Battery cell cover plate and battery cell

Abstract

The utility model relates to the technical field of batteries, in particular to a battery cell cover plate and a battery cell. The battery cell cover plate is characterized in that a cover plate main body is provided with an exhaust hole, a convex boss surrounding the exhaust hole is formed on the cover plate main body, and a groove communicated with the exhaust hole and the outside of the battery cell is formed in the boss; the pressure relief assembly comprises a pressure relief piece and a protection piece. The pressure relief piece is arranged at the exhaust hole; the protection piece is arranged on one side of the cover plate body and covers the exhaust hole, and at least part of the groove is not shielded by the protection piece. The bosses in the battery cell cover plate can effectively prevent electrolyte from entering the pressure relief piece, prevent the electrolyte from being in contact with the protection piece, and prevent the situation that the viscosity of the protection piece is reduced and the protection piece falls off due to electrolyte pollution, so that the process yield and the production efficiency of the battery cell are improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to battery technology field especially is related to a kind of battery cell cover plate and battery cell. BACKGROUND

[0002] Lithium ion battery is widely used in traffic power supply, electric power storage power supply, new energy storage power supply, aerospace military industry and other fields due to its advantages of large capacity, high working voltage, strong charge retention ability and long cycle life. The structure of lithium ion battery includes cover plate, shell, pole group, electrolyte, bare battery cell insulating sheet, blue insulating tape and cover plate top cover patch. The cover plate is connected with the shell by laser welding, providing a sealed space with certain strength to protect the pole group. The cover plate integrates electrode terminal, liquid injection hole, explosion-proof valve and other components. As a key pressure relief port, the explosion-proof valve plays a crucial role in the safety of single cell and even the whole battery pack against thermal runaway and heat spread.

[0003] In the prior art, the explosion-proof valve is usually protected by an explosion-proof valve film. The explosion-proof valve film is designed with a helium detection notch to facilitate timely detection by helium detection means in the event of abnormal conditions such as breakage or cracking of the explosion-proof valve during cover plate processing or battery cell processing. However, during the liquid injection and pre-charging processes in battery cell processing, a small amount of electrolyte may flow out of the liquid injection port and contaminate the explosion-proof valve film, reducing the adhesive strength of the film and causing the film to fall off, which affects the production efficiency of the battery cell. SUMMARY

[0004] Therefore, the purpose of the present application is to provide a battery cell cover plate and battery cell to solve the problem of electrolyte contamination of the explosion-proof valve film on the existing battery cell cover plate, which reduces the adhesive strength of the film and causes the film to fall off, affecting the production efficiency of the battery cell.

[0005] The utility model provides a kind of battery cell cover plate in the first aspect of the utility model, wherein the battery cell cover plate includes:

[0006] Cover plate main body is provided with exhaust hole, the boss that is projected and is surrounded in the exhaust hole is formed on the cover plate main body, recess is provided on the boss and is communicated with the exhaust hole and the outside of battery cell;

[0007] Pressure relief assembly includes pressure relief piece and protection piece;The pressure relief piece is arranged in the exhaust hole;The protection piece is arranged on one side of the cover plate main body and covers the exhaust hole, at least part of the recess is not blocked by the protection piece, so that the exhaust hole is communicated with the outside of battery cell.

[0008] Preferably, the protection piece is attached to the side of the boss facing the outside of the battery cell.

[0009] Preferably, the boss is formed as a closed annular structure.

[0010] Preferably, the inner wall of the boss is coplanar with the hole wall of the exhaust hole.

[0011] Preferably, the groove is arranged on the inner wall of the boss and does not penetrate the outer wall of the boss.

[0012] Preferably, the circumferential side wall of the pressure relief member is connected with the hole wall of the exhaust hole to block the exhaust hole.

[0013] Preferably, a liquid injection hole is arranged on the cover plate body and is spaced apart from the boss.

[0014] Preferably, the pressure relief member is formed with a recessed explosion-preventing notch, and the explosion-preventing notch is formed as an annular structure with an opening.

[0015] Preferably, the pressure relief member is formed with a recessed explosion groove, and the explosion-preventing notch is arranged on the groove wall of the explosion groove.

[0016] The second aspect of the utility model provides a battery cell, comprising the battery cell cover plate of any one of the preceding technical solutions.

