A battery case and a secondary battery

Abstract

The utility model discloses a battery case and a secondary battery, the battery case includes two first side plates and two second side plates, two first side plates and two second side plates enclose and form the cuboid cylinder structure, the first side plate includes the body portion and the connecting portion that forms after the body portion both ends respectively to the same direction bending, the connecting portion all or partial overlap on the second side plate to with second side plate welding fixed, in the utility model, the first side plate adopts "U" shape structure, can increase the thickness of battery case in the welding area, can avoid the molten pool subsidence of welding area in the welding process, prevents the scratch of the battery case inside installation's electric core in the subsequent use process, simple structure, and the practicality is strong.

Description

Technical Field

[0001] This utility model belongs to the field of secondary battery technology, and specifically relates to a battery casing and a secondary battery. Background Technology

[0002] Existing battery casings (such as those for blade batteries) are generally rectangular cylindrical in shape, comprising four side plates: two wide side plates forming the large surfaces of the casing and two narrow side plates forming the small surfaces. The manufacturing process typically involves first machining the two wide and two narrow side plates separately, then assembling the two wide side plates together to form the battery casing, with a weld seam at the junction of adjacent side plates. However, during welding, traditional fixtures struggle to achieve precise multi-dimensional positioning because the four side plates must be joined sequentially. For example, angular deviations can easily occur when connecting the wide and narrow side plates, causing the weld seam to deviate from its intended trajectory, and weld burn-through is prone to occur at the weld seam, resulting in significant manufacturing difficulties for the battery casing. Utility Model Content

[0003] In view of the shortcomings of the prior art, the technical problem to be solved by this utility model is to provide a battery casing and a secondary battery.

[0004] To solve the above-mentioned technical problems, this utility model provides the following technical solution:

[0005] A battery casing includes two first side plates and two second side plates arranged opposite to each other, the two first side plates and the two second side plates forming a cuboid cylindrical structure; the first side plates have a first outer side and a first inner side arranged opposite to each other, and the second side plates have a second outer side and a second inner side arranged opposite to each other; the first side plates have a "U" shaped structure, including a body portion and a connecting portion formed by bending both ends of the body portion in the same direction, the connecting portion overlapping the second outer side or the second inner side and being welded and fixed to the second side plates.

[0006] Furthermore, the first side plate is used to form the large surface of the battery casing, and the second side plate is used to form the small surface of the battery casing; or

[0007] The first side plate is used to form the small surface of the battery casing, and the second side plate is used to form the large surface of the battery casing.

[0008] Furthermore, the wall thickness of the second side plate is greater than that of the first side plate. The second side plate has a first recessed step on its second outer side at the position of the connecting part on both sides. The connecting part overlaps on the first recessed step, and a weld is formed at the end of the connecting part and the step surface of the first recessed step by welding.

[0009] Furthermore, the width of the first sunken step is 0.5mm to 1mm, and the depth of the first sunken step is greater than or equal to the wall thickness of the first side plate.

[0010] Furthermore, the wall thickness of the first side plate is 0.2mm to 0.5mm, and the wall thickness of the second side plate is 0.2mm to 0.5mm greater than that of the first side plate.

[0011] Furthermore, the second side plate has a second recessed step on its second inner side surface at both ends along its axial direction. The depth of the second recessed step is 0.05mm to 0.5mm. The second recessed step is used for positioning when installing the cover plate. The width of the second recessed step is greater than or equal to the thickness of the cover plate.

[0012] Furthermore, the wall thickness of the first side plate is greater than that of the second side plate, and the first outer side of the connecting part is provided with a third recessed step. The two ends of the second side plate are respectively located on the third recessed step of the corresponding connecting part of the two first side plates, thereby overlapping with the connecting part, and a weld is formed at the end of the second side plate and the step surface of the third recessed step by welding.

[0013] Furthermore, the wall thickness of the second side plate is 0.2mm to 0.5mm, and the wall thickness of the first side plate is 0.2mm to 0.5mm greater than that of the second side plate; the width of the third recessed step is 0.5mm to 1mm, and the depth of the third recessed step is greater than or equal to the wall thickness of the second side plate.

[0014] Furthermore, the first side plate has a fourth recessed step on its first inner side surface at both ends along its axial direction. The depth of the fourth recessed step is 0.05mm to 0.5mm. The fourth recessed step is used for positioning when installing the cover plate. The width of the fourth recessed step is greater than or equal to the thickness of the cover plate.

[0015] A secondary battery comprising a battery casing as described in any of the preceding claims.

