Battery cell and battery pack with same

Abstract

The utility model discloses a single battery and a battery pack with the single battery, the single battery comprises a shell assembly, a pole group and a protective film, the shell assembly defines a mounting space, and the inner surface of the shell assembly is provided with a welding seam; the pole group is arranged in the mounting space; and the protective film is arranged between the pole group and the shell assembly and is opposite to the welding seam. According to the battery monomer disclosed by the utility model, the protective film is arranged between the pole group and the shell assembly and is opposite to the welding seam, so that the pole group can be protected by the protective film, short circuit caused by contact between the pole group and the shell assembly at the welding seam is avoided, and the electrical safety of the battery monomer is improved. The sealing effect of the protective film is good, the sealing performance of the welding position of the shell assembly can be further improved, and the overall sealing effect of the shell assembly is improved.

Description

Technical Field

[0001] The utility model mainly relates to the technical field of batteries, and particularly relates to a battery cell and a battery pack having the same. Background Art

[0002] In the prior art, since the weld seam on the inner side of the housing assembly of the battery cell may protrude from the inner surface, it is easy to scratch the electrode group, causing safety risks. Summary of the Utility Model

[0003] The utility model aims to solve at least one of the technical problems existing in the prior art. For this purpose, the utility model provides a battery cell, which can prevent the electrode group from contacting the housing assembly at the weld seam and causing a short circuit, and improve the electrical safety of the battery cell.

[0004] The utility model also provides a battery pack, which includes the above-mentioned battery cell.

[0005] The battery cell according to the embodiment of the utility model includes a housing assembly, an electrode group and a protective film. The housing assembly defines an installation space, and the inner surface of the housing assembly is provided with a weld seam; the electrode group is arranged in the installation space; the protective film is arranged between the electrode group and the housing assembly and is disposed opposite to the weld seam.

[0006] The battery cell according to the embodiment of the utility model, by arranging the protective film between the electrode group and the housing assembly and opposite to the weld seam, the protective film can protect the electrode group, prevent the electrode group from contacting the housing assembly at the weld seam and causing a short circuit, and improve the electrical safety of the battery cell. And the sealing effect of the protective film is good, which can further improve the sealing performance of the welded part of the housing assembly and improve the overall sealing effect of the housing assembly.

[0007] In some embodiments of the utility model, the dimension t in the thickness direction of the protective film satisfies: 0.1mm ≤ t ≤ 0.3mm.

[0008] In some embodiments of the utility model, along the width direction of the protective film, the housing assembly includes a plurality of side plates, the weld seam is arranged on one of the side plates, the width dimension of the inner wall of the side plate provided with the weld seam is K, and the dimension in the width direction of the protective film is H and satisfies 2mm ≤ K - H ≤ 6mm.

[0009] In some embodiments of the utility model, along the length direction of the protective film, the length dimension of the inner wall of the side plate provided with the weld seam is L, and the dimension in the length direction of the protective film is M and satisfies 2mm ≤ L - M ≤ 6mm.

[0010] In some embodiments of the present utility model, an insulating film is wrapped around the outside of the electrode group. The insulating film is disposed inside the housing assembly. The insulating film includes a main body portion and a folding portion. The main body portion wraps the outer peripheral wall of the electrode group.

[0011] In some embodiments of the present utility model, a plurality of first positioning holes are provided on the folding portion. A plurality of second positioning holes are provided on a portion of the main body portion, which is away from the folding portion and is used for laminating with the folding portion. The plurality of first positioning holes and the plurality of second positioning holes are opposite and communicate with each other.

[0012] In some embodiments of the present utility model, the protective film is adhesively connected to the housing assembly.

[0013] In some embodiments of the present utility model, the protective film is a PET piece; or, the protective film is a PC piece.

[0014] In some embodiments of the present utility model, open ends are provided at both ends of the housing assembly in the length direction. The battery cell further includes a cover plate, and the cover plate covers the open ends.

[0015] The battery pack according to the embodiment of the present utility model includes the above-mentioned battery cell.