[0017] Compared with the prior art, the utility model has the advantages of:

[0018] The battery cell cover plate of the utility model, the boss which is arranged around the exhaust hole is formed on the cover plate body, and the groove which is communicated with the exhaust hole and the outside of the battery cell is arranged on the boss, the protection member is arranged on one side of the cover plate body and covers the exhaust hole, at least part of the groove is not shielded by the protection member, thereby forming the helium detection opening which is communicated with the exhaust hole and the outside of the battery cell and is used for helium detection, and the helium detection opening is formed on the boss, even if the electrolyte is left on the surface of the cover plate body, the boss can effectively prevent the electrolyte from entering the pressure relief member, and the electrolyte is prevented from contacting the protection member, thereby preventing the protection member from falling off due to the viscosity reduction caused by the electrolyte pollution, and the process yield and production efficiency of the battery cell are improved.

[0019] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the following preferred embodiments are described in detail below, and the accompanying drawings are described as follows. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the specific embodiments of the utility model or the technical solutions in the prior art, the following will briefly introduce the drawings needed to be used in the specific embodiments or the prior art description, and obviously, the drawings in the following description are some embodiments of the utility model, and those skilled in the art can also obtain other drawings according to these drawings without creating any creative labor.

[0021] Figure 1 A structure schematic view of the electric core cover plate provided by the embodiment of the utility model;

[0022] Figure 2 A structure schematic view of the electric core provided by the embodiment of the utility model;

[0023] Figure 3 A structure schematic view of the protection member in the electric core cover plate provided by the embodiment of the utility model;

[0024] Figure 4 A structure schematic view of the pressure relief member in the electric core cover plate provided by the embodiment of the utility model;

[0025] Figure 5 A structure schematic view of the electric core cover plate provided by the embodiment of the utility model after removing the protection member;

[0026] Figure 6 A structure schematic view of the electric core cover plate provided by the embodiment of the utility model after removing the protection member; Figure 5 An enlarged structure schematic view of A in the figure.

[0027] Icon: 10 - cover plate main body; 11 - exhaust hole; 12 - liquid injection hole; 100 - boss; 101 - groove; 20 - pressure relief member; 201 - blasting groove; 210 - anti-explosion notch; 21 - protection member; 30 - pole column. DETAILED DESCRIPTION

[0028] The following detailed description is provided to help the reader obtain a complete understanding of the methods, devices, and / or systems described herein. However, various changes, modifications, and equivalents of the methods, devices, and / or systems described herein will be apparent after an understanding of the disclosure provided herein. For example, the order of the operations described herein is merely an example and is not limited to the order described herein, but changes can be made, in addition to operations that must occur in a particular order, that will be apparent after an understanding of the disclosure provided herein. Also, the description of features known in the art can be omitted in order to improve clarity and conciseness.

[0029] The features described herein can be implemented in different forms and should not be construed as being limited to the examples described herein. Rather, the examples described herein have been provided for the purpose of illustrating some of the many possible ways of implementing the methods, devices, and / or systems described herein, which will be apparent after an understanding of the disclosure provided herein.

[0030] Throughout the specification, when an element (such as a layer, region or substrate) is referred to as being "on" another element, "connected to" another element, "coupled to" another element, "adjacent to" another element, "on top of" another element, or terms similar thereto, it is understood that an intervening element may be present or absent. For example, if a layer is described as being "on" a substrate, it is understood that an intervening layer may be present or absent. In contrast, when an element is referred to as being "directly on," "directly connected to," "directly coupled to," "directly adjacent to," "directly on top of," or terms similar thereto, it is understood that no intervening element is present.

[0031] As used herein, the term "and / or" includes any one of the listed items and any combination of two or more of the listed items.

[0032] Although terms such as "first" and "second" and "third" can be used herein to describe various components, assemblies, regions, layers or sections, these components, assemblies, regions, layers or sections are not limited by these terms. Rather, these terms are only used to distinguish one component, assembly, region, layer or section from another component, assembly, region, layer or section. Thus, a component, assembly, region, layer or section referred to as a first component, assembly, region, layer or section in one example described herein can also be referred to as a second component, assembly, region, layer or section in another example without departing from the teachings of the examples.

