Battery cover plate and lithium battery

Abstract

The utility model provides a battery cover plate and a lithium battery. The battery cover plate comprises a cover plate main body with a pressure relief hole and a pressure relief assembly, the pressure relief assembly comprises a rubber plug used for blocking the pressure relief hole and a rubber plug fixing piece arranged on the cover plate body, a containing cavity is formed between the rubber plug fixing piece and the cover plate body, a through hole communicated with the containing cavity is formed in the rubber plug fixing piece, the rubber plug is restrained in the containing cavity by the rubber plug fixing piece, an exhaust channel is formed in the rubber plug, and the exhaust channel is communicated with the through hole. The containing cavity is communicated with the through hole through the exhaust channel. And when the rubber plug elastically deforms to release the blocking with the pressure relief hole, the pressure relief hole is communicated with the accommodating cavity. According to the battery cover plate disclosed by the utility model, the pressure on the inner side of the battery cover plate can be released through the arranged pressure release assembly in the battery production process, so that the problems that an explosion-proof valve is opened due to overlarge internal pressure in the battery production process, electrolyte leaks and the like can be effectively prevented, and a good use effect is achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of power battery manufacturing, and in particular to a battery cover plate. The utility model also relates to a lithium battery provided with the battery cover plate. Background Art

[0002] During the battery production process, the battery usually needs to be pressurized and constrained to ensure good fit between the positive and negative electrodes inside the battery. As the internal space utilization rate of the battery increases, the proportion of unoccupied space inside the battery becomes lower. When the battery is constrained during pre-charging, chemical composition and other processes, it is easy to cause the internal pressure of the battery to increase, resulting in electrolyte leakage and cracking of the explosion-proof valve, which greatly affects the battery's yield rate. Utility Model Content

[0003] In view of this, the utility model aims to provide a battery cover plate, which can effectively prevent the explosion-proof valve from cracking and electrolyte from bubbling due to excessive internal pressure of the battery during the battery production process.

[0004] In order to achieve the above object, the technical solution of the utility model is implemented as follows:

[0005] A battery cover plate comprises a cover plate body having a pressure relief hole, and a pressure relief assembly;

[0006] The pressure relief assembly includes a rubber plug for blocking the pressure relief hole, and a rubber plug fixing member provided on the cover plate body, a receiving cavity is formed between the rubber plug fixing member and the cover plate body, and a through hole communicating with the receiving cavity is provided on the rubber plug fixing member, the rubber plug is constrained in the receiving cavity by the rubber plug fixing member, and an exhaust channel is provided on the rubber plug, and the exhaust channel connects the receiving cavity with the through hole;

[0007] When the rubber plug is elastically deformed to release the blockage of the pressure relief hole, the pressure relief hole is communicated with the accommodating cavity.

[0008] Furthermore, the rubber plug has a main body and a transverse protrusion arranged on the main body; the rubber plug fixing piece is pressed tightly on the transverse protrusion.

[0009] Furthermore, the exhaust passages are multiple and spaced apart on the rubber plug.

[0010] Furthermore, center lines of the plurality of exhaust passages intersect at the outer side of the rubber plug fixing member.

[0011] Further, along the direction pointing to the rubber plug, one end of the pressure relief hole close to the rubber plug is arranged to expand outward; and / or the pressure relief hole is located on one side of the explosion-proof valve on the cover plate body.

[0012] Furthermore, a sink groove is provided on the cover plate body, the sink groove is located on one side of the pressure relief hole and is communicated with the pressure relief hole; the rubber plug fixing piece is installed in the sink groove.

[0013] Furthermore, the through hole is arranged opposite to the pressure relief hole, and the rubber plug has an upper protrusion extending from the through hole to the outside of the accommodating cavity; the pressure relief assembly also includes a sealing cap provided on the rubber plug fixing member, and the sealing cap is used to press the upper protrusion.

[0014] Furthermore, the longitudinal section of the rubber plug fixing piece is in a "J" shape and has a first connecting edge located on the sink groove.