[0016] In this invention, the first side plate adopts a "U"-shaped structure, which increases the thickness of the battery casing in the welding area. This prevents the molten pool in the welding area from sinking during welding, thus preventing scratches on the battery cells installed inside the battery casing during subsequent use. By setting a recessed step in the area where the second side plate overlaps with the connecting part, accurate positioning can be achieved when the connecting part is connected to the second side plate, improving the dimensional accuracy of the battery casing and allowing adjustment so that the outer surface of the connecting part is flush with the second outer surface of the second side plate. Attached Figure Description

[0017] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0018] Figure 1 This is a schematic diagram of the structure of an embodiment of a battery casing according to the present invention.

[0019] Figure 2 for Figure 1 This is an exploded view.

[0020] Figure 3 for Figure 1 The main view.

[0021] Figure 4 for Figure 3 Enlarged view of point A in the middle.

[0022] Figure 5 This is a front view of another embodiment of the battery casing of this utility model.

[0023] Figure 6 for Figure 5 Enlarged view of point B in the middle.

[0024] The diagrams in the instruction manual are labeled as follows:

[0025] First side plate - 100; First outer side surface - 101; First inner side surface - 102; Main body - 110; Connecting part - 120; Third sunken step - 131; Fourth sunken step - 132;

[0026] Second side panel - 200; Second outer side panel - 201; Second inner side panel - 202; First sunken step - 211; Second sunken step - 212;

[0027] Weld seam -300. Detailed Implementation

[0028] The following specific examples illustrate the implementation of this utility model. The illustrations provided in the following embodiments are only schematic representations of the basic concept of this utility model. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0029] Example 1

[0030] Please see Figure 1 , Figure 1This is a schematic diagram of a battery casing according to an embodiment of the present invention. The battery casing of this embodiment includes two first side plates 100 and two second side plates 200 arranged opposite each other. The two first side plates 100 and the two second side plates 200 are sequentially connected and fixed to form a rectangular cylindrical structure. The first side plates 100 and the second side plates 200 are preferably made of stainless steel.

[0031] Please see Figure 2 , Figure 3 and Figure 4 The first side plate 100 has a first outer side surface 101 and a first inner side surface 102 disposed opposite to each other, and the second side plate 200 has a second outer side surface 201 and a second inner side surface 202 disposed opposite to each other. In this embodiment, the first side plate 100 is used to form the large surface (i.e., the wider surface in the battery housing) of the battery housing, and the second side plate 200 is used to form the small surface (i.e., the narrower surface in the battery housing) of the battery housing. Of course, in other embodiments, the first side plate 100 can also be used to form the small surface of the battery housing, and the second side plate 200 can also be used to form the large surface of the battery housing.

[0032] To facilitate welding and fixing of the first side plate 100 and the second side plate 200, the first side plate 100 has a "U"-shaped structure, including a main body 110 and connecting portions 120 formed by bending both ends of the main body 110 in the same direction. A portion of the connecting portion 120 overlaps the outer surface of the second side plate 200 and is welded and fixed to the second side plate 200. In this embodiment, about half of the connecting portion 120 overlaps with the second side plate 200; of course, the overlap between the connecting portion 120 and the second side plate 200 can be more than half, and if necessary, the entire connecting portion 120 can overlap the second outer surface 201 of the second side plate 200.

[0033] To facilitate positioning during connection, the wall thickness of the second side plate 200 can be greater than that of the first side plate 100, thereby facilitating the creation of a first recessed step 211 on the second outer surface 201 of the second side plate 200 at the positions corresponding to the connecting portions 120 on both sides. In this embodiment, the wall thickness d1 of the first side plate 100 is preferably 0.2mm to 0.5mm, and the wall thickness d2 of the second side plate 200 is generally 0.2mm to 0.5mm greater than that of the first side plate 100; for example, the wall thickness d2 of the second side plate 200 can preferably be 0.5mm to 0.8mm.

[0034] The connecting portion 120 overlaps the first recessed step 211, and the overlap width is determined by the width of the first recessed step 211. The width L1 of the first recessed step 211 is preferably 0.5mm to 1mm, and the depth g1 of the first recessed step 211 is greater than or equal to the wall thickness d1 of the first side plate 100. In this embodiment, the depth of the first recessed step 211 is preferably equal to the wall thickness of the first side plate 100, i.e., g1 = d1, so that the first outer surface 101 corresponding to the connecting portion 120 in the first side plate 100 is flush with the second outer surface 201 of the second side plate 200, avoiding the formation of uneven areas on the outer surface of the battery casing.

[0035] A weld 300 is formed at the end of the connecting part 120 and the step surface of the first sinking step 211 by laser welding. Since the wall thickness of the second side plate 200 is relatively thick (the total thickness of the overlapping area of ​​the connecting part 120 is d2-g1+d1=d2, which is the same as the wall thickness of the second side plate 200), the molten pool in the welding area can be prevented from sinking during the welding process, which would cause the inner wall of the battery casing to deform and thus scratch the battery cells installed inside the battery casing.