[0016] In the battery pack according to the embodiment of the present utility model, by disposing the protective film between the electrode group and the housing assembly and opposite to the weld seam, the protective film can protect the electrode group, avoid the electrode group contacting the housing assembly at the weld seam and causing a short circuit, and increase the electrical safety of the battery cell. Moreover, the sealing effect of the protective film is relatively good, which can further increase the sealing performance of the welded part of the housing assembly and improve the overall sealing effect of the housing assembly.

[0017] The additional aspects and advantages of the present utility model will be partially given in the following description, partially become obvious from the following description, or be understood through the practice of the present utility model. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The above and / or additional aspects and advantages of the present utility model will become obvious and easy to understand from the description of the embodiments in conjunction with the following drawings, in which:

[0019] Figure 1 is a cross-sectional view of a battery cell according to an embodiment of the present utility model;

[0020] Figure 2 is Figure 1 an enlarged view of part A in

[0021] Figure 3 is a cross-sectional view of the housing assembly and the protective film of a battery cell according to an embodiment of the present utility model;

[0022] Figure 4 It is a perspective view of a battery cell according to an embodiment of the present invention.

[0023] Reference numerals:

[0024] 100, battery cell;

[0025] 1, housing assembly; 11, installation space; 12, weld seam;

[0026] 2, electrode group;

[0027] 3, protective film;

[0028] 4, cover plate; 41, positive electrode post; 42, explosion-proof valve. Detailed implementation manners

[0029] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary and are only used to explain the present invention and should not be construed as a limitation of the present invention.

[0030] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. In addition, the features defined as "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, the meaning of "a plurality" is two or more.

[0031] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0032] Next, refer to Figures 1 - 4Describe a battery cell 100 according to an embodiment of the present utility model.

[0033] As Figure 1 and Figure 2 shown, the battery cell 100 according to an embodiment of the present utility model includes a housing assembly 1, an electrode assembly 2, and a protective film 3.

[0034] Specifically, the housing assembly 1 defines an installation space 11. The inner surface of the housing assembly 1 is provided with a weld seam 12. The housing assembly 1 is formed by folding a whole metal plate. After folding, the housing assembly 1 needs to be welded. The strength of the welded part is relatively poor compared to the housing assembly 1 itself. When there is high-pressure gas inside the housing assembly 1, the housing assembly 1 will burst at the welded part, failing to meet the requirement that the battery cell 100 can withstand a certain pressure value. After welding, there is a weld seam 12 inside the housing assembly 1. When butt-welding the housing assembly 1, the extrusion amount needs to be increased so that the height of the weld seam 12 is higher than the inner wall of the housing. However, the weld seam 12 is relatively sharp, and when the electrode assembly 2 is inserted into the housing assembly 1, it is easy to scratch the electrode assembly 2, easily causing a short circuit inside the battery cell 100. After welding, the weld seam 12 will be cleaned, but there are still some burrs at the weld seam 12 after cleaning.

[0035] As Figure 1 and Figure 2 shown, the electrode assembly 2 is disposed in the installation space 11. The protective film 3 is disposed between the electrode assembly 2 and the housing assembly 1 and is disposed opposite to the weld seam 12. The protective film 3 can protect the electrode assembly 2, avoiding the electrode assembly 2 from contacting the housing assembly 1 at the weld seam 12 and causing a short circuit, increasing the electrical safety of the battery cell 100.

[0036] Moreover, the sealing effect of the protective film 3 is good, which can further increase the sealing performance of the welded part of the housing assembly 1 and increase the overall sealing effect of the housing assembly 1.

[0037] For the battery cell 100 according to an embodiment of the present utility model, by disposing the protective film 3 between the electrode assembly 2 and the housing assembly 1 and opposite to the weld seam 12, the protective film 3 can protect the electrode assembly 2, avoiding the electrode assembly 2 from contacting the housing assembly 1 at the weld seam 12 and causing a short circuit, increasing the electrical safety of the battery cell 100. Moreover, the sealing effect of the protective film 3 is good, which can further increase the sealing performance of the welded part of the housing assembly 1 and increase the overall sealing effect of the housing assembly 1.

