Battery and battery pack

Abstract

The utility model relates to the technical field of batteries, and discloses a battery and a battery pack. The pole group is arranged in the shell; the insulating film is coated outside the pole group; the protective plate is connected with the inner surface, facing the pole group, of the insulating film, the protective plate is arranged between the outer surface of the pole group and the inner surface of the insulating film, and the protective plate corresponds to the welding seam. According to the utility model, the protective plate is arranged between the welding seam and the pole group, so that the welding seam and the pole group are effectively isolated, the damage of the welding seam position of the shell to the pole group is avoided, and the short circuit risk in the pole group and the short circuit risk caused by contact between the pole group and the shell are further avoided.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, specifically to batteries and battery packs. Background Technology

[0002] A battery typically consists of an external structure and an internal structure. The external structure includes a cover and a casing, which together form a sealed space with a certain structural strength. The internal structure includes electrode arrays, which are housed within this sealed space and encased in an insulating film to prevent short circuits caused by contact between the electrode arrays and the casing. The casing can be formed using bending and welding processes, resulting in weld seams. When the electrode arrays are installed in the casing, these weld seams can easily damage the insulating film and even the electrode arrays, potentially leading to a short circuit risk. Utility Model Content

[0003] In view of this, the present invention provides a battery and battery pack to solve the problem that the weld seams of the casing in existing batteries can easily damage the insulating film or even the electrode assembly, which can easily lead to short circuit risks.

[0004] In a first aspect, the present invention provides a battery comprising: a casing having a weld seam; an electrode assembly disposed within the casing; an insulating film covering the outside of the electrode assembly; and a protective plate connected to the inner surface of the insulating film facing the electrode assembly, the protective plate being disposed between the outer surface of the electrode assembly and the inner surface of the insulating film, the protective plate being disposed corresponding to the weld seam.

[0005] Beneficial effects: By setting a protective plate between the weld and the electrode assembly, the weld and the electrode assembly are effectively isolated, avoiding damage to the electrode assembly caused by the weld position of the shell, thereby avoiding the risk of short circuit inside the electrode assembly and the risk of short circuit caused by contact between the electrode assembly and the shell.

[0006] In one optional embodiment, along the x-direction, the outer width of the shell is A, the width of the protective plate is B, the width of the weld is C, the wall thickness of the shell is T, the edges of the shell are rounded, and the radius of the rounded corners is R, satisfying C≤B≤A-2×T-2×R.

[0007] Beneficial effects: While avoiding interference between the protective plate and the shell, it ensures that the protective plate effectively covers the weld seam and improves the protective effect of the protective plate on the electrode assembly.

[0008] In one optional embodiment, the outer width A of the housing satisfies 13mm ≤ A ≤ 80mm.

[0009] In one optional embodiment, the wall thickness T of the housing satisfies 0.3mm≤T≤1.0mm; and / or, the radius R of the rounded corner structure satisfies 1.0mm≤R≤1.5mm.

[0010] In one optional embodiment, the width C of the weld seam satisfies 1mm ≤ C ≤ 3mm.

[0011] In one alternative implementation, the thickness of the protective plate along the y-direction is K, satisfying 0.3mm≤K≤1mm.

[0012] Beneficial effects: While ensuring effective isolation between the protection plate and the electrode assembly and weld seam, it avoids the protection plate occupying too much space inside the casing, thereby ensuring the energy density of the battery.

[0013] In one optional implementation, when 0.35mm≤T≤0.4mm, 0.5mm≤K≤1mm is satisfied; when 0.45mm≤T≤0.5mm, 0.3mm≤K≤0.5mm is satisfied.

[0014] In one optional embodiment, along the z-direction, the length of the housing is H, the length of the protective plate is I, and the length of the insulating film is L, satisfying (H-4)mm≤L≤(H-3)mm, (L-20)mm≤I≤(L-15)mm.

[0015] In one alternative embodiment, the protective plate and the insulating film are fixedly connected by heat fusion.

[0016] Secondly, this utility model also provides a battery pack, including the aforementioned battery. Attached Figure Description

[0017] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the connection structure between the protective plate and the insulating film in an embodiment of the present utility model;

[0019] Figure 2 This is an exploded structural diagram of the battery according to an embodiment of the present invention;

[0020] Figure 3 This is a schematic diagram of the mating structure of the shell and protective plate in the xy plane according to an embodiment of the present invention;

[0021] Figure 4 This is a side view of the battery according to an embodiment of the present utility model;

[0022] Figure 5 for Figure 4 A sectional view of DD.

