Secondary lithium battery

Abstract

The utility model provides a secondary lithium battery which is of a square structure, the middle part of the upper end of the battery is provided with an inward concave surface, the two sides of the concave surface are provided with upward bulges, the concave surface is provided with two pole columns, the concave surface is provided with two liquid injection holes, the two liquid injection holes are respectively arranged at the outer sides of the pole columns, and the two liquid injection holes are communicated with the concave surface. An anti-explosion hole is formed in the protrusion, and an anti-explosion valve is installed on the anti-explosion hole. The two sides of the battery are respectively provided with one anti-explosion valve, the intersection point of the plurality of scratches coincides with the geometric center of the upper surface of the anti-explosion valve, when the thickness of the anti-explosion valve is uniform, the geometric center of the surface of the anti-explosion valve is the weakest position, and when the air pressure in the battery is too large, the anti-explosion valve is very easy to explode from the geometric center of the anti-explosion valve, so that the anti-explosion effect is good. Therefore, the detonation sensitivity of the explosion-proof valve is improved, and the use safety of the power battery is improved.

Description

Technical Field

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

[0002] With the extensive application of power batteries, their safety performance has attracted more and more attention. When the battery is abnormal, a large amount of gas will be generated inside the battery, causing the internal pressure of the battery to increase sharply. At this time, if the large amount of gas generated cannot be discharged in time, the battery will explode and cause a safety accident. In order to avoid the occurrence of explosions and improve the safety performance of batteries, the explosion-proof device on the battery cover is the key.

[0003] The existing explosion-proof devices for power batteries have low detonation sensitivity. Once the explosion-proof device fails, it may fail to open in time under dangerous air pressure, which may cause the risk of battery explosion. At the same time, when a battery fails, the instantaneous air pressure in the battery is very high. The area for a single explosion-proof device to discharge air pressure is too small, and the gas in the battery cannot be discharged in time, which may easily cause the risk of battery explosion.

[0004] To this end, we propose a secondary lithium battery to solve the problem of battery safety. Utility Model Content

[0005] The purpose of the utility model is to solve the shortcomings of the prior art. In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0006] A secondary lithium battery comprises a battery, the battery is of a square structure, the middle part of the upper end of the battery has a concave surface that is sunken inwards, both sides of the concave surface have upward protrusions, two poles are installed on the concave surface, two injection holes are provided on the concave surface, the two injection holes are respectively arranged on the outer sides of the poles, an explosion-proof hole is provided on the protrusion, and an explosion-proof valve is installed on the explosion-proof hole.

[0007] Further preferably, the explosion-proof valve is provided with cross notches, the cross notches include multiple scratches, there is at least one intersection between the multiple scratches, the intersection coincides with the geometric center of the upper surface of the explosion-proof valve, the geometric center position of the surface of the explosion-proof valve is the weakest position, when the internal air pressure of the battery is too high, the explosion-proof valve can easily explode from its own geometric center, thereby improving the detonation sensitivity of the explosion-proof valve and improving the safety of the power battery.

[0008] Further preferably, the pole includes a positive pole and a negative pole.

[0009] Further preferably, the battery further comprises a shell, a bare cell and a top cover, wherein the shell and the top cover are enclosed to form a containing space, and the containing space is used to accommodate the bare cell.

[0010] Further preferably, the bare battery cell is connected to the pole via a pole ear.

[0011] Compared with the prior art, the beneficial effects of the utility model are:

[0012] The utility model installs an explosion-proof valve on both sides of the battery respectively, and the intersection of multiple scratches coincides with the geometric center of the upper surface of the explosion-proof valve. When the thickness of the explosion-proof valve is uniform, the geometric center position of the surface of the explosion-proof valve is the weakest position. When the internal air pressure of the battery is too high, the explosion-proof valve can easily explode from its own geometric center, thereby improving the detonation sensitivity of the explosion-proof valve and improving the safety of the power battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the structure of the utility model;

[0014] Figure 2 It is a schematic diagram of the explosion structure of the utility model;

[0015] Figure 3 for Figure 1 A local enlarged schematic diagram of point A in the middle.

[0016] In the figure: battery 1, protrusion 2, concave surface 3, pole 4, injection hole 5, explosion-proof valve 6, shell 11, bare battery cell 12, top cover 13, cross notch 61. DETAILED DESCRIPTION

[0017] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments.

