Aluminum-plastic film edge sealing structure of soft package lithium ion battery cell

Abstract

The utility model discloses an aluminum-plastic film edge sealing structure of a soft package lithium ion battery cell, belongs to the technical field of lithium batteries, and solves the technical problems of small gas production space, liquid leakage and glue overflow of the existing edge sealing structure of the soft package battery cell. Comprising a battery cell body and an aluminum-plastic film edge sealing structure arranged on the side edge of the battery cell body, the aluminum-plastic film edge sealing structure comprises a gas generating and glue overflowing area and a heat sealing area, the gas generating and glue overflowing area is communicated with the battery cell body, and the joint of the gas generating and glue overflowing area and the heat sealing area is of a zigzag structure or a wavy structure; according to the utility model, enough space is reserved for circulating gas production of the side cell and excessive glue of heat sealing of the aluminum-plastic film, so that the side sealing strength is ensured, the bad excessive glue is effectively avoided, and the production yield, safety and reliability of the soft package cell are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of lithium batteries, in particular to an aluminum-plastic film edge sealing structure for a soft-package lithium-ion battery cell. Background Art

[0002] The soft-pack lithium battery contains aluminum-plastic film, electrolyte, positive and negative electrodes, etc. The aluminum-plastic film on the side of the battery cell is not sealed before injection. In order to prevent dust and moisture in the air from entering the battery cell after the subsequent injection process, the battery needs to be sealed on the side of the battery cell after the electrolyte is injected.

[0003] Lithium batteries usually need to be tested for safety. Soft-pack cells gradually produce gas during the cycle. If the gas production is severe, the pressure inside the cell will be too high, causing the seal at the cell tab to fail, resulting in battery leakage, short circuit, etc., posing a safety hazard. Before the cell is offline, the edge voltage and voltage drop test need to be tested to screen out abnormal cells. Some abnormal cells may short-circuit due to poor edge seal glue overflow.

[0004] Existing soft-pack battery cell packaging mostly adopts rectangular head heat sealing, and the final sealing width is about 5-10mm. On the one hand, this edge sealing structure does not reserve gas production space on the side, which easily leads to the concentration of circulating gas production at the battery cell ear, resulting in excessive pressure at the battery cell ear, the ear glue breaks through the seal, causing leakage, and posing a safety hazard. On the other hand, this edge sealing structure has a small reserved space in the unsealed area inside the battery cell, and the aluminum-plastic film often overflows, affecting the internal structure of the battery cell, causing abnormal voltage at the battery cell edge and internal short circuit. Utility Model Content

[0005] The utility model aims to solve the technical problems of small gas production space, liquid leakage and glue overflow in the edge sealing structure of the existing soft-pack battery cell, and aims to provide an aluminum-plastic film edge sealing structure for a soft-pack lithium-ion battery cell, which reserves sufficient space for the gas production of the side battery cell cycle and the glue overflow caused by the aluminum-plastic film heat sealing, thereby ensuring the side sealing strength and effectively avoiding the poor glue overflow, thereby improving the production rate and safety reliability of the soft-pack battery cell.

[0006] The utility model is realized by the following technical solutions:

[0007] The utility model provides an aluminum-plastic film edge sealing structure for a soft-pack lithium-ion battery cell, comprising a battery cell body and an aluminum-plastic film edge sealing structure arranged on the side of the battery cell body, wherein the aluminum-plastic film edge sealing structure comprises a gas production and glue overflow area and a heat sealing area, wherein the gas production and glue overflow area is connected to the battery cell body, and the connection between the gas production and glue overflow area and the heat sealing area is a serrated structure or a wavy structure.

[0008] As a further technical solution of the utility model, the width of the heat-sealing area is 2-5 mm.

[0009] As a further technical solution of the utility model, the width of the gas production and glue overflow area is 2-5 mm.

[0010] As a further technical solution of the utility model, the distance between the vertex of the sawtooth structure pointing to the heat-sealing area and the battery cell body is 2-5 mm.

[0011] As a further technical solution of the utility model, the distance between the vertex of the sawtooth structure pointing to the battery cell body and the battery cell body is 0.5-1.5 mm.

[0012] As a further technical solution of the utility model, in the sawtooth structure, the distance between two adjacent vertices on the same horizontal plane is 3-6 mm.

[0013] As a further technical solution of the utility model, the distance between the vertex of the wavy structure pointing to the heat-sealing area and the battery cell body is 2-5 mm.

[0014] As a further technical solution of the utility model, the distance between the vertex of the wave-like structure pointing to the battery cell body and the battery cell body is 0.5-1.5 mm.

[0015] As a further technical solution of the utility model, in the wavy structure, the distance between two adjacent vertices on the same horizontal plane is 3-6 mm.

[0016] As a further technical solution of the utility model, a positive electrode and a negative electrode are arranged on the battery body.

[0017] Compared with the prior art, the utility model has the following advantages and beneficial effects:

[0018] 1. In the utility model, the aluminum-plastic film edge sealing structure is provided with a gas production and glue overflow area connected to the battery body in addition to the heat sealing area, which reserves sufficient space for the side battery cell circulation gas production and the aluminum-plastic film heat sealing glue overflow, which not only ensures the side sealing strength, but also effectively avoids the poor glue overflow, thereby improving the production rate and safety reliability of the soft-pack battery cell.

