Locally reinforced insulating film and lithium ion battery

Abstract

The utility model relates to a locally reinforced insulating film which wraps the outer side surface of a pole core of a lithium ion battery and comprises a film main body, the film main body is of a sheet-shaped film structure, at least one strip-shaped reinforcing sheet is arranged on the surface of the film main body, and the strip-shaped reinforcing sheet extends along the length direction of the film main body; the utility model also relates to a lithium ion battery which comprises a shell, a shell cover, a pole core and a locally reinforced insulating film, and the insulating film is wrapped on the outer surface of the pole core; an opening is formed in the end of the shell in the length direction, the pole core wrapped with the insulating film is inserted into the containing cavity of the shell through the opening, and the shell cover is installed on the opening in a sealed mode. The rigidity of the pole core is locally enhanced by the long-strip reinforcing sheet of the insulating film, the pole core is conveniently arranged in the shell after being locally enhanced, and the insulating film is not easily scraped by an opening of the shell.

Description

Technical Field

[0001] This utility model relates to the field of lithium-ion batteries, specifically to a locally reinforced insulating film and a lithium-ion battery. Background Technology

[0002] Existing lithium-ion batteries are used in the field of new energy vehicles. The insulating film of a lithium-ion battery is typically a single sheet-like thin film wrapped around the outer side of the electrode core, and the insulating film has a uniform thickness. The electrode core is located inside the lithium-ion battery casing, and the insulating film is located between the casing and the electrode core, serving as an insulating component between the electrode core and the casing. The insulating film has no reinforcing structure; after the insulating film wraps around the electrode core, the electrode core is relatively soft. When the length of the battery and the electrode core is long, the electrode core may deform and sag when inserted into the casing, affecting the insertion efficiency and also posing a risk that the insulating film may be scratched by the opening in the casing. Utility Model Content

[0003] In view of the technical problems existing in the prior art, the purpose of this utility model is to provide a locally reinforced insulating film, wherein the long strip reinforcing sheet can locally enhance the rigidity of the electrode core.

[0004] This utility model also provides a lithium-ion battery with a partially reinforced outer side of the electrode core for easy installation into the casing.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A locally reinforced insulating film is used to wrap the outer side of the electrode core of a lithium-ion battery. The insulating film includes a film body, which is a sheet-like thin film structure. At least one long reinforcing strip is disposed on the surface of the film body, and the long reinforcing strip extends along the length direction of the film body.

[0007] As a preferred embodiment, multiple through holes are formed on the surface of the long reinforcing strip, and the multiple through holes are randomly distributed on the surface of the long reinforcing strip.

[0008] As a preferred embodiment, multiple through holes are arranged in a row along the length of the long reinforcing strip.

[0009] As a preferred embodiment, there are two long reinforcing strips, and the positions of the two long reinforcing strips correspond to the two opposite sides of the cuboid-shaped pole core.

[0010] As a preferred option, the long reinforcing strip is fixed to the inner or outer surface of the membrane body.

[0011] As a preferred option, the long reinforcing strip is fixed to the surface of the membrane body by ultrasonic welding, laser welding, or hot melting.

[0012] As a preferred embodiment, the membrane body is made of PP, PE, PET, modified PP, modified PE, modified PET, or any combination of the above materials; the long reinforcing strip is made of PP, PET, PPS, PI, ceramic sheet, or any combination of the above materials.

[0013] As a preferred embodiment, the length of the reinforcing strip is no greater than the length of the membrane body, and the length of the reinforcing strip is 300mm-1000mm; the thickness of the membrane body is 0.05mm-0.15mm, and the thickness of the reinforcing strip is 0.2mm-0.8mm.

[0014] A lithium-ion battery includes a casing, a cover, an electrode core, and a partially reinforced insulating film, the insulating film being wrapped around the outer surface of the electrode core; the casing has an opening at its longitudinal end, through which the electrode core wrapped with the insulating film is inserted into the receiving cavity of the casing, and the opening is sealed to install the cover.

[0015] As a preferred embodiment, both the electrode core and the shell are cuboids, with two long reinforcing strips corresponding to two opposite sides of the electrode core.

[0016] This utility model has the following advantages:

[0017] (1) By setting long strip reinforcing pieces on the insulating film, when the electrode core is inserted into the housing, the length direction of the electrode core is strengthened by the long strip reinforcing pieces and will not sag, thereby improving the strength of the electrode core and making it easier to insert the electrode core into the housing, increasing the efficiency of inserting into the housing; at the same time, the insulating film is not easily scratched by the opening of the housing, improving the yield of electrode core coating, improving the yield of inserting into the housing, and increasing the yield of lithium-ion batteries.

