Battery shell, battery casing and battery

Abstract

A battery comprises a battery casing, which comprises a battery shell and a cover plate. The battery shell comprises a main body (1), the main body (1) enclosing an accommodating space, and laser cladding regions (101) being formed on the main body (1), wherein the laser cladding regions (101) extend inwards in the direction of the wall thickness of the main body (1) from the outer surface of the main body (1); alternatively, the laser cladding regions (101) extend outwards in the direction of the wall thickness of the main body (1) from the inner surface of the main body (1); and in the circumferential direction of the main body (1), several laser cladding regions (101) are provided at intervals. By means of laser cladding, the laser cladding regions (101) are formed on the machined main body (1), thereby enhancing the overall structural strength of the battery shell. Thus, when the battery undergoes thermal runaway, the battery shell is not easily broken, thereby avoiding safety accidents; and after the battery is loaded into a battery pack, the battery shell is not easily bent and deformed, thereby ensuring the performance of the battery.

Description

Battery casing, battery shell and battery

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to the Chinese patent application filed with the China Patent Office on February 4, 2024, with application number 2024101548125 and invention name “Battery shell, battery casing and battery”, the entire contents of which are incorporated by reference into this application. Technical Field

[0003] The present application relates to the field of battery technology, and in particular to a battery casing, a battery housing and a battery. Background Art

[0004] A power battery generally consists of an internal structure and an external structure. The internal structure primarily consists of the cell electrode group, while the external structure, also known as the battery casing, primarily comprises the battery cover and battery housing. The battery housing houses the cell electrode group and is welded to the battery cover to form an enclosed space, ultimately forming the complete battery structure.

[0005] Battery casings are typically formed by bending sheet metal and welding the joints using high-frequency or laser welding. To reduce production costs and achieve lightweighting, the battery casing walls are often thin, resulting in insufficient strength. When a battery experiences thermal runaway, the casing can easily rupture, leading to battery failure and a safety incident. Once installed in a battery pack, the casing can easily bend and deform, seriously affecting battery performance.

[0006] Summary of the Invention

[0007] In view of this, the present application provides a battery casing, a battery shell and a battery to solve the problem in the prior art that the battery casing is insufficient in strength and is easily broken or deformed.

[0008] In a first aspect, the present application provides a battery case, comprising: a main body, the main body enclosing a receiving space, the main body forming a laser cladding zone, the laser cladding zone extending inward from the outer surface of the main body along the wall thickness direction of the main body, or the laser cladding zone extending outward from the inner surface of the main body along the wall thickness direction of the main body; along the circumference of the main body, a plurality of laser cladding zones are arranged at intervals.

[0009] Beneficial effects: Laser cladding is used to form a laser cladding area on the processed main body, which strengthens the overall structural strength of the battery shell. When the battery experiences thermal runaway, the battery shell is not easy to rupture, avoiding safety accidents. When the battery is installed in the battery pack, the battery shell is not easy to bend and deform, ensuring the performance of the battery.

[0010] In an optional embodiment, the laser cladding area is provided at least corresponding to an edge of the main body.

[0011] Beneficial effect: By improving the structural strength of the edges of the main body, the overall structural strength of the battery shell is improved, effectively ensuring that the battery shell is not easy to break and not easy to bend and deform.

[0012] In an optional embodiment, the main body is formed by bending along the length direction of the plate, two sides of the plate are butted and welded, and a plurality of laser cladding areas are spaced apart along the length direction of the plate.

[0013] In an optional embodiment, four laser cladding zones are arranged in sequence along the length direction of the plate, wherein the center distance between the two laser cladding zones located in the middle of the plate is b, the center distance between one laser cladding zone located at the edge of the plate and another adjacent laser cladding zone is a, the width of the main body is Y, the thickness of the main body is Z, and a=Y, b=Z is satisfied.

[0014] In an optional embodiment, the wall thickness H of the main body is 0.3 mm to 3 mm.

[0015] In an optional embodiment, the thickness h of the laser cladding zone accounts for 1 / 3 to 2 / 3 of the wall thickness H of the main body; and / or the thickness h of the laser cladding zone is 0.1 mm to 2 mm.

[0016] Beneficial effect: The laser cladding area has a suitable thickness, which can not only improve the structural strength of the battery shell, but also facilitate the processing of the laser cladding area.

[0017] In an optional embodiment, the width l of the laser cladding zone is 2.5 mm to 6.8 mm.

[0018] Beneficial effect: The laser cladding zone has a suitable width, ensuring that the laser cladding zone can cover the edges of the main body.

