Battery cover plate and battery
By using an integrated electrode post and laser-welded lithium-ion battery cover design, the problems of electrode post space occupation and poor sealing are solved, achieving a battery structure with high energy density, low cost and high safety.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- 中汽新能(天津)电池科技有限公司
- Filing Date
- 2025-05-19
- Publication Date
- 2026-07-14
Smart Images
Figure CN224502098U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of lithium-ion battery technology, specifically relating to a battery cover and a battery. Background Technology
[0002] In the current booming development of new energy vehicles, the power battery, as its core component, plays a decisive role in vehicle performance, safety, and lifespan. The battery cover, as a crucial part of the power battery, directly affects the overall performance of the battery.
[0003] Currently, most lithium-ion battery covers use either a terminal post riveting structure or an injection molding structure to combine the terminal posts with structural components such as the aluminum plate. In the terminal post riveting structure, the independent terminal post is fixed to the aluminum plate by riveting. Although this method can achieve a certain degree of connection, the bottom of the terminal post extends into the cell. The injection molding structure connects the terminal post with other components through injection molding. During the injection molding process, additional injection molding structural components are required to ensure a stable connection.
[0004] These traditional structures have many drawbacks. The bottom of the terminal post occupies internal space within the cell, resulting in wasted space along the cell's height and limiting the improvement of cell energy density, thus failing to meet the high-energy-density battery requirements of new energy vehicles. Gaps between components lead to poor sealing performance, allowing external moisture, air, and other impurities to easily enter the cell, triggering abnormal internal chemical reactions, affecting cell safety, and shortening battery life. Furthermore, the complex structure and process increase battery manufacturing costs, hindering large-scale production and widespread application. Utility Model Content
[0005] The purpose of this utility model is to provide a battery cover and battery to solve the technical problem in the prior art where the bottom of the terminal post occupies the internal space of the battery cell, resulting in wasted space.
[0006] To achieve the above objectives, this utility model provides the following technical solution:
[0007] This utility model provides a battery cover, including a plain aluminum plate, an adhesive-coated terminal portion, an insulating portion of the battery cover, and an explosion-proof sheet.
[0008] The aluminum plate is formed into an integrated pole by a stamping process. The integrated pole is provided with a pole riveting groove, which is riveted and fixed to the pole coating riveting part in the pole coating part.
[0009] The inner bottom surface of the integrated pole is connected to the connecting piece welding part by laser welding, and its outer end face is used to be welded to the module busbar.
[0010] The aluminum plate, the integrated electrode post, and the electrode post encapsulation part together constitute a sealed structure, and the insulating part of the battery cover is injection molded and assembled with the aluminum plate.
[0011] Preferably, the thickness of the integrated pole is 1.5mm to 2.5mm.
[0012] Preferably, the stamping groove of the aluminum plate formed by the stamping process matches the geometry of the integrated pole post to eliminate component gaps.
[0013] Preferably, the electrode post coating part and the battery cover insulating part are integrally formed by injection molding, and the battery cover insulating part is provided with through holes for fixing the explosion-proof sheet.
[0014] Preferably, the explosion-proof sheet is sealed to the insulating part of the battery cover through an explosion-proof sheet film.
[0015] A lithium-ion battery includes a battery casing, electrode assembly, and connecting pieces, wherein the battery casing and battery cover are sealed and assembled by laser welding.
[0016] The electrode assembly connection part of the electrode assembly is fixed to the bottom surface of the connecting piece welding part of the connecting piece by ultrasonic welding.
[0017] The connecting piece body of the connecting piece is electrically connected to the electrode group body.
[0018] Preferably, the welding area of the electrode assembly connection portion and the welding bottom surface of the connecting piece covers ≥80%.
[0019] Preferably, the burst pressure of the explosion-proof sheet of the battery cover is 0.5MPa to 1.2MPa.
[0020] Preferably, the battery casing is made of aluminum alloy with a wall thickness of 0.8mm to 1.2mm.
[0021] Preferably, the electrode assembly body is a wound structure, and its electrode material includes lithium iron phosphate or ternary materials.
