the second protrusion relative to the side shell partially overlap, so that the first and second protrusions simultaneously clamp the front and back surfaces of the side shell, achieving reliable positioning of the cover and the side shell.

[0011] Preferably, the shape of the peripheral surface of the second boss matches the shape of the inner surface of the side shell.

[0012] By setting the above structural dimensions, the positioning effect between the second boss of the cover and the side shell can be improved.

[0013] Preferably, the thickness of the outer surface of the cover to the positioning surface is t1, and the thickness of the second boss is t2, where t2 ≥ t1;

[0014] And / or, the thickness of the side shell is t, and the thickness dimension from the outer surface of the cover to the positioning surface is t1, t1 = (1~5)t.

[0015] The above structural design can improve the assembly feasibility and welding stability between the cover and the side shell.

[0016] Preferably, the battery cell housing further includes an explosion-proof sheet, and the outer surface of the cover has a through hole arranged along the thickness direction of the cover. The explosion-proof sheet is fixed to the outer surface of the cover and covers the through hole. The explosion-proof sheet is made of nickel.

[0017] By using a nickel-based explosion-proof sheet, weldability between it and the steel-based cover is ensured, and the yield strength meets the explosion-proof requirements.

[0018] Preferably, the thickness of the explosion-proof sheet is t3, where t3 = 0.5-1.1 mm;

[0019] And / or, the battery cell housing further includes a base plate, the base plate being made of steel, and the explosion-proof sheet being fixed to the cover via the base plate;

[0020] And / or, the outer surface of the cover has a recess for accommodating the explosion-proof sheet, the depth of the recess being D, where D = 0.25-0.55 mm.

[0021] Compared to the current 1.5mm explosion-proof sheet wall thickness design, this design can improve space utilization.

[0022] By creating recesses on the surface of the cover to accommodate the explosion-proof sheet, it is easy to clamp and weld.

[0023] Preferably, the wall thickness of the side shell is t, where t = 0.2~0.5 mm.

[0024] The side shell has a wall thickness between 0.2mm and 0.5mm, which is thinner than the current solution using aluminum alloy, thus improving space utilization. At the same time, the thinner thickness also reduces the difficulty of forming and processing the steel material.

[0025] Preferably, the outer fillet radius at the corner of the side shell is R1, where R1 = 1.2-1.5 mm;

[0026] And / or, the inner fillet radius at the corner of the side shell is R2, where R2 = 1.0-1.5 mm.

[0027] By limiting the outer and inner fillets of the side shell at the corners, the dimensions are prevented from being too small and difficult to bend and process.

[0028] Meanwhile, compared to the current aluminum alloy rounded corner size setting scheme of more than 2.5mm, the above size setting scheme can also avoid the steel casing rounded corner size being too large, which would affect the internal space utilization of the battery cell casing.

[0029] Preferably, there are two covers, and the side shell has two through openings on both sides, with the two covers respectively disposed at the two openings on both sides of the side shell.

[0030] The through-end design of the side shell makes it easier to process when the material is steel. At the same time, by setting a cover at each of the two openings of the side shell to close the openings, a complete internal closed structure of the cell shell is formed.

[0031] The positive and progressive effects of this utility model are as follows: This utility model provides multiple first protrusions on the positioning surface of the cover, and achieves positioning by the contact between the first protrusions and the outer surface of the side shell. Furthermore, by providing multiple first protrusions and aligning at least some of them with the shell corners of the side shell, the cover can achieve reliable positioning relative to the side shell using these first protrusions, thereby reducing the clamping difficulty during the welding process. Attached Figure Description

[0032] Figure 1 This is a perspective view of the battery cell housing of Embodiment 1 of this utility model.

[0033] Figure 2This is an exploded structural diagram of the battery cell housing according to Embodiment 1 of this utility model.

[0034] Figure 3 This is a schematic diagram of the installation of the battery cell housing in Embodiment 1 of this utility model.

[0035] Figure 4 This is a schematic diagram of the cover of Embodiment 1 of this utility model.

[0036] Figure 5 This is a side view of the cover of Embodiment 1 of this utility model.

[0037] Figure 6 for Figure 4 A magnified view of part A in the image.

[0038] Figure 7 This is a diagram showing the positional relationship between the side shell and the second boss in Embodiment 1 of this utility model.

[0039] Figure 8 This is a partial structural diagram of the cover body of Embodiment 1 of this utility model.

[0040] Figure 9 This is a partial structural diagram of the side shell of Embodiment 1 of this utility model.

[0041] Figure 10 This is a perspective view of the battery cell housing of Embodiment 2 of this utility model.

