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 comprises a pressure relief piece; an exhaust hole is formed in the cover plate main body; the pressure relief piece is arranged in the exhaust hole; the insulating part is arranged on one side, facing the interior of the battery cell, of the cover plate main body, a groove is formed in one side, facing the cover plate main body, of the insulating part so as to define an exhaust space with the cover plate main body, and the exhaust space is communicated with the exhaust hole; the blocking piece is arranged in the exhaust space, and a communicating hole is formed in the blocking piece; the area of the blocking piece is S1, the area of the pressure relief piece is S2, the area of the communication hole is S3, and S1 > S2 > S3. According to the utility model, when the electrolyte in the battery cell shakes, the blocking piece can effectively buffer the impact of the electrolyte on the pressure relief piece and also can ensure smooth exhaust when the pressure relief piece is started, so that the pressure relief piece is protected, the situation that the battery cell leaks liquid or the pressure relief piece is started in advance is avoided, and the safety performance and the service life of the battery cell are further ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a cell cover plate and a cell. Background Art

[0002] With the increasing maturity of lithium-ion battery technology, lithium-ion batteries are widely used as power batteries in electric vehicles and energy storage fields, and the requirements for the use performance and safety of lithium-ion batteries are increasing day by day.

[0003] The main structure of the battery includes: a cover plate integrating a pole column, an explosion-proof valve, an upper plastic, a lower plastic, and a liquid injection hole, a connecting piece, a pole group, an aluminum shell, a blue film, etc. After the cover plate and the aluminum shell are laser welded, a closed space with a certain mechanical strength capable of protecting the pole group is formed; the bare cell insulating sheet and the lower plastic of the cover plate are heat-melted and wrapped outside the pole group; the lower plastic of the cover plate presses the pole group diaphragm, so that the pole group is well fixed in the shell to avoid internal short circuit caused by the shaking of the pole group. The lower plastic presses the pole group diaphragm to form a sufficient cavity to ensure smooth exhaust when the battery fails.

[0004] At present, to improve the safety of vehicles, the battery is inverted after the battery modules are grouped, so that the opening direction of the explosion-proof valve faces the bottom of the vehicle to reduce the harm caused by battery thermal runaway. When the battery is inverted, the electrolyte in the battery will gather in the cavity for exhaust; when the battery pack is vibrated, the electrolyte will shake back and forth in the exhaust cavity and continuously impact the explosion-proof valve, causing damage to the explosion-proof valve, resulting in cell leakage and premature opening of the explosion-proof valve, thereby reducing the service life and safety of the cell. Summary of the Utility Model

[0005] In view of this, the purpose of this application is to provide a cell cover plate and a cell to solve the problem that when the battery is inverted, the electrolyte in the battery will gather in the cavity corresponding to the explosion-proof valve; when the battery is vibrated, the electrolyte will shake back and forth in the cavity and continuously impact the explosion-proof valve, causing damage to the explosion-proof valve, resulting in cell leakage and premature opening of the explosion-proof valve, thereby reducing the service life and safety of the cell.

[0006] The first aspect of the utility model provides a cell cover plate, wherein the cell cover plate includes:

[0007] A pressure relief member;

[0008] A cover plate main body provided with an exhaust hole, and the pressure relief member is arranged in the exhaust hole;

[0009] An insulating member arranged on the side of the cover plate main body facing the inside of the cell. A groove is formed on the side of the insulating member facing the cover plate main body to enclose an exhaust space with the cover plate main body, and the exhaust space is communicated with the exhaust hole;

[0010] A blocking member is disposed in the exhaust space, and a communication hole is formed in the blocking member;

[0011] The area of the blocking member is S1, the area of the pressure relief member is S2, and the area of the communication hole is S3, where S1 > S2 > S3.

[0012] Preferably, the length dimension of the pressure relief member in the first direction is E, and the width dimension in the second direction is F;

[0013] The length dimension of the blocking member in the first direction is C, and the width dimension in the second direction is D;

[0014] C > E, and / or D > F.

[0015] Preferably, S1 = C × D, in units of mm 2 。

[0016] Preferably, S2 = π × (F / 2) 2 +(E - F) × F, in units of mm 2 。

[0017] Preferably, a plurality of the communication holes are provided, and the plurality of communication holes are arranged in a rectangular array or a circular array.

[0018] Preferably, the communication hole is formed into a circular hole structure, S3 = n × π × R 2 , where n is the number of the communication holes, and R is the radius of the communication hole, in units of mm.

[0019] Preferably, the distance between the blocking member and the pressure relief member in the third direction is A, 0.1 mm ≤ A ≤ 0.5 mm.