[0023] Explanation of reference numerals in the attached figures:

[0024] 1. Shell; 11. Rounded corner structure; 12. First side plate; 13. Second side plate; 2. Weld; 3. Electrode group; 4. Insulating film; 5. Protective plate; 6. Hot melting point; 7. Battery cover. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0026] In related technologies, depending on the size of the battery, the common manufacturing processes for the casing 1 generally include deep drawing, bending and welding, and hot extrusion. For long battery structures with a relatively small opening size and a length exceeding 350mm (i.e., smaller width along the x-direction and smaller height along the y-direction, and larger length along the z-direction) (such as blade batteries), bending and welding processes are currently commonly used. The bending and welding process flow is as follows: aluminum plate bending - laser welding / high-frequency welding at the aluminum plate joint - smoothing of weld seam 2 - blanking - opening treatment - cleaning and drying - dimensional measurement - finished product delivery. However, the length of weld seam 2 in this type of casing 1 is very long, and in order to ensure that the strength of weld seam 2 is not lower than the strength of casing 1, a boss with a height of 0.05mm to 0.2mm is reserved on both the inner and outer sides of casing 1 at weld seam 2, which is then smoothed by tooling after welding. However, due to the long length of weld 2, the requirements for the leveling tooling and operation process are high. This can easily lead to unevenness of weld 2 along the length of shell 1 after leveling, and / or the presence of small burrs. In addition, the boss of weld 2 itself has a certain height difference with shell 1. After the electrode group 3 is assembled with shell 1, there is also a risk of damaging the electrode group 3 at the corners of the boss, which affects the safety performance of the battery.

[0027] The following is combined with Figures 1 to 5 The following describes embodiments of the present invention.

[0028] According to an embodiment of the present invention, a battery is provided, comprising: a housing 1 having a weld 2; an electrode assembly 3 disposed within the housing 1; an insulating film 4 covering the outside of the electrode assembly 3; and a protective plate 5 connected to the inner surface of the insulating film 4 facing the electrode assembly 3, the protective plate 5 being disposed between the outer surface of the electrode assembly 3 and the inner surface of the insulating film 4, the protective plate 5 being disposed corresponding to the weld 2.

[0029] In the battery of this embodiment, by setting a protective plate 5 between the weld 2 and the electrode group 3, the weld 2 and the electrode group 3 are effectively isolated, avoiding damage to the electrode group 3 caused by the weld 2 of the casing 1, thereby avoiding the risk of short circuit inside the electrode group 3 and the risk of short circuit caused by contact between the electrode group 3 and the casing 1.

[0030] It is worth noting that when the electrode assembly 3 is installed in the casing, the burrs and protrusions at the weld seam 2 can easily scratch the insulating film 4. After the electrode assembly 3 is installed, the insulating film 4 can be easily punctured or damaged by the pressure of the casing 1 or during battery movement, leading to a short circuit inside the electrode assembly 3 or a short circuit when the electrode assembly 3 comes into contact with the casing 1. In this embodiment, a protective plate 5 is provided between the electrode assembly 3 and the weld seam 2. Even if the insulating film 4 is punctured or scratched, the protective plate 5 can still play a role in isolation and insulation, preventing the burrs and protrusions at the weld seam 2 from damaging the electrode assembly 3, thereby ensuring the safety performance of the battery.

[0031] In one embodiment, such as Figure 3 As shown, along the x-direction, the outer width of the shell 1 is A, the width of the protective plate 5 is B, the width of the weld 2 is C, the wall thickness of the shell 1 is T, and the edges of the shell 1 are rounded corner structures 11 with a radius of R, satisfying C≤B≤A-2×T-2×R. This arrangement avoids interference between the protective plate 5 and the shell 1 while ensuring effective coverage of the weld 2 by the protective plate 5, thus improving the protective effect of the protective plate 5 on the electrode assembly 3.

[0032] It is worth noting that if the value of B is too small, the protective plate 5 cannot completely cover the weld 2 in the x direction, and there is still a risk that the pole group 3 will be punctured or damaged, resulting in a short circuit. If the value of B is too large, the edge of the housing 1 in the x direction is likely to fall on the rounded corner structure 11 of the edge, and may even cause the edge of the protective plate 5 to interfere with the housing 1, which cannot guarantee the smooth assembly of the protective plate 5 and the stability of the protective plate 5 inside the housing 1.

[0033] It should be further explained that, while ensuring that the protective plate 5 is positioned to correspond with the flat plate structure on the side of the housing 1 to avoid the rounded corner structure 11, the width B of the protective plate 5 can be increased as much as possible to improve the protective effect.