[0042] Explanation of reference numerals in the attached figures:

[0043] Cell casing 100

[0044] Side shell 1

[0045] Opening 10

[0046] Shell sidewall 11

[0047] 12-degree angle of the shell

[0048] Cover 2

[0049] Positioning surface 21

[0050] First protrusion 22

[0051] Second protrusion 23

[0052] Through hole 24

[0053] Explosion-proof sheet 3 Detailed Implementation

[0054] The present invention will be described more clearly and completely below with reference to the accompanying drawings, using a preferred embodiment.

[0055] Example 1

[0056] This embodiment provides a cell housing 100 for accommodating electrode assemblies to form a cell. The specific structure of the cell housing 100 is as follows: Figure 1 , Figure 2 and Figure 3 As shown, the battery cell housing 100 includes a side shell 1 and a cover 2. Both the side shell 1 and the cover 2 are made of steel. The side shell 1 includes four housing side walls 11 arranged circumferentially and at an angle. The side shell 1 also includes four housing corners 12 connected between the four housing side walls 11. The cover 2 includes a positioning surface 21 that contacts the edge of the opening 10 of the side shell 1, and a first boss 22 that is provided on the positioning surface 21 of the cover 2 facing the side shell 1. The first boss 22 abuts against the outer surface of the side shell 1, and a portion of the first boss 22 is provided corresponding to the housing corners 12.

[0057] In this embodiment, the upper end of the side shell 1 is open to form an opening 10, and the lower end is closed. The cover 2 closes the opening 10 of the side shell 1 to form a receiving space for accommodating the electrode assembly. Both the side shell 1 and the cover 2 are made of steel. Compared with aluminum alloy, steel has a significantly higher melting point, yield strength, and compressive strength, and is easier to process and weld. Using steel instead of aluminum alloy can ensure structural strength while reducing thickness, thereby improving the space utilization rate within the cell housing 100 composed of the side shell 1 and the cover 2, and increasing the energy density of the manufactured cell. Specifically, in this embodiment, both the side shell 1 and the cover 2 are made of 304 stainless steel to obtain relatively better structural strength and greater corrosion resistance, significantly improving durability.

[0058] In this embodiment, the shell sidewall 11 has a planar structure, and adjacent shell sidewalls 11 are connected by shell corner 12. The size of the cover 2 is larger than the size of the opening 10. The positioning surface 21 of the cover 2 facing the opening 10 is provided with a plurality of first protrusions 22. The first protrusions 22 are located at the edge of the cover 2 and abut against the outer surface of the side shell 1. Specifically, as shown... Figure 5 As shown, three first protrusions 22 are provided on one side of the cover 2 along its length. The leftmost and rightmost first protrusions 22 correspond to the shell corners 12 of the side shell 1, and the middle first protrusion 22 corresponds to the shell sidewall 11 of the side shell 1. By having part of the first protrusions 22 abut against the shell corners 12, the cover 2 is positioned on the outer surface of the side shell 1, preventing the cover 2 from shifting relative to the side shell 1. This allows the cover 2 to be reliably positioned relative to the side shell 1 using these first protrusions 22, thereby reducing the clamping difficulty during the welding process.

[0059] In this embodiment, the side shell 1 has a rectangular cross-section and includes four shell corners 12. The cover 2 is provided with corresponding first protrusions 22 at each of these four shell corners 12 to achieve reliable positioning of the cover 2 relative to the side shell 1. Specifically, the cover 2 is provided with four first protrusions 22 corresponding to the four shell corners 12. The first protrusions 22 have an arc-shaped structure, and each first protrusion 22 at least partially covers the shell corner 12. Therefore, by providing first protrusions 22 at all shell corners 12 of the side shell 1 for positioning with the side shell 1, the positioning effect of the first protrusions 22 relative to the side shell 1 is improved.

[0060] like Figure 4 , Figure 5 and Figure 6 As shown, in this embodiment, a second protrusion 23 is provided at the positioning surface 21 of the cover 2, and the second protrusion 23 is used to contact the inner surface of the side shell 1. When the cover 2 closes the opening 10, the first protrusion 22 is located on the outer surface of the side shell 1, and the second protrusion 23 is located on the inner surface of the side shell 1. Furthermore, in the thickness direction of the side shell 1, the contact area of ​​the second protrusion 23 relative to the side shell 1 at least partially overlaps with the contact area of ​​the first protrusion 22 relative to the side shell 1. The side shell 1 is positioned between the first protrusion 22 and the second protrusion 23, and the first protrusion 22 and the second protrusion 23 simultaneously clamp the front and back surfaces of the side shell 1. This layout scheme provides a better positioning effect for the side shell 1 than setting the first protrusion 22 and the second protrusion 23 to be staggered in the thickness direction of the side shell 1, and enables the cover 2 to achieve reliable positioning of the cover 2 and the side shell 1 from the relative directions of the inner and outer surfaces of the side shell 1.

