Lithium battery cover and battery thereof

Abstract

The utility model belongs to the technical field of lithium ion batteries, and particularly relates to a lithium battery cover which comprises an aluminum plate, a positive pole module, a negative pole module, an anti-explosion valve and lower plastic cement, the positive pole module and the negative pole module are fixed on the aluminum plate in an injection molding and riveting mode, the aluminum plate is connected in an insulating mode, a liquid injection hole is formed in the aluminum plate, and the anti-explosion valve is arranged in the liquid injection hole. The anti-explosion valve is installed on the aluminum plate, and a reinforcing mechanism is arranged at the bottom of the aluminum plate. On the premise of not increasing the weight of the cover plate and the occupied space, the strength of the battery cover plate is improved, the deformation of the battery cover is reduced, unstable valve opening pressure caused by deformation of the cover plate of the anti-explosion valve is prevented, and the stability of the cover plate is improved.

Description

Technical Field

[0001] This utility model belongs to the field of lithium-ion battery technology, specifically relating to a lithium battery cover and its battery. Background Technology

[0002] With the increasing development of electric vehicles, people have higher and higher requirements for battery capacity, charging and discharging speed, and safety. Among them, the increase in capacity will inevitably lead to an increase in the size of the battery cell, that is, the size of the battery cell. The problem that comes with the increase in battery cell size is the strength of the battery cell cover plate. Especially in the middle of the cover plate, where the installation hole of the explosion-proof valve is superimposed, the strength is weakest and the most susceptible to deformation. During the operation of the battery cell, if uncontrolled gas is generated, resulting in excessive internal pressure, the cover plate will bulge upward and deform. This may cause the explosion-proof valve and the terminal of the cover plate to fail due to deformation, resulting in the risk of the battery cell explosion-proof valve not opening and gas leakage at the terminal.

[0003] Currently, the battery cover base generally uses plain aluminum plate or adds reinforcing ribs to the front of the battery cover. When the width of the cover increases, the basic choice is to increase the strength by thickening the plain aluminum plate or adding reinforcing ribs to the front. This approach will inevitably lead to an increase in weight or an increase in the risk of short circuits, which in turn affects the energy density of the battery cell and the risk of high voltage failure.

[0004] Chinese patent discloses a lithium-ion power battery cover plate (publication number: CN210325871 U), comprising a cover plate substrate with a liquid injection hole, two electrode through holes, and an explosion-proof valve hole, an insulating bracket, two electrodes, and an explosion-proof valve; the upper end face of the cover plate substrate has electrode through hole bosses around the two electrode through holes, and the upper end face of the cover plate substrate has explosion-proof valve through hole bosses around the explosion-proof valve hole; the lower end face of the cover plate substrate has liquid injection through hole bosses around the liquid injection hole, and the lower end face of the cover plate substrate also has a reinforcing support device, which includes multiple bent reinforcing ribs, multiple circular reinforcing ribs, and multiple straight reinforcing ribs; the insulating bracket is provided with a second liquid injection hole, two second electrode through holes, and an explosion-proof valve hole corresponding sequentially to the first liquid injection hole, the two first electrode through holes, and the first explosion-proof valve hole on the cover plate substrate, and the insulating bracket is fixed to the lower end face of the cover plate substrate. The patent describes the design of multiple bent reinforcing ribs, multiple circular reinforcing ribs, and multiple straight reinforcing ribs beneath the cover plate, as described in the document. Figure 6 As shown, these reinforcing ribs are actually formed by hollowing out the cover plate. Their main purpose is to reduce the weight of the cover plate, but they do not actually improve the strength of the cover plate. Utility Model Content

[0005] The purpose of this utility model is to provide a lithium battery cover and its battery, thereby solving the problems existing in the prior art.

[0006] To achieve the above objectives, this utility model provides the following technical solution:

[0007] This utility model provides a lithium battery cover, including an aluminum plate, a positive electrode terminal module, a negative electrode terminal module, an explosion-proof valve, and a lower plastic. The positive electrode terminal module and the negative electrode terminal module are fixed to the aluminum plate by injection molding and riveting, and the aluminum plate is insulated from each other. The aluminum plate has a liquid injection hole, the explosion-proof valve is installed on the aluminum plate, and a reinforcement mechanism is provided at the bottom of the aluminum plate.