[0038] In the prior art, a side plate is placed between the electrode assembly 2 and the housing assembly 1, which can prevent the weld seam 12 from scratching the electrode assembly 2. However, the thickness of the side plate is relatively large, occupying a large space inside the housing assembly 1.

[0039] In some embodiments of the present utility model, as Figure 1 and Figure 2As shown, the dimension t in the thickness direction of the protective film 3 (such as Figure 2 the first direction shown) satisfies: 0.1 mm ≤ t ≤ 0.3 mm. It can be understood that the dimension t in the thickness direction of the protective film 3 can be 0.1 mm, 0.11 mm, 0.12 mm, 0.13 mm, 0.14 mm, 0.15 mm, 0.16 mm, 0.17 mm, 0.18 mm, 0.19 mm, 0.2 mm, 0.21 mm, 0.22 mm, 0.23 mm, 0.24 mm, 0.25 mm, 0.26 mm, 0.27 mm, 0.28 mm, 0.29 mm or 0.3 mm. The dimension t in the thickness direction of the protective film 3 being not less than 0.1 mm can ensure the strength of the protective film 3 and prevent the weld 12 from breaking through the protective film 3 and scratching the electrode group 2; the dimension t in the thickness direction of the protective film 3 being not greater than 0.3 mm makes the dimension in the thickness direction of the protective film 3 smaller and occupies less space in the housing assembly 1.

[0040] In some embodiments of the present utility model, such as Figure 1 and Figure 2 shown, along the width direction of the protective film 3 (such as Figure 2 the second direction shown), the housing assembly 1 includes a plurality of side plates, the weld 12 is provided on one of the side plates, the width dimension of the inner wall of the side plate provided with the weld 12 is K, and the dimension in the width direction of the protective film 3 is H and satisfies 2 mm ≤ K - H ≤ 6 mm. It can be understood that the value of the width dimension K of the inner wall of the side plate provided with the weld 12 minus the dimension H in the width direction of the protective film 3 can be 2 mm, 2.2 mm, 2.4 mm, 2.6 mm, 2.8 mm, 3 mm, 3.2 mm, 3.4 mm, 3.6 mm, 3.8 mm, 4 mm, 4.2 mm, 4.4 mm, 4.6 mm, 4.8 mm, 5 mm, 5.2 mm, 5.4 mm, 5.6 mm, 5.8 mm or 6 mm. The value of the width dimension K of the inner wall of the side plate provided with the weld 12 minus the dimension H in the width direction of the protective film 3 being not less than 2 mm can make the protective film 3 have a certain distance from the edge of the side plate provided with the weld 12 along the width direction of the protective film 3, facilitating the installation of the protective film 3; the value of the width dimension K of the inner wall of the side plate provided with the weld 12 minus the dimension H in the width direction of the protective film 3 being not greater than 6 mm can prevent the distance between the protective film 3 and the edge of the inner wall of the side plate from being too large, ensuring the covering and protecting effect of the protective film 3 on the weld 12.

[0041] In this embodiment, along the width direction of the protective film 3, the unilateral distance between the protective film 3 and the edge of the side plate provided with the weld 12 is 1 - 3 mm, which facilitates the installation of the protective film 3 and can prevent the distance between the protective film 3 and the edge of the inner wall of the side plate from being too large, ensuring the covering and protecting effect of the protective film 3 on the weld 12.