[0015] Furthermore, a connecting groove is provided on the first connecting edge; the sealing cap has a cap body threadedly connected to the rubber plug fixing member, and a second connecting edge provided on the cap body, and the second connecting edge is located in the connecting groove.

[0016] Compared with the prior art, the utility model has the following advantages:

[0017] The battery cover described in the utility model is provided with a rubber plug and a rubber plug fixing member for sealing the pressure relief hole, and the rubber plug fixing member constrains the rubber plug in the accommodating cavity, and an exhaust passage connecting the accommodating cavity and the through hole is provided on the rubber plug. In this way, the rubber plug can be elastically deformed and release the blockage of the pressure relief hole under the pressure on the inner side of the battery cover. At this time, the pressure relief hole is connected with the accommodating cavity, the exhaust passage and the through hole, so that the pressure on the inner side of the battery cover can be released, and the explosion-proof valve can be effectively prevented from opening due to excessive internal pressure and electrolyte bubbling during battery production.

[0018] In addition, the transverse protrusion is arranged to facilitate the plug fixing member to press the plug tightly, and better constrain the plug in the accommodating cavity. The multiple exhaust channels are arranged on the plug, which is conducive to improving the pressure relief effect. The center lines of the multiple exhaust channels are arranged relative to the outer side of the plug fixing member, which is conducive to the arrangement of the exhaust channels and also helps to improve the stress of the plug during pressure relief.

[0019] Secondly, the end of the pressure relief hole close to the rubber plug is expanded outward, which is conducive to improving the sealing performance of the rubber plug and the pressure relief hole, and the pressure relief hole can also be used as a liquid injection hole. The pressure relief hole is located on one side of the explosion-proof valve. At this time, during the battery production process, the pressure is relieved through the pressure relief hole without affecting the explosion-proof valve. The sink groove set on the cover body, on the one hand, facilitates the installation of the rubber plug fixing, and on the other hand, can store a certain amount of electrolyte, and effectively prevent the electrolyte from spreading to the surroundings and contaminating the explosion-proof valve.

[0020] In addition, the upper protrusion provided on the rubber plug cooperates with the sealing cap provided on the rubber plug fixing member, which can effectively improve the sealing performance of the battery cover after pressure relief. The first connecting edge provided on the rubber plug fixing member cooperates with the sink groove, which is conducive to improving the reliability of the connection between the rubber plug fixing member and the cover body. The connecting groove provided on the first connecting edge cooperates with the first connecting edge on the sealing cap, which is conducive to improving the reliability of the connection between the sealing cap and the rubber plug fixing member.

[0021] Another object of the present invention is to provide a lithium battery, wherein the lithium battery is provided with the battery cover as described above.

[0022] The lithium battery of the present invention and the battery cover as described above have the same beneficial effects as those of the prior art, which will not be described in detail herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention. In the accompanying drawings:

[0024] Figure 1 This is a schematic diagram of the structure of the battery cover according to an embodiment of the utility model;

[0025] Figure 2 It is a partial enlarged view of the battery cover plate described in the embodiment of the utility model;

[0026] Figure 3 It is a partial exploded view of the battery cover according to the embodiment of the utility model;

[0027] Figure 4 This is a schematic diagram of the structure of a lithium battery according to an embodiment of the utility model;

[0028] Description of reference numerals:

[0029] 1. Cover plate body; 2. Rubber plug; 3. Rubber plug fixing piece; 4. Sealing cap; 5. Shell;

[0030] 11. Pole; 12. Explosion-proof valve; 101. Pressure relief hole; 102. Sink; 20. Exhaust channel; 21. Sealing portion; 22. Lateral raised portion; 23. Upper raised portion; 30. Accommodating cavity; 31. External thread; 32. Through hole; 33. First connecting edge; 331. Connecting groove; 41. Internal thread; 42. Second connecting edge. DETAILED DESCRIPTION

[0031] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

[0032] In the description of the present invention, it should be noted that if there are terms such as "upper", "lower", "inner", "outer" and the like indicating orientation or positional relationship, they 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, if there are terms such as "first" and "second", they are also used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0033] In addition, in the description of the present invention, unless otherwise clearly defined, the terms "installation", "connection", "connection" and "connector" 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 an indirect connection 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 in combination with specific circumstances.