[0022] The beneficial effects of this invention are as follows: Firstly, compared with traditional riveting and injection molding structures, it significantly reduces component gaps and internal resistance, improving sealing performance and conductivity. The electrode thickness is limited to 1.5mm to 2.5mm, optimizing structural strength and reducing material redundancy, resulting in a significant reduction in battery volume and weight, and an increase in energy density of over 20%. Furthermore, the integrated design simplifies the assembly process, reduces injection-molded structural parts and sealing processes, lowering manufacturing costs by approximately 15%, while avoiding the problem of traditional electrode posts occupying internal cell space, further improving cell safety and lifespan. Secondly, the battery casing and cover are sealed and assembled using laser welding, ensuring the overall sealing of the battery and preventing external impurities from entering and internal electrolyte leakage. The electrode connection and the bottom surface of the connecting piece are ultrasonically welded with a large welding area, ensuring connection stability and conductivity, and improving battery performance during charging and discharging. The reasonable setting of the explosion-proof pressure enhances battery safety under abnormal conditions. The battery casing is made of aluminum alloy with a moderate wall thickness, ensuring mechanical strength while helping to reduce battery weight. The wound structure of the electrode assembly and the use of lithium iron phosphate or ternary materials as electrode materials improve the energy density and charge / discharge efficiency of the battery, enabling lithium-ion batteries to better meet the market's demand for high-performance batteries. Attached Figure Description
[0023] Figure 1 A perspective view of a single battery cell is provided for this utility model;
[0024] Figure 2 A top view of a single battery cell is provided for this utility model;
[0025] Figure 3 for Figure 2 A sectional view along the middle AA;
[0026] Figure 4 for Figure 3 The cross-sectional view of the battery cover shown;
[0027] Figure 5 for Figure 4 A magnified view of the battery cover at point B shown in the image;
[0028] Figure 6 This is an exploded view of the battery cover of this utility model;
[0029] Figure 7 This is a schematic diagram of the integrated terminal post of the new battery cover.
[0030] Figure 8 for Figure 7 A magnified view of the integrated terminal post of the battery cover at point C shown in the figure;
[0031] The attached diagram is described below:
[0032] 1. Battery cover; 11. Plain aluminum plate; 111. Stamping groove of plain aluminum plate; 12. Integrated terminal post; 121. Terminal post riveting groove; 122. Inner bottom surface of terminal post; 123. Outer end face of terminal post; 13. Glue-coated part of terminal post; 131. Glue-coated riveting part of terminal post; 14. Insulating part of battery cover; 141. Through hole of insulating part of battery cover; 15. Explosion-proof sheet; 16. Explosion-proof sheet film; 2. Battery casing; 3. Terminal group; 31. Terminal group connecting part; 32. Terminal group body; 4. Connecting piece; 41. Welding part of connecting piece; 411. Welded top surface of connecting piece; 412. Welded bottom surface of connecting piece; 42. Connecting piece body. Detailed Implementation
[0033] It should be noted that, without conflict, the embodiments and features in the embodiments of this utility model can be combined with each other.
[0034] 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.
[0035] 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.
[0036] The specific embodiments of this utility model are described in detail below with reference to the accompanying drawings and preferred embodiments.
[0037] like Figure 4-8As shown, this embodiment provides an integrated positive electrode terminal battery cover 1, the main body of which is formed by stamping a plain aluminum plate 11. The plain aluminum plate 11 is made of aluminum alloy material with a thickness of 0.6mm. During stamping, a blanking groove 111 is formed in a predetermined position, and an integrated terminal 12 with a height of 3mm is integrally formed. The thickness of the integrated terminal 12 is 2.0mm, ranging from 1.5mm to 2.5mm. It has a terminal rivet groove 121 at its top, which is fixed to the terminal rivet part 131 in the terminal lining part 13 by mechanical riveting. The terminal lining part 13 is made of nylon material and is combined with the plain aluminum plate 11 and the integrated terminal 12 by injection molding. During the injection molding process, the battery cover insulation part 14 is formed simultaneously. The battery cover insulating part 14 is provided with a through hole 141 for installing an explosion-proof sheet 15. The explosion-proof sheet 15 is sealed and bonded to the insulating part 14 through an explosion-proof sheet film 16. Its burst pressure is set to 0.8MPa in the range of 0.5MPa to 1.2MPa.
[0038] The inner bottom surface 122 of the integrated electrode post 12 is fixed to the top surface 411 of the connecting piece welding part 41 by laser welding with a power of 800W and a welding speed of 10mm / s. The outer end face 123 of the electrode post is reserved as a flat welding surface for subsequent laser welding with the module busbar. The assembly gap between the aluminum plate 11 and the electrode post rubber coating part 13 is less than 0.1mm to ensure sealing. In this embodiment, the die accuracy of the stamping process is ±0.05mm to eliminate component gaps and avoid electrolyte leakage. For the electrode group 3, if the electrode group body 32 is a wound structure, the positive and negative electrode materials, separator, etc. are first wound according to the design requirements to produce the electrode group body 32. The electrode material of the electrode group body 32 can be selected from lithium iron phosphate or ternary materials according to actual needs. After winding is completed, the electrode assembly connection part 31 is connected to the electrode assembly body 32. The connection method can be welding or other reliable connection processes to ensure good conductive connection between the electrode assembly connection part 31 and the electrode assembly body 32, so that the electrode assembly 3 becomes a complete electrochemical energy storage component.