[0033] For ease of description, spatial terms such as "on," "upper," "beneath," and "lower" can be used with respect to the orientation of one element relative to another element as illustrated in the figures. Such spatial terms are intended to encompass different orientations of the device in use or operation, in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, a component described as relative to another component on the "upper" side of another component would then be oriented on the "lower" side of that component. Accordingly, the term "on" encompasses both a orientation of above and below. The device can be otherwise oriented (e.g., rotated 90 degrees or at other orientations) and the spatial terms used herein interpreted accordingly.

[0034] The terminology used herein is for the purpose of describing various examples only and is not intended to be limiting. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms "comprises," "comprising," "includes," "including" and "has" are listed means the stated features, numbers, operations, components, elements, and / or combinations thereof are present, but do not preclude the presence or addition of one or more other features, numbers, operations, components, elements, and / or combinations thereof.

[0035] Variations in the shapes illustrated in the drawings can occur as a result of manufacturing processes and / or tolerances. Thus, the examples described herein are not limited to the specific shapes illustrated in the drawings, but include variations in shapes that occur during manufacturing.

[0036] Features of the examples described herein can be combined with one another as would be apparent to one of ordinary skill in the art after understanding the disclosure provided herein. Furthermore, although examples described herein have a variety of configurations, other configurations are possible in which are apparent after understanding the disclosure provided herein.

[0037] According to a first aspect of the present application, an electric core cover plate is provided, which specifically comprises a cover plate body 10 and a pressure relief assembly.

[0038] Hereinafter, the specific structure of the electric core cover plate according to the present embodiment will be described as described above.

[0039] In the present embodiment, as shown in Figure 1 , Figure 5 and Figure 6 , the cover plate body 10 is formed as a plate structure, which is a rectangular plate structure when the electric core is a square shell electric core or a blade electric core, and is formed as a circular plate structure when the electric core is a cylindrical electric core. An exhaust hole 11 is formed on the cover plate body 10, which is formed as a through hole structure penetrating through the cover plate body 10. A boss 100 is formed on the cover plate body 10 and surrounds the exhaust hole 11. A groove 101 is formed on the boss 100 and is in communication with the exhaust hole 11 and the outside of the electric core.

[0040] As shown in Figures 1 to 6As shown, the pressure relief assembly includes a pressure relief piece 20 and a protective piece 21; the pressure relief piece 20 can be an explosion-proof valve, and the pressure relief piece 20 is arranged at the exhaust hole 11, when the battery cell fails and the internal gas reaches a preset pressure, the pressure relief piece 20 can be opened, so that the inside and outside of the battery cell are communicated through the exhaust hole 11, and the pressure is relieved in time to alleviate the battery cell failure; the protective piece 21 is arranged on one side of the cover plate body 10 and covers the exhaust hole 11 to protect the pressure relief piece 20, and the protective piece 21 can be a PET film. After the protective piece 21 is installed, at least part of the groove 101 is not blocked by the protective piece 21, so that the unblocked part forms a helium detection port for communicating the exhaust hole 11 and the outside of the battery cell and for helium detection, that is, the part of the groove 101 not covered by the protective piece 21 forms the helium detection port, so that the helium detection port is arranged on the boss 100, even if the electrolyte remains on the surface of the cover plate body 10, the boss 100 can effectively block the electrolyte from entering the pressure relief piece 20, and the electrolyte is prevented from contacting the protective piece 21, preventing the protective piece 21 from falling off the cover plate body 10 due to the viscosity reduction caused by the electrolyte pollution, thereby improving the process yield and production efficiency of the battery cell.

[0041] It should be noted that during the preparation of the battery cell, when abnormal conditions such as damage or leakage of the pressure relief piece 20 occur, helium detection using the helium detection port can timely detect the abnormality.