[0042] In some embodiments of the present utility model, such as Figure 1 and Figure 3 shown, along the length direction of the protective film 3 (such as the third direction shown in Figure 3 ), the length dimension of the inner wall of the side plate provided with the weld 12 is L, and the dimension in the length direction of the protective film 3 is M, and 2 mm ≤ L - M ≤ 6 mm. It can be understood that the value obtained by subtracting the dimension M in the length direction of the protective film 3 from the length dimension L of the inner wall of the side plate provided with the weld 12 can be 2 mm, 2.2 mm, 2.4 mm, 2.6 mm, 2.8 mm, 3 mm, 3.2 mm, 3.4 mm, 3.6 mm, 3.8 mm, 4 mm, 4.2 mm, 4.4 mm, 4.6 mm, 4.8 mm, 5 mm, 5.2 mm, 5.4 mm, 5.6 mm, 5.8 mm or 6 mm. The value obtained by subtracting the dimension M in the length direction of the protective film 3 from the length dimension L of the inner wall of the side plate provided with the weld 12 is not less than 2 mm, which can make the protective film 3 have a certain distance from the edge of the side plate provided with the weld 12 along the length direction of the protective film 3, facilitating the installation of the protective film 3; the value obtained by subtracting the dimension M in the length direction of the protective film 3 from the length dimension L of the inner wall of the side plate provided with the weld 12 is not greater than 6 mm, which can avoid the distance between the protective film 3 and the edge of the inner wall of the side plate from being too large, ensuring the covering and protecting effect of the protective film 3 on the weld 12.

[0043] In this embodiment, along the length direction of the protective film 3, the unilateral distance between the protective film 3 and the edge of the side plate provided with the weld 12 is 1 - 3 mm, which is convenient for the installation of the protective film 3 and can avoid the distance between the protective film 3 and the edge of the inner wall of the side plate from being too large, ensuring the covering and protecting effect of the protective film 3 on the weld 12.

[0044] In some embodiments of the present utility model, the outer side of the electrode group 2 is coated with an insulating film. The insulating film is arranged in the housing assembly 1. The insulating film includes a main body part and a folding part. The main body part wraps the outer peripheral wall of the electrode group 2. The insulating film can protect the electrode group 2 and make the electrode group 2 have a good insulating effect.

[0045] Further, a plurality of first positioning holes are provided on the folding part, and a plurality of second positioning holes are provided on the part of the main body part away from the folding part for laminating with the folding part. The plurality of first positioning holes and the plurality of second positioning holes are opposite and communicated. After the assembly of the electrode group 2 and the insulating film is completed, it can be detected by inserting a detection rod into the first positioning hole and the second positioning hole and detecting whether the detection rod can contact the electrode group 2. When the detection rod can contact the electrode group 2, the folding of the insulating film is successful; when the detection rod cannot contact the electrode group 2, the folding of the insulating film fails. The folding effect of the insulating film can be detected more conveniently, and the assembly efficiency of the electrode group 2 and the insulating film is relatively high.

[0046] In some embodiments of the present utility model, the insulating film is a Mylar film. The Mylar film has excellent insulating properties, which can prevent the pole group 2 from short - circuiting and increase the reliability of the battery cell 100.

[0047] In some embodiments of the present utility model, the protective film 3 is adhesively connected to the housing assembly 1. The protective film 3 and the housing assembly 1 do not require complex process equipment, are easy to operate, and reduce the requirements for production equipment and the environment. During the bonding process of the protective film 3 and the housing assembly 1, the stress distribution can be made more uniform, avoiding the stress concentration problem that may be brought about by the mechanical fastening method, thereby improving the overall strength and durability of the protective film 3 and the housing assembly 1.

[0048] In this embodiment, the protective film 3 and the housing assembly 1 are adhesively connected through double - sided tape, and the connection between the protective film 3 and the housing assembly 1 is relatively simple and reliable.

[0049] In some embodiments of the present utility model, the protective film 3 is a PET (polyethylene glycol terephthalate) part. The PET material has good chemical stability, can resist the erosion of various chemical substances and solvents, can resist the erosion of the electrolyte inside the battery cell 100, and ensure the safety and stability inside the battery cell 100.

[0050] In some embodiments of the present utility model, the protective film 3 is a PC (Polycarbonate) part. The PC material has good chemical stability, can resist the erosion of various chemical substances and solvents, can resist the erosion of the electrolyte inside the battery cell 100, and ensure the safety and stability inside the battery cell 100.