[0019] 2. The utility model greatly increases the area of ​​the gas production and glue overflow area by setting a serrated structure or a wavy structure at the connection between the gas production and glue overflow area and the heat sealing area, effectively ensuring the glue overflow space for the side battery cell cycle gas production and aluminum-plastic film heat sealing, and further improving the safety performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings described herein are used to provide a further understanding of the embodiments of the present utility model, constitute a part of this application, and do not constitute a limitation of the embodiments of the present utility model. In the drawings:

[0021] Figure 1This is a schematic diagram of the first structure of the utility model;

[0022] Figure 2 for Figure 1 A magnified view of the middle A area;

[0023] Figure 3 This is a second structural schematic diagram of the utility model;

[0024] Figure 4 for Figure 3 Magnified view of area B.

[0025] Marks and corresponding parts names in the attached drawings:

[0026] 1-battery body, 2-negative electrode, 3-positive electrode, 4-aluminum-plastic film edge sealing structure, 401-heat sealing area, 402-gas production and glue overflow area, 403-serrated structure, 404-wavy structure. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solutions and advantages of the utility model more clearly understood, the utility model is further described in detail below in conjunction with embodiments and drawings. The schematic implementation manner of the utility model and its description are only used to explain the utility model and are not intended to limit the utility model.

[0028] In the following description, a large number of specific details are set forth in order to provide a thorough understanding of the present invention. However, it is apparent to those skilled in the art that these specific details are not necessary to implement the present invention. In other embodiments, in order to avoid confusing the present invention, well-known structures, circuits, materials or methods are not specifically described.

[0029] Throughout the specification, references to "one embodiment," "an embodiment," "an example," or "an example" mean that a particular feature, structure, or characteristic described in conjunction with the embodiment or example is included in at least one embodiment of the present invention. Therefore, the phrases "one embodiment," "an embodiment," "an example," or "an example" appearing in various places throughout the specification do not necessarily all refer to the same embodiment or example. In addition, particular features, structures, or characteristics may be combined in one or more embodiments or examples in any suitable combination and / or sub-combination. In addition, it will be appreciated by those of ordinary skill in the art that the figures provided herein are for illustrative purposes and that the figures are not necessarily drawn to scale. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0030] In the description of the present utility model, the indicated orientation or position relationship is based on the orientation or position relationship shown in the drawings, or is the orientation or position relationship in which the product of the application is usually placed when in use, or is the orientation or position relationship commonly understood by technical personnel in this field. It is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0031] Meanwhile, the terms "set", "assemble", "connect", and "connect" 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 direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0032] Example

[0033] This embodiment 1 provides a soft-pack lithium-ion battery core aluminum-plastic film edge sealing structure, such as Figure 1-Figure 4 As shown, it includes a battery cell body 1 and an aluminum-plastic film edge sealing structure 4 arranged on the side of the battery cell body 1, the battery cell body 1 is provided with a positive electrode 3 and a negative electrode 2, the aluminum-plastic film edge sealing structure 4 includes a gas production and glue overflow area 402 and a heat sealing area 401, the gas production and glue overflow area 402 is connected to the battery cell body 1, and the connection between the gas production and glue overflow area 402 and the heat sealing area 401 is a serrated structure 403 or a wavy structure 404.

[0034] After the soft-pack lithium battery is formed and the gas is extracted, the heat-sealed area 401 of the aluminum-plastic film sealing structure 4 is heated to 180° C. and hot-pressed at a pressure of 10 MPa to obtain a Figure 1 Or the structure shown in 3, in the utility model, the aluminum-plastic film edge sealing structure 4 is provided with a gas production and glue overflow area 402 connected to the battery body 1 in addition to the heat sealing area 401, which reserves sufficient space for the side battery cell circulation gas production and the aluminum-plastic film heat sealing glue overflow, which not only ensures the side sealing strength, but also effectively avoids the poor glue overflow, thereby improving the production rate and safety reliability of the soft-pack battery cell.

[0035] The utility model greatly increases the area of ​​the gas production and glue overflow area 402 by arranging a sawtooth structure 403 or a wave-shaped structure 404 at the connection between the gas production and glue overflow area 402 and the heat sealing area 401, effectively ensuring the glue overflow space for the side battery cell cycle gas production and aluminum-plastic film heat sealing, and further improving the safety performance.

[0036] like Figure 1 and 3As shown, in one or more embodiments of the utility model, the width of the heat-sealing area 401 is 2-5mm, and the width of the gas production and glue overflow area 402 is 2-5mm. In the prior art, the soft-pack battery cell is directly heat-sealed with a rectangular head, so that the space reserved in the unsealed area inside the battery cell is very small, and the aluminum-plastic film often overflows, which affects the internal structure of the battery cell, causing abnormal voltage and internal short circuit at the edge of the battery cell. At the same time, it is easy to cause the circulating gas production to be concentrated at the battery cell pole ear, resulting in excessive pressure at the battery cell pole ear, and the pole ear glue breaks the seal, causing leakage, and there is a safety hazard. The present utility model is improved on the basis of the heat-sealing structure of the prior art, and a gas production and glue overflow area 402 is set near the battery cell, which reserves enough space for the side battery cell circulating gas production and aluminum-plastic film heat sealing. It is beneficial to ensure the production rate and safety reliability of the soft-pack battery cell.

