CN220358269U - Top cap subassembly, secondary cell and battery package - Google Patents

Abstract

The utility model discloses a top cover assembly, a secondary battery and a battery pack. The top cover assembly includes a cover plate and an explosion-proof valve embedded in the cover plate. A buffer groove is provided on the cover plate, and the buffer groove is arranged around the explosion-proof valve. Using this utility model, a buffer groove is provided around the explosion-proof valve on the cover plate. The thickness of the cover plate at the buffer groove is small and weak compared to other parts. When the battery core breathes, it can bear part of the stress together with the explosion-proof disc, reducing the explosion-proof effect. At the same time, when the cover plate is subjected to external stress, the buffer groove can absorb deformation or preferentially deform, reducing the impact on the explosion-proof disk of the explosion-proof valve, ensuring that the function of the explosion-proof valve remains reliable even when the top cover assembly is subjected to external forces.

Description

Top cover assembly, secondary battery and battery pack

Technical field

The utility model relates to the technical field of power batteries, and in particular to a top cover assembly, a secondary battery and a battery pack.

Background technique

There is a pressure relief hole running through the battery top cover, and the explosion-proof valve is fixed in the pressure relief hole. The explosion-proof valve includes a scored explosion-proof disc, which is welded in the pressure relief hole as a weak area of the battery core structure. When an abnormality occurs in the battery core, the internal gas produced breaks through the explosion-proof disc and the entire explosion-proof valve, releasing the pressure in time to prevent the battery core from exploding and reducing the risk of thermal runaway.

The internal air pressure of the battery core continues to increase and decrease with the charging and discharging process, and changes periodically. This "breathing effect" acts on the explosion-proof disc, which will cause the strength of the explosion-proof disc to weaken due to fatigue, which in turn causes the explosion pressure of the explosion-proof valve to gradually attenuate with the breathing effect. affect its service life. At the same time, during the use of the battery, there is a certain chance that the top cover will be impacted. When the top cover is deformed by a slight impact, the explosion-proof disc will be pulled, causing the explosion-proof disc to be unable to maintain the designed burst pressure, resulting in functional failure and battery scrapping.

Utility model content

In view of this, the utility model provides a top cover assembly, a secondary battery and a battery pack. A buffer groove is provided around the explosion-proof valve on the cover plate. The thickness of the cover plate at the buffer groove is small and weaker than other parts. When the battery core breathes, it can bear part of the stress together with the explosion-proof disc, reducing the fatigue attenuation of the strength of the explosion-proof disc. , at the same time, when the cover plate is subjected to external stress, the cover plate at the buffer groove can absorb deformation or preferentially deform, reducing the impact on the explosion-proof disk of the explosion-proof valve, ensuring that the function of the explosion-proof valve remains reliable when the top cover assembly is subjected to external forces.

The top cover assembly provided by the utility model includes a cover plate and an explosion-proof valve embedded in the cover plate. A buffer groove is provided on the cover plate, and the buffer groove is arranged around the explosion-proof valve.

Optionally, the side wall of the buffer tank close to the explosion-proof valve is configured as a slope; or/and, the side wall of the buffer tank away from the explosion-proof valve is configured as a slope.

Optionally, the side walls of the buffer groove close to and far away from the explosion-proof valve are both configured as vertical surfaces, and one end far away from the notch has a slope extending relatively toward the direction of the notch.

Optionally, the width of the buffer groove ranges from 0.5 to 3 mm.

Optionally, the distance between the side wall of the buffer groove close to the explosion-proof valve and the explosion-proof valve is 2-20 mm.

Optionally, the thickness of the cover plate at the buffer groove is greater than 0.2 mm.

Optionally, the buffer grooves are provided at corresponding positions on opposite side surfaces of the cover plate.

Optionally, the buffer groove and the cover plate are integrally formed.

The utility model also provides a secondary battery, including the top cover assembly described in any one of the above.

The utility model also provides a battery pack, including the above-mentioned secondary battery.

