CN212907968U

CN212907968U - Safety valve block for sealing square lithium ion battery

Info

Publication number: CN212907968U
Application number: CN202021904784.8U
Authority: CN
Inventors: 王永琛; 钱建峰; 朱华君; 赵成龙; 王正伟
Original assignee: Xingheng Power Supply Chuzhou Co ltd
Current assignee: Xingheng Power Supply Chuzhou Co ltd
Priority date: 2020-09-03
Filing date: 2020-09-03
Publication date: 2021-04-06
Anticipated expiration: 2030-09-03

Abstract

The utility model discloses a safety valve block for sealing a square lithium ion battery, which comprises a safety valve substrate matched with the shape and the size of a safety valve hole on a battery cover plate; the method is characterized in that: the side surface of the safety valve substrate is distributed with a plurality of convex points, the convex points are in a bulge shape, and the maximum size d2 of the convex points in the plane direction vertical to the safety valve substrate is not more than the thickness d3 of the substrate. The utility model provides a welding that appears when welding the safety valve block explodes fire phenomenon, improves the yield of welding workshop section greatly and reduces the cost of labor.

Description

Safety valve block for sealing square lithium ion battery

Technical Field

The utility model relates to a lithium ion battery, concretely relates to a safety valve block structure for square lithium ion battery.

Background

The lithium ion battery is divided into a cylinder, a soft package and a square according to the shape. In the field of electric automobiles, square lithium ion batteries are the mainstream model. The square lithium ion battery cover plate is often provided with a positive pole and a negative pole, a liquid injection hole and an explosion-proof valve. The positive and negative electrode posts are a connecting structure for leading positive and negative electrodes in the battery to the outside; the liquid injection hole is a hole required when the electrolyte is injected into the battery; the explosion-proof valve is a pressure relief device for preventing explosion when the internal pressure of the battery is too high.

For example, chinese utility model patent CN206098514U discloses a dual-safety valve power battery top cover and a power battery, which includes a battery cover plate provided with a liquid injection hole, an anode post, two explosion-proof valves and a cathode post, wherein the two explosion-proof valves are symmetrically arranged on the battery cover plate between the anode post and the cathode post, each explosion-proof valve is composed of an upper explosion-proof membrane, a middle O-ring and a lower explosion-proof valve bottom plate; the base material of the base plate of the explosion-proof valve is metal aluminum, the base plate is welded on the battery cover plate through spot welding, and the compressive strength of the base plate of the explosion-proof valve is 0.5-0.6 MPa. The utility model discloses an explosion-proof valve film that adopts metallic aluminum to constitute passes through the structure of spot welding on the battery apron, wherein, has set up the explosion-proof security performance of two relief valves in order to further guarantee the battery. However, in this case, the pour hole and the safety valve hole are independent from each other, and therefore, it is necessary to weld the explosion-proof valve to the safety valve hole, and it is necessary to separately close the pour hole after the pouring and chemical conversion processes.

In order to realize that the safety valve hole is used as a liquid injection hole, and the safety valve plate is welded after the battery is formed, Chinese utility model patent CN204632816U discloses a cover plate for a square battery, which improves the structure around the cover plate so as to facilitate the welding of the cover plate and reduce the use of laser; meanwhile, the safety valve hole in the center of the cover plate is provided with the step, the safety valve hole is simultaneously used as a liquid injection hole in the battery liquid injection and formation stages, and the safety valve plate is welded conveniently by using the step when formation is completed. Therefore, the technical scheme does not have a separate liquid injection hole, and only the safety valve hole needs to be sealed, so that the structure of the cover plate is simplified, and the cost of the cover plate is reduced. However, when the safety valve is welded after formation of the battery, the safety valve plate is placed at the position of the safety valve hole and enters a welding process, and a gap is formed between the safety valve plate and the safety valve hole due to vibration in the process of normal flow line conveying, and laser during laser welding may penetrate through electrolyte to cause welding explosion, so that welding failure needs rework. Therefore, solving this problem will greatly increase the yield of the welding section and reduce the cost of labor.

