Lithium battery and insulation bag thereof

Abstract

The utility model discloses a lithium battery and its insulating bag, belongs to the lithium battery technical field, the insulating bag includes insulating film and collet piece, the insulating film includes the film top surface, the both sides of the film top surface are connected with the film large surface respectively, the one side of each film large surface opposite to the film top surface is connected with the film bottom surface, the collet piece is connected with the film bottom surface, and the film bottom surface is connected with the collet piece. Two sides, adjacent to the film top surface, of each film large surface are respectively connected with a film side surface, the film top surface covers the top surface of the battery cell, the film large surfaces are folded from top to bottom by the film top surface, and the film side surfaces and the film bottom surface are spliced to form a bag body for wrapping the battery cell; and the bottom supporting sheet is connected with the bottom surface of one of the films in a fitting manner. The lithium battery comprises a battery cell, a cover plate assembly and the insulating bag, the cover plate assembly is connected with the membrane top surface, and the battery cell is wrapped in the insulating bag. The utility model can solve the problems that the insulation bag is wrapped from bottom to top, and the insulation bag blanching process may cause that the tab is exposed to contact with the aluminum shell to cause short circuit due to unqualified blanching.

Description

Technical Field

[0001] The utility model relates to the technical field of lithium batteries, in particular to a lithium battery and an insulation bag thereof. Background Art

[0002] With the continuous development of lithium battery technology, the proportion of new energy vehicles in the total vehicle volume in my country is also increasing. Compared with other traditional batteries, lithium batteries have become the main power source for new energy vehicles due to their high energy density, long cycle life, safety and environmental protection. Insulation bags are made of insulating materials and are used to cover conductive parts. In the production process of square lithium batteries, the fixing of insulation bags is a very important process.

[0003] However, in the prior art, the insulating bag is generally fixed by a hot-scalding process, which may cause the battery cell diaphragm to be burned, and the hot-scalding process has unstable hot-scalding quality. The insulating film after hot-scalding is easy to fall off during later use, which seriously reduces the yield rate of battery cell processing and increases production costs.

[0004] For example, a Chinese patent document with the announcement number CN216389666U discloses a power battery, including a battery cell, a cover plate, an insulating bag and an insulating bottom support sheet, wherein the insulating bag is a cylindrical structure with an open top formed by folding a flat insulating film, the bottom of the insulating bag is wrapped around the bottom of the battery, the cylindrical side of the insulating bag extends upward from the bottom of the battery cell and wraps the circumferential side of the battery cell, the top of the insulating bag is fixed on the cover plate, and a first positioning hole is opened at the bottom of the insulating bag. This process of wrapping the insulating bag from bottom to top and then hot-stamping the insulating bag on the stop frame may have problems such as unqualified hot stamping of the insulating bag, poor hot stamping of the insulating bag, and leakage of the tabs and contact with the aluminum shell for short circuit. Utility Model Content

[0005] The utility model aims to provide a lithium battery and an insulation bag thereof, so as to solve the problem that in the prior art, the insulation bag is wrapped from bottom to top and then hot-stamped on a stop frame, and the insulation bag may be hot-stamped unqualified or poorly hot-stamped, resulting in leakage of the pole ear and contact with the aluminum shell for short circuit.

[0006] In order to achieve the above-mentioned purpose, the utility model provides a lithium battery insulation bag for wrapping a battery cell, including an insulation film and a bottom support sheet, the insulation film including a film top surface, the two sides of the film top surface are respectively connected to a film large surface, each of the film large surfaces is connected to a film bottom surface on one side opposite to the film top surface, each of the film large surfaces is respectively connected to a film side surface on two sides adjacent to the film top surface, the film top surface covers the top surface of the battery cell, and the film large surface is folded from top to bottom by the film top surface and the film side surface and the film bottom surface are spliced ​​to form a bag body wrapping the battery cell; the bottom support sheet is fitted and connected to one of the film bottom surfaces.