[0020] Preferably, the blocking member is formed into a plate-like structure, and the thickness dimension of the blocking member in the third direction is B, 0.4 mm ≤ B ≤ 0.6 mm.

[0021] Preferably, the blocking member is connected to the two side walls of the groove in the second direction; and / or the blocking member is integrally formed with the insulating member.

[0022] In a second aspect of the present invention, a battery cell is provided, including the battery cell cover plate according to any one of the above technical solutions.

[0023] Compared with the prior art, the beneficial effects of the present invention are:

[0024] For the cell cover of the present utility model, a barrier member is provided in the exhaust space formed by the insulating member and the cover body. A communication hole is provided on the barrier member. In this way, when the electrolyte in the cell shakes, the barrier member can effectively buffer the impact of the electrolyte on the pressure relief member, reducing the force of the electrolyte impacting the pressure relief member, thereby playing a role in protecting the pressure relief member and avoiding the occurrence of cell liquid leakage or premature opening of the pressure relief member, and further ensuring the safety performance and service life of the cell. In addition, the area of the barrier member is S1, the area of the pressure relief member is S2, and the area of the communication hole is S3, where S1 > S2 > S3, so as to ensure that the barrier member can effectively buffer the impact of the electrolyte on the pressure relief member and also ensure smooth exhaust when the pressure relief member opens, improving the safety performance of the cell.

[0025] To make the above objects, features, and advantages of the present application more obvious and understandable, the following specifically gives preferred embodiments and, in conjunction with the accompanying drawings, makes a detailed description as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the specific embodiments of the present utility model or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the following drawings are some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0027] Figure 1 Structural schematic diagram of the cell cover provided by the embodiment of the present utility model;

[0028] Figure 2 Along Figure 1 Cross-sectional view taken along A-A in

[0029] Figure 3 For Figure 2 Enlarged structural schematic diagram at P in

[0030] Figure 4 Structural schematic diagram of the cell cover provided by the embodiment of the present utility model with the cover body removed;

[0031] Figure 5 Structural schematic diagram of the insulating member in the cell cover provided by the embodiment of the present utility model;

[0032] Figure 6 Structural schematic diagram of the cell cover provided by the embodiment of the present utility model assembled into a cell.

[0033] Icons: 10 - pressure relief component; 20 - cover body; 21 - exhaust hole; 30 - insulating component; 31 - groove; 32 - exhaust space; 40 - blocking component; 41 - communication hole; 50 - electrode group; 60 - electrolyte; 70 - housing; D1 - first direction; D2 - second direction; D3 - third direction. Detailed implementation manners

[0034] The following detailed implementation manners are provided to help readers obtain a comprehensive understanding of the methods, devices, and / or systems described herein. However, after understanding the disclosure of this application, various changes, modifications, and equivalents of the methods, devices, and / or systems described herein will be obvious. For example, the order of the operations described herein is merely an example and is not limited to the order set forth herein. Rather, changes that will be obvious after understanding the disclosure of this application can be made, except for operations that must occur in a specific order. In addition, descriptions of features known in the art may be omitted for the sake of clarity and conciseness.

[0035] The features described herein may be implemented in different forms and should not be construed as limited to the examples described herein. Rather, the examples described herein are provided only to illustrate some of the many possible ways of implementing the methods, devices, and / or systems described herein that will be obvious after understanding the disclosure of this application.

[0036] Throughout the specification, when an element (such as a layer, region, or substrate) is described as "on" another element, "connected to" another element, "bonded to" another element, "above" another element, or "covering" another element, it may be directly "on" another element, "connected to" another element, "bonded to" another element, "above" another element, or "covering" another element, or there may be one or more other elements between them. In contrast, when an element is described as "directly on" another element, "directly connected to" another element, "directly bonded to" another element, "directly above" another element, or "directly covering" another element, there may be no other elements between them.

[0037] As used herein, the term "and / or" includes any one of the listed related items and any combination of any two or more of them.

[0038] Although terms such as "first", "second", and "third" may be used herein to describe various components, elements, regions, layers, or sections, these components, elements, regions, layers, or sections are not limited by these terms. Rather, these terms are only used to distinguish one component, element, region, layer, or section from another. Thus, a first component, element, region, layer, or section described in an example herein may also be referred to as a second component, element, region, layer, or section without departing from the teachings of the example.