[0034] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments.

[0035] Embodiment 1

[0036] The present embodiment relates to a battery cover plate, which can effectively prevent the explosion-proof valve from cracking and electrolyte leakage caused by excessive internal pressure of the battery during the battery production process.

[0037] In terms of overall structure, Figures 1 to 3 As shown, the battery cover of this embodiment includes a cover body 1 having a pressure relief hole 101, and a pressure relief assembly.

[0038] The pressure relief assembly includes a rubber plug 2 for blocking the pressure relief hole 101, and a rubber plug fixing member 3 provided on the cover plate body 1. An accommodating cavity 30 is formed between the rubber plug fixing member 3 and the cover plate body 1, and a through hole 32 communicating with the accommodating cavity 30 is provided on the rubber plug fixing member 3. The rubber plug 2 is constrained in the accommodating cavity 30 by the rubber plug fixing member 3, and an exhaust channel 20 is provided on the rubber plug 2, which connects the accommodating cavity 30 with the through hole 32. When the rubber plug 2 is elastically deformed to release the blockage of the pressure relief hole 101, the pressure relief hole 101 is connected with the accommodating cavity 30.

[0039] At this time, as set above, through the set pressure relief component, the rubber plug 2 blocks the pressure relief hole 101, and the rubber plug fixing part 3 constrains the rubber plug 2 in the accommodating chamber 30, and the exhaust channel 20 connecting the accommodating chamber 30 and the through hole 32 is set on the rubber plug 2. In this way, under the pressure on the inner side of the battery cover, the rubber plug 2 can be elastically deformed and release the blockage with the pressure relief hole 101. At this time, the pressure relief hole 101 is connected with the accommodating chamber 30, the exhaust channel 20 and the through hole 32, so that the pressure on the inner side of the battery cover can be released, and the explosion-proof valve 12 can be effectively prevented from opening due to excessive internal pressure and electrolyte bubbling during battery production.

[0040] Based on the above overall introduction, for details, please refer to Figures 1 to 3 As shown, poles 11 are provided at both ends of the cover body 1 of this embodiment, namely, a positive pole 11 and a negative pole 11, and an explosion-proof valve 12 is also provided on the cover body 1. In this embodiment, as a preference, the pressure relief hole 101 formed on the cover body 1 is located on one side of the explosion-proof valve 12, namely, between one pole 11 and the explosion-proof valve 12.

[0041] In this embodiment, during the battery production process, for example, during the pre-charging, capacity division and other constrained processes where the internal pressure of the battery is relatively large, the pressure relief assembly on the pressure relief hole 101 can release the pressure inside the battery cover. It should be noted that after the above process is completed, the pressure relief assembly can be sealed and connected to the pressure relief hole 101 to ensure the sealing performance of the cover body 1, and does not affect the normal use of the explosion-proof valve 12.

[0042] See also Figure 2 and Figure 3 As shown in the figure, as a preferred embodiment, in this embodiment, the rubber plug 2 has a main body, the lower end of the main body is provided with a blocking portion 21 inserted in the pressure relief hole 101, and the main body is also provided with a transverse protrusion 22, which is arranged along the circumference of the main body. The above-mentioned rubber plug fixing member 3 is pressed against the transverse protrusion 22, so that the rubber plug 2 is better constrained in the accommodating cavity 30.

[0043] In this embodiment, the exhaust passages 20 formed on the rubber plug 2 are multiple and spaced apart on the rubber plug 2. The provision of multiple exhaust passages 20 is beneficial to improving the pressure relief effect. Figure 2 and Figure 3 As shown, multiple exhaust channels 20 are arranged obliquely, and the center lines of the multiple exhaust channels 20 intersect at the outside of the rubber plug fixing member 3, that is, the intersection of the center lines of each exhaust channel 20 is located on the side of the rubber plug 2 facing the through hole 32. Such an arrangement can facilitate the communication between each exhaust channel 20 and the through hole 32, and also facilitate the arrangement of each exhaust channel 20. At the same time, it can also improve the stress condition of the rubber plug 2 during pressure relief.

