Battery cover plate and battery thereof

Abstract

The utility model belongs to lithium ion battery technical field, concretely relates to a battery cover plate and battery, including light aluminium plate and with light aluminium plate combination's lower plastic, be equipped with positive pole column, negative pole column and explosion -proof valve on the light aluminium plate, be equipped with first liquid injection hole and second liquid injection hole on the light aluminium plate, first liquid injection hole and second liquid injection hole are located respectively on both sides of explosion -proof valve, be equipped with first liquid inlet with first liquid injection hole corresponding and with second liquid inlet corresponding on the lower plastic of second liquid injection hole, be equipped with shunt on the lower plastic, shunt with first liquid inlet and second liquid inlet intercommunication, a plurality of electrolyte lead -out holes are distributed on shunt, design two liquid injection holes in the battery cover corresponding battery core part position, can realize electrolyte from pole group core part beginning fast infiltration pole piece.

Description

Technical Field

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

[0002] With the development of science and technology, the demand for lithium-ion power batteries is increasing. High-energy-density batteries have become a development trend. The space inside the battery casing that can hold electrolyte is becoming smaller and smaller. In addition, the design of high compaction and high infill ratio makes it difficult for electrolyte to quickly wet the electrode sheets, which ultimately leads to problems of difficult electrolyte filling and low electrolyte filling efficiency. This will directly affect the production efficiency of the battery.

[0003] Chinese patent discloses a battery cover plate, a cover plate, and a battery electrolyte injection method (publication number: CN113161656B). The battery cover plate is used to seal two rolled cores arranged side by side along a first direction within the battery casing. The battery cover plate includes a plate body, with the first direction parallel to the plate body. The plate body has two injection holes, each corresponding to a rolled core located above it. This patent aims to improve the electrolyte injection efficiency through two injection holes. However, for square batteries with high compaction, high in-case ratio, and large thickness, the high electrode compaction results in low electrode porosity; the high in-case ratio results in less space occupied by the electrolyte; and the large electrode thickness results in a longer time for the electrolyte to reach the core. All three design factors lead to slow electrolyte wetting, thus causing injection difficulties. In addition, simply increasing the injection flow rate will cause excessive impact on the powder, increasing the risk of battery short circuits and increasing the battery defect rate.

[0004] Chinese patent also discloses a battery cover assembly (publication number: CN111599951B). This structure includes a lower plastic layer with an injection channel located in the main body of the lower plastic layer. The injection channel is configured to disperse and drain the electrolyte entering the injection channel. The electrolyte injected into the battery has a dispersed dripping pattern, allowing it to drip onto the cell at more locations, thus accelerating the wetting of the electrode sheets. Furthermore, the injection channel has multiple dispersed holes, so blockage of individual holes during negative pressure injection will not affect the normal injection process. However, this patent uses only one injection hole, and the injection channel is only distributed around the explosion-proof valve. It cannot directly inject electrolyte into the C-corner position and is also unsuitable for high-compact, high-fill-to-shell ratio, and thick prismatic batteries, as it will also result in slow electrolyte wetting and injection difficulties. Utility Model Content

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

[0006] To achieve the above objectives, this utility model provides the following technical solution: This utility model provides a battery cover, comprising a plain aluminum plate and a lower plastic sheet bonded to the plain aluminum plate. The plain aluminum plate is provided with a positive electrode post, a negative electrode post, and an explosion-proof valve. The aluminum plate is provided with a first injection hole and a second injection hole, which are located on both sides of the explosion-proof valve, respectively. The lower plastic body is provided with a first liquid inlet corresponding to the first liquid injection hole and a second liquid inlet corresponding to the second liquid injection hole; The lower plastic body is provided with a diversion pipe, which is connected to the first liquid inlet and the second liquid inlet; The shunt tube has multiple electrolyte outlet holes.

[0007] Preferably, the diversion pipe is arranged in a loop-shaped structure.

[0008] Preferably, the shunt tube is located in the area between the positive electrode tab groove and the negative electrode tab groove on the lower plastic, and extends to the outside of the groove.

[0009] Preferably, the diameters of the first injection hole and the second injection hole are both 1-5 mm.

[0010] Preferably, the diameter of the electrolyte outlet hole is 0.5-1 mm.

[0011] Preferably, the number of electrolyte outlet holes is 30-100.

[0012] Preferably, the lower plastic part is provided with a venting mesh at the position corresponding to the explosion-proof valve.

