Battery case and battery cell

Abstract

The utility model belongs to the technical field of batteries, and discloses a battery shell and a battery monomer. The battery case includes a case body and a seal. The shell comprises a plurality of side walls formed by bending a plate, and a containing cavity is defined by the side walls; the plurality of side walls comprise a first wall body formed by bending the head end of the plate and a second wall body formed by bending the tail end of the plate, the first wall body and the second wall body are welded to form a welding seam, and welding mark areas are formed on the inner wall and the outer wall of the shell after the welding seam is subjected to scar removal treatment. The sealing piece extends in the first direction and can completely cover a welding mark area on the inner wall of the shell in the second direction, the first direction is the length direction of the welding seam, and the second direction is the width direction of the welding seam. The battery shell is high in structural strength and long in service life.

Description

Technical Field

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

[0002] Longer battery casings (over 350mm in length) are typically manufactured using a stainless steel sheet bending and welding process. Specifically, the stainless steel sheet is first bent to obtain the casing shape, and then the bent ends are spliced ​​and welded together. To avoid affecting cell assembly and for aesthetic purposes, the weld seams are treated to remove weld scars after welding. However, after weld scar removal, uneven weld mark areas (referred to as weld marks) will appear on the inner and outer surfaces of the battery casing.

[0003] After the battery is filled with electrolyte, the electrolyte can easily penetrate and erode the weld area through the uneven structure of the solder area. Especially during long-term charge and discharge cycles, this can reduce the fatigue strength of the battery casing metal by 40%-60%, increase the risk of stress corrosion cracking by 3-5 times, and ultimately lead to through-cracks in the battery casing and electrolyte leakage.

[0004] Therefore, there is an urgent need to propose a battery casing and a battery cell to solve the above problems. Utility Model Content

[0005] The first objective of this invention is to provide a battery casing with high structural strength and long service life.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] Battery casing, including:

[0008] The housing includes a plurality of sidewalls formed by bending a sheet metal, the plurality of sidewalls enclosing a receiving cavity, the plurality of sidewalls including a first wall formed by bending from the first end of the sheet metal and a second wall formed by bending from the end of the sheet metal, the first wall and the second wall being welded to form a weld seam, and the weld seam being descaled to form a weld mark area on the inner and outer walls of the housing;

[0009] A seal extending along a first direction and along a second direction, the seal being able to completely cover the weld area on the inner wall of the housing, the first direction being the length direction of the weld and the second direction being the width direction of the weld.

[0010] As an optional technical solution for the battery casing, the sealing element includes a sealing strip, which is adhered to the solder area.

[0011] As an optional technical solution for the battery casing, the thickness of the sealing strip is H, and the value of H ranges from 0.03mm to 0.5mm; the Shore hardness of the sealing strip is 60HA-80HA.

[0012] As an optional technical solution for the battery casing, the adhesive strength of the sealing strip is not less than 3 N / mm. 2 .

[0013] As an optional technical solution for the battery casing, along the second direction, the coverage width of the sealing strip is B, where B ≥ 1 mm.

[0014] As an optional technical solution for the battery casing, the sealing element is a dot-applied adhesive, which can be applied to the solder area.

[0015] As an optional technical solution for the battery casing, the battery casing further includes two cover plates, and the receiving cavity has two openings, with the two cover plates respectively covering the two openings of the receiving cavity.

[0016] As an optional technical solution for the battery casing, the multiple sidewalls further include a third wall and a fourth wall, which are adjacent to the first wall and the second wall, respectively. The opposite sides of the cover plate are welded to the third wall and the fourth wall, respectively. Along the first direction, the length L of the seal is not greater than the length of the casing.

[0017] As an optional technical solution for the battery casing, the multiple sidewalls also include a fifth wall, which is located on the opposite side of the first wall and the second wall. Along the thickness direction of the cover plate, one side of the cover plate is welded to the first wall and the second wall respectively, and the other side of the cover plate is welded to the fifth wall. Along the first direction, the distance from both ends of the seal to both ends of the casing is not less than 1.5mm.