[0019] In an optional embodiment, the length X of the main body is 300 mm to 2000 mm, the width Y of the main body is 40 mm to 150 mm, and the thickness Z of the main body is 12 mm to 55 mm; or, the length X of the main body is 100 mm to 600 mm, the width Y of the main body is 50 mm to 250 mm, and the thickness Z of the main body is 10 mm to 100 mm; or, the length X of the main body is 600 mm to 1500 mm, the width Y of the main body is 50 mm to 250 mm, and the thickness Z of the main body is 10 mm to 100 mm.

[0020] In a second aspect, the present application also provides a battery housing, comprising the above-mentioned battery shell.

[0021] In a third aspect, the present application also provides a battery, comprising the above-mentioned battery casing. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the specific implementation methods or the description of the prior art. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0023] FIG1 is a front view of a battery housing according to an embodiment of the present application;

[0024] FIG2 is a schematic diagram of a plate material used to make the battery housing shown in FIG1 ;

[0025] FIG3 is a perspective view of the battery housing in FIG1 .

[0026] Description of reference numerals: 1. Main body; 101. Laser cladding area. DETAILED DESCRIPTION

[0027] To make the purpose, technical solutions, and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative efforts shall fall within the scope of protection of this application.

[0028] The following describes an embodiment of the present application in conjunction with FIG1 to FIG3 .

[0029] According to an embodiment of the present application, in one aspect, a battery case is provided, comprising a main body 1. The main body 1 encloses a housing space. The main body 1 is formed with a laser cladding zone 101. The laser cladding zone 101 extends inward from the outer surface of the main body 1 along the wall thickness direction of the main body 1, or the laser cladding zone 101 extends outward from the inner surface of the main body 1 along the wall thickness direction of the main body 1. A plurality of laser cladding zones 101 are spaced apart along the circumference of the main body 1.

[0030] By adopting the laser cladding method, a laser cladding area 101 is formed on the processed main body 1, thereby strengthening the overall structural strength of the battery shell. When the battery has thermal runaway, the battery shell is not easy to rupture, thereby avoiding causing a safety accident. When the battery is installed in the battery pack, the battery shell is not easy to bend and deform, thereby ensuring the performance of the battery.

[0031] It is worth noting that, referring to FIG. 1 , the circumferential direction of the main body 1 is the enclosed direction of the main body 1 shown in FIG. 1 .

[0032] It should be noted that laser cladding technology uses a high-energy-density laser beam to rapidly melt, expand, and solidify alloys with different compositions and properties on the surface of the substrate (battery shell plate), and clad a layer of material with special physical, chemical, or mechanical properties on the surface of the substrate. This coating and the interface of the substrate are metallurgically bonded to form a new composite material to make up for the lack of high performance of the substrate. This technology can increase the strength of the substrate, improve the wear resistance of the substrate surface, improve the performance of the battery shell, and avoid problems such as easy breakage and bending deformation.

[0033] It should be further clarified that the alloys with different compositions and properties mentioned above can be high-strength alloys such as titanium alloys, magnesium alloys, and aluminum alloys. Laser cladding process parameters primarily include laser output power, laser spot size, spot amplitude and oscillation frequency, scanning speed, and coating thickness. Laser cladding can utilize picosecond lasers, femtosecond lasers, and other lasers. These process parameters and laser type can be adjusted based on specific operating conditions.

[0034] It is worth noting that laser cladding technology has the following advantages: the laser action time is short and the energy density is high, so the heat-affected zone of the base material is small, and the deformation caused by processing stress is also small, and the cladding yield is high; the cladding layer has a fine and uniform structure, a dense structure, and few microscopic defects, so the hardness is generally higher, and the wear resistance and corrosion resistance are also more superior; the interface between the coating and the substrate is metallurgically bonded, the composition and dilution rate of the cladding layer are controllable, and selective cladding and automated preparation are easy to achieve; and the pollution to the environment is small.

[0035] In one embodiment, as shown in FIG1 , the laser cladding area 101 is provided corresponding to the edge of the body 1. By improving the structural strength of the edge of the body 1, the overall structural strength of the battery housing is improved, effectively ensuring that the battery housing is not easily broken or deformed.

[0036] It is worth noting that, referring to FIG. 1 , the main body 1 is a square structure having four edges. Accordingly, four laser cladding areas 101 are provided, and the four laser cladding areas 101 are provided in one-to-one correspondence with the four edges.

[0037] Of course, in other alternative embodiments, the laser cladding area 101 may also be provided in the non-edge area of ​​the main body 1 , that is, within the surface area of ​​the main body 1 .

[0038] It is worth noting that in the related art, the blade battery housing is relatively long. When the battery housing strength is low, it is prone to bending and deformation. Therefore, in the related art, in order to increase the strength of the blade battery housing, prevent the housing from bending and deformation, and maintain the shape of the electrode group, a side plate structure is usually added between the mating surface of the battery cell electrode group and the battery housing. It is understandable that the provision of the side plate structure will occupy the internal space of the battery, reduce the internal space utilization of the battery, and lead to increased costs.