[0039] For ease of description, spatial relationship terms such as "above", "upper", "below", and "lower" may be used herein to describe the relationship of one element to another as shown in the figures. Such spatial relationship terms are intended to include 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 flipped, an element described as "above" or "upper" relative to another element will then be "below" or "lower" relative to the other element. Thus, the term "above" includes both the orientation of "above" and "below" depending on the spatial orientation of the device. The device may also be positioned in other ways (e.g., rotated 90 degrees or in other orientations), and the spatial relationship terms used herein will be interpreted accordingly.

[0040] The terms used herein are for the purpose of describing various examples only and are not intended to limit the disclosure. Unless the context clearly dictates otherwise, the singular forms are also intended to include the plural forms. The terms "comprises", "comprising", and "having" list the stated features, quantities, operations, components, elements, and / or combinations thereof that exist, but do not preclude the presence or addition of one or more other features, quantities, operations, components, elements, and / or combinations thereof.

[0041] Due to manufacturing techniques and / or tolerances, variations in the shapes shown in the figures may occur. Thus, the examples described herein are not limited to the specific shapes shown in the figures but include changes in shape that occur during manufacturing.

[0042] The features of the examples described herein may be combined in various ways that will be apparent after understanding the disclosure of this application. In addition, although the examples described herein have a variety of configurations, other configurations are possible as will be apparent after understanding the disclosure of this application.

[0043] According to a first aspect of the present utility model, a battery cell cover plate is provided, which specifically includes a pressure relief member 10, a cover plate body 20, an insulating member 30, and a blocking member 40.

[0044] In the following, the specific structure of the battery cell cover plate according to the present embodiment will be described as above.

[0045] In this embodiment, as Figures 1 to 3 shown, the pressure relief member 10 can be an explosion-proof valve. Specifically, the pressure relief member 10 is formed into a sheet-like structure, and a recessed notch is formed on the surface of the pressure relief member 10 to thin the thickness of a local area of the pressure relief member 10, so that when the gas in the battery cell expands due to gas generation, the pressure relief member 10 can be pushed open, causing the pressure relief member 10 to crack along the shape of the notch, so that the inside and outside of the battery cell are communicated, thereby realizing pressure relief.

[0046] The cover plate main body 20 is formed into a plate-like structure. When the battery cell is a square battery cell or a blade battery cell, the cover plate main body 20 is formed into a rectangular plate-like structure. When the battery cell is a cylindrical battery cell, the cover plate main body 20 is formed into a circular plate-like structure. An exhaust hole 21 is formed on the cover plate main body 20. The exhaust hole 21 is a through-hole structure penetrating the cover plate main body 20. The pressure relief member 10 is arranged in the exhaust hole 21. Thus, when the battery cell fails and the pressure relief member 10 is opened, the gas inside the battery cell can be discharged from the exhaust hole 21.

[0047] As Figure 3 shown, the exhaust hole 21 is formed into a stepped hole. The size of the side of the exhaust hole 21 facing the inside of the battery cell is larger than the size of the side facing the outside of the battery cell, so that a protruding stepped structure is formed on the inner wall of the exhaust hole 21, and the pressure relief member 10 is arranged on the stepped structure. Thus, it plays a limiting role in the assembly of the pressure relief member 10 on the exhaust hole 21.

[0048] The insulating member 30 can be made of plastic material. The insulating member 30 is arranged on the side of the cover plate main body 20 facing the inside of the battery cell to provide insulating protection for the cover plate main body 20 and prevent short circuits. When the battery cell cover plate is assembled with the housing 70, the cover plate main body 20 and the housing 70 are welded together, and the insulating member 30 is embedded inside the housing 70.

[0049] A groove 31 is formed on the side of the insulating member 30 facing the cover plate main body 20 to enclose an exhaust space 32 with the cover plate main body 20. The exhaust space 32 is communicated with the exhaust hole 21 to ensure that the gas inside the battery cell flows to the exhaust hole 21 through the exhaust space 32.

[0050] As Figure 6 shown, the bottom wall of the groove 31 abuts against the electrode group 50 inside the battery cell housing 70, so that the insulating member 30 presses the separator in the electrode group 50, thereby ensuring that the exhaust space 32 meets the exhaust requirements when the battery cell fails. The groove 31 can be formed into a rectangular body or a frustum-shaped groove structure.

[0051] In this embodiment, as Figure 5As shown, through holes are provided on both the bottom wall and the side wall of the groove 31. The through holes can be formed as rectangular strip-shaped holes. When the battery cell is inverted, the electrolyte 60 inside the battery cell will flow into the exhaust space 32 through the strip-shaped holes. In this embodiment, as Figure 5 shown, reinforcing ribs are provided on the inner wall of the groove 31. The reinforcing ribs are formed as strip-shaped structures in the shape of a triangle or a rectangle and are respectively connected to the side wall and the bottom wall of the groove 31 to enhance the mechanical structure strength of the groove 31. Preferably, a plurality of reinforcing ribs are provided, and the plurality of reinforcing ribs are arranged at intervals.