[0018] The second objective of this invention is to provide a battery cell that has good safety and a long service life.

[0019] To achieve this objective, the present invention adopts the following technical solution:

[0020] A battery cell includes a cell pack and the aforementioned battery casing, wherein the cell pack is disposed within the receiving cavity.

[0021] The beneficial effects of this utility model are:

[0022] The battery casing provided by this utility model includes a casing and a sealing element. The first wall and the second wall of the casing are welded together to form a weld. After the weld is descaled, a weld mark area is formed on the inner and outer walls of the casing. The sealing element can completely cover the weld mark area on the inner wall of the casing to seal the weld mark area, thereby reducing the welding corrosion of the inner wall of the casing by the electrolyte in the cavity, thereby improving the connection strength of the first wall and the second wall of the casing and extending the service life of the battery casing. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the first structure of the battery casing provided in Embodiment 1 of this utility model;

[0024] Figure 2 yes Figure 1 Sectional view along the AA direction;

[0025] Figure 3 yes Figure 2 A magnified view of the area at D1;

[0026] Figure 4 This is a schematic diagram of the second structure of the battery casing provided in Embodiment 1 of this utility model;

[0027] Figure 5 yes Figure 4 Enlarged view of the layout at point D2;

[0028] Figure 6 This is a schematic diagram of the third structure of the battery casing provided in Embodiment 1 of this utility model;

[0029] Figure 7 yes Figure 6 A magnified view of the area at D3;

[0030] Figure 8 An exploded view of a single battery cell provided in Embodiment 1 of this utility model;

[0031] Figure 9 This is a schematic diagram of the battery casing provided in Embodiment 2 of this utility model;

[0032] Figure 10 yes Figure 9 Sectional view at EE;

[0033] Figure 11 yes Figure 10 A magnified view of the area at D4.

[0034] In the picture:

[0035] 1. Housing; 11. First wall; 12. Second wall; 13. Third wall; 14. Fourth wall; 15. Fifth wall; 101. Receiving cavity; 2. Seal; 3. Cover plate; 4. Battery pack; 5. Inner protective film; 6. Outer protective film; 7. Side patch. Detailed Implementation

[0036] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, not the entire structure.

[0037] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0038] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0039] In the description of this embodiment, the terms "upper," "lower," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.

[0040] Example 1

[0041] This embodiment provides a battery casing with high structural strength and long service life.

[0042] Specifically, such as Figures 1 to 7As shown, the battery casing includes a housing 1 and a sealing element 2. The housing 1 includes multiple sidewalls formed by bending a sheet metal, which together form a receiving cavity 101. The multiple sidewalls include a first wall 11 formed by bending from the first end of the sheet metal and a second wall 12 formed by bending from the end of the sheet metal. The first wall 11 and the second wall 12 are welded together to form a weld seam. After the weld seam is descaled, weld imprint areas are formed on the inner and outer walls of the housing 1. The sealing element 2 extends along a first direction and along a second direction, and the sealing element 2 can completely cover the weld imprint areas on the inner wall of the housing 1. The first direction is the length direction of the weld seam, and the second direction is the width direction of the weld seam.

[0043] Based on the above design, the first wall 11 and the second wall 12 of the housing 1 are welded to form a weld. After the weld is descaled, a weld mark area is formed on the inner and outer walls of the housing 1. The sealing element 2 can completely cover the weld mark area on the inner wall of the housing 1 to seal the weld mark area, thereby reducing the welding corrosion of the inner wall of the housing 1 by the electrolyte in the cavity 101, thereby improving the connection strength of the first wall 11 and the second wall 12 of the housing 1 and extending the service life of the battery case.

[0044] It should be noted that the aforementioned sheet metal is manufactured by a stamping process, the specific stamping process of which is existing technology in the field and will not be described in detail here. In this embodiment, the sheet metal is stainless steel; however, in other embodiments, aluminum or other materials may also be used.

[0045] It should also be noted that the bending and welding process of the housing 1 is also existing technology in this field, and will not be described in detail here.