Compared with the existing technology, the above technical solution provided by the utility model has at least the following beneficial effects:

Using the top cover assembly, secondary battery and battery pack of the present utility model, a buffer groove is provided around the explosion-proof valve on the cover plate. The thickness of the cover plate at the buffer groove is small and weak compared to other parts. When the battery core breathes, it can Together with the explosion-proof disc, it bears part of the stress to reduce the fatigue attenuation of the strength of the explosion-proof disc. At the same time, when the cover plate is subjected to external stress, the buffer groove can absorb deformation or preferentially deform, reducing the impact on the explosion-proof disc of the explosion-proof valve and ensuring that the top cover assembly is The function of the explosion-proof valve is still reliable under external force.

Description of the drawings

Figure 1 is a schematic diagram of a top cover assembly according to an embodiment of the present invention;

Figure 2 is a cross-sectional view of the top cover assembly shown in Figure 1 at position A-A;

Figure 3 is a cross-sectional view of the top cover assembly according to another embodiment of the present invention.

Reference signs:

1: Cover plate; 2: Explosion-proof valve; 21: Explosion-proof disc; 22: Protection disc; 3: Buffer tank; 4: Positive terminal; 5: Negative terminal; 6: Liquid injection hole.

Detailed ways

The specific embodiments of the present invention will be further described below in conjunction with the accompanying drawings.

It is easy to understand that according to the technical solution of the present invention, those of ordinary skill in the art can interchange various structural modes and implementation modes without changing the essential spirit of the present invention. Therefore, the following specific embodiments and drawings are only illustrative descriptions of the technical solutions of the present utility model, and should not be regarded as the entirety of the present utility model or as limitations or restrictions on the technical solutions of the utility model.

Orientation terms such as upper, lower, left, right, front, back, front, back, top, and bottom mentioned or may be mentioned in this specification are defined relative to the structure shown in each drawing, and they are It is a relative concept, so it may change accordingly according to its different locations and different uses. Therefore, these or other directional terms should not be construed as restrictive terms.

Figure 1 is a schematic diagram of the top cover assembly according to one embodiment of the present invention; Figure 2 is a cross-sectional view of the top cover assembly shown in Figure 1 at position A-A; Figure 3 is a cross-sectional view of the top cover assembly according to another embodiment of the present utility model. . As shown in Figures 1 to 3, the top cover assembly includes a cover plate 1 and an explosion-proof valve 2 embedded in the cover plate 1. A buffer groove 3 is provided on the cover plate 1. The buffer groove 3 Set around the explosion-proof valve 2.

The top cover assembly is sealed on the battery shell and surrounds the battery core. When the internal air pressure of the battery core continues to increase and decrease with the charging and discharging process and changes periodically, the weak explosion-proof valve area is subject to periodic changes. The air pressure will cause periodic deformation and recovery, resulting in a certain degree of fatigue attenuation. At the same time, the thickness of the cover plate 1 at the buffer groove 3 is reduced due to the existence of the buffer groove. Compared with other parts of the cover plate 1 The area has also become a weak point. During the periodic change of the air pressure inside the battery core, the explosion-proof valve 2 bears part of the stress, and periodically undergoes a certain degree of deformation and recovery, dispersing part of the air pressure, thereby reducing the The fatigue attenuation degree of the explosion-proof valve 2. When the cover plate 1 near the buffer tank 3 is subjected to external stress, the buffer tank 3 will be deformed preferentially due to its thin thickness, so that excessive stress will not continue to be transmitted to the explosion-proof valve 2, causing all The explosion-proof disc 21 of the explosion-proof valve 2 is subject to less stress, and the whole is still on a plane, which does not affect the blasting function. When the position of the cover plate 1 away from the buffer groove 3 is subjected to external stress, the position of the buffer groove 3 absorbs the stress and produces a slight deformation, so that the stress can hardly be transmitted to the explosion-proof valve 2 , thus causing damage to the explosion-proof valve 2 The impact of the explosion-proof disc 21 is small.