[0008] Preferably, the reinforcement mechanism includes a reinforcing strip, and the bottom of the aluminum plate is provided with a reinforcing strip hole, into which the reinforcing strip is embedded.

[0009] Preferably, the reinforcing strip consists of two pieces, located on both sides of the explosion-proof valve.

[0010] Preferably, the reinforcing strip is fixed to the aluminum plate by friction welding.

[0011] Preferably, a reinforcing strip rivet is provided in the reinforcing strip hole, and the reinforcing strip rivet rivets rivet the reinforcing strip into the reinforcing strip hole.

[0012] Preferably, the aluminum plate has an explosion-proof valve hole in the middle, an explosion-proof valve reinforcing frame is embedded in the explosion-proof valve hole, the explosion-proof valve is embedded in the hollow part of the explosion-proof valve reinforcing frame and fixed by laser welding.

[0013] Preferably, the explosion-proof valve hole is provided with an explosion-proof valve reinforcing frame rivet, which fixes the explosion-proof valve reinforcing frame inside the explosion-proof valve hole.

[0014] Preferably, the reinforcing mechanism includes a reinforcing rib, which is disposed at the bottom of the aluminum plate, and a clearance groove is provided on the lower plastic corresponding to the reinforcing rib.

[0015] Preferably, there are four reinforcing ribs and four corresponding clearance grooves. When the aluminum plate is fastened to the lower plastic, the corresponding reinforcing ribs are embedded in the clearance grooves.

[0016] This utility model also discloses a battery, including an electrode assembly body and a battery casing, wherein the electrode assembly body is installed inside the battery casing, and the upper part of the battery casing is equipped with a lithium battery cover as described in any one of claims 1-9.

[0017] The beneficial effects of this utility model are as follows: The reinforcing mechanism of this utility model adopts reinforcing strips, which improves the strength of the battery cover and reduces the deformation of the battery cover without increasing the weight and space occupation of the cover. This prevents the explosion-proof valve from having unstable opening pressure due to cover deformation and improves the stability of the cover. The reinforcing mechanism adopts reinforcing ribs, which prevent the explosion-proof valve from deforming under the protection of the reinforcing ribs, ensuring the opening stability of the explosion-proof valve and ensuring the normal operation of the explosion-proof valve. At the same time, since the reinforcing ribs are on the back side of the cover, there is no risk of short circuit with the external live structural components of the battery cell. Attached Figure Description

[0018] Figure 1 This is an exploded view of the first embodiment of the present invention;

[0019] Figure 2 This is a schematic diagram of the back side of the aluminum plate in the first embodiment of this utility model;

[0020] Figure 3 This is a perspective view of the reinforcing strip and the explosion-proof valve reinforcing frame installed on the back side of the aluminum plate in the first embodiment of this utility model;

[0021] Figure 4 This is an exploded view of the second embodiment of the present invention;

[0022] Figure 5 This is a perspective view of the reverse side of the aluminum plate according to the second embodiment of this utility model;

[0023] Figure 6 This is a cross-sectional view of the second embodiment of the present utility model;

[0024] Figure 7 This is a side view of the aluminum plate in the second embodiment of the present invention;

[0025] Figure 8 This is a perspective view of the second embodiment of the present utility model;

[0026] The attached diagram is described below:

[0027] 1. Aluminum plate; 2. Positive electrode post module; 3. Negative electrode post module; 4. Explosion-proof valve; 5. Lower plastic; 6. Reinforcing rib; 7. Clearance groove; 8. Injection hole; 9. Reinforcing strip; 10. Explosion-proof valve reinforcing frame; 11. Positive electrode post hole; 12. Reinforcing strip hole; 13. Explosion-proof valve hole; 14. Negative electrode post hole; 15. Reinforcing strip rivet; 16. Explosion-proof valve reinforcing frame rivet; 17. Friction welding. Detailed Implementation

[0028] It should be noted that, without conflict, the embodiments and features in the embodiments of this utility model can be combined with each other.