Disclosure of Invention

The utility model aims at providing a square lithium ion battery seals uses safe valve block solves the welding that probably appears when welding safe valve block through structural design and explodes fiery phenomenon to improve the yield of welding workshop section.

In order to achieve the purpose of the invention, the technical scheme adopted by the utility model is as follows: a safety valve plate for sealing a square lithium ion battery comprises a safety valve substrate matched with the shape and size of a safety valve hole on a battery cover plate; the side surface of the safety valve substrate is distributed with a plurality of convex points, the convex points are in a bulge shape, and the maximum size d2 of the convex points in the plane direction vertical to the safety valve substrate is not more than the thickness d3 of the substrate.

During the use, through the bump on the relief valve substrate side, easily will the utility model discloses a safety valve block is pressed to the safety valve hole on and is realized the block to in assembly line transportation process, can not form the gap because of the vibration between safety valve block and the cap, thereby the welding that probably takes place when having solved the welding safety valve block explodes the fire phenomenon.

According to the preferable technical scheme, the safety valve substrate is a circular thin sheet, the number of the salient points is 3, and the outer center of a triangle formed by connecting the outer ends of the 3 salient points is superposed with the circle center of the circular thin sheet.

In the technical scheme, the distance from the outer end of the salient point to the circle center of the safety valve substrate is d1, the safety valve hole in the battery cover plate is a round hole, the radius of the round hole is R, and the requirement that d1-R is more than 0 and less than or equal to 1mm is met.

In another technical scheme, the safety valve plate can be in any shape matched with the safety valve hole, the distance from the outer end of the salient point to the center of the safety valve substrate is d1a, the edge center distance of the safety valve hole on the battery cover plate corresponding to the installation position of the salient point is Ra, and the requirement that d1a-Ra is more than 0 and less than or equal to 1mm is met.

The safety valve substrate is rectangular, round-corner rectangular or long-strip with two semicircular ends, and at least one salient point is arranged on the corresponding side surface of each straight-line segment or arc segment.

In the above technical solution, the safety valve substrate is a portion having the smallest thickness in the entire battery case.

In the above technical scheme, the safety valve plate is made of aluminum or aluminum alloy.

Because of the application of the technical scheme, compared with the prior art, the utility model has the following advantages:

1. the utility model discloses set up the bump on the substrate, easily press the safety valve block of the utility model to the safety valve opening and realize the block when the battery seals, the safety valve block can not produce the removal because of assembly line conveying relatively the cap, is difficult for forming the gap between the two to welding the fire-blasting phenomenon that appears when having solved welding safety valve block, improve the yield of welding workshop section greatly and reduce the cost of labor costs;

2. because the thickness of the safety valve plate is smaller than that of the shell, when the internal pressure of the battery reaches a certain threshold value, the safety valve plate can be broken to release the pressure, so that explosion is avoided; compared with the safety valve in which an annular thin nick is additionally arranged to reach a weak area so as to release the internal pressure, the cost is further reduced;

3. adopt the utility model discloses a structure can unite two into one safety valve block and notes liquid mouth sealing aluminum sheet, reduces structural complexity, and is simple effective, further reduces the cost of cap spare part.

Drawings

Fig. 1 is a schematic top view of a safety valve plate according to an embodiment of the present invention;

FIG. 2 is a schematic side view of the safety valve sheet of the embodiment.

Wherein, 1, a safety valve substrate; 2. and (4) bumps.