Using the top cover assembly of the present utility model, the buffer groove 3 is provided around the explosion-proof valve 2 on the cover plate 1. The thickness of the cover plate 1 at the buffer groove 3 is small and weak compared to other parts. When the core breathes, it can withstand part of the stress together with the explosion-proof disc 21 of the explosion-proof valve 2, reducing the fatigue attenuation of the strength of the explosion-proof disc. At the same time, when the cover plate 1 is subjected to external stress, the buffer groove 3 can absorb deformation. Or deform preferentially to reduce the impact on the explosion-proof disc 21 of the explosion-proof valve 2 and ensure that the function of the explosion-proof valve 2 remains reliable even when the top cover assembly is subjected to external force.

In this embodiment, as shown in Figures 1 to 3, a pressure relief hole is provided in the center of the cover plate 1, and the explosion-proof valve 2 is fixed in the pressure relief hole. The left and right sides of the cover plate 1 The positive terminal 4 and the negative terminal 5 are respectively fixed at both ends, and a liquid injection hole 6 is provided. The explosion-proof valve 2 includes an explosion-proof disc 21 and a protective sheet 22 covering the explosion-proof disc 21. The explosion-proof disc 21 faces the inside of the battery core and is engraved with a score, and the protective sheet 22 faces away from the battery core. Inside the core. As shown in Figure 1, the explosion-proof disc 21 is in an elliptical shape as a whole. The buffer groove 3 is closed around the explosion-proof disc 21 and is also in an elliptical shape as a whole. As shown in Figures 2 and 3, the buffer groove 3 is The cover plate 1 is thinner than other locations and becomes a weaker area. According to the actual application situation, the specific shape of the buffer groove 3 as well as the width, depth, circumference and other dimensions can be adjusted, and the buffer groove 3 can be formed using any manufacturing process, as long as the buffer groove 3 surrounds the explosion-proof valve 2 is closed, so that the cover plate 1 at the buffer tank 3 can absorb the stress inside and outside the battery core, reduce the stress on the explosion-proof valve 2, and maintain sufficient strength. When the pressure inside the battery core is abnormal, When the explosion-proof valve 2 explodes and releases pressure, it only needs to remain intact.

During the normal use of the battery core, the bursting pressure of the explosion-proof valve 2 gradually decreases with breathing. When designing the initial pressure of the explosion-proof disc 21, it should be considered that the bursting pressure at the end of the life is still greater than the internal air pressure of the battery core. At the same time, when the internal pressure of the battery core increases sharply, the explosion-proof disc 21 should be able to release the pressure in time to avoid more serious consequences. The earlier the pressure is released, the higher the safety. These two situations jointly determine the designable range of the pressure relief pressure of the explosion-proof valve 2. Using the battery top cover plate of the present invention, because the cover plate 1 at the buffer tank 3 shares the stress on the explosion-proof valve 2, the initial design pressure range of the explosion-proof disc is also broadened, and the safety performance of the battery core is improved. .

Optionally, the side wall of the buffer tank 3 close to the explosion-proof valve 2 is configured as a slope; or/and, the side wall of the buffer tank 3 away from the explosion-proof valve 2 is configured as a slope. This arrangement enables the buffer groove 3 to have a stronger ability to absorb deformation.

In this embodiment, as shown in Figure 2, the buffer groove 3 is provided on both the upper and lower sides of the cover plate 1, and the buffer groove 3 located on the same side as the explosion-proof disc 21 is close to the explosion-proof disk 21. The inner wall of one side of the valve 2 is a vertical plane perpendicular to the explosion-proof disc 21, and the inner wall of the side away from the explosion-proof valve 2 is an inclined plane toward the explosion-proof disc 21, with an inclination angle of about 45°; and the protection sheet 22 is located on the same side of the buffer tank 3. The inner wall of the side close to the explosion-proof valve 2 is an inclined plane away from the protection sheet 22, with an inclination angle of about 45°. The inner wall of the side far away from the explosion-proof valve 2 is perpendicular to The vertical surfaces of the protective sheet 22 and the inclined surfaces of the buffer groove 3 on the upper and lower sides of the cover plate 1 are arranged in parallel. As shown in Figure 3, the upper and lower sides of the cover plate 1 are also provided with the buffer groove 3, which is arranged around the explosion-proof valve 2, wherein the buffer groove 3 located on the same side as the protective sheet 22, The inner walls close to and away from the explosion-proof valve 2 are both inclined planes, and the two are relatively inclined, so that the cross-section of the buffer tank 3 is configured as an isosceles triangle. According to actual application conditions, the side walls of the buffer tank 3 close to and away from the explosion-proof valve 2 can be individually set as inclined planes, or both can be set as inclined planes, and the inclination angle of the inclined planes can be adjusted appropriately.