[0029] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this utility model. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0030] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," "fixed connection," and "fixed connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0031] The specific embodiments of this utility model are described in detail below with reference to the accompanying drawings and preferred embodiments.

[0032] Example 1:

[0033] like Figure 1-3 As shown, a lithium battery cover plate comprises an aluminum plate 1, a positive electrode post module 2, a negative electrode post module 3, an explosion-proof valve 4, a lower plastic 5, an injection hole 8, a reinforcing strip 9, and an explosion-proof valve reinforcing frame 10. The back side of the aluminum plate includes positive electrode post holes 11, reinforcing strip holes 12, explosion-proof valve holes 13, negative electrode post holes 14, reinforcing strip rivets 15, and explosion-proof valve reinforcing frame rivets 16. In this technical solution, the reinforcement mechanism is a reinforcing strip design, such as... Figure 2As shown, the positive terminal module is an aluminum post encased in a rubber ring, tightly bonded to the aluminum plate by riveting, with plastic used to isolate the contact points with the aluminum plate for sealing and insulation. The negative terminal module is a copper-aluminum composite structure encased in a rubber ring, tightly bonded to the aluminum plate by riveting, with plastic used to isolate the contact points with the aluminum plate for sealing and insulation. The reinforcing strip 9 is embedded in the reinforcing strip hole 12 and secured to the aluminum plate by reinforcing strip rivets 15. The perimeter joints are connected and fixed by friction welding 17, increasing the strength between the reinforcing strip and the aluminum plate. The explosion-proof valve reinforcing frame 10 is a structural component with a hollow center and slightly thinner edges. The explosion-proof valve is a thin metal sheet with grooves. When the internal pressure of the battery cell is too high, the grooves break and burst, relieving pressure on the battery cell. The explosion-proof valve reinforcing frame mates with the explosion-proof valve hole in the aluminum plate and is fixed by explosion-proof valve reinforcing frame rivets 16 at relevant locations.

[0034] In this embodiment, primary aluminum is selected for the aluminum plate due to the need for good weldability. For the reinforcing strips and explosion-proof valve reinforcing frame, considering factors such as different materials deforming differently at high temperatures and the ease with which different materials can detach, tertiary aluminum is selected. Firstly, tertiary aluminum has higher strength, increasing the strength of the cover plate. Secondly, its coefficient of thermal expansion is similar to that of primary aluminum (primary aluminum: 23.6 × 10⁻⁶ / ℃; tertiary aluminum: 10⁻⁶ / ℃), reducing the risk of the reinforcing strips or frame detaching from the aluminum plate due to excessive differences in expansion dimensions.

[0035] The above solution, while ensuring the avoidance of short circuit risk and without increasing the weight of the battery cover, increases the strength of the battery cover terminals and explosion-proof valve positions, enhances the stability of the battery cover valve opening, and reduces the risk of terminal failure.

[0036] Example 2:

[0037] like Figure 1 As shown, this utility model provides another lithium battery cover, which is composed of an aluminum plate 1, a positive electrode post module 2, a negative electrode post module 3, an explosion-proof valve 4, and a lower plastic 5; the reinforcing mechanism in this technical solution is a reinforcing rib, specifically as follows: on the back side of the aluminum plate of the battery cover, as shown... Figure 2 The explosion-proof valve has a reinforced structure (hereinafter referred to as the reinforcing rib 6) added to both sides and the positive and negative pole modules near the middle to improve the strength of the cover plate. The material is the same as that of the aluminum plate.

[0038] The reinforcing ribs are strip-shaped and oriented in the same direction as the width of the cover plate—that is, to increase the strength in the width direction and suppress deformation in the width direction of the cover plate; the distance between the reinforcing ribs on both sides of the explosion-proof valve and the edge of the explosion-proof valve should not be less than 5mm to prevent the processing of the reinforcing ribs from affecting the explosion-proof valve.

[0039] The distance from the edge of the positive and negative terminal module to the edge of the nearby reinforcing rib should be no less than 3.5mm. The function of these two reinforcing ribs is to increase the strength of the aluminum plate near the terminal and prevent the aluminum plate from deforming and causing damage to the inside of the terminal.