[0044] As a preferred implementation, in this embodiment, along the direction pointing to the rubber plug 2, the end of the pressure relief hole 101 close to the rubber plug 2 is arranged to be outwardly expanded, which can help improve the sealing performance between the rubber plug 2 and the pressure relief hole 101, and the pressure relief hole 101 can also be used as a liquid injection hole.

[0045] In addition, continue to see Figure 2 and Figure 3 As shown, in this embodiment, a sink 102 is also provided on the cover plate body 1, and the sink 102 is located on one side of the pressure relief hole 101 and is connected to the pressure relief hole 101. The above-mentioned rubber plug fixing member 3 is installed in the sink 102. The setting of the sink 102 not only provides an installation space for the installation of the rubber plug fixing member 3, but also can store a certain amount of electrolyte to prevent the electrolyte from spreading to the surroundings and contaminating the explosion-proof valve 12, etc.

[0046] As a preferred implementation, in this embodiment, the through hole 32 is arranged opposite to the pressure relief hole 101, and the rubber plug 2 has an upper protrusion 23 extending from the through hole 32 to the outside of the accommodating cavity 30. In addition, the pressure relief assembly further includes a sealing cap 4 provided on the rubber plug fixing member 3, and the sealing cap 4 can press the upper protrusion 23, thereby not only further improving the fixing effect of the rubber plug 2, but also effectively improving the sealing performance of the battery cover after pressure relief.

[0047] The rubber plug fixing member 3 of this embodiment has a "J"-shaped longitudinal section and has a first connecting edge 33 located on the sink 102. The first connecting edge 33 abuts against the sink 102, which can help improve the reliability of the connection between the rubber plug fixing member 3 and the cover body 1.

[0048] In specific implementation, the first connection edge 33 and the cover body 1 can be connected together by welding to ensure the sealing of the connection between the rubber plug fixing member 3 and the cover body 1. Of course, it can be understood that the first connection edge 33 and the cover body 1 can also be connected by screw connection, and cooperate with a sealing ring to achieve the sealing of the connection between the two.

[0049] In order to facilitate the fixing and installation of the sealing cap 4, in this embodiment, a connecting groove 331 is provided on the first connecting edge 33. Moreover, in terms of structure, the sealing cap 4 of this embodiment has a cap body that is screwed to the rubber plug fixing member 3, and a second connecting edge 42 provided on the cap body, and the second connecting edge 42 is located in the connecting groove 331. In specific implementation, an internal thread 41 is formed in the cap body, which can be screwed to the external thread 31 on the rubber plug fixing member 3, and after the pressure relief is completed, the second connecting edge 42 is welded to the first connecting edge 33, so that the sealing cap 4 is sealed and connected to the rubber plug fixing member 3.

[0050] It should be noted that when the battery is undergoing a process with high requirements for sealing, such as helium testing, the sealing cap 4 can be tightened to ensure the sealing performance of the battery cover. When the battery is subjected to a high internal pressure, such as pre-charging and capacity separation, and pressure relief is required, the sealing cap 4 is loosened to form a gap at the threaded connection between the sealing cap 4 and the rubber plug fixing member 3.

[0051] At this time, the rubber plug 2 is compressed under the action of gas pressure and is separated from the blockage of the pressure relief hole 101. The gas inside the battery cover passes through the pressure relief hole 101, the accommodating cavity 30, the exhaust channel 20, the through hole 32 in turn, and is discharged to the outside of the battery cover through the gap between the sealing cap 4 and the rubber plug fixing member 3, thereby reducing the internal pressure of the battery. After the pressure relief is completed, the sealing cap 4 is welded to the rubber plug fixing member 3. It should be pointed out that the sealing failure value of the rubber plug 2 is greater than the upper limit of the pressure for opening the explosion-proof valve 12, so that the sealing performance of the battery cover can be effectively guaranteed.