[0052] In this embodiment, as Figures 2 to 4 and Figure 6 shown, the blocking member 40 is disposed in the exhaust space 32, so that the impact of the electrolyte 60 on the pressure relief member 10 can be effectively buffered, the force of the electrolyte 60 impacting the pressure relief member 10 is weakened, thereby playing a role in protecting the pressure relief member 10 and avoiding the occurrence of battery cell liquid leakage or premature opening of the pressure relief member 10. In addition, a communication hole 41 is provided on the blocking member 40. The area of the blocking member 40 is S1, the area of the blocking member 40 includes the area of the communication hole 41, the area of the pressure relief member 10 is S2, and the area of the communication hole 41 is S3, where S1 > S2 > S3, so as to ensure that the blocking member 40 can effectively buffer the impact of the electrolyte 60 on the pressure relief member 10 and can also ensure smooth exhaust when the pressure relief member 10 is opened.

[0053] Further, in this embodiment, as Figure 4 and Figure 6 shown, the pressure relief member 10 is formed as a runway-shaped structure with a rectangle in the middle and semi-circles at both ends. The length dimension of the pressure relief member 10 in the first direction D1 is E, and the width dimension of the pressure relief member 10 in the second direction D2 is F; the length dimension of the blocking member 40 in the first direction D1 is C, and the width dimension of the blocking member 40 in the second direction D2 is D, where the units of E, F, C, and D are all mm; preferably, C > E and / or D > F, so that the blocking member 40 covers the pressure relief member 10 in at least one of the first direction D1 and the second direction D2, thereby enhancing the buffering effect of the blocking member 40 on the electrolyte 60.

[0054] Even further, in this embodiment, as Figure 4 shown, the blocking member 40 is formed as a rectangular plate-like structure, S1 = C × D, unit mm 2 .

[0055] The pressure relief member 10 is formed as a runway-shaped structure with a rectangle in the middle and semi-circles at both ends, S2 = π × (F / 2) 2 + (E - F) × F, unit mm 2 .

[0056] Preferably, as Figure 4As shown, a plurality of communication holes 41 are provided on the blocking member 40, and the plurality of communication holes 41 are arranged in a rectangular array or a circular array, so that a plurality of channels communicating with the exhaust holes 21 are formed on the blocking member 40. Thus, while ensuring smooth exhaust when the pressure relief member 10 is opened, the area of the communication holes 41 is further divided to reduce the size of the communication holes 41, preventing the electrolyte 60 from quickly passing through the communication holes 41 under the action of impact force and damaging the pressure relief member 10.

[0057] In this embodiment, as Figure 4 shown, the communication hole 41 is formed into a circular hole structure, and S3 = n×π×R 2 , where n is the number of the communication holes 41, and R is the radius of the communication hole 41, with the unit of mm.

[0058] In this embodiment, C×D > π×(F / 2) 2 +(E - F)×F > n×π×R 2 .

[0059] In addition, in this embodiment, as Figure 2 and Figure 3 shown, the blocking member 40 is arranged at the opening of the groove 31, that is, the blocking member 40 is arranged on the side away from the bottom wall of the groove 31. The distance between the blocking member 40 and the pressure relief member 10 in the third direction D3 is A, and 0.1mm ≤ A ≤ 0.5mm. In this way, it is avoided that the size of A is too large, resulting in the blocking member 40 being unable to effectively block the impact of the electrolyte 60 on the pressure relief member 10, or the size of A is too small, causing the impact of the electrolyte 60 on the blocking member 40 to cause a certain deformation of the blocking member 40. The deformed blocking member 40 contacts the pressure relief member 10, making the pressure relief member 10 unable to open according to the preset pressure, resulting in an early opening situation.

[0060] Furthermore, in this embodiment, as Figure 3 shown, the blocking member 40 is formed into a plate-like structure, and the thickness dimension of the blocking member 40 in the third direction D3 is B, and 0.4mm ≤ B ≤ 0.6mm. In this way, it is ensured that the volume of the exhaust space 32 meets the exhaust requirements, avoiding that the thickness dimension of the blocking member 40 is too large, resulting in the reduction of the volume of the exhaust space 32 and the gas being unable to be discharged in time, and also avoiding that the thickness dimension of the blocking member 40 is too small, making the mechanical structure strength of the blocking member 40 insufficient to effectively protect the pressure relief member 10.