[0039] The battery case of this embodiment utilizes a laser-clad region 101 formed on the body 1 (particularly along the edges), thereby enhancing the structural strength of the battery case and thereby ensuring that the battery is not easily bent or deformed. Consequently, no additional side panels are required, reducing the internal space occupied by the battery, improving internal space utilization, and lowering production costs.

[0040] Optionally, the increased strength of the battery casing itself increases the strength of the finished battery. When the blade battery is installed in a pack, its long, thin shape offers the advantage of good heat dissipation and can serve as a structural component. Combined with module-free CTP and CTC technologies, this can improve the safety and energy volume density of the entire battery pack while reducing costs.

[0041] In one embodiment, as shown in FIG1 and FIG2 , the main body 1 is formed by bending along the length direction of the plate, two sides of the plate are butted and welded, and a plurality of laser cladding areas 101 are spaced apart along the length direction of the plate.

[0042] It is worth noting that, referring to FIG. 1 and FIG. 2 , the length of the plate is the perimeter of the main body 1 after bending, and the wall thickness of the main body 1 is the thickness of the plate.

[0043] In one embodiment, as shown in Figures 1 and 2, four laser cladding zones 101 are sequentially spaced along the length of the plate. The center distance between the two laser cladding zones 101 in the middle of the plate is b, and the center distance between a laser cladding zone 101 and its adjacent laser cladding zone 101 at the edge of the plate is a. The width of the main body 1 is Y, and the thickness of the main body 1 is Z, satisfying a = Y, b = Z. Therefore, after the plate is bent and formed, the laser cladding zones 101 can be arranged corresponding to the edges of the main body 1.

[0044] It should be noted that, referring to FIG2 , the four laser cladding zones 101 are arranged in ascending order from left to right. The center distance a between the second laser cladding zone 101 and the first laser cladding zone 101 is equal to the width Y of the main body 1, and the center distance b between the second laser cladding zone 101 and the third laser cladding zone 101 is equal to the thickness Z of the main body 1. Optionally, the center distance a between the third laser cladding zone 101 and the fourth laser cladding zone 101 is also equal to the width Y of the main body 1.

[0045] In one embodiment, as shown in Figures 1 and 2 , the wall thickness H of the main body 1 is 0.3 mm to 3 mm, that is, the thickness of the plate is 0.3 mm to 3 mm.

[0046] In one embodiment, as shown in FIG2 , the thickness h of the laser cladding zone 101 accounts for 1 / 3 to 2 / 3 of the wall thickness H of the main body 1 ; and / or, the thickness h of the laser cladding zone 101 is 0.1 mm to 2 mm.

[0047] It is worth noting that, referring to Figures 1 and 2 , the laser cladding zone 101 only occupies a portion of the body 1 in the thickness direction (i.e., the thickness of the plate). This ensures that the laser cladding zone 101 has an appropriate thickness, which not only improves the structural strength of the battery housing but also facilitates processing of the laser cladding zone 101.

[0048] In one embodiment, as shown in FIG. 2 , the width l of the laser cladding zone 101 is 2.5 mm to 6.8 mm.

[0049] It is worth noting that, referring to FIG. 1 , a fillet structure is formed at the edge of the main body 1 . Typically, the inner fillet radius r of the fillet structure is 1 mm. Therefore, the outer fillet radius R of the fillet structure is R=r+H, and the value range of the outer fillet radius R is 1.3 mm to 4 mm. The length of the outer fillet of each fillet structure (1 / 4 of the circular circumference, i.e., 1 / 4×2×π×R) is 2.04 mm to 6.28 mm. The width of the laser cladding zone 101 is set to be slightly larger (typically 0.5 mm longer) than the length of the outer fillet of the fillet structure, thereby providing the laser cladding zone 101 with an appropriate width to ensure that the laser cladding zone 101 can cover the edges of the main body 1 .

[0050] Of course, in other alternative embodiments, the thickness and width of the laser cladding zone 101 can be specifically selected according to actual needs.

[0051] In one embodiment, as shown in Figure 1 , the length X of the main body 1 is 300mm to 2000mm, the width Y of the main body 1 is 40mm to 150mm, and the thickness Z of the main body 1 is 12mm to 55mm. Optionally, X=500mm, Y=120mm, and Z=16mm.

