Lithium ion battery

Abstract

The utility model relates to the technical field of lithium ion batteries, in particular to a lithium ion battery. The utility model provides a lithium ion battery. The lithium ion battery comprises a battery cell top cover and an exhaust part fixed on the battery cell top cover, and the joint of the exhaust part and the battery cell top cover is pre-broken. The exhaust part is arranged in a weak area, and an anti-explosion valve plate is omitted, so that the material cost of the battery cell is lower, the exhaust area is larger, and the safety of the battery cell is higher.

Description

Technical Field

[0001] The utility model relates to the technical field of lithium ion batteries, in particular to lithium ion batteries. Background Art

[0002] Safety is one of the important technical indicators of batteries. In order to ensure the safety of power batteries, explosion-proof valves are usually used to release pressure. The explosion-proof valve is usually set on the top cover or shell. When the air pressure inside the battery exceeds the safe value due to abnormal use, the air pressure inside the battery will break through the explosion-proof plate at the burst line position and release the air pressure inside the battery in time, thereby avoiding excessive internal pressure in the battery causing the battery to explode.

[0003] The explosion pressure consistency of the explosion-proof valve in the related technology is low. When the air pressure inside the battery does not accumulate in the explosion-proof valve area and cannot trigger the explosion-proof valve to release pressure, there is a high probability that the battery cell weld will tear and explode.

[0004] Therefore, how to promptly discharge the internal gas after thermal runaway of the battery cell is a technical problem that urgently needs to be solved in this field. Utility Model Content

[0005] The purpose of the utility model is to provide a lithium ion battery to solve the above problems.

[0006] In order to achieve the above object, the present invention provides a lithium ion battery, comprising

[0007] The cell cover, and

[0008] An exhaust member fixed to the top cover of the battery cell; wherein

[0009] The connection between the exhaust member and the battery cell top cover is pre-broken.

[0010] Preferably, the exhaust member comprises an upper exhaust sheet, and the upper exhaust sheet is arranged along the long side direction of the battery cell top cover.

[0011] Preferably, the thickness of the upper exhaust sheet is smaller than the thickness of the battery cell top cover.

[0012] Preferably, a first groove is provided on the inner wall of the upper exhaust piece sheet near the top cover of the battery cell as the connection point.

[0013] Preferably, the exhaust member comprises a lower exhaust sheet, and the lower exhaust sheet is arranged along the long side direction of the battery cell top cover.

[0014] Preferably, the thickness of the lower exhaust sheet is smaller than the thickness of the battery cell top cover.

[0015] Preferably, a second groove is provided on the inner wall of the lower exhaust piece and close to the top cover of the battery cell as the connection point.

[0016] Preferably, the upper exhaust fin and the lower exhaust fin have approximately the same size; that is,

[0017] The thickness range of the upper exhaust sheet and the lower exhaust sheet is 1.0-1.5 mm; and

[0018] The thickness of the battery cell top cover is not less than 2 mm.

[0019] Preferably, the width of the upper exhaust fin and the lower exhaust fin are both in the range of 5-50 mm.

[0020] Preferably, the first groove and the second groove have approximately the same opening size; that is,

[0021] The groove width of the first groove and the second groove are both in the range of 1-3 mm;

[0022] The groove depth range of the first groove and the second groove is 0.5-0.8mm.

[0023] Compared with the prior art, the embodiments of the lithium-ion battery of the utility model have the following beneficial effects: by setting the thickness of the exhaust plate to be smaller than the top cover of the battery cell, and by setting two grooves, when the battery cell has thermal runaway, the pressure inside the battery cell can push open the exhaust plate, thereby achieving the effect of quickly exhausting the gas and avoiding the explosion of the battery cell.

[0024] Other features and advantages of the present invention will be set forth in the following description, and in part will become apparent from the description, or may be understood by implementing the present invention.

[0025] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1 A three-dimensional diagram of a lithium-ion battery of the present invention is shown;

[0028] Figure 2 A front view of a lithium-ion battery of the present invention is shown;

[0029] Figure 3A longitudinal cross-sectional view of the battery cell top cover and the exhaust member of the utility model is shown;

[0030] Figure 4 A partial enlarged view of the upper exhaust plate and the first groove of the utility model is shown.

[0031] In the figure:

[0032] 1. Cell top cover; 2. Exhaust member; 21. Upper exhaust plate; 22. Lower exhaust plate; 23. First groove; 24. Second groove. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solution and advantages of the embodiments of the utility model clearer, the technical solution of the utility model will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0034] like Figures 1 to 4 As shown, at least one embodiment provides a lithium-ion battery, comprising: a battery cell top cover 1, and a vent member 2 fixed on the battery cell top cover 1; the connection between the vent member 2 and the battery cell top cover 1 is pre-fractured. Specifically, by setting the thickness of the vent sheet to be smaller than the battery cell top cover 1, and setting two grooves, when the battery cell has thermal runaway, the pressure in the battery cell can push open the vent sheet, thereby achieving the effect of rapid gas discharge and avoiding battery cell explosion.