[0051] In some embodiments of the present utility model, as Figure 3 and Figure 4 shown, both ends of the housing assembly 1 in the length direction (such as the third direction shown in Figure 3 are provided with open mouths. The battery cell 100 further includes a cover plate 4. The cover plate 4 is arranged at the open mouths to block the space inside the housing assembly 1 and ensure the reliability of the position of the pole group 2. The battery cell 100 further includes a positive electrode post 41 and a negative electrode post. One of the positive electrode post 41 and the negative electrode post is arranged on one of the cover bodies, and the other of the positive electrode post 41 and the negative electrode post is arranged on the other cover body; or, the positive electrode post 41 and the negative electrode post are arranged on one of the cover bodies. In this embodiment, one of the positive electrode post 41 and the negative electrode post is arranged on one of the cover bodies, and the other of the positive electrode post 41 and the negative electrode post is arranged on the other cover body, so that the electrical connection of the positive and negative electrode posts of the battery cell 100 is separated, which can increase the electrical safety of the battery cell 100.

[0052] In this embodiment, asFigure 4 As shown, an explosion-proof valve 42 is provided on the cover body provided with the positive electrode post 41. When thermal runaway occurs in the battery cell 100, the hot air inside the battery cell 100 can rush out of the housing assembly 1 through the explosion-proof valve 42, avoiding the explosion of the battery cell 100 and increasing the thermal safety of the battery cell 100.

[0053] The battery pack according to an embodiment of the present invention includes the above-mentioned battery cell 100.

[0054] In the battery pack according to an embodiment of the present invention, by disposing the protective film 3 between the electrode group 2 and the housing assembly 1 and opposite to the weld 12, the protective film 3 can protect the electrode group 2, avoiding the short circuit caused by the contact between the electrode group 2 and the housing assembly 1 at the weld 12, and increasing the electrical safety of the battery cell 100. Moreover, the sealing effect of the protective film 3 is good, which can further increase the sealing performance of the welded part of the housing assembly 1 and increase the overall sealing effect of the housing assembly 1.

[0055] The other constitutions and operations of the battery cell 100 and the battery pack having the same according to an embodiment of the present invention are known to those of ordinary skill in the art and will not be described in detail here.

[0056] In the description of this specification, the descriptions referring to terms such as "an embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0057] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and purposes of the present invention, and the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A battery cell, characterized in that, Comprising: A housing assembly, the housing assembly defining an installation space, and a weld seam being provided on the inner surface of the housing assembly; An electrode group, the electrode group being disposed in the installation space; A protective film, the protective film being disposed between the electrode group and the housing assembly and being disposed opposite to the weld seam. Along the width direction of the protective film, the housing assembly includes a plurality of side plates, the weld seam is provided on one of the side plates, the width dimension of the inner wall of the side plate provided with the weld seam is K, the dimension in the width direction of the protective film is H and satisfies 2mm ≤ K - H ≤ 6mm.

2. The battery cell according to claim 1, characterized in that, The dimension t in the thickness direction of the protective film satisfies: 0.1mm ≤ t ≤ 0.3mm.

3. The battery cell according to claim 1, wherein Along the length direction of the protective film, the length dimension of the inner wall of the side plate provided with the weld seam is L, the dimension in the length direction of the protective film is M and satisfies 2mm ≤ L - M ≤ 6mm.

4. The battery cell according to claim 1, wherein The outer side of the electrode group is coated with an insulating film, the insulating film is disposed in the housing assembly, and the insulating film includes a main body portion and a folding portion, and the main body portion wraps the outer peripheral wall of the electrode group.

5. The battery cell according to claim 4, characterized in that, A plurality of first positioning holes are provided on the folding portion, and a plurality of second positioning holes are provided on the portion of the main body portion away from the folding portion for laminating with the folding portion, and the plurality of first positioning holes and the plurality of second positioning holes are opposite and communicated.

6. The battery cell according to claim 1, wherein The protective film is adhesively connected to the housing assembly.

7. The battery cell according to claim 1, wherein The protective film is a PET part; Or, the protective film is a PC part.

8. The battery cell according to claim 1, wherein Openings are provided at both ends of the housing assembly in the length direction, and the battery cell further includes: A cover plate, the cover plate covering the openings.

9. A battery pack, characterized in that, Including the battery cell according to any one of claims 1 - 8.

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