[0039] like Figures 1 to 3 As shown, the lithium-ion battery of this embodiment includes a battery cover plate 1, a battery casing 2, an electrode assembly 3, and a connecting piece 4. The battery casing 2 is made of aluminum alloy with a wall thickness of 1.0 mm, ranging from 0.8 mm to 1.2 mm. Its top edge is sealed and assembled with the plain aluminum plate 11 of the battery cover plate 1 via laser welding at a power of 1000 W and a welding speed of 8 mm / s. The electrode assembly 3 has a wound structure. Its electrode assembly connecting part 31 is fixed to the connecting piece welding part 41 of the connecting piece welding part 41 via ultrasonic welding at a frequency of 20 kHz and a pressure of 300 N. The welding area covers ≥85% of the surface to reduce contact resistance. The connecting piece body 42 of the connecting piece 4 is made of copper-nickel composite material and is connected to the electrode ears of the electrode assembly body 32 via laser spot welding.
[0040] The electrode material of the electrode assembly 32 is a ternary material LiNiCoMnO2, with an active material coating thickness of 80μm and an electrode porosity of 35%. The explosion-proof sheet 15 of the battery cover 1 has been verified through burst pressure testing, with a burst threshold of 0.8MPa±0.1MPa, matching the battery thermal runaway pressure. After the battery casing 2 is filled with electrolyte and activated through a formation process, the final battery energy density reaches 265Wh / kg, with a cycle life exceeding 2000 cycles and a capacity retention rate of ≥80%.
[0041] In use, first connect the connecting piece welding portion 41 of the connecting piece 4 to the electrode group 3 and the integrated electrode post 12 respectively. First, align the bottom surface 412 of the connecting piece welding portion 41 with the electrode group connecting portion 31, and perform ultrasonic welding. During welding, control parameters such as ultrasonic power, welding time, and pressure to ensure that the welding area covers no less than 80%, ensuring a firm connection and good conductivity. Then, align the top surface 411 of the connecting piece welding portion 41 with the inner bottom surface 122 of the integrated electrode post 12, and perform laser welding to ensure welding quality and achieve a stable electrical connection.
[0042] Next, the assembled electrode assembly 3 and connecting piece 4 are placed into the battery casing 2, ensuring that each component is accurately positioned within the casing 2. Finally, the prepared battery cover is laser-welded to the battery casing 2 for sealing. During the welding process, welding parameters are strictly controlled to ensure a continuous and well-sealed weld area, preventing electrolyte leakage and the entry of external impurities into the battery, thus completing the overall assembly of the lithium-ion battery.
[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 battery cover, characterized in that: It includes a plain aluminum plate (11), an insulated terminal block (13), an insulating battery cover (14), and an explosion-proof sheet (15). The aluminum plate (11) is formed into an integrated pole (12) by a stamping process. The integrated pole (12) is provided with a pole riveting groove (121) and is riveted and fixed to the pole adhesive riveting part (131) in the pole adhesive part (13). The inner bottom surface (122) of the integrated pole post (12) is connected to the connecting piece welding part (41) by laser welding, and its outer end face (123) is used to weld to the module busbar; The aluminum plate (11), the integrated electrode post (12), and the electrode post encapsulation part (13) together constitute a sealing structure. The battery cover insulation part (14) is injection molded and assembled with the aluminum plate (11).
2. The battery cover according to claim 1, characterized in that: The thickness of the integrated pole post (12) is 1.5mm to 2.5mm.
3. The battery cover according to claim 1, characterized in that: The stamping groove (111) formed by the stamping process of the aluminum plate (11) matches the geometry of the integrated pole post (12) to eliminate component gaps.
4. The battery cover according to claim 1, characterized in that: The electrode post coating part (13) and the battery cover insulating part (14) are integrally formed by injection molding, and the battery cover insulating part (14) is provided with a through hole (141) for fixing the explosion-proof sheet (15).
5. The battery cover according to claim 1, characterized in that: The explosion-proof sheet (15) is sealed to the insulating part (14) of the battery cover through the explosion-proof sheet film (16).
6. A lithium-ion battery, characterized in that: It includes a battery case (2), an electrode assembly (3), and a connecting piece (4), wherein the battery case (2) is sealed and assembled with the battery cover plate (1) according to any one of claims 1-5 by laser welding; The electrode assembly connecting part (31) of the electrode assembly (3) is fixed to the bottom surface (412) of the connecting piece welding part (41) of the connecting piece welding part (41) by ultrasonic welding; The connecting piece body (42) of the connecting piece (4) is electrically connected to the electrode group body (32).
7. The lithium-ion battery according to claim 6, characterized in that: The welding area of the electrode connection part (31) and the welding bottom surface (412) of the connecting piece covers ≥80%.
8. The lithium-ion battery according to claim 6, characterized in that: The burst pressure of the explosion-proof sheet (15) of the battery cover (1) is 0.5MPa to 1.2MPa.
9. The lithium-ion battery according to claim 6, characterized in that: The battery casing (2) is made of aluminum alloy with a wall thickness of 0.8mm to 1.2mm.
10. The lithium-ion battery according to claim 6, characterized in that: The electrode assembly (3) has a wound structure in its main body (32), and its electrode material includes lithium iron phosphate or ternary materials.