[0036] To facilitate the positioning of the cover plate during subsequent installation on the battery casing, the second side plate 200 is positioned along its axial direction (i.e., Figure 1 The two ends of the second side plate 200 (in the y-axis direction) have a second recessed step 212 on its second inner side surface 202. The depth g2 of the second recessed step 212 is 0.05mm to 0.5mm. The second recessed step 212 at both ends of the second side plate 200 is used for positioning when the upper cover plate and the lower cover plate are installed at the two openings of the battery casing respectively. The width L2 of the second recessed step 212 is generally equal to the thickness of the corresponding cover plate (i.e., the upper cover plate or the lower cover plate).

[0037] In this embodiment, the first side plate 100 adopts a "U"-shaped structure, which can increase the thickness of the battery casing in the welding area. This prevents the molten pool in the welding area from sinking during welding, thus preventing scratches to the battery cells installed inside the battery casing during subsequent use. By increasing the wall thickness of the second side plate 200 used to form the small facet of the battery casing, the thickness can be increased in the height direction of the battery casing (i.e.,...). Figure 1The support force is increased along the z-axis to prevent deformation of the battery casing due to compression when the batteries are installed overlapping in the height direction. In addition, by setting the first recessed step 211 in the area where the second side plate 200 overlaps with the connecting part 120 at both ends, accurate positioning can be achieved when the connecting part 120 is connected to the second side plate 200, improving the dimensional accuracy of the battery casing, and allowing the outer side of the connecting part 120 (i.e., the area of ​​the first outer side 101 corresponding to the connecting part 120) to be flush with the second outer side 201 of the second side plate 200; by opening the second recessed step 212 on the second inner side 202 of the second side plate 200, positioning can be facilitated when installing the cover plate.

[0038] Example 2

[0039] Please see Figure 5 , Figure 5 This is a front view of another embodiment of the battery casing according to the present invention. The battery casing of this embodiment includes two first side plates 100 and two second side plates 200 arranged opposite each other. The two first side plates 100 and the two second side plates 200 are sequentially connected and fixed to form a rectangular cylindrical structure. The first side plates 100 and the second side plates 200 are preferably made of stainless steel.

[0040] Please see Figure 6 The first side plate 100 has a first outer side surface 101 and a first inner side surface 102 disposed opposite to each other, and the second side plate 200 has a second outer side surface 201 and a second inner side surface 202 disposed opposite to each other. In this embodiment, the second side plate 200 is used to form the large surface of the battery casing, and the first side plate 100 is used to form the small surface of the battery casing. Of course, the first side plate 100 can also be used to form the large surface of the battery casing, and the second side plate 200 can also be used to form the small surface of the battery casing.

[0041] The first side plate 100 has a U-shaped structure, including a main body 110 and connecting portions 120 formed by bending both ends of the main body 110 in the same direction. A portion of the connecting portion 120 overlaps the inner surface of the second side plate 200 and is welded to the second side plate 200. Of course, if necessary, the entire connecting portion 120 can overlap the second inner surface 202 of the second side plate 200.

[0042] The wall thickness of the first side plate 100 is greater than that of the second side plate 200, and the first outer side surface 101 of the connecting portion 120 is provided with a third recessed step 131. In this embodiment, the wall thickness d2 of the second side plate 200 is preferably 0.2mm to 0.5mm, and the wall thickness d1 of the first side plate 100 is generally 0.2mm to 0.5mm greater than that of the second side plate 200; for example, the wall thickness d1 of the first side plate 100 can preferably be 0.5mm to 0.8mm.

[0043] The two ends of the second side plate 200 are respectively located on the third recessed step 131 of the corresponding connecting portion 120 in the two first side plates 100, thus overlapping with the area of ​​the third recessed step 131 of the connecting portion 120. The overlap width is determined by the width of the third recessed step 131. The width L3 of the third recessed step 131 is preferably 0.5mm to 1mm, and the depth g3 of the third recessed step 131 is greater than or equal to the wall thickness d2 of the second side plate 200. In this embodiment, the depth of the third recessed step 131 is preferably equal to the wall thickness of the second side plate 200, i.e., g3 = d2, so that the first outer surface 101 of the connecting portion 120 in the first side plate 100 is flush with the second outer surface 201 of the second side plate 200, avoiding the formation of uneven areas on the outer surface of the battery casing.

[0044] Weld 300 is formed at the end of the second side plate 200 and the step surface of the third recessed step 131 by welding. Since the wall thickness of the first side plate 100 is relatively thick (the total thickness of the overlapping area of ​​the connecting part 120 is d1-g3+d2=d1, which is the same as the wall thickness of the first side plate 100), the welding area can be prevented from being laser-welded through during the welding process, thus avoiding the scrapping of the battery casing.