[0007] In a preferred embodiment of the present invention, fold lines are provided between the top surface of the membrane and the large surface of the membrane, between the large surface of the membrane and the bottom surface of the membrane, and between the large surface of the membrane and the side surface of the membrane.

[0008] In a preferred embodiment of the present invention, the folding line includes at least one fold.

[0009] In a preferred embodiment of the present invention, the two film bottom surfaces are overlapped and arranged on the bottom surface of the bag body, and the bottom supporting sheet is located at the outermost side of the bottom surface of the bag body.

[0010] In a preferred embodiment of the present invention, the bottom supporting sheet is provided with a plurality of supporting sheet through holes penetrating the sheet body.

[0011] In a preferred embodiment of the present invention, the two bottom surfaces of the membranes are fixed by adhesive or tape.

[0012] In a preferred embodiment of the present invention, the two large film surfaces are located on opposite sides of the bag body, the film side surfaces on the two large film surfaces overlap each other and are arranged on the side surfaces of the bag body, and the overlapping film side surfaces are fixed by glue or tape.

[0013] In a preferred embodiment of the present invention, there is a first gap between the bottom surface of the membrane and the adjacent side surface of the membrane, and there is a second gap between the top surface of the membrane and the adjacent side surface of the membrane.

[0014] In a preferred embodiment of the present invention, the top surface of the membrane is provided with a negative pole column hole, an explosion-proof valve vent hole, a liquid injection hole and a positive pole column hole.

[0015] The utility model also provides a lithium battery, comprising a battery cell, a cover plate assembly and the above-mentioned insulation bag, wherein the cover plate assembly is connected to the top surface of the membrane, and the battery cell is wrapped in the insulation bag.

[0016] Compared with the existing known technologies, the technical solution provided by the utility model has the following beneficial effects:

[0017] The utility model discloses an insulating bag for lithium batteries, wherein a bag body for wrapping a battery cell is formed by folding a large film surface from the top to the bottom and splicing the film side surfaces and the film bottom surfaces, thereby changing the wrapping direction of the insulating bag. The insulating bag is wrapped from the top to the bottom, and the pole ear is directly wrapped in the insulating bag, thereby preventing the pole ear from contacting the battery shell and causing a short circuit, thereby improving the safety of the overall winding core.

[0018] It will be apparent that elements or features described above in the context of a single embodiment may be used alone or in combination in other embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In the drawings, the sizes and proportions do not represent the sizes and proportions of actual products. The drawings are merely illustrative, and some non-essential elements or features are omitted for clarity.

[0020] Figure 1 This is a schematic diagram of an insulation bag in an expanded state according to an embodiment of the utility model;

[0021] Figure 2 This is a schematic diagram of the combined state of the insulation bag and the cover plate assembly of the embodiment of the utility model;

[0022] Figure 3 This is a schematic diagram of the state where the insulation bag covers the battery cell according to the embodiment of the utility model;

[0023] Figure 4 This is a schematic diagram of an insulation bag in an embodiment of the utility model in a folded state outside a battery core;

[0024] Figure 5 It is a schematic diagram of the state of the insulation bag covering the battery cell in the embodiment of the utility model.

[0025] Description of Reference Numerals

[0026] 100, insulating film; 110, membrane top surface; 111, negative pole hole; 112, explosion-proof valve vent hole; 113, injection hole; 114, positive pole hole; 120, membrane bottom surface; 130, membrane large surface; 140, membrane side surface; 150, first notch; 160, second notch; 200, bottom support plate; 210, support plate through hole; 300, cover plate assembly; 400, battery cell. DETAILED DESCRIPTION

[0027] The present invention will be described in detail with reference to the accompanying drawings. What is described here is only a preferred embodiment of the present invention, and those skilled in the art can think of other ways to implement the present invention based on the preferred embodiment, and other ways also fall within the scope of the present invention.

