Self-fusing nickel sheet of battery pack

Abstract

The invention discloses a self-fusing nickel sheet of a battery pack, and belongs to the field of lithium battery safety, the self-fusing nickel sheet is divided into an upper part and a lower part, each of the upper part and the lower part is provided with a common welding spot and a self-fusing welding spot, the common welding spots and the self-fusing welding spots correspond to each other in a staggered manner, and an automatic fusing cantilever is additionally arranged between the self-fusing welding spots and a nickel sheet body. A welding spot structure of a traditional whole nickel sheet is improved, firstly, a plurality of self-fusion welding spots are arranged, and a section of slender cantilever is arranged between the welding spots and the nickel sheet, so that the cantilever of the nickel sheet can be automatically fused to disconnect positive and negative electrodes of the battery under the conditions of short circuit or over-limit current value and thermal runaway of one or more batteries; therefore, the whole battery pack is protected from fire and explosion.

Description

Technical Field

[0001] The invention relates to the field of lithium battery safety, and in particular to a self-fusing nickel sheet of a battery pack. Background Art

[0002] Lithium batteries are widely used in many fields due to their high energy density, long life and environmental protection. However, the safety risks of lithium batteries cannot be ignored. Their fire and explosion problems mainly stem from the conflict between energy density and rapid release. When the energy inside the battery is released rapidly in an abnormal way, it is converted into a large amount of heat energy, causing the temperature to rise sharply, which in turn triggers a series of chain reactions.

[0003] The main reasons for lithium battery fire and explosion:

[0004] External short circuit: caused by improper operation or misuse, external short circuit will increase the battery discharge current and generate a lot of heat, which may cause the diaphragm inside the battery cell to shrink or be damaged, causing an internal short circuit and causing an explosion.

[0005] Internal short circuit: Internal short circuit will cause the battery cell to discharge with a large current, generate a lot of heat, burn the diaphragm, cause a larger short circuit, decompose the electrolyte into gas, and cause excessive internal pressure. When the battery cell shell cannot withstand it, the battery cell will explode.

[0006] Overcharge: When the battery cell is overcharged, excessive release of lithium from the positive electrode will change the structure of the positive electrode. Excessive release of lithium will also make it difficult for the negative electrode to be inserted, causing lithium deposition on the negative electrode surface. When the voltage reaches above 4.5V, the electrolyte will decompose to produce a large amount of gas, which will lead to an explosion.

[0007] Existing battery packs usually use a whole nickel sheet to connect the two ends of the battery without any special structural treatment. In this design, when a battery catches fire or explodes, the adjacent batteries will continue to catch fire due to the spot welding design of the whole nickel sheet, causing the entire battery pack to explode seriously and uncontrollably. Summary of the invention

[0008] The main purpose of the present invention is to provide a self-fusing nickel sheet for a battery pack, which can effectively solve the problems mentioned in the background technology.

[0009] To achieve the above object, the technical solution adopted by the present invention is:

[0010] A self-fusing nickel sheet for a battery pack comprises an upper nickel sheet and a lower nickel sheet, wherein the upper nickel sheet and the lower nickel sheet are respectively welded to two poles of the battery pack, and ordinary welding spots and self-fusing welding spots are arranged on the upper nickel sheet and the lower nickel sheet, and the ordinary welding spots and the self-fusing welding spots on the upper nickel sheet and the lower nickel sheet correspond to each other in an interlaced manner, and a cantilever that can automatically fuse is arranged between the self-fusing welding spots and the bodies of the upper nickel sheet and the lower nickel sheet.

[0011] Preferably, the battery pack mainly includes lithium batteries, and the exterior of the lithium batteries is wrapped by an outer shell consisting of an upper shell and a lower shell.

[0012] Preferably, through holes are respectively opened on the surfaces of the upper shell and the lower shell to expose the positive and negative electrodes of the lithium battery, and the upper nickel sheet and the lower nickel sheet are welded and connected to the positive and negative electrodes of the lithium battery through these through holes, and insulating plates are also respectively arranged on the outside of the upper nickel sheet and the lower nickel sheet.

[0013] Preferably, the common welding points and the self-melting welding points are integrated with the upper nickel sheet and the lower nickel sheet and are formed by stamping.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] In the present invention, by improving the welding point structure of the traditional whole nickel sheet, a plurality of self-melting welding points are firstly arranged, and a slender cantilever is arranged between the welding point and the nickel sheet, so that when a short circuit occurs in one or more battery cells, or the current value exceeds the limit or thermal runaway occurs, the cantilever of the nickel sheet will automatically fuse and disconnect the positive and negative poles of the battery, so as to protect the entire battery pack from fire and explosion. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0017] Figure 2 It is an exploded view of the overall structure of the present invention;

[0018] Figure 3 This is a schematic diagram of the corresponding positions of the upper nickel sheet and the lower nickel sheet of the present invention;

[0019] Figure 4 It is a schematic diagram of the structure of a common solder joint and a self-melting solder joint of the present invention.