[0037] like Figure 1 and 2 As shown, in one or more embodiments of the utility model, the distance between the vertex of the sawtooth structure 403 pointing to the heat-sealing area 401 and the battery body 1 is 2-5mm, the distance between the vertex of the sawtooth structure 403 pointing to the battery body 1 and the battery body 1 is 0.5-1.5mm, and in the sawtooth structure 403, the distance between two adjacent vertices on the same horizontal plane is 3-6mm. By setting the boundary between the gas production and glue overflow area 402 and the heat-sealing area 401 as a sawtooth structure 403, the area of ​​the gas production and glue overflow area 402 is increased. At the same time, due to the characteristics of the sawtooth structure 403, the side sealing strength of the heat-sealing area 401 can be effectively guaranteed. At the same time, by reasonably setting the distance between the sawtooth structure 403 and the battery body 1, the glue overflow space for the side battery cell cycle gas production and aluminum-plastic film heat sealing is further guaranteed.

[0038] like Figure 3 and 4 As shown, in one or more embodiments of the utility model, the distance between the vertex of the wavy structure 404 pointing to the heat-sealing area 401 and the battery body 1 is 2-5mm, the distance between the vertex of the wavy structure 404 pointing to the battery body 1 and the battery body 1 is 0.5-1.5mm, and in the wavy structure 404, the distance between two adjacent vertices on the same horizontal plane is 3-6mm. By setting the boundary between the gas production and glue overflow area 402 and the heat-sealing area 401 as a wavy structure 404, the area of ​​the gas production and glue overflow area 402 is increased. At the same time, due to the characteristics of the wavy structure 404, the side sealing strength of the heat-sealing area 401 can be effectively guaranteed. At the same time, by reasonably setting the distance between the wavy structure 404 and the battery body 1, the glue overflow space for the side battery cell cycle gas production and aluminum-plastic film heat sealing is further guaranteed.

[0039] The specific implementation methods described above further illustrate the purpose, technical solutions and beneficial effects of the utility model in detail. It should be understood that the above description is only the specific implementation method of the utility model and is not used to limit the protection scope of the utility model. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the utility model should be included in the protection scope of the utility model.

Claims

1. A soft-package lithium-ion battery core aluminum-plastic film edge sealing structure, characterized in that: The invention comprises a battery cell body (1) and an aluminum-plastic film edge sealing structure (4) arranged on the side of the battery cell body (1), wherein the aluminum-plastic film edge sealing structure (4) comprises a gas generation and glue overflow area (402) and a heat sealing area (401), wherein the gas generation and glue overflow area (402) is connected to the battery cell body (1), and the connection between the gas generation and glue overflow area (402) and the heat sealing area (401) is a sawtooth structure (403) or a wavy structure (404).

2. The aluminum-plastic film edge sealing structure of a soft-package lithium-ion battery according to claim 1, characterized in that: The width of the heat-sealing area (401) is 2-5 mm.

3. The aluminum-plastic film edge sealing structure of a soft-package lithium-ion battery according to claim 1, characterized in that: The width of the gas generation and glue overflow area (402) is 2-5 mm.

4. The aluminum-plastic film edge sealing structure of a soft-package lithium-ion battery according to claim 1, characterized in that: The distance between the vertex of the sawtooth structure (403) pointing to the heat-sealing area (401) and the battery cell body (1) is 2-5 mm.

5. The aluminum-plastic film edge sealing structure of a soft-package lithium-ion battery according to claim 1, characterized in that: The distance between the vertex of the sawtooth structure (403) pointing to the battery cell body (1) and the battery cell body (1) is 0.5-1.5 mm.

6. The aluminum-plastic film edge sealing structure of a soft-package lithium-ion battery according to claim 1, characterized in that: In the sawtooth structure (403), the distance between two adjacent vertices on the same horizontal plane is 3-6 mm.

7. The aluminum-plastic film edge sealing structure of a soft-package lithium-ion battery according to claim 1, characterized in that: The distance between the vertex of the wavy structure (404) pointing to the heat-sealing area (401) and the battery cell body (1) is 2-5 mm.

8. The aluminum-plastic film edge sealing structure of a soft-package lithium-ion battery according to claim 1, characterized in that: The distance between the vertex of the wavy structure (404) pointing to the battery cell body (1) and the battery cell body (1) is 0.5-1.5 mm.

9. The aluminum-plastic film edge sealing structure of a soft-package lithium-ion battery according to claim 1, characterized in that: In the wavy structure (404), the distance between two adjacent vertices on the same horizontal plane is 3-6 mm.

10. The aluminum-plastic film edge sealing structure of a soft-package lithium-ion battery according to any one of claims 1 to 9, characterized in that: The battery cell body (1) is provided with a positive electrode (3) and a negative electrode (2).

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