[0013] Preferably, the diversion tube is integrally formed with the lower plastic, the upper part of the diversion tube is open, and it is fastened to the bottom of the aluminum plate.

[0014] The present invention also discloses a battery, including a battery casing and an electrode assembly disposed within the battery casing, wherein the battery casing has an opening with the battery cover plate.

[0015] Preferably, the first injection hole and the second injection hole are located directly above the two electrode cores of the electrode assembly.

[0016] The beneficial effects of this utility model are as follows: This patent effectively improves the electrolyte injection efficiency and reliability of high-compact, high-fill-in-the-shell ratio batteries through the synergistic design of dual injection holes and an integrated shunt tube. Specifically, the two injection holes are precisely located above the electrode core, allowing the electrolyte to directly and quickly wet the center area of ​​the electrode sheet, fundamentally solving the problem of difficult internal wetting of thick electrode sheets. At the same time, the "U"-shaped shunt tube set on the lower plastic can quickly divert the electrolyte, which not only significantly reduces the direct impact of the liquid flow on the electrode powder during injection and reduces the risk of powder shedding, but also guides the electrolyte evenly to the storage gaps such as the C-corners inside the battery case and around the tabs through multiple electrolyte outlet holes distributed on it, realizing rapid storage and distribution of the electrolyte.

[0017] Furthermore, this structural design, through a multi-path, multi-point injection method, significantly increases the electrolyte flow area, thereby substantially improving the overall injection speed. This design is not only suitable for the initial injection but also promotes rapid and uniform mixing of the newly injected electrolyte with the existing electrolyte in the shell during secondary injections, further shortening the settling time and improving production efficiency. In summary, this invention achieves highly efficient and highly uniform electrolyte injection by working together on three key aspects: accelerating core wetting, reducing physical impact, and expanding the distribution area. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the aluminum plate in this utility model; Figure 2 This is a schematic diagram of the lower plastic component in this utility model; Figure 3 This is a top view of a single battery cell in this utility model; The attached diagram is described below: 1: Plain aluminum plate; 11: Positive electrode post; 12: Negative electrode post; 13: First liquid injection hole; 14: Second liquid injection hole; 15: Explosion-proof valve; 2: Lower plastic; 21: Positive electrode tab groove; 22: Negative electrode tab groove; 23: First liquid inlet; 24: Second liquid inlet; 25: Vent mesh; 26: Diverter pipe; 27: Electrolyte outlet hole; 3: Battery casing; 31: Electrode assembly; 32: Electrode assembly core position; 33: Electrolyte. Detailed Implementation

[0019] It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this utility model can be combined with each other.

[0020] 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.

[0021] 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.

[0022] The specific embodiments of this utility model are described in detail below with reference to the accompanying drawings and preferred embodiments.

[0023] like Figure 1 As shown, this utility model provides a battery cover plate, including a smooth aluminum plate 1 and a lower plastic plate 2 fixed below it. The smooth aluminum plate is provided with a first liquid injection hole 13 and a second liquid injection hole 14. The lower plastic plate is provided with a first liquid inlet 23 and a second liquid inlet 24 that communicate with and correspond to the first liquid injection hole 13 and the second liquid injection hole 14. The two liquid injection holes designed at the battery cover corresponding to the battery core position enable the electrolyte to quickly wet the electrode sheets starting from the electrode core.

[0024] Furthermore, a diversion tube 26 is provided on the lower plastic sheet, which is connected to the first liquid inlet 23 and the second liquid inlet 24. The diversion tube has a plurality of electrolyte outlet holes 27 evenly distributed on it. The diversion tube reduces the impact of the electrolyte on the electrode powder in the electrode assembly due to the negative pressure environment during injection. The electrolyte outlet holes on the diversion tube allow the electrolyte to drip evenly to various positions above the electrode assembly, quickly storing the electrolyte in gaps that can accommodate it. Specifically, the diversion tubes are distributed in a "U" shape on the lower plastic sheet. The diversion tubes are not only located in the middle of the two electrode tab grooves, but also outside the electrode tab grooves. The electrolyte outlet holes on the diversion tubes allow the electrolyte to drip evenly to various positions above the electrode assembly. Excessive impact on the powder increases the risk of battery short circuits and increases battery defect rates. This device, with its diversion tube and electrolyte outlet structure, can divert the electrolyte, reducing the impact of the electrolyte on the electrode powder during injection.