[0042] In this embodiment, as shown in Figure 1 and Figure 5 , the cover plate body 10 is also provided with a liquid injection hole 12, which is formed as a through hole structure penetrating through the cover plate body 10, and after the battery cell cover plate and the shell are assembled into a battery cell, the electrolyte is injected into the inside of the battery cell through the liquid injection hole 12, the boss 100 extends outward from the side of the cover plate body 10 facing the outside of the battery cell, so that the boss 100 is higher than the liquid injection hole 12, and the setting position of the protective piece 21 is higher than the end of the liquid injection hole 12 facing the outside of the battery cell, so that even if the electrolyte remains on the surface of the cover plate body 10 during the injection process, the electrolyte will not pollute the protective piece 21 under the blocking action of the boss 100, thereby ensuring that the protective piece 21 is firmly and reliably assembled. In addition, the protective piece 21 does not need to leave a notch structure for helium detection, thereby ensuring the integrity of the protective piece 21, so that the protective piece 21 can completely cover the pressure relief piece 20, and the reliability of the protective piece 21 protecting the pressure relief piece 20 is improved.

[0043] In a preferred embodiment, as shown in Figure 1 and Figure 2 , the liquid injection hole 12 and the boss 100 are arranged with a predetermined distance therebetween, so as to reduce the probability of the electrolyte contacting the boss 100 during the injection process, thereby further improving the effectiveness of preventing the electrolyte from polluting the protective piece 21.

[0044] In the embodiment, as shown in Figure 2 The side of the protection piece 21 facing the cover plate body 10 is provided with a glue layer, and the protection piece 21 is attached to the side of the boss 100 facing the outside of the battery cell, that is, the protection piece 21 is arranged on the side of the cover plate body 10 facing the outside of the battery cell, so that the protection piece 21 can block the impact of the outside of the battery cell on the pressure relief piece 20, and avoid the pressure relief piece 20 from being opened prematurely.

[0045] Further, in the embodiment, as shown in Figure 5 The boss 100 is formed in a closed ring structure to ensure that the boss 100 can completely surround the exhaust hole 11 and improve the effectiveness of preventing the electrolyte from contaminating the protection piece 21.

[0046] Further, in the embodiment, as shown in Figure 5 and Figure 6 The protection piece 21 is installed on the side of the boss 100 facing the outside of the battery cell, and the inner wall of the boss 100 is coplanar with the hole wall of the exhaust hole 11, so as to avoid the gap between the inner wall of the boss 100 and the exhaust hole 11, facilitate the boss 100 to be integrally formed with the cover plate body 10, and also reduce the area of the protection piece 21 and save costs.

[0047] Further, in the preferred embodiment, as shown in Figure 5 and Figure 6 The groove 101 is arranged on the inner wall of the boss 100 in a ring structure, and the groove 101 does not penetrate the outer wall of the boss 100 in a ring structure, so as to ensure that the boss 100 is a closed ring structure, so as to meet the helium detection requirement while avoiding the electrolyte from entering the groove 101.

[0048] In the embodiment, as shown in Figure 5 and Figure 6 The circumferential side wall of the pressure relief piece 20 is connected with the hole wall of the exhaust hole 11 to block the exhaust hole 11, so as to ensure the sealing property when the battery cell is normally used. The pressure relief piece 20 can be welded with the hole wall of the exhaust hole 11.

[0049] In the embodiment, as shown in Figure 5 and Figure 6As shown, the pressure relief member 20 is formed with a recessed explosion-proof score line 210, which is formed as a ring structure with an opening, for example, the explosion-proof score line 210 can be a C-shaped structure, so that when the internal pressure of the battery cell breaks through the pressure relief member 20, it tears along the shape of the explosion-proof score line 210 which is thinner in thickness than other positions, so as to lift the area surrounded by the explosion-proof score line 210, and keep the lifted part connected with other parts of the pressure relief member 20 at the opening position of the ring structure, avoiding the lifted part from falling off and causing short circuit due to metal lapping, and improving safety. Preferably, the explosion-proof score line 210 with an opening is a ring structure, and the length of the line connecting the two ends of the opening is 5mm-10mm, so as to effectively ensure that after the pressure relief member 20 is opened, the lifted part will not fall off.