Optionally, the side walls of the buffer groove 3 close to and far away from the explosion-proof valve 2 are both configured as vertical surfaces, and one end far away from the notch has a slope extending relatively toward the direction of the notch. This arrangement enables the buffer groove 3 to have a stronger ability to absorb deformation.

In this embodiment, as shown in Figure 3, the buffer groove 3 located on the same side as the explosion-proof disc 21 is close to and away from the side wall of the explosion-proof valve 2, that is, the buffer groove in Figure 3 The left and right inner walls of 3 are both vertical surfaces, and mirror-symmetrical inclined planes extend from the end away from the notch, that is, the upper ends of the vertical surfaces on both sides in Figure 3 are relatively downward, that is, relatively toward the direction of the notch. , and the two inclined surfaces are respectively parallel to the inner wall of the triangular buffer groove 3 on one side of the protective sheet 22 in Figure 3 . According to the actual application situation, the inclination angles of the two inclined planes extending from the two side walls of the buffer tank 3 close to and away from the explosion-proof valve 2 can be the same or different, and the two inclined planes can intersect or not intersect, as long as the above-mentioned The cover plate 1 at the buffer tank 3 can absorb the stress inside and outside the battery core to a greater extent. At the same time, when the abnormal pressure inside the battery core causes the explosion-proof valve 2 to burst and release pressure, it can ensure sufficient strength and will not Just break it there.

Optionally, the width of the buffer groove 3 ranges from 0.5 to 3 mm. This arrangement can not only ensure that the cover plate 1 at the buffer tank 3 can absorb the stress inside and outside the battery core to a greater extent, but also ensure that the explosion-proof valve 2 explodes and leaks due to abnormal pressure inside the battery core. It has enough strength to avoid rupture when pressed. For example, the width of the buffer groove 3 can be selected as 1mm, 2mm, etc. According to actual application conditions, the width of the buffer groove 3 can be selected arbitrarily within this range.

Optionally, the distance between the side wall of the buffer groove 3 close to the explosion-proof valve 2 and the explosion-proof valve 2 is 2-20 mm. With this arrangement, when the cover plate 1 is hit by an external force, the buffer groove 3 can absorb stress and deform to a greater extent, protecting the explosion-proof valve 2 from being affected by external stress, or being affected by less stress.

The distance between the side walls of the buffer tank 3 close to the explosion-proof valve 2 and the explosion-proof valve 2 may be equal or different. For example, the distance between the two may be 5mm, 10mm, 15mm, etc. . According to actual application conditions, the distance between the buffer tank 3 and the explosion-proof valve 2 can be appropriately adjusted within this range.

Optionally, the thickness of the cover plate 1 at the buffer groove 3 is greater than 0.2 mm. This arrangement can not only ensure that the cover plate 1 at the buffer tank 3 can absorb the stress inside and outside the battery core to a greater extent, but also ensure that the explosion-proof valve 2 explodes and leaks due to abnormal pressure inside the battery core. It has enough strength to avoid rupture when pressed.

The thickness of the explosion-proof disc 21 is 0.1mm. According to test data, the thickness of the cover plate 1 at the buffer tank 3 is greater than 0.2mm, which can ensure that when the explosion-proof valve 2 explodes and releases pressure, the buffer No cracking will occur at slot 3. According to actual application conditions, the thickness of the cover plate 1 at the buffer groove 3 can be adjusted, for example, 0.3 mm, 0.4 mm, etc. can be selected, and accordingly, the depth of the buffer groove 3 can be adjusted.

Optionally, the buffer grooves 3 are provided at corresponding positions on the opposite side surfaces of the cover plate 1 . This arrangement makes the cover plate 1 at the buffer tank 3 more sensitive to stress changes inside and outside the battery core, which is conducive to further protecting the explosion-proof valve 2 and reducing the possibility of deformation and failure of the explosion-proof disc 21 .