[0018] (2) The insulating film of this utility model is provided with long strip reinforcing pieces. The two long strip reinforcing pieces correspond to the two opposite narrow sides of the electrode core which is shaped like a cuboid. The space utilization rate is high, and it does not occupy the battery thickness space. At the same time, it improves the rigidity of the entire electrode core and greatly improves the efficiency of inserting the electrode core into the housing and the yield rate of inserting the housing.

[0019] (3) When the long strip reinforcing sheet is fixed on the inner surface of the membrane body, the long strip reinforcing sheet is located between the membrane body and the electrode core. The through hole facilitates the electrolyte to pass through the long strip reinforcing sheet, ensuring that the electrolyte better wets the electrode core. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the structure of the insulating film of this utility model.

[0022] Figure 2 This is a left view of the insulating film.

[0023] Figure 3 A schematic diagram of a structure in which the through holes of a long reinforcing strip are arranged in a row.

[0024] Figure 4 This is a schematic diagram of a structure in which the through holes of a long reinforcing strip are arranged in two intersecting rows.

[0025] Figure 5 for Figure 1 A schematic diagram of the structure after the insulating film is wrapped around the electrode core and then the electrode core is removed.

[0026] Figure 6 for Figure 5 The left view.

[0027] Figure 7 for Figure 6 Enlarged view of point A.

[0028] Figure 8 This is a disassembled diagram of a lithium-ion battery.

[0029] Figure 9 This is a top view of a lithium-ion battery.

[0030] Figure 10 for Figure 7 A cross-sectional view of BB.

[0031] Figure 11 for Figure 8 Enlarged view of point C.

[0032] The components are: 1. Membrane body; 2. Long strip reinforcing sheet; 3. Through hole; 4. Electrode core; 5. Narrow side; 6. Shell; 7. Opening; 8. Shell cover; 9. Wide side. Detailed Implementation

[0033] 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, and 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.

[0034] Example 1

[0035] like Figures 1-7As shown, a locally reinforced insulating film wraps the outer side of the electrode core 4 of a lithium-ion battery. The insulating film includes a film body 1, which is a sheet-like thin film structure. At least one long reinforcing strip 2 is provided on the surface of the film body 1 to form a whole. The long reinforcing strip 2 extends along the length direction of the film body 1.

[0036] The length of the elongated reinforcing strip 2 is 300mm-1000mm. The length of the elongated reinforcing strip 2 is not greater than the length of the membrane body 1; the length of the elongated reinforcing strip 2 is slightly shorter than the length of the lithium-ion battery. The thickness of the membrane body 1 is 0.05mm-0.15mm, and the thickness of the elongated reinforcing strip 2 is 0.2mm-0.8mm. In this embodiment, the thickness of the elongated reinforcing strip 2 is preferably 0.2mm-0.5mm.

[0037] Multiple through holes 3 are formed on the surface of the elongated reinforcing sheet 2. The diameter of the through holes 3 is no greater than half the width of the elongated reinforcing sheet 2. The multiple through holes 3 are randomly distributed on the surface of the elongated reinforcing sheet 2. In this embodiment, it is preferable that the multiple through holes 3 are arranged in a row along the length direction of the elongated reinforcing sheet 2, or arranged in two rows in a crisscross pattern.

[0038] There are two elongated reinforcing strips 2, and the positions of the two elongated reinforcing strips 2 correspond to the two opposite sides of the cuboid-shaped pole core 4. The sides of the cuboid pole core 4, which is wrapped with insulating film, include two opposite wide sides 9 and two opposite narrow sides 5. In this embodiment, it is preferable that the positions of the two elongated reinforcing strips 2 correspond to the two opposite narrow sides 5 of the pole core 4.

[0039] The long reinforcing strip 2 is fixed to the inner or outer surface of the membrane body 1.

[0040] The long reinforcing strip 2 is fixed to the surface of the membrane body 1 by ultrasonic welding, laser welding, or hot melting.

[0041] The membrane body 1 is made of plastic. In this embodiment, the membrane body 1 is preferably made of PP, PE, PET, modified PP, modified PE, modified PET, or any combination of the above materials. The long strip reinforcing sheet 2 is made of plastic or a sheet-like non-metallic material with an insulating coating. In this embodiment, the long strip reinforcing sheet 2 is preferably made of PP, PET, PPS, PI, ceramic sheet, or any combination of the above materials. The long strip reinforcing sheet 2 has excellent insulation properties. Among them, PP is polypropylene, PE is polyethylene, PET is polyethylene terephthalate, modified PP is modified polypropylene, modified PE is modified polyethylene, modified PET is modified polyethylene terephthalate, PPS is polyphenylene sulfide, PI is polyimide, and the ceramic sheet is a sheet-like non-metallic material with an insulating coating.