[0045] To facilitate the positioning of the cover plate when installing it on the battery casing, the first side plate 100 has a fourth recessed step 132 on its first inner side surface 102 at both ends along its axial direction. The depth g4 of the fourth recessed step 132 is 0.05mm to 0.5mm. The fourth recessed step 132 is used for positioning when installing the cover plate. The width of the fourth recessed step 132 is generally equal to the thickness of the corresponding cover plate.

[0046] In this embodiment, the first side plate 100 adopts a "U"-shaped structure, which can increase the thickness of the battery casing in the welding area. This prevents the molten pool in the welding area from sinking during welding, thus preventing scratches on the battery cells installed inside the battery casing during subsequent use. By providing a third recessed step 131 in the connecting portion 120 and increasing the wall thickness of the first side plate 100, the thickness of the battery casing in the height direction (i.e., Figure 1The support force is increased in the z-axis direction. In addition, by setting the third recessed step 131, the connection part 120 can be accurately positioned when connecting with the second side plate 200, improving the dimensional accuracy of the battery casing, and the outer side of the connection part 120 can be adjusted to be flush with the second outer side 201; by opening the fourth recessed step 132, positioning can be conveniently performed when installing the cover plate.

[0047] This utility model also discloses a secondary battery, which is provided with the battery casing of any of the above embodiments. The secondary battery using the above-described battery casing has high dimensional accuracy, making it suitable for applications requiring high dimensional precision. Furthermore, it has significant support in the height direction, facilitating overlapping installation of batteries in that direction. Additionally, the inner wall of the battery casing does not form sharp points, protecting the battery cells installed inside the casing.

[0048] The above embodiments only illustrate preferred implementations of this utility model, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A battery casing, characterized in that: It includes two first side plates and two second side plates arranged opposite to each other, the two first side plates and the two second side plates forming a cuboid cylindrical structure; the first side plates have a first outer side and a first inner side arranged opposite to each other, and the second side plates have a second outer side and a second inner side arranged opposite to each other; the first side plates have a "U" shaped structure, including a main body and a connecting part formed by bending both ends of the main body in the same direction, the connecting part overlapping the second outer side or the second inner side in whole or in part, and being welded and fixed to the second side plates.

2. A battery case as defined in claim 1, wherein: The first side plate is used to form the large surface of the battery casing, and the second side plate is used to form the small surface of the battery casing; or The first side plate is used to form the small surface of the battery casing, and the second side plate is used to form the large surface of the battery casing.

3. A battery housing as claimed in claim 1 or 2, characterized in that: The wall thickness of the second side plate is greater than that of the first side plate. The second side plate has a first recessed step on its second outer side at the position of the connecting part on both sides. The connecting part overlaps on the first recessed step, and a weld is formed at the end of the connecting part and the step surface of the first recessed step by welding.

4. A battery case as defined in claim 3, wherein: The width of the first sunken step is 0.5mm to 1mm, and the depth of the first sunken step is greater than or equal to the wall thickness of the first side plate.

5. A battery case as defined in claim 3, wherein: The wall thickness of the first side plate is 0.2mm to 0.5mm, and the wall thickness of the second side plate is 0.2mm to 0.5mm greater than that of the first side plate.

6. A battery case as defined in claim 3, wherein: The second side plate has a second recessed step on its second inner side at both ends along its axial direction. The depth of the second recessed step is 0.05mm to 0.5mm. The second recessed step is used for positioning when installing the cover plate. The width of the second recessed step is greater than or equal to the thickness of the cover plate.

7. A battery housing as claimed in claim 1 or 2, characterized in that: The wall thickness of the first side plate is greater than that of the second side plate, and the first outer side of the connecting part is provided with a third recessed step. The two ends of the second side plate are respectively located on the third recessed step of the corresponding connecting part of the two first side plates, thereby overlapping with the connecting part, and a weld is formed at the end of the second side plate and the step surface of the third recessed step by welding.

8. A battery case as defined in claim 7, wherein: The wall thickness of the second side plate is 0.2mm to 0.5mm, and the wall thickness of the first side plate is 0.2mm to 0.5mm greater than that of the second side plate; the width of the third sunken step is 0.5mm to 1mm, and the depth of the third sunken step is greater than or equal to the wall thickness of the second side plate.

9. A battery case as defined in claim 7, wherein: The first side plate has a fourth recessed step on its first inner side surface at both ends along its axial direction. The depth of the fourth recessed step is 0.05mm to 0.5mm. The fourth recessed step is used for positioning when installing the cover plate. The width of the fourth recessed step is greater than or equal to the thickness of the cover plate.

10. A secondary battery, characterized in that: Includes a battery casing as described in any one of claims 1 to 9.

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