[0052] Of course, in other alternative embodiments, the length X of the main body 1 is 100 mm to 600 mm, the width Y of the main body 1 is 50 mm to 250 mm, and the thickness Z of the main body 1 is 10 mm to 100 mm; or, the length X of the main body 1 is 600 mm to 1500 mm, the width Y of the main body 1 is 50 mm to 250 mm, and the thickness Z of the main body 1 is 10 mm to 100 mm.

[0053] It is worth noting that the battery housing can be made of materials such as aluminum and steel.

[0054] The following are strength, elongation and hardness tests on different laser cladding plates.

[0055] For the first type of plate, the material of the plate is AL3003, the length of the plate is 272 mm (i.e., 2×Y+2×Z, where Y=120 mm, Z=16 mm), the width of the plate is 500 mm (i.e., X=500 mm), and the thickness H of the plate is 1.2 mm. The test results are shown in Tables 1 and 2.

[0056] Table 1 Experimental results of the embodiment

[0057] Table 2 Comparative Example Experimental Results

[0058] For the second type of plate, the material of the plate is AL3003, the length of the plate is 272 mm (i.e., 2×Y+2×Z, where Y=120 mm, Z=16 mm), the width of the plate is 500 mm (i.e., X=500 mm), and the thickness H of the plate is 2.4 mm. The test results are shown in Tables 3 and 4.

[0059] Table 3 Experimental results of the examples

[0060] Table 4 Comparative Example Experimental Results

[0061] As can be seen from Tables 1 and 3, the plates with laser cladding zones in Examples 1 to 15 in each table are superior to the original plates (i.e., plates without laser cladding zones) in terms of yield strength, tensile strength, elongation, and hardness. Therefore, by providing the laser cladding zone 101 on the main body 1, the structural performance of the battery housing can be improved.

[0062] It is worth noting that tensile specimens were taken from the laser-clad plate and placed on a tensile testing machine until they broke. The yield strength, tensile strength, and elongation of the specimens were recorded. A Vickers hardness tester was used to measure the depth of the metal rod pressed into the sample surface.

[0063] According to an embodiment of the present application, on the other hand, a battery housing is provided, comprising the above-mentioned battery shell.

[0064] In one embodiment, the battery housing further includes a cover plate, which is arranged corresponding to the end opening of the battery housing.

[0065] According to an embodiment of the present application, on another aspect, a battery is provided, comprising the above-mentioned battery casing.

[0066] Although the embodiments of the present application 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 application, and such modifications and variations shall fall within the scope defined by the appended claims.

Claims

1. A battery housing, characterized in that: include: The main body encloses a receiving space, and the main body is formed with a laser cladding zone, and the laser cladding zone extends inward from the outer surface of the main body along the wall thickness direction of the main body, or the laser cladding zone extends outward from the inner surface of the main body along the wall thickness direction of the main body; along the circumference of the main body, a plurality of laser cladding zones are arranged at intervals.

2. The battery case according to claim 1, wherein: The laser cladding area is at least arranged corresponding to the edge of the main body.

3. The battery case according to claim 1 or 2, characterized in that: The main body is formed by bending along the length direction of the plate, two sides of the plate are butted and welded, and a plurality of laser cladding areas are spaced apart along the length direction of the plate.

4. The battery case according to claim 3, characterized in that Four laser cladding zones are arranged in sequence along the length direction of the plate, wherein the center distance between the two laser cladding zones located in the middle of the plate is b, the center distance between one laser cladding zone located at the edge of the plate and another adjacent laser cladding zone is a, the width of the main body is Y, the thickness of the main body is Z, and a=Y, b=Z is satisfied.

5. The battery case according to claim 1 or 2, characterized in that: The wall thickness H of the main body is 0.3 mm to 3 mm.

6. The battery case according to claim 1 or 2, characterized in that: The thickness h of the laser cladding zone accounts for 1 / 3 to 2 / 3 of the wall thickness H of the main body; and / or the thickness h of the laser cladding zone is 0.1 mm to 2 mm.

7. The battery case according to claim 1 or 2, characterized in that: The width l of the laser cladding zone is 2.5 mm to 6.8 mm.

8. The battery case according to claim 1 or 2, characterized in that: The length X of the main body is 300 mm to 2000 mm, the width Y of the main body is 40 mm to 150 mm, and the thickness Z of the main body is 12 mm to 55 mm; or The length X of the main body is 100 mm to 600 mm, the width Y of the main body is 50 mm to 250 mm, and the thickness Z of the main body is 10 mm to 100 mm; or, The length X of the main body is 600 mm to 1500 mm, the width Y of the main body is 50 mm to 250 mm, and the thickness Z of the main body is 10 mm to 100 mm.

9. A battery casing, characterized in that: A battery casing comprising the battery casing according to any one of claims 1 to 8.

10. A battery, characterized in that: The battery casing comprises the battery casing according to claim 9.

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