[0028] Example

[0029] Reference Figure 1-Figure 5The present embodiment provides a lithium battery insulation bag for wrapping a battery cell 400, comprising an insulation film 100 and a bottom support sheet 200, wherein the insulation film 100 comprises a film top surface 110, and two sides of the film top surface 110 are respectively connected with a film large surface 130, and one side of each film large surface 130 opposite to the film top surface 110 is connected with a film bottom surface 120, and two sides of each film large surface 130 adjacent to the film top surface 110 are respectively connected with a film side surface 140, and the film top surface 110 covers the top surface of the battery cell 400, and the film large surface 130 is folded from top to bottom by the film top surface 110, and the film side surface 140 and the film bottom surface 120 are assembled to form a bag body wrapping the battery cell 400; the insulation bag wrapping the battery cell 400 from top to bottom changes the wrapping direction of the battery cell 400, and the pole ear of the battery cell 400 can be directly wrapped in the insulation bag to prevent the pole ear from contacting the battery shell and short-circuiting, thereby improving the safety of the overall winding core. The bottom support sheet 200 is connected to one of the bottom surfaces 120 of the membranes in a close fit.

[0030] It should be noted that the bottom support sheet 200 is made of insulating material, and an insulating bottom support sheet 200 is provided at the bottom of the insulating bag. On the one hand, since the insulating bag itself is relatively thin and easily deformed during assembly, the bottom thickness of the insulating bag can be increased after adding the bottom support sheet 200, which is more conducive to positioning during assembly; on the other hand, when the battery cell 400 is wrapped in the insulating bag and installed in the aluminum shell, the battery cell 400 will also have a downward pressure on the insulating bag. After adding the bottom support sheet 200, the bottom strength of the insulating bag can be improved, the pressure-bearing effect is better, and the insulating bag also plays a certain protective role. Furthermore, the bottom support sheet 200 is provided with a plurality of support sheet through holes 210 that penetrate the sheet body. On the one hand, the support sheet through holes 210 play a role in reducing the weight of the bottom support sheet 200, thereby reducing the weight of the entire battery; on the other hand, the support sheet through holes 210 can facilitate the electrolyte to infiltrate the battery cell 400 and improve the permeability of the electrolyte. In this embodiment, the support plate through hole 210 is mainly designed to be a circular hole. In addition, the support plate through hole 210 can also be designed to be an elliptical hole, a square hole, a trapezoidal hole or other polygonal hole shapes.

[0031] Please refer to Figure 1 In this embodiment, folding lines are arranged between the film top surface 110 and the film large surface 130, between the film large surface 130 and the film bottom surface 120, and between the film large surface 130 and the film side surface 140. The folding lines include a long fold or multiple discontinuous short folds. The folding lines make it very convenient to fold the film top surface 110, the film large surface 130, the film bottom surface 120 and the film side surface 140, thereby improving the efficiency of folding the flat film into a bag.

[0032] Specifically, Figure 2-Figure 5As shown, the two film bottom surfaces 120 are overlapped and arranged on the bottom surface of the bag body, and the bottom support sheet 200 is located at the outermost side of the bottom surface of the bag body. After the battery cell 400 is installed in the aluminum shell, the bottom support sheet 200 is located at the outermost side of the bottom surface of the bag body and can contact the aluminum shell to isolate the aluminum shell from the bag body, thereby increasing the gap between the battery cell 400 and the bottom surface of the aluminum shell and the four corners of the bottom of the aluminum shell, which is safer and has a better insulation effect. The two film bottom surfaces 120 are fixed by glue or tape. The two large film surfaces 130 are located on the opposite sides of the bag body, and the film side surfaces 140 on the two large film surfaces 130 are overlapped and arranged on the sides of the bag body, and the overlapping film side surfaces 140 are fixed by glue or tape. The method of fixing with glue or tape eliminates the hot-stamping process of the insulating bag, simplifies the process, avoids the undesirable problems of hot-stamping of the insulating bag, and improves the product quality.

[0033] Furthermore, there is a first notch 150 between the film bottom surface 120 and the adjacent film side surface 140, and there is a second notch 160 between the film top surface 110 and the adjacent film side surface 140. The first notch 150 and the second notch 160 form an escape space, so that the film bottom surface 120 and the adjacent film side surface 140 are folded, and the film top surface 110 and the adjacent film side surface 140 are folded without interference.