As shown in Figures 2 and 3, the buffer grooves 3 are provided at corresponding positions on the upper and lower surfaces of the cover plate 1, and the buffer grooves 3 on the upper and lower sides have the same width and spread shape on the plane. same.

Optionally, the buffer groove 3 and the cover plate 1 are integrally formed. The one-piece molding process is adopted to reduce the manufacturing process and help improve manufacturing efficiency.

In this embodiment, the buffer groove 3 and the cover plate 1 are integrally extruded.

The utility model also provides a secondary battery, including the top cover assembly described in any of the above embodiments.

The battery includes a casing and an electric core arranged in the casing. The top cover assembly is detachably connected to the casing and covers the electric core inside.

Using the secondary battery of the present invention, the buffer groove 3 is provided around the explosion-proof valve 2 on the cover plate 1. The thickness of the cover plate 1 at the buffer groove 3 is small and weak compared to other parts. When the core breathes, it can withstand part of the stress together with the explosion-proof disc 21 of the explosion-proof valve 2, reducing the fatigue attenuation of the strength of the explosion-proof disc. At the same time, when the cover plate 1 is subjected to external stress, the buffer groove 3 can absorb deformation. Or deform preferentially to reduce the impact on the explosion-proof disc 21 of the explosion-proof valve 2 and ensure that the function of the explosion-proof valve 2 remains reliable even when the top cover assembly is subjected to external force.

The utility model also provides a battery pack, including the secondary battery described in the above embodiment.

Using the battery pack of the present invention, the buffer groove 3 is provided around the explosion-proof valve 2 on the cover plate 1. The thickness of the cover plate 1 at the buffer groove 3 is small and weak compared to other parts. When breathing, it can withstand part of the stress together with the explosion-proof disc 21 of the explosion-proof valve 2, reducing the degree of fatigue attenuation of the strength of the explosion-proof disc. At the same time, when the cover plate 1 is subjected to external stress, the buffer groove 3 can absorb deformation or Prioritize deformation to reduce the impact on the explosion-proof disc 21 of the explosion-proof valve 2 and ensure that the function of the explosion-proof valve 2 remains reliable even when the top cover assembly is subjected to external force.

According to needs, the above technical solutions can be combined to achieve the best technical effect.

The above are only the principles and preferred embodiments of the present utility model. It should be noted that for those of ordinary skill in the art, several other modifications can be made based on the principles of the present utility model, which should also be regarded as the protection scope of the present utility model.

Claims (9)

1. The utility model provides a top cap subassembly, includes the apron, and inlay in explosion-proof valve on the apron, its characterized in that:

the cover plate is provided with a buffer groove, and the buffer groove is arranged around the explosion-proof valve;

the side wall of the buffer groove, which is close to the explosion-proof valve, is provided with an inclined surface; or/and the combination of the two,

the side wall of the buffer groove far away from the explosion-proof valve is provided with an inclined plane.

2. The header assembly of claim 1, wherein:

the buffer groove is close to and far away from the side wall of the explosion-proof valve is arranged to be a vertical surface, and one end far away from the notch extends out of the inclined surface towards the notch direction relatively.

3. The header assembly of claim 1 or 2, wherein:

the width of the buffer groove ranges from 0.5 mm to 3mm.

4. The header assembly of claim 1 or 2, wherein:

the distance between the side wall of the buffer groove, which is close to the explosion-proof valve, and the explosion-proof valve is 2-20mm.

5. The header assembly of claim 1 or 2, wherein:

the thickness of the cover plate at the buffer groove is larger than 0.2mm.

6. The header assembly of claim 1 or 2, wherein:

the buffer grooves are formed in corresponding positions of the surfaces of the two opposite sides of the cover plate.

7. The header assembly of claim 1 or 2, wherein:

the buffer groove and the cover plate are integrally formed.

8. A secondary battery comprising the top cap assembly according to any one of claims 1 to 7.

9. A battery pack comprising the secondary battery according to claim 8.