[0046] There are various structural forms of the seal 2, as long as the seal 2 can cover the weld area to seal the weld area.

[0047] In one embodiment, the sealant 2 is a dot-applied adhesive, which can be applied to the solder area. The specific dot-applied process is prior art and will not be described in detail here.

[0048] Optionally, the seal 2 includes a sealing strip that is adhered to the solder area.

[0049] The thickness of the sealing strip is H, which ranges from 0.03mm to 0.50mm. For example, H can be 0.03mm, 0.12mm, 0.21mm, 0.30mm, 0.39mm, or 0.50mm. The Shore hardness of the sealing strip is 60HA-80HA, for example, it can be 60HA, 65HA, 70HA, 75HA, or 80HA. This thickness and Shore hardness of the sealing strip ensures sufficient structural strength.

[0050] In addition to sufficient structural strength, the sealing strip also needs sufficient adhesive strength to prevent it from detaching from the housing 1. Therefore, the adhesive strength of the sealing strip must be no less than 3 N / mm². 2 For example, the adhesive strength can be 3 N / mm. 2 4N / mm 2 Or 5N / mm 2 wait.

[0051] Meanwhile, the sealing strip needs to withstand an electrolyte expansion rate of <5% within 240 hours at 60°C. For example, the electrolyte expansion rate can be 1%, 2%, 3%, or 4%.

[0052] In order for the sealing strip to completely cover the solder area along the second direction, the coverage width of the sealing strip along the second direction is B, where B ≥ 1 mm. For example, B can be 1 mm, 1.5 mm, 2 mm, or 2.5 mm, etc.

[0053] like Figure 8 As shown, the battery casing also includes two cover plates 3. The receiving cavity 101 has two openings located at both ends of the casing 1 along the first direction. The two cover plates 3 are respectively placed over the two openings of the receiving cavity 101 to seal the casing 1. In this embodiment, the casing 1 is a cuboid structure with four faces, wherein the first wall 11 and the second wall 12 are spliced ​​together to form one face; the cover plate 3 is a rectangular plate that is perpendicular to all four faces of the casing 1.

[0054] Optionally, the multiple sidewalls also include a third wall 13 and a fourth wall 14, which are adjacent to the first wall 11 and the second wall 12, respectively, and are arranged opposite to each other along the second direction. The cover plate 3 is welded to the third wall 13 and the fourth wall 14 on opposite sides along the second direction, respectively. That is, the cover plate 3 is installed to the housing 1 by welding the cover plate 3 to the housing 1 on the two sides along the second direction. At this time, along the first direction, the length of the seal 2 is not greater than the length of the housing 1, that is, the length of the seal 2 can be the same as the length of the housing 1 (the seal 2 completely covers the weld area along the first direction); the length of the seal 2 can also be less than the length of the housing 1, but of course, it cannot be too much smaller to affect the sealing performance of the seal 2.

[0055] Furthermore, the multiple sidewalls of the housing 1 also include a fifth wall 15, which is located on the opposite side of the first wall 11 and the second wall 12 along the thickness direction of the cover plate 3.

[0056] This embodiment also provides a battery cell that has high safety and long service life.

[0057] Specifically, the battery cell includes a cell pack 4 and the aforementioned battery casing. The cell pack 4 is disposed inside the receiving cavity 101, and two cover plates 3 are respectively covering the two openings of the receiving cavity 101.

[0058] It should be noted that one of the two cover plates is the positive electrode cover plate, and the other is the negative electrode cover plate.

[0059] Continue, as Figure 8 As shown, the battery cell also includes an outer protective film 6, an inner protective film 5, and two side patches 7. The inner protective film and the outer protective film 6 are wrapped around the cell pack 4 in sequence. The two side patches 7 are located on both sides of the cell pack 4 covered with the inner protective film 5 and the outer protective film 6 along the thickness direction of the seal 2, so as to prevent the outer protective film 6 from being scratched when the cell pack 4 covered with the inner protective film 5 and the outer protective film 6 is assembled into the housing 1.