[0035] Reference Figure 2 and Figure 3 In some embodiments, the exhaust member 2 includes an upper exhaust sheet 21, and the upper exhaust sheet 21 is arranged along the long side direction of the battery cell top cover 1. The thickness of the upper exhaust sheet 21 is less than the thickness of the battery cell top cover 1. A first groove 23 is provided on the inner wall of the upper exhaust member 2 as the connection point, and the first groove 23 is provided at the upper exhaust member 2 near the battery cell top cover 1.

[0036] In some embodiments, the exhaust member 2 includes a lower exhaust sheet 22, and the lower exhaust sheet 22 is arranged along the long side direction of the battery cell top cover 1. The thickness of the lower exhaust sheet 22 is less than the thickness of the battery cell top cover 1.

[0037] In some embodiments, a second groove 24 is provided on the inner wall of the lower exhaust member 2 as the connection point, and the second groove 24 is provided on the lower exhaust member 2 near the cell top cover 1 .

[0038] In some embodiments, the upper exhaust fin 21 and the lower exhaust fin 22 are approximately the same in size, that is, the thickness range of the upper exhaust fin 21 and the lower exhaust fin 22 is: 1.0-1.5mm; the thickness of the battery cell top cover 1 is not less than 2mm. The width range of the upper exhaust fin 21 and the lower exhaust fin 22 is 5-50mm. Among them, the upper exhaust fin 21 and the lower exhaust fin 22 are approximately the same in size specifically means that the corresponding sizes of the upper exhaust fin 21 and the lower exhaust fin 22 may not be exactly the same, and they can be considered to be approximately the same within the above ranges.

[0039] In some embodiments, the groove sizes of the first groove 23 and the second groove 24 are approximately the same; that is, the groove width range of the first groove 23 and the second groove 24 is 1-3 mm; the groove depth range of the first groove 23 and the second groove 24 is 0.5-0.8 mm. Specifically, the first groove 23 and the second groove 24 are approximately the same in size, which means that the corresponding sizes of the first groove 23 and the second groove 24 may not be completely the same, and they can be considered to be approximately the same within the above ranges.

[0040] By setting the thickness of the upper exhaust sheet 21 and the lower exhaust sheet 22 to be smaller than the thickness of the battery cell top cover 1, and at the same time, opening a first groove 23 at the connection between the upper exhaust sheet 21 and the battery cell top cover 1, and opening a second groove 24 at the connection between the lower exhaust sheet 22 and the battery cell top cover 1, when the battery cell thermal runaway occurs, the gas in the battery cell can break through the upper exhaust sheet 21 and the lower exhaust sheet 22, causing it to break from the battery cell top cover 1, thereby achieving the purpose of exhausting the gas. At the same time, compared with the traditional explosion-proof valve, this embodiment has a larger exhaust area, is easier to exhaust the gas, and relieves the pressure inside the battery cell, thereby avoiding the explosion of the battery cell.

[0041] In the description of the embodiments of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" 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.

[0042] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are 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 cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0043] Based on the above ideal embodiments of the utility model, the relevant staff can make various changes and modifications without departing from the technical concept of the invention through the above description. The technical scope of the invention is not limited to the content of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A lithium ion battery, characterized in that: include: A battery cell top cover (1), and an exhaust member (2) fixed on the battery cell top cover (1); The connection between the exhaust member (2) and the battery cell top cover (1) is pre-fractured; The exhaust member (2) comprises an upper exhaust sheet (21), and the upper exhaust sheet (21) is arranged along the long side direction of the battery cell top cover (1); The exhaust member (2) comprises a lower exhaust sheet (22), and the lower exhaust sheet (22) is arranged along the long side direction of the battery cell top cover (1).

2. The lithium-ion battery according to claim 1, characterized in that The thickness of the upper exhaust sheet (21) is smaller than the thickness of the battery cell top cover (1).

3. The lithium ion battery according to claim 1, characterized in that A first groove (23) is provided on the inner wall of the upper exhaust plate (21) as the connection point, and the first groove (23) is provided on the upper exhaust plate (21) near the battery cell top cover (1).

4. The lithium ion battery according to claim 1, characterized in that The thickness of the lower exhaust sheet (22) is smaller than the thickness of the battery cell top cover (1).

5. The lithium ion battery according to claim 4, characterized in that The inner wall of the lower exhaust sheet (22) is provided with a lower second groove (24) as the connection point, and the second groove (24) is provided on the lower exhaust sheet (22) near the battery cell top cover (1).

6. The lithium ion battery according to claim 1, characterized in that The upper exhaust sheet (21) and the lower exhaust sheet (22) have the same size, that is, the thickness of the upper exhaust sheet (21) and the lower exhaust sheet (22) is 1.0-1.5 mm; The thickness of the battery cell top cover (1) is not less than 2 mm.

7. The lithium ion battery according to claim 6, characterized in that The width of the upper exhaust plate (21) and the lower exhaust plate (22) is 5-50 mm.

8. The lithium ion battery according to claim 3, characterized in that The first groove (23) and the second groove (24) have the same groove size; that is, The groove width of the first groove (23) and the second groove (24) is 1-3 mm; The groove depths of the first groove (23) and the second groove (24) are 0.5-0.8 mm.

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