[0034] Specifically, such as Figure 3As shown, the housing 1 includes a first side plate 12 and a second side plate 13. Two first side plates 12 and two second side plates 13 are provided. The two first side plates 12 are spaced apart from each other, and the two second side plates 13 are also spaced apart from each other. The first side plates 12 and the second side plates 13 are sequentially connected circumferentially. The connection between adjacent first side plates 12 and second side plates 13 forms the aforementioned rounded corner structure 11. Both the first side plates 12 and the second side plates 13 are flat. Further, the first side plate 12 forms the small facet of the battery, and the second side plate 13 forms the large facet. The weld seam 2 is provided corresponding to the small facet of the battery, and the protective plate 5 is located between the first side plate 12 and the electrode group 3. The outer width of the housing 1 is the distance between the outer surfaces of the two second side plates 13.

[0035] In one embodiment, the outer width A of the housing 1 satisfies 13mm≤A≤80mm.

[0036] In one embodiment, the wall thickness T of the housing 1 satisfies 0.3mm≤T≤1.0mm.

[0037] In one embodiment, the radius R of the rounded corner structure 11 satisfies 1.0mm≤R≤1.5mm.

[0038] In one embodiment, the width C of weld 2 satisfies 1mm ≤ C ≤ 3mm.

[0039] In one embodiment, such as Figure 3 As shown, the thickness of the protection plate 5 along the y-direction is K, satisfying 0.3mm≤K≤1mm. This configuration ensures effective isolation between the protection plate 5 and the electrode group 3 and the weld seam 2, while avoiding the protection plate 5 occupying too much space inside the casing 1, thereby ensuring the energy density of the battery.

[0040] It is worth noting that if the value of K is too small, the protection board 5 is at risk of being punctured or scratched, which may result in a short circuit risk in the battery. If the value of K is too large, the protection board 5 will occupy too much internal space in the casing 1, affecting the energy density of the battery.

[0041] In one embodiment, when 0.35mm≤T≤0.4mm, 0.5mm≤K≤1mm is satisfied; when 0.45mm≤T≤0.5mm, 0.3mm≤K≤0.5mm is satisfied.

[0042] In one embodiment, such as Figure 5 As shown, along the z-direction, the length of the shell 1 is H, the length of the protective plate 5 is I, and the length of the insulating film 4 is L, satisfying (H-4)mm≤L≤(H-3)mm, (L-20)mm≤I≤(L-15)mm.

[0043] In one embodiment, the protective plate 5 and the insulating film 4 are fixedly connected by heat fusion. Further, as...Figure 1 As shown, multiple hot-melt points 6 are provided along the length of the protective plate 5 to stably connect the protective plate 5 and the insulating film 4.

[0044] Specifically, first, the protective plate 5 and the insulating film 4 are heat-fused and fixed; then, the insulating film 4 with the protective plate 5 is wrapped around the circumference of the electrode assembly 3, and the film is overlapped by a certain width on one side of the electrode assembly 3 and fixed at the end, with the protective plate 5 corresponding to the other side of the electrode assembly 3; finally, the insulating film 4 is heat-fused and fixed to the lower plastic of the battery cover 7, and then the electrode assembly 3 is installed into the housing 1, so that the protective plate 5 is located between the electrode assembly 3 and the weld 2.

[0045] It should be noted that the material of the protective plate is usually the same as that of the insulating film, for example, PP material can be used.

[0046] Batteries with abnormal voltage during production, including those without protection board 5 and those with protection boards 5 of different sizes, were disassembled, and the statistical analysis results are shown in Table 1.

[0047] Table 1. Statistical Analysis Results of Batteries

[0048] T / mm B / mm A / mm K / mm Verification effect Comparative Example 1 0.35 / / 0 Weld puncture / pressure injury group had more abnormal problems, accounting for about 0.055% Comparative Example 2 0.35 / / 0 Weld puncture / pressure injury group had more abnormal problems, accounting for about 0.062% Example 1 0.35 11 15 0.2 Weld puncture / pressure injury group had more abnormal problems, accounting for about 0.044% Example 2 0.35 11 15 0.3 Weld puncture / pressure injury group had more abnormal problems, accounting for about 0.024% Example 3 0.35 11 15 0.5 Weld puncture / pressure injury group had less abnormal problems, accounting for about 0.0023% Example 4 0.35 11 15 0.6 Weld puncture / pressure injury group had less abnormal problems, accounting for about 0.0031% Example 5 0.35 11 15 0.8 Weld puncture / pressure injury group had less abnormal problems, accounting for about 0.0018% Example 6 0.35 11 15 1.0 Weld puncture / pressure injury group had less abnormal problems, accounting for about 0.0010% Comparative Example 3 0.5 / / 0 Weld puncture / pressure injury group had more abnormal problems, accounting for about 0.065% Comparative Example 4 0.5 / / 0 Weld puncture / pressure injury group had more abnormal problems, accounting for about 0.058% Example 7 0.5 11 15 0.15 Weld puncture / pressure injury group had more abnormal problems, accounting for about 0.054% Example 8 0.5 11 15 0.20 Weld puncture / pressure injury group had more abnormal problems, accounting for about 0.048% Example 9 0.5 11 15 0.25 Weld puncture / pressure injury group had more abnormal problems, accounting for about 0.042% Example 10 0.5 11 15 0.3 Weld puncture / pressure injury group had less abnormal problems, accounting for about 0.0012% Example 11 0.5 11 15 0.4 Weld puncture / pressure injury group had less abnormal problems, accounting for about 0.0002% Example 12 0.5 11 15 0.5 Weld puncture / pressure injury group had less abnormal problems, accounting for about 0.0015%