[0060] Example 2

[0061] The difference between the battery casing provided in this embodiment and the battery casing provided in Embodiment 1 is as follows:

[0062] Specifically, such as Figures 9 to 11 As shown, the multiple sidewalls of the housing 1 also include a fifth wall 15, which is located on the opposite side of the first wall 11 and the second wall 12. Along the thickness direction of the cover plate 3 (i.e., the thickness direction of the seal 2), one side of the cover plate 3 is welded to the first wall 11 and the second wall 12 respectively, and the other side of the cover plate 3 is welded to the fifth wall 15. Along the first direction, the distance from both ends of the seal 2 to both ends of the housing 1 is not less than 1.5 mm, which can be 1.5 mm, 2.0 mm, or 2.5 mm, for example. The cover plate 3 needs to be welded to the first wall 11 and the second wall 12 where the weld is located, and space needs to be reserved for welding. Therefore, a gap of not less than 1.5 mm needs to be reserved at both ends of the sealing strip in the first direction.

[0063] Example 2 differs from Example 1 only in the above-described manner; all other aspects are the same, and the similarities will not be repeated here.

[0064] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating the present utility model, and are not intended to limit the implementation of the present utility model. Those skilled in the art can make various obvious changes, readjustments, and substitutions without departing from the protection scope of this utility model. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. A battery casing, characterized in that, include: The housing (1) includes a plurality of sidewalls formed by bending a sheet metal, the plurality of sidewalls enclosing a receiving cavity (101), the plurality of sidewalls including a first wall (11) formed by bending from the first end of the sheet metal and a second wall (12) formed by bending from the end of the sheet metal, the first wall (11) and the second wall (12) being welded to form a weld, the weld being descaled to form a weld mark area on the inner and outer walls of the housing (1); A sealing element (2) extends along a first direction and along a second direction, the sealing element (2) being able to completely cover the weld area on the inner wall of the housing (1), the first direction being the length direction of the weld and the second direction being the width direction of the weld.

2. The battery casing according to claim 1, characterized in that, The seal (2) includes a sealing strip, which is adhered to the solder area.

3. The battery casing according to claim 2, characterized in that, The thickness of the sealing strip is H, and the value of H ranges from 0.03mm to 0.5mm; the Shore hardness of the sealing strip is 60HA-80HA.

4. The battery casing according to claim 2, characterized in that, The adhesive strength of the sealing strip is not less than 3 N / mm. 2 .

5. The battery casing according to claim 2, characterized in that, Along the second direction, the coverage width of the sealing strip is B, where B ≥ 1 mm.

6. The battery casing according to claim 1, characterized in that, The sealing element (2) is a dot-applied adhesive, which can be applied to the solder area.

7. The battery casing according to claim 1, characterized in that, The battery casing also includes two cover plates (3), and the receiving cavity (101) has two openings, with the two cover plates (3) respectively covering the two openings of the receiving cavity (101).

8. The battery casing according to claim 7, characterized in that, The multiple sidewalls also include a third wall (13) and a fourth wall (14), the third wall (13) and the fourth wall (14) being adjacent to the first wall (11) and the second wall (12) respectively, the opposite sides of the cover plate (3) being welded to the third wall (13) and the fourth wall (14) respectively, and along the first direction, the length L of the seal (2) is not greater than the length of the housing (1).

9. The battery casing according to claim 7, characterized in that, The multiple sidewalls also include a fifth wall (15), which is located on the opposite side of the first wall (11) and the second wall (12). Along the thickness direction of the cover plate (3), one side of the cover plate (3) is welded to the first wall (11) and the second wall (12) respectively, and the other side of the cover plate (3) is welded to the fifth wall (15). Along the first direction, the distance from both ends of the seal (2) to both ends of the housing (1) is not less than 1.5 mm.

10. A single battery cell, characterized in that, It includes a cell pack (4) and a battery case according to any one of claims 1-9, wherein the cell pack (4) is disposed within the receiving cavity (101).

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