Detailed Description

The invention will be further described with reference to the following examples:

example (b):

a safety valve plate for sealing a square lithium ion battery is shown in figures 1 and 2 and comprises a safety valve substrate 1 matched with a safety valve hole in a battery cover plate in shape and size. In the embodiment, the safety valve substrate 1 is a circular aluminum sheet, 3 salient points 2 are distributed on the side surface of the safety valve substrate 1, the salient points 2 are uniformly distributed, the top end connecting lines form a regular triangle, and the outer center of the regular triangle is superposed with the circle center of the circular aluminum sheet. The salient point 2 is in a bulge shape, and referring to fig. 2, the maximum dimension d2 of the salient point 2 in the direction vertical to the plane of the safety valve substrate 1 is less than or equal to the thickness d3 of the substrate.

The convex points are in a bulge shape and have a certain curved surface, so that the pressing action is easy to realize. The arranged salient points need to have a buckling function, so that the distance d1 between the outer ends of the salient points and the circle center of the substrate is larger than the radius R of the liquid injection round hole for supporting the cover plate of the safety valve plate, the buckling effect of the too small d1-R difference value is poor, and the pressing action is difficult due to the too large difference value.

Triangle-shaped is the most firm shape, thereby the three bump of setting is pressed the back and is embedded into safe valve port and realize firm buckle effect, and the safety valve block is whole because the battery that is detained produces the gap between safety valve block and apron when the vibration can not be in the transfer of transfer line to welding that causes when having avoided welding safety valve block explodes fiery phenomenon, improves the yield of welding workshop section greatly and reduces the cost of labor that the rework caused.

The bumps may be formed by direct stamping, spot welding, or the like.

To test the effectiveness of this example, tests were conducted using different d1-R values, the results of which are shown in Table 1 below.

TABLE 1

	Welding yield (statistics hundreds of thousands)
		Safety valve plate without convex point	97.03%
Safety valve plate with salient point (d1-R =1mm)	99.90%
		Safety valve plate with salient point (d1-R =0.05mm)	97.21%
Safety valve plate with salient point (d1-R =0.5mm)	99.99%

As table 1, the statistics of the traditional bump-free safety valve plate adopted when producing the welding safety valve of the production line and the utility model discloses there is one hundred thousand welding yields of bump safety valve plate. Experiments show that the welding yield of the common safety valve plate in the prior art is 97.03%, the welding yield is improved under the condition of different sizes of the salient points by adopting the structure of the embodiment, and the welding yield of the optimal scheme is improved to 99.99% (d1-R =0.5 mm).

Claims

1. A safety valve plate for sealing a square lithium ion battery comprises a safety valve substrate matched with the shape and size of a safety valve hole on a battery cover plate; the method is characterized in that: the side surface of the safety valve substrate is distributed with a plurality of convex points, the convex points are in a bulge shape, and the maximum size d2 of the convex points in the plane direction vertical to the safety valve substrate is not more than the thickness d3 of the substrate.

2. The safety valve sheet for sealing a square lithium ion battery of claim 1, wherein: the safety valve substrate is a circular thin sheet, the number of the salient points is 3, and the outer center of a triangle formed by connecting the outer ends of the 3 salient points is superposed with the circle center of the circular thin sheet.

3. The safety valve sheet for sealing a square lithium ion battery of claim 2, wherein: the distance from the outer end of the salient point to the center of the safety valve substrate is d1, the safety valve hole on the battery cover plate is a round hole, the radius of the round hole is R, and the requirement that d1-R is more than 0 and less than or equal to 1mm is met.

4. The safety valve sheet for sealing a square lithium ion battery of claim 1, wherein: the distance from the outer end of the salient point to the center of the safety valve substrate is d1a, the edge center distance of the safety valve hole on the battery cover plate corresponding to the installation position of the salient point is Ra, and the d1a-Ra is more than 0 and less than or equal to 1 mm.

5. The safety valve sheet for sealing a square lithium ion battery of claim 4, wherein: the safety valve substrate is rectangular, round-corner rectangular or long-strip with two semicircular ends, and at least one salient point is arranged on the corresponding side surface of each straight-line segment or arc segment.

6. The safety valve sheet for sealing a square lithium ion battery of claim 1, wherein: the safety valve substrate is a portion having the smallest thickness in the entire battery case.