[0050] Further, in the present embodiment, as shown in Figure 5 and Figure 6 , the pressure relief member 20 is formed with a recessed explosion groove 201, which can be formed by stamping, so that while thinning the groove wall, it can also ensure that the circumferential side wall of the pressure relief member 20 has sufficient contact area with the hole wall of the exhaust hole 11, ensuring the connection strength of the pressure relief member 20 and the exhaust hole 11, and ensuring that the pressure relief member 20 can be opened smoothly, and the explosion-proof score line 210 is arranged on the groove wall of the explosion groove 201, preferably, the explosion-proof score line 210 is arranged on the groove bottom of the explosion groove 201, and the pressure relief member 20 is arranged along the edge of the groove bottom of the explosion groove 201, so as to ensure that the pressure relief member 20 has sufficient communication area after being opened, accelerate the exhaust speed, and improve the reliability of relieving failure.

[0051] In addition, in the present embodiment, as shown in Figure 1 , Figure 2 and Figure 5 , the battery cell cover plate further comprises a pole 30, which is installed on the cover plate body 10, and the two ends of the pole 30 in the axial direction respectively protrude out of the cover plate body 10 to realize the transmission of electrical energy between the inside and outside of the battery cell. In the preferred embodiment, the height of the end of the pole 30 protruding out of the cover plate body 10 and facing the outside of the battery cell is greater than the height of the end of the boss 100 protruding out of the cover plate body 10 and facing the outside of the battery cell, so as to avoid the boss 100 occupying the volume of the battery cell and affecting the capacity of the battery cell.

[0052] According to the electric core cover plate provided by the utility model, the boss is formed on the cover plate main body and is arranged around the exhaust hole, the groove is arranged on the boss and is communicated with the exhaust hole and the outside of the electric core, the protection member is arranged on one side of the cover plate main body and covers the exhaust hole, at least part of the groove is not shielded by the protection member, thereby forming the helium detection opening which is communicated with the exhaust hole and the outside of the electric core and is used for helium detection, and the helium detection opening is formed on the boss, even if the electrolyte is left on the surface of the cover plate main body, the boss can effectively prevent the electrolyte from entering the pressure relief member, and the electrolyte is prevented from contacting the protection member, thereby preventing the situation that the protection member is dropped due to the viscosity reduction of the protection member caused by the electrolyte pollution.

[0053] According to the electric core provided by the utility model, the boss on the electric core cover plate can effectively prevent the electrolyte from contacting the pressure relief assembly, thereby improving the process yield and production efficiency of the electric core.

[0054] Finally, it should be noted that: the above-described embodiments are merely specific embodiments of the present application, which are used to illustrate the technical solutions of the present application, rather than limit them, and the protection scope of the present application is not limited thereto, although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: any person skilled in the art in the technical field of the present application within the scope of the technology disclosed by the present application, they can still modify or easily think of changes to the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part of the technical features; and these modifications, changes or replacements do not make the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and all should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A battery cell cover plate, characterized in that, The cell cover plate includes: The cover plate body has an exhaust hole, and a protrusion is formed on the cover plate body that protrudes and surrounds the exhaust hole. A groove is formed on the protrusion that communicates with the exhaust hole and the outside of the battery cell. A pressure relief assembly includes a pressure relief component and a protective component; the pressure relief component is disposed at the vent hole; the protective component is disposed on one side of the cover plate body and covers the vent hole, at least part of the groove is not blocked by the protective component, so that the vent hole is in communication with the outside of the battery cell.

2. The cell cover plate according to claim 1, characterized in that, The protective component is attached to the side of the boss facing the outside of the battery cell.

3. The cell cover plate according to claim 1, characterized in that, The boss is formed as a closed ring structure.

4. The cell cover plate according to claim 3, characterized in that, The inner wall of the boss is coplanar with the wall of the vent hole.

5. The cell cover plate according to claim 3, characterized in that, The groove is provided on the inner wall of the boss and does not penetrate the outer wall of the boss.

6. The cell cover plate according to claim 1, characterized in that, The circumferential sidewall of the pressure relief component is connected to the wall of the vent hole to seal the vent hole.

7. The cell cover plate according to claim 1, characterized in that, The cover plate body has an injection hole, which is spaced apart from the boss.

8. The cell cover plate according to claim 1, characterized in that, The pressure relief component has recessed explosion-proof grooves, which are formed into annular structures with openings.

9. The cell cover plate according to claim 8, characterized in that, The pressure relief component has a recessed burst groove, and the explosion-proof groove is provided on the groove wall.

10. A battery cell, characterized in that, Includes the cell cover plate as described in any one of claims 1 to 9.

Images