[0049] As can be seen from Table 1, for batteries with a casing wall thickness of 0.35 mm, in Examples 1 and 2, the thickness of the protective plate 5 is less than 0.5 mm, and the problem of weld seam 2 puncturing or damaging the electrode assembly 3 causing abnormalities is reduced compared to the batteries in Comparative Examples 1 and 2. In Examples 3 to 6, when the thickness of the protective plate 5 is in the range of 0.5 mm to 1 mm, the problem of weld seam 2 puncturing or damaging the electrode assembly 3 causing abnormalities is significantly reduced.

[0050] As can be seen from Table 1, for batteries with a casing wall thickness of 0.5 mm, in Examples 7 to 9, the thickness of the protective plate 5 is less than 0.3 mm, and the problem of weld seam 2 puncturing or damaging the electrode assembly 3 causing abnormalities is reduced compared to the batteries of Comparative Examples 3 and 4. In Examples 10 to 12, when the thickness of the protective plate 5 is in the range of 0.3 mm to 0.5 mm, the problem of weld seam 2 puncturing or damaging the electrode assembly 3 causing abnormalities is significantly reduced.

[0051] In summary, by setting a protective plate 5 between the electrode assembly 3 and the weld 2, and by reasonably limiting the size of the protective plate 5, the problem of short circuit caused by the weld 2 puncturing or scratching the electrode assembly 3 can be effectively solved, thereby improving production yield and battery safety.

[0052] According to an embodiment of the present invention, another aspect provides a battery pack including the battery described above.

[0053] Although embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A battery, characterized in that, include: The shell has welds; The electrode assembly is disposed within the housing; An insulating film is used to cover the outside of the electrode assembly; A protective plate is connected to the inner surface of the insulating film facing the electrode assembly. The protective plate is disposed between the outer surface of the electrode assembly and the inner surface of the insulating film, and the protective plate is disposed corresponding to the weld.

2. The battery according to claim 1, characterized in that, Along the x-direction, the outer width of the shell is A, the width of the protective plate is B, the width of the weld is C, the wall thickness of the shell is T, the edges of the shell are rounded, and the radius of the rounded corners is R, satisfying C≤B≤A-2×T-2×R.

3. The battery according to claim 2, characterized in that, The outer width A of the shell satisfies 13mm≤A≤80mm.

4. The battery according to claim 2, characterized in that, The wall thickness T of the shell satisfies 0.3mm ≤ T ≤ 1.0mm; and / or, The radius R of the rounded corner structure satisfies 1.0mm≤R≤1.5mm.

5. The battery according to claim 2, characterized in that, The width C of the weld seam satisfies 1mm ≤ C ≤ 3mm.

6. The battery according to any one of claims 2 to 5, characterized in that, Along the y-direction, the thickness of the protective plate is K, which satisfies 0.3mm≤K≤1mm.

7. The battery according to claim 6, characterized in that, When 0.35mm≤T≤0.4mm, the condition 0.5mm≤K≤1mm is satisfied. When 0.45mm≤T≤0.5mm, the condition 0.3mm≤K≤0.5mm is satisfied.

8. The battery according to any one of claims 1 to 5, characterized in that, Along the z-direction, the length of the shell is H, the length of the protective plate is I, and the length of the insulating film is L, satisfying (H-4)mm≤L≤(H-3)mm, (L-20)mm≤I≤(L-15)mm.

9. The battery according to any one of claims 1 to 5, characterized in that, The protective plate and the insulating film are fixedly connected by heat fusion.

10. A battery pack, characterized in that, The battery includes any one of claims 1 to 9.

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