[0020] In the figure: 1. battery pack; 2. upper nickel sheet; 3. lower nickel sheet; 4. lithium battery; 5. upper shell; 6. lower shell; 7. ordinary welding point; 8. self-melting welding point; 9. insulating plate; 10. cantilever. DETAILED DESCRIPTION

[0021] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below in conjunction with specific implementation methods.

[0022] like Figure 1-Figure 2 The battery pack shown is equipped with a self-fusing nickel sheet, and the battery pack 1 mainly includes a lithium battery 4. The outside of the lithium battery 4 is wrapped by an outer shell composed of an upper shell 5 and a lower shell 6. The surfaces of the upper shell 5 and the lower shell 6 are respectively provided with through holes to expose the positive and negative electrodes of the lithium battery 4, and the upper nickel sheet 2 and the lower nickel sheet 3 are welded and connected to the positive and negative electrodes of the lithium battery 4 through these through holes.

[0023] like Figure 3-Figure 4 As shown, the self-fusing nickel sheet installed on the above-mentioned battery pack 1 includes an upper nickel sheet 2 and a lower nickel sheet 3, and ordinary welding points 7 and self-fusing welding points 8 are provided on the upper nickel sheet 2 and the lower nickel sheet 3. The ordinary welding points 7 and the self-fusing welding points 8 are both integrated with the upper nickel sheet 2 and the lower nickel sheet 3, and the cantilever 10 is formed by stamping.

[0024] In actual application, after the upper shell 5 and the lower shell 6 package and fix the lithium battery 4, the positive and negative electrodes of the lithium battery 4 are exposed, and the upper nickel sheet 2 and the lower nickel sheet 3 can be welded to the positive and negative electrodes of the lithium battery 4 respectively. The ordinary welding points 7 and the self-melting welding points 8 on the upper nickel sheet 2 and the lower nickel sheet 3 are arranged alternately, but it must be ensured that at least one welding point of the positive and negative electrodes of each lithium battery 4 is a self-melting welding point 8, so as to ensure that the self-melting design works normally. Under normal circumstances, the positive and negative electrodes of the lithium battery 4 are one ordinary welding point 7 and one self-melting welding point 8. When a short circuit or overcharging causes a single or multiple battery to exceed the current limit and thermal runaway, the self-melting welding point 8 connected to the positive or negative electrode of the lithium battery 4 will self-melt at the slender cantilever 10 to disconnect the positive and negative electrodes of the battery and prevent the lithium battery 4 from catching fire and exploding.

[0025] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A self-fusing nickel sheet for a battery pack, comprising an upper nickel sheet (2) and a lower nickel sheet (3), characterized in that: The upper nickel sheet (2) and the lower nickel sheet (3) are respectively welded to the two poles of the battery pack (1); the upper nickel sheet (2) and the lower nickel sheet (3) are both provided with common welding points (7) and self-melting welding points (8); the common welding points (7) and the self-melting welding points (8) on the upper nickel sheet (2) and the lower nickel sheet (3) correspond to each other in an interlaced manner; and a cantilever (10) that can automatically melt is provided between the self-melting welding points (8) and the bodies of the upper nickel sheet (2) and the lower nickel sheet (3).

2. The self-fusing nickel sheet of a battery pack according to claim 1, characterized in that: The battery pack (1) mainly comprises a lithium battery (4), and the exterior of the lithium battery (4) is wrapped by an outer shell consisting of an upper shell (5) and a lower shell (6).

3. The self-fusing nickel sheet of a battery pack according to claim 2, characterized in that: The surfaces of the upper shell (5) and the lower shell (6) are respectively provided with through holes to expose the positive and negative electrodes of the lithium battery (4); the upper nickel sheet (2) and the lower nickel sheet (3) are welded and connected to the positive and negative electrodes of the lithium battery (4) through the through holes; and insulating plates (9) are also respectively provided outside the upper nickel sheet (2) and the lower nickel sheet (3).

4. The self-fusing nickel sheet of a battery pack according to claim 1, characterized in that: The common welding points (7) and the self-melting welding points (8) are both integrated with the upper nickel sheet (2) and the lower nickel sheet (3) and are formed by stamping.

Images