[0034] Another aspect of the present application further provides a lithium battery, including a battery cell 400, a cover assembly 300 and the above-mentioned insulation bag, the cover assembly 300 is connected to the membrane top surface 110, and the battery cell 400 is wrapped in the insulation bag. The membrane top surface 110 is provided with a negative pole hole 111, an explosion-proof valve vent hole 112, a liquid injection hole 113 and a positive pole hole 114, which can be conveniently positioned and installed with the cover assembly 300, and at the same time, a space for avoidance is left to avoid interference with components such as the negative pole, explosion-proof valve, liquid injection hole and positive pole on the cover assembly 300.

[0035] In the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "front", "rear", "left", "right", "up", "down", "top", "bottom", "inside", "outside", etc. are based on the directions or positional relationships 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 direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0036] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0037] The protection scope of the present invention is limited only by the claims. Thanks to the teachings of the present invention, those skilled in the art will easily recognize that alternative structures to the structures disclosed in the present invention can be used as feasible alternative embodiments, and the embodiments disclosed in the present invention can be combined to generate new embodiments, which also fall within the scope of the appended claims.

Claims

1. A lithium battery insulation bag, used for wrapping a battery cell (400), comprising an insulation film (100) and a bottom support sheet (200), characterized in that: The insulating film (100) comprises a film top surface (110), and the two sides of the film top surface (110) are respectively connected to film large surfaces (130), and the side of each film large surface (130) opposite to the film top surface (110) is connected to the film bottom surface (120), and the two sides of each film large surface (130) adjacent to the film top surface (110) are respectively connected to film side surfaces (140), and the film top surface (110) covers the top surface of the battery cell (400), and the film top surface (110) is folded from top to bottom to form a bag body that wraps the battery cell (400); the bottom support sheet (200) is bonded and connected to one of the film bottom surfaces (120).

2. A lithium battery insulation bag according to claim 1, characterized in that: Folding lines are provided between the top surface (110) of the membrane and the large surface (130) of the membrane, between the large surface (130) of the membrane and the bottom surface (120) of the membrane, and between the large surface (130) of the membrane and the side surface (140) of the membrane.

3. A lithium battery insulation bag according to claim 2, characterized in that: The folding line includes at least one fold.

4. A lithium battery insulation bag according to claim 1, characterized in that: The two film bottom surfaces (120) are overlapped and arranged on the bottom surface of the bag body, and the bottom supporting sheet (200) is located at the outermost side of the bottom surface of the bag body.

5. A lithium battery insulation bag according to claim 4, characterized in that: The bottom support sheet (200) is provided with a plurality of support sheet through holes (210) penetrating the sheet body.

6. A lithium battery insulation bag according to claim 4, characterized in that: The two film bottom surfaces (120) are fixed by glue or tape.

7. A lithium battery insulation bag according to claim 1, characterized in that: The two large film surfaces (130) are located on opposite sides of the bag body, and the film side surfaces (140) on the two large film surfaces (130) are overlapped and arranged on the side surfaces of the bag body, and the overlapped film side surfaces (140) are fixed by adhesive or tape.

8. The lithium battery insulation bag according to claim 1, characterized in that: There is a first gap (150) between the bottom surface (120) of the membrane and an adjacent side surface (140) of the membrane, and there is a second gap (160) between the top surface (110) of the membrane and an adjacent side surface (140) of the membrane.

9. The lithium battery insulation bag according to claim 1, characterized in that: The membrane top surface (110) is provided with a negative pole column hole (111), an explosion-proof valve vent hole (112), a liquid injection hole (113) and a positive pole column hole (114).

10. A lithium battery, characterized in that: It comprises a battery cell (400), a cover plate assembly (300) and an insulation bag according to any one of claims 1 to 9, wherein the cover plate assembly (300) is connected to the top surface (110) of the film, and the battery cell (400) is wrapped in the insulation bag.

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