[0025] In this invention, the lower plastic sheet is provided with a positive electrode recess 21 and a negative electrode recess 22, and the shunt pipe is distributed around the positive electrode recess and the negative electrode recess. A venting mesh 25 is provided in the center of the lower plastic sheet. Correspondingly, the aluminum plate is provided with a positive electrode post 11 and a negative electrode post 12, which correspond to the positive electrode recess and the negative electrode recess.

[0026] An explosion-proof valve 15 is installed in the middle of the aluminum plate, corresponding to the venting mesh 25. The venting mesh serves to prevent battery explosion. When a lithium-ion battery experiences an internal short circuit, is exposed to a humid environment for an extended period, or is overcharged, a large amount of gas will be generated inside the battery. When the internal pressure generated by the gas becomes too high for the battery casing to withstand, an explosion will occur. The gas generated by the battery's internal problems can pass through the venting mesh and be discharged from the battery through the explosion-proof valve, preventing an explosion due to gas accumulation inside the battery.

[0027] Furthermore, to accelerate the electrolyte wetting of the high-voltage solid electrode, the first injection hole 13 and the second injection hole 14 are located on both sides of the explosion-proof valve 15, and the first injection hole 13 and the second injection hole are located directly above the core of each of the two electrode groups. Generally, square batteries undergo electrolyte replenishment after pre-forming, meaning a two-stage injection process. Injecting all the electrolyte into the battery at once would significantly increase the injection time. Additionally, if too much electrolyte is injected, most of it will be drawn away during negative pressure pre-forming, resulting in waste. Therefore, a two-stage injection method is adopted.

[0028] In this utility model, the diversion tube is integrally formed with the lower plastic, the upper part of the diversion tube is open, the cross-section of the diversion tube is U-shaped, and it is injection molded into a whole with the lower plastic, and the whole is fastened to the bottom of the light aluminum plate.

[0029] This utility model also discloses a battery, including an electrode assembly body 31 and a battery casing 3. The electrode assembly body is installed inside the battery casing, and the battery cover plate is installed on the upper part of the battery casing. The first electrolyte injection hole 13 and the second electrolyte injection hole are located in the center of the electrode assembly core position 32, and the electrolyte 33 fills the casing. Figure 3 As shown, the first injection hole 13 and the second injection hole are located directly above the core of the two electrode groups, which can accelerate the electrolyte wetting of the high-voltage solid electrode.

[0030] 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 battery cover, characterized in that: It includes a bare aluminum plate (1) and a lower plastic (2) bonded to the bare aluminum plate (1), wherein the bare aluminum plate (1) is provided with a positive electrode post (11), a negative electrode post (12) and an explosion-proof valve (15). The aluminum plate (1) is provided with a first injection hole (13) and a second injection hole (14), and the first injection hole (13) and the second injection hole (14) are located on both sides of the explosion-proof valve (15). The lower plastic (2) is provided with a first liquid inlet (23) corresponding to the first liquid injection hole (13) and a second liquid inlet (24) corresponding to the second liquid injection hole (14). The lower plastic (2) is provided with a diversion pipe (26), which is connected to the first liquid inlet (23) and the second liquid inlet (24); The shunt tube (26) has multiple electrolyte outlet holes (27).

2. The battery cover according to claim 1, characterized in that: The diversion pipe (26) is arranged in a loop-shaped structure.

3. The battery cover according to claim 2, characterized in that: The shunt tube (26) is located in the area between the positive tab groove (21) and the negative tab groove (22) on the lower plastic (2) and extends to the outside of the two grooves.

4. The battery cover according to claim 1, characterized in that: The diameters of the first injection hole (13) and the second injection hole (14) are both 1-5 mm.

5. The battery cover according to claim 1, characterized in that: The diameter of the electrolyte outlet hole (27) is 0.5-1 mm.

6. The battery cover according to claim 1, characterized in that: The number of electrolyte outlet holes (27) is 30-100.

7. The battery cover according to claim 1, characterized in that: The lower plastic (2) is provided with a ventilation mesh (25) at the position corresponding to the explosion-proof valve (15).

8. The battery cover according to claim 1, characterized in that: The diversion tube is integrally molded with the lower plastic, and the upper part of the diversion tube is open and fastened to the bottom of the aluminum plate.

9. A battery, comprising a battery casing (3) and an electrode assembly (31) disposed within the battery casing (3), characterized in that: The opening of the battery casing (3) is provided with a battery cover plate as described in any one of claims 1-8.

10. The battery according to claim 9, characterized in that: The first injection hole (13) and the second injection hole (14) are located directly above the two pole cores (32) of the pole group (31), respectively.

Images