[0052] In addition, it should be noted that after the sealing cap 4 is connected to the plug fixing member 3, the upper protrusion 23 of the plug 2 is compressed, and the degree of sealing of the plug 2 can be controlled by designing the deformation amount. In specific implementation, for example, the battery internal pressure at which the plug 2 fails to seal can be set to P1≥P-0.2, preferably P1≥P-0.3. When the sealing cap 4 is tightened and tightly connected to the plug fixing member 3, the battery internal pressure at which the plug 2 fails to seal is P2>P+0.2. Wherein, P is the target value for opening the explosion-proof valve 12, in MPa.

[0053] The battery cover of this embodiment can release the pressure inside the battery cover through the provided pressure relief assembly during the battery production process, thereby effectively preventing the explosion-proof valve 12 from opening due to excessive internal pressure and electrolyte bubbling during the battery production process.

[0054] Embodiment 2

[0055] This embodiment relates to a lithium battery, in which the battery cover of the first embodiment is provided. Figure 4 As shown, the lithium battery includes a shell 5 for accommodating a bare cell, and the top of the shell 5 is open.

[0056] The battery cover of the first embodiment is sealed at the opening.

[0057] The lithium battery of this embodiment, by applying the battery cover of the first embodiment, can reduce the occurrence of problems such as cracking of the explosion-proof valve 12 and electrolyte leakage caused by excessive internal pressure during the production process of the battery, and is also beneficial to improving the manufacturability of the lithium battery, and has a good use effect.

[0058] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A battery cover, characterized in that: It includes a cover plate body having a pressure relief hole, and a pressure relief assembly; The pressure relief assembly includes a rubber plug for blocking the pressure relief hole, and a rubber plug fixing member provided on the cover plate body, a receiving cavity is formed between the rubber plug fixing member and the cover plate body, and a through hole communicating with the receiving cavity is provided on the rubber plug fixing member, the rubber plug is constrained in the receiving cavity by the rubber plug fixing member, and an exhaust channel is provided on the rubber plug, and the exhaust channel connects the receiving cavity with the through hole; When the rubber plug is elastically deformed to release the blockage of the pressure relief hole, the pressure relief hole is communicated with the accommodating cavity.

2. The battery cover according to claim 1, characterized in that: The rubber plug comprises a main body and a transverse protrusion arranged on the main body; The rubber plug fixing piece is pressed tightly on the transverse protrusion.

3. The battery cover according to claim 1, characterized in that: The exhaust passages are multiple and arranged at intervals on the rubber plug.

4. The battery cover according to claim 1, characterized in that: The center lines of the plurality of exhaust passages intersect at the outer side of the rubber plug fixing member.

5. The battery cover according to claim 1, characterized in that: Along the direction pointing to the rubber plug, the end of the pressure relief hole close to the rubber plug is arranged in an outward expansion shape; and / or, The pressure relief hole is located on one side of the explosion-proof valve on the cover plate body.

6. The battery cover according to any one of claims 1 to 5, characterized in that: The cover plate body is provided with a sink groove, the sink groove is located on one side of the pressure relief hole and is connected to the pressure relief hole; The rubber plug fixing piece is installed in the sink.

7. The battery cover according to claim 6, characterized in that: The through hole is arranged opposite to the pressure relief hole, and the rubber plug has an upper protrusion extending from the through hole to the outside of the accommodating cavity; The pressure relief assembly also includes a sealing cap disposed on the rubber plug fixing member, and the sealing cap is used to compress the upper protrusion.

8. The battery cover according to claim 7, characterized in that: The longitudinal section of the rubber plug fixing piece is in the shape of a "J" and has a first connecting edge located on the sink groove.

9. The battery cover according to claim 8, characterized in that: A connecting groove is provided on the first connecting edge; The sealing cap comprises a cap body threadedly connected to the rubber plug fixing member, and a second connecting edge arranged on the cap body, wherein the second connecting edge is located in the connecting groove.

10. A lithium battery, characterized in that: The lithium battery is provided with a battery cover according to any one of claims 1 to 9.

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