[0061] In this embodiment, to ensure the positioning effect when the second boss 23 contacts the inner surface of the side shell 1, such as... Figure 4 and Figure 5 As shown, the shape of the peripheral surface of the second boss 23 matches the shape of the inner surface of the side shell 1. That is, the inner surface of the side shell 1 is rectangular, and the peripheral surface of the second boss 23 is also rectangular. This structural arrangement increases the contact area between the second boss 23 and the inner surface of the side shell 1, ensuring the positioning effect and making the clamping of the cover 2 more stable after it contacts the side shell 1.

[0062] like Figure 7 As shown, in this embodiment, the thickness of the outer surface of the cover 2 to the positioning surface 21 is t1, and the thickness of the second protrusion 23 is t2, where t2 ≥ t1. Specifically, by setting the thickness of the second protrusion 23 used for positioning to be greater than the thickness of the cover 2 itself, the positioning effect between the cover 2 and the side shell 1 is better than if the thickness of the cover 2 is greater than the thickness of the second protrusion 23. At the same time, the thickness of the cover 2 will not be too thick, thus achieving the purpose of weight reduction.

[0063] Furthermore, the thickness of the side shell 1 is t, and the thickness from the outer surface of the cover 2 to the positioning surface 21 is t1. The value of t1 ranges from 1 to 5 times the thickness t of the side shell 1. This is because the side shell 1 is made of steel, and the thickness t of the side shell 1 is thinner than other materials such as aluminum alloy. For example, when the side shell 1 is made of steel, its wall thickness t ranges from 0.2mm to 0.5mm while meeting the strength requirements of the battery cell. This is thinner than the conventional wall thickness of 0.6 / 0.8mm for aluminum alloy materials. On the one hand, the saved wall thickness space can be used as a space to accommodate the battery cell, thus improving space utilization. On the other hand, a thinner side shell 1 can improve the assembly feasibility and welding stability between the cover 2 and the side shell 1 during assembly.

[0064] like Figure 2 As shown, the battery cell housing 100 also includes an explosion-proof sheet 3. The outer surface of the cover 2 has a through hole 24 arranged along the thickness direction of the cover 2. The explosion-proof sheet 3 is fixed to the outer surface of the cover 2 and covers the through hole 24. In this embodiment, the explosion-proof sheet 3 is made of nickel. By using an explosion-proof sheet 3 made of nickel, the weldability between it and the cover 2 made of steel is ensured, and the yield strength can meet the explosion-proof requirements.

[0065] Specifically, the explosion-proof plate 3 is disposed on the surface of the cover 2 opposite to the positioning surface 21, such as... Figure 8 As shown, a through hole 24 is provided on the cover body 2. The through hole 24 penetrates the cover body 2 along the thickness direction. An explosion-proof sheet 3 is placed on the through hole 24 to seal the through hole 24. The explosion-proof sheet 3 is welded to the opening of the through hole 24 to achieve a reliable connection between the explosion-proof sheet 3 and the cover body 2.

[0066] In this embodiment, the thickness of the explosion-proof sheet 3 is t3, and the preferred value of t3 is between 0.5mm and 1.1mm. The cover 2 is made of steel, ensuring welding feasibility and stability. This allows for a further reduction in the thickness of the explosion-proof sheet 3 along the thickness direction of the cover 2, thereby improving space utilization. In other embodiments, the battery cell housing 100 may further include a base plate at the through hole 24. The base plate is made of the same material as the cover 2, namely steel, allowing the explosion-proof sheet 3 to be fixed to the cover 2 via the base plate.

[0067] In this embodiment, as Figure 8As shown, corresponding to the location of the through hole 24, a recess for accommodating the explosion-proof disc 3 is provided on the outer surface of the cover 2. The depth of the recess is D, and the preferred value of D is between 0.25mm and 0.55mm. By providing a recess at the position corresponding to the opening of the through hole 24, the through hole 24 becomes a stepped hole, forming a step to accommodate the explosion-proof disc 3. This supports the explosion-proof disc 3 embedded in the through hole 24, reducing the space occupied by the explosion-proof disc 3 on the surface of the cover 2, thereby improving space utilization. At the same time, providing a recess to accommodate the explosion-proof disc 3 makes clamping and welding easier.

[0068] Since the side shell 1 is made of steel, the preferred value of the wall thickness t of the side shell 1 is between 0.2 mm and 0.5 mm, so that the thickness of the side shell 1 is thinner than the current solution using aluminum alloy. The thinner side shell 1 can reduce the difficulty of forming and processing steel.