[0040] The distance from the reinforcing rib to the edge of the injection hole should be no less than 5mm; the distance from the reinforcing rib to the front of the aluminum plate should be no less than 4mm, and the same applies to the opposite side. The width of the reinforcing rib should be controlled within the range of 1mm-15mm, and the height should be controlled within the range of 0.2mm-1.5mm. When the distance between the edge of the pole module and the edge of the explosion-proof valve is no more than 40mm, the number of reinforcing ribs should be changed to two, that is, one between the explosion-proof valve and each between the positive and negative pole modules.

[0041] The lower plastic has an additional clearance groove 7 at the corresponding position to avoid the reinforcing rib. Since the reinforcing rib is placed on the back side of the battery cover, compared with adding a reinforcing rib on the front of the battery cover, other external charged metal structures will not come into contact with the reinforcing rib of the battery cover during PACK welding, reducing the risk of short circuit and electrical connection.

[0042] When a battery cell malfunctions, gas is produced, increasing internal pressure and causing deformation of the cover. This deformation leads to changes in the opening pressure of the explosion-proof valve, preventing the battery cover from opening properly. Furthermore, the deformation of the cover damages the internal structure of the terminals, affecting sealing and increasing potential hazards. By adding a reinforcing structure to the back of the battery cover, the strength of the cover is increased without increasing its weight. This reduces the risk of battery cover deformation, improves terminal strength, and enhances the opening stability of the explosion-proof valve, allowing it to burst normally.

[0043] For those skilled in the art, several improvements and modifications can be made without departing from the principle of this utility model, and these improvements and modifications should also be considered within the scope of protection of this utility model.

Claims

1. A lithium battery cover, characterized in that: It includes an aluminum plate, a positive electrode module, a negative electrode module, an explosion-proof valve, and a bottom plastic. The positive and negative electrode modules are fixed to the aluminum plate by injection molding and riveting, and the aluminum plate is insulated from the connection. The aluminum plate has a liquid injection hole. The explosion-proof valve is installed on the aluminum plate. The bottom of the aluminum plate is provided with a reinforcement mechanism.

2. The lithium battery cover according to claim 1, characterized in that: The reinforcement mechanism includes a reinforcing strip, and the bottom of the aluminum plate is provided with a reinforcing strip hole, into which the reinforcing strip is embedded.

3. The lithium battery cover according to claim 2, characterized in that: The reinforcing strip consists of two pieces, located on both sides of the explosion-proof valve.

4. The lithium battery cover according to claim 2, characterized in that: The reinforcing strip is fixed to the aluminum plate by friction welding.

5. The lithium battery cover according to claim 2, characterized in that: The reinforcing strip hole is provided with a reinforcing strip rivet, which rivets the reinforcing strip into the reinforcing strip hole.

6. The lithium battery cover according to claim 1, characterized in that: The aluminum plate has an explosion-proof valve hole in the middle, and an explosion-proof valve reinforcing frame is embedded in the explosion-proof valve hole. The explosion-proof valve is embedded in the hollow part of the explosion-proof valve reinforcing frame and fixed by laser welding.

7. The lithium battery cover according to claim 6, characterized in that: The explosion-proof valve hole is provided with explosion-proof valve reinforcing frame rivets, which fix the explosion-proof valve reinforcing frame inside the explosion-proof valve hole.

8. The lithium battery cover according to claim 1, characterized in that: The reinforcement mechanism includes reinforcing ribs, which are disposed at the bottom of the aluminum plate, and clearance grooves are provided on the lower plastic corresponding to the reinforcing ribs.

9. The lithium battery cover according to claim 8, characterized in that: There are four reinforcing ribs and four corresponding clearance grooves. When the aluminum plate is fastened to the lower plastic, the corresponding reinforcing ribs are embedded in the clearance grooves.

10. A battery, comprising an electrode assembly body and a battery casing, wherein the electrode assembly body is housed within the battery casing, characterized in that: The upper part of the battery casing is equipped with a lithium battery cover as described in any one of claims 1-9.

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