[0018] Reference Figure 1-Figure 3 A secondary lithium battery comprises a battery 1, wherein the battery 1 is a square structure, wherein the middle part of the upper end of the battery 1 has a concave surface 3 which is sunken inward, and both sides of the concave surface 3 have upward protrusions 2, wherein two poles 4 are mounted on the concave surface 3, and two injection holes 5 are provided on the concave surface 3, and the two injection holes 5 are respectively arranged on the outer sides of the pole 4, and an explosion-proof hole is provided on the protrusion 2, and an explosion-proof valve 6 is installed on the explosion-proof hole.

[0019] In the embodiment: an explosion-proof valve 6 is installed on each side of the battery, and the explosion-proof valves 6 are respectively located on the protrusions 2. The explosion-proof valves 6 on both sides are symmetrically arranged. When one of the explosion-proof valves 6 fails, when the pressure inside the accommodating cavity is too high, the other explosion-proof valve 6 can be better exploded, thereby improving the reliability and safety of the power battery.

[0020] In the embodiment, there are two injection holes 5, which are located on both sides of the concave surface 3, increasing the distance between the two injection holes 5. When one of the two injection holes 5 is injecting liquid, the other one is venting, which greatly improves the injection efficiency.

[0021] The explosion-proof valve 6 is provided with a cross notch 61 , and the cross notch 61 includes a plurality of notches, and there is at least one intersection point between the plurality of notches, and the intersection point coincides with the geometric center of the upper surface of the explosion-proof valve 6 .

[0022] In the embodiment: the intersection of multiple scratches coincides with the geometric center of the upper surface of the explosion-proof valve 6. When the thickness of the explosion-proof valve 6 is uniform, the geometric center of the surface of the explosion-proof valve 6 is the weakest position. When the internal air pressure of the battery is too high, the explosion-proof valve 6 can easily explode from its own geometric center, thereby improving the detonation sensitivity of the explosion-proof valve 6 and improving the safety of the power battery.

[0023] The battery 1 also includes a shell 11, a bare cell 12 and a top cover 13. The shell 11 and the top cover 13 are combined to form a housing space, and the housing space is used to accommodate the bare cell 12. The pole 4 includes a positive pole and a negative pole. The bare cell 12 is connected to the pole 4 through a pole ear.

[0024] In the embodiment: the battery 1 utilizes the concave space to install the battery pole, which reduces the space occupied by the pole in the vertical direction, thereby improving the utilization rate of the battery space.

[0025] The utility model installs an explosion-proof valve 6 on both sides of the battery respectively, and the intersection of multiple scratches coincides with the geometric center of the upper surface of the explosion-proof valve 6. When the thickness of the explosion-proof valve 6 is uniform, the geometric center position of the surface of the explosion-proof valve 6 is the weakest position. When the internal air pressure of the battery is too high, the explosion-proof valve 6 can easily explode from its own geometric center, thereby improving the detonation sensitivity of the explosion-proof valve 6 and improving the safety of the power battery.

Claims

1. A secondary lithium battery, characterized in that: The invention comprises a battery, which is a square structure, wherein the middle part of the upper end of the battery has a concave surface which is sunken inwards, and both sides of the concave surface have upward protrusions, two poles are installed on the concave surface, and two injection holes are provided on the concave surface, and the two injection holes are respectively arranged on the outer sides of the poles, and an explosion-proof hole is provided on the protrusion, and an explosion-proof valve is installed on the explosion-proof hole.

2. A secondary lithium battery according to claim 1, characterized in that: The explosion-proof valve is provided with cross notches, and the cross notches include a plurality of notches, and there is at least one intersection point between the plurality of notches, and the intersection point coincides with the geometric center of the upper surface of the explosion-proof valve.

3. A secondary lithium battery according to claim 1, characterized in that: The poles include a positive pole and a negative pole.

4. A secondary lithium battery according to claim 1, characterized in that: The battery further comprises a shell, a bare cell and a top cover, wherein the shell and the top cover are combined to form a containing space, and the containing space is used to accommodate the bare cell.

5. A secondary lithium battery according to claim 4, characterized in that: The bare battery cell is connected to the pole via the pole lug.

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