[0061] In a preferred embodiment, the plate-like blocking member 40 is parallel to the surface of the pressure relief member 10.

[0062] In this embodiment, as Figures 2 to 4As shown, the blocking member 40 is connected to the two side walls of the groove 31 in the second direction D2; preferably, the blocking member 40 and the insulating member 30 are integrally formed. For example, the blocking member 40 and the insulating member 30 are both injection molded, which saves costs, is convenient for processing and manufacturing, and saves the assembly time of the battery cell. However, in other alternative embodiments, the blocking member 40 and the insulating member 30 can also be connected by bonding, welding or snap connection, etc., as long as the connection strength between the blocking member 40 and the insulating member 30 can be ensured.

[0063] In this embodiment, the first direction D1, the second direction D2 and the third direction D3 are perpendicular to each other. When the cover body 20 is formed into a rectangular plate-like structure, the first direction D1 is the width direction of the cover body 20, the second direction D2 is the length direction of the cover body 20, and the third direction D3 is the thickness direction of the cover body 20.

[0064] According to a battery cell cover provided by the present invention, a blocking member is arranged in the exhaust space surrounded by the insulating member and the cover body, and a communication hole is provided on the blocking member. In this way, when the electrolyte in the battery cell shakes, the blocking member can effectively buffer the impact of the electrolyte on the pressure relief member, weaken the force of the electrolyte impacting the pressure relief member, thereby playing a role in protecting the pressure relief member and avoiding the occurrence of battery cell leakage or premature opening of the pressure relief member. In addition, the area of the blocking member is S1, the area of the pressure relief member is S2, and the area of the communication hole is S3, and S1 > S2 > S3, so as to ensure that the blocking member can effectively buffer the impact of the electrolyte on the pressure relief member and can also ensure smooth exhaust when the pressure relief member opens.

[0065] According to a battery cell provided by the present invention, it includes the battery cell cover as described above. The blocking member in the battery cell cover can effectively relieve the impact of the electrolyte on the pressure relief member, thereby playing a role in protecting the pressure relief member, avoiding the occurrence of battery cell leakage or premature opening of the pressure relief member, and further ensuring the safety performance and service life of the battery cell.

[0066] Finally, it should be noted that: the above embodiments are only specific embodiments of the present application, used to illustrate the technical solutions of the present application, rather than limiting them. 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 of ordinary skill in the art should understand that: any person skilled in the art within the technical scope disclosed by the present application can still modify the technical solutions recorded in the foregoing embodiments, or can easily think of changes, or perform equivalent replacements on some of the technical features; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be covered within 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, characterized in that: The battery cover plate comprises: Pressure relief parts; The cover plate body is provided with an exhaust hole, and the pressure relief member is arranged at the exhaust hole; An insulating member is disposed on a side of the cover plate body facing the inside of the battery cell, and a groove is formed on the side of the insulating member facing the cover plate body to enclose an exhaust space with the cover plate body, and the exhaust space is communicated with the exhaust hole; A blocking member is arranged in the exhaust space, and a communication hole is opened on the blocking member; The area of ​​the blocking member is S1, the area of ​​the pressure relief member is S2, the area of ​​the connecting hole is S3, and S1>S2>S3.

2. The cell cover plate according to claim 1, characterized in that: The length dimension of the pressure relief member in the first direction is E, and the width dimension in the second direction is F; The blocking member has a length dimension C in the first direction and a width dimension D in the second direction; C>E, and / or D>F.

3. The cell cover plate according to claim 2, characterized in that: S1=C×D,unit: mm 2 .

4. The battery cover according to claim 2, characterized in that: S2=π×(F / 2) 2 +(EF)×F, unit: mm 2 .

5. The cell cover plate according to claim 1, characterized in that: A plurality of the communicating holes are provided, and the plurality of communicating holes are arranged in a rectangular array or a ring array.

6. The cell cover plate according to claim 1, characterized in that: The connecting hole is formed into a circular hole structure, S3 = n × π × R 2 , where n is the number of the connecting holes, and R is the radius of the connecting holes, in mm.

7. The cell cover plate according to claim 1, characterized in that: In the third direction, the distance between the blocking member and the pressure relief member is A, 0.1 mm≤A≤0.5 mm.

8. The cell cover plate according to claim 1, characterized in that: The blocking member is formed into a plate-shaped structure, and a thickness dimension of the blocking member in the third direction is B, 0.4 mm≤B≤0.6 mm.

9. The cell cover plate according to claim 1, characterized in that: The blocking member is connected to two side walls of the groove in the second direction; and / or the blocking member is integrally formed with the insulating member.

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

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