[0042] Methods for manufacturing insulating film: The position of the long strip reinforcing piece 2 can be measured and marked on the film body 1 in advance, and then the long strip reinforcing piece 2 can be fixed on the insulating film by welding or hot melting; Alternatively, the film body 1 can be wrapped around the pole core 4 first, and then the long strip reinforcing piece 2 can be fixedly connected on the narrow side 5 of the film body 1 corresponding to the pole core 4.

[0043] Example 2

[0044] like Figures 8-11 As shown, a lithium-ion battery includes a casing 6, a cover 8, an electrode core 4, and a partially reinforced insulating film as described in Embodiment 1. The insulating film wraps around the outer surface of the electrode core 4. Both the electrode core 4 and the casing 6 are cuboids. The casing 6 has an opening 7 at one end along its length, and openings 7 are also provided at the top and bottom of the casing 6. There are two covers 8, one for the positive electrode and one for the negative electrode. The electrode core 4, wrapped with the insulating film, is inserted into the receiving cavity of the casing 6 through the openings 7, and each opening 7 is sealed by a cover 8. Long reinforcing strips 2 partially reinforce the insulating film, with two long reinforcing strips 2 corresponding to two opposite narrow sides 5 of the electrode core 4. This strengthens the electrode core 4, giving it greater rigidity along its length, making it less prone to bending and sagging, and facilitating insertion of the electrode core 4 into the casing 6.

[0045] The two narrow sides 5 of the electrode core 4 are reinforced by the elongated reinforcing strip 2, which strengthens the protection of the battery side and strengthens the corresponding side of the lithium-ion battery in the entire pack system. Since the narrow side 5 of the electrode core 4 is placed downward in the pack system, the elongated reinforcing strip 2 improves the bottom protection performance of the pack system. When the bottom of the pack system is bumped during use, the elongated reinforcing strip 2 can protect the electrode core 4 and prevent the electrode core 4 from internal short circuit due to the bump, which greatly improves the safety performance of the pack system.

[0046] The aforementioned encapsulation system is a highly integrated component of lithium-ion battery packs. The encapsulation system includes the lithium-ion battery pack and the encapsulation structure. It not only protects the internal electronic components from physical damage, but also provides necessary structural support, thermal management, and electrical insulation.

[0047] The present invention has been further described above with reference to specific embodiments. However, it should be understood that the specific description herein should not be construed as limiting the substance and scope of the present invention. Various modifications made by those skilled in the art to the above embodiments after reading this specification are all within the scope of protection of the present invention.

Claims

1. A locally reinforced insulating film, wrapping the outer side of the electrode core (4) of a lithium-ion battery, the insulating film comprising a film body (1), the film body (1) being a sheet-like thin film structure, characterized in that: At least one long reinforcing strip (2) is provided on the surface of the membrane body (1), and the long reinforcing strip (2) extends along the length direction of the membrane body (1).

2. The locally reinforced insulating film according to claim 1, characterized in that: Multiple through holes (3) are opened on the surface of the long strip reinforcing sheet (2), and the multiple through holes (3) are randomly distributed on the surface of the long strip reinforcing sheet (2).

3. The locally reinforced insulating film according to claim 2, characterized in that: Multiple through holes (3) are arranged in a row along the length of the long strip reinforcing sheet (2).

4. The locally reinforced insulating film according to claim 1, characterized in that: There are two long reinforcing strips (2), and the positions of the two long reinforcing strips (2) correspond to the two opposite sides of the cuboid-shaped pole core (4).

5. The locally reinforced insulating film according to claim 1, characterized in that: The long reinforcing strip (2) is fixed on the inner or outer surface of the membrane body (1).

6. The locally reinforced insulating film according to claim 1, characterized in that: The long reinforcing strip (2) is fixed to the surface of the membrane body (1) by ultrasonic welding, laser welding, or hot melting.

7. The locally reinforced insulating film according to claim 1, characterized in that: The length of the long reinforcing strip (2) is not greater than the length of the membrane body (1), and the length of the long reinforcing strip (2) is 300mm-1000mm; the thickness of the membrane body (1) is 0.05mm-0.15mm, and the thickness of the long reinforcing strip (2) is 0.2mm-0.8mm.

8. A lithium-ion battery, characterized in that: The device includes a housing (6), a cover (8), an electrode core (4), and a locally reinforced insulating film as described in any one of claims 1-7. The insulating film is wrapped around the outer surface of the electrode core (4). An opening (7) is provided at the end of the housing (6) in the longitudinal direction. The electrode core (4) wrapped with the insulating film is inserted into the receiving cavity of the housing (6) through the opening (7). The opening (7) seals the cover (8).

9. A lithium-ion battery according to claim 8, characterized in that: Both the pole core (4) and the shell (6) are cuboids, and two long strip reinforcing plates (2) correspond to the two opposite sides of the pole core (4).

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