[0069] like Figure 9 As shown, the outer corner radius of the side shell 1 is R1, and the value of R1 ranges from 1.2mm to 1.5mm. Simultaneously, the inner corner radius of the side shell 1 is R2, and the value of R2 ranges from 1.0mm to 1.5mm. By limiting the outer and inner corner radius dimensions of the side shell 1 at the corners, the dimensions are prevented from being too small and making bending difficult.

[0070] Meanwhile, compared to the current aluminum alloy rounded corner size setting scheme of 2.5mm or more, the above-mentioned size restrictions on the outer and inner rounded corner sizes can also avoid the steel casing corner 12 being too large, thus affecting the internal space utilization of the cell casing 100.

[0071] Example 2

[0072] This embodiment provides a cell housing 100, whose structure is largely the same as that of the cell housing 100 provided in Embodiment 1, except that, as Figure 10 As shown, in this embodiment, there are two cover bodies 2, and the side shell 1 has two through openings 10 on both sides, with the two cover bodies 2 respectively disposed at the two through openings 10 on both sides of the side shell 1.

[0073] Specifically, the side shell 1 is formed by connecting four rectangular shell side walls 11 sequentially end to end along the circumferential direction. Adjacent shell side walls 11 are connected by shell corners 12. Both ends of the side shell 1 are open, forming openings 10. A cover 2 is used to close the openings 10 at both ends of the side shell 1 to form a space for accommodating the battery cell. Compared to a side shell 1 with one end closed and the other end open, this open-ended design of the side shell 1 is easier to process when the material is steel. Furthermore, by providing a cover 2 at each of the two openings 10 of the side shell 1 with both ends open to close them, an internal space for accommodating the electrode assembly is formed.

[0074] While specific embodiments of this utility model have been described above, those skilled in the art should understand that these are merely illustrative examples, and the scope of protection of this utility model is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of this utility model, but all such changes and modifications fall within the scope of protection of this utility model.

Claims

1. A battery cell housing, comprising a side shell and a cover, characterized in that, Both the side shell and the cover are made of steel. The side shell includes at least two circumferentially angled sidewalls and a housing corner connecting the sidewalls. The cover includes a positioning surface that contacts the opening edge of the side shell and a first protrusion facing the side shell at the positioning surface of the cover. The first protrusion abuts against the outer surface of the side shell, and at least a portion of the first protrusion corresponds to the housing corner.

2. The cell housing as described in claim 1, characterized in that, The side shell includes four shell corners located between the four shell side walls, and the cover is provided with corresponding first protrusions at the positions of the four shell corners.

3. The cell housing as described in claim 1, characterized in that, A second protrusion is also provided at the positioning surface of the cover. The second protrusion contacts the inner surface of the side shell. In the thickness direction of the side shell, the contact area of ​​the second protrusion relative to the side shell at least partially overlaps with the contact area of ​​the first protrusion relative to the side shell.

4. The cell housing as described in claim 3, characterized in that, The shape of the peripheral surface of the second boss matches the shape of the inner surface of the side shell.

5. The cell housing as described in claim 3, characterized in that, The thickness of the outer surface of the cover to the positioning surface is t1, and the thickness of the second boss is t2, where t2 ≥ t1; And / or, the thickness of the side shell is t, and the thickness dimension from the outer surface of the cover to the positioning surface is t1, t1 = (1~5)t.

6. The cell housing as described in claim 1, characterized in that, The battery cell housing also includes an explosion-proof sheet, and the outer surface of the cover has a through hole arranged along the thickness direction of the cover. The explosion-proof sheet is fixed to the outer surface of the cover and covers the through hole. The explosion-proof sheet is made of nickel.

7. The cell housing as described in claim 6, characterized in that, The thickness of the explosion-proof sheet is t3, where t3 = 0.5-1.1 mm; And / or, the battery cell housing further includes a base plate, the base plate being made of steel, and the explosion-proof sheet being fixed to the cover via the base plate; And / or, the outer surface of the cover has a recess for accommodating the explosion-proof sheet, the depth of the recess being D, where D = 0.25-0.55 mm.

8. The cell housing as described in any one of claims 1-7, characterized in that, The wall thickness of the side shell is t, where t = 0.2~0.5 mm.

9. The cell housing as described in claim 8, characterized in that, The outer fillet radius at the corner of the side shell is R1, where R1 = 1.2-1.5 mm; And / or, the inner fillet radius at the corner of the side shell is R2, where R2 = 1.0-1.5 mm.

10. The cell housing as described in any one of claims 1-7, characterized in that, The number of the cover is two, and the side shell has two through openings on both sides, with the two covers respectively disposed at the two through openings on both sides of the side shell.

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