Composite pole and battery cell cover plate
By adopting a non-planar interlocking structure design in the composite terminal of the lithium battery, the copper-aluminum interface forms a geometric interlock, which solves the problem of insufficient interface bonding strength and achieves high reliability and low cost battery connection.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- HUIZHOU KEDALI PRECISION IND CO LTD
- Filing Date
- 2025-06-27
- Publication Date
- 2026-07-21
AI Technical Summary
The copper-aluminum interface bonding strength of existing lithium battery composite electrodes is insufficient, which easily leads to interface fatigue due to differences in thermal expansion coefficients and stress concentration, and the manufacturing cost is high.
The non-planar interlocking structure design is adopted, and the copper part and the aluminum part form a geometric interlock through protrusions and grooves, which increases the contact area and disperses stress, achieving a purely mechanical connection.
Improve interface mechanical stability, reduce manufacturing costs, enhance battery reliability under vibration and temperature cycling, and avoid interface aging and increased resistance.
Smart Images
Figure CN224537296U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of battery structure technology, and in particular to a composite electrode for lithium batteries and a cell cover plate containing the electrode. Background Technology
[0002] In the manufacturing of lithium battery cell covers, composite terminals, as key components connecting the internal and external circuits of the battery, directly affect battery safety and lifespan due to the reliability of their copper-aluminum interface bonding. Currently, the industry mainstream employs two composite processes: Friction welding process: The copper-aluminum interface is thermally fused together by high-speed rotation friction, but the high temperature process can easily lead to coarsening of the interface grains and the formation of a brittle intermetallic compound layer. During long-term use, microcracks may be caused by vibration or thermal cycling. Composite panel process: Copper and aluminum plates are rolled and pressed together to form a planar interface. This structure is prone to delamination under interfacial shear forces, especially when gas generation inside the battery causes deformation of the cover plate. The planar interface lacks a mechanical constraint mechanism to resist interlayer separation. (See attached image) Figure 8 Copper plate 01 and aluminum plate 02 are bonded together by rolling and pressing to form a planar interface.
[0003] The planar interfaces formed by the above processes share common defects: the contact area is limited to a two-dimensional plane, and stress concentrates in the interface edge region; the difference in thermal expansion coefficients between copper and aluminum generates periodic shear stress during temperature changes, accelerating interface fatigue; to compensate for insufficient bonding strength, auxiliary structures (such as riveting points or adhesive layers) are often required, increasing manufacturing costs. Therefore, there is an urgent need for a composite pole solution that fundamentally improves interface reliability. Utility Model Content
[0004] In view of this, the present invention provides a composite electrode to improve the bonding strength of the copper-aluminum interface, reduce manufacturing costs, and improve the long-term reliability of the battery.
[0005] The objective of this utility model is achieved through the following technical solution: A composite pole includes a copper portion and an aluminum portion, wherein the joint surfaces of the copper portion and the aluminum portion form a non-planar interlocking structure, the interlocking structure comprising at least one protrusion and at least one groove that cooperate with each other.
[0006] This structure employs a non-planar interlocking design, creating continuous alternating protrusions and grooves at the interface between the copper and aluminum components. This results in a geometric interlocking effect between the two metals during the composite process. This interlocking structure significantly increases the effective contact area while dispersing interfacial stress through mechanical interlocking. Compared to traditional planar bonding, this design can resist multi-directional external impacts and reduces the risk of interlaminar shearing due to differences in thermal expansion coefficients. The non-planar interlocking structure disperses interfacial stress through the geometric fit of protrusions and grooves, enhancing the overall structural integrity. Furthermore, this design eliminates the need for high-precision welding or expensive composite processes, reducing processing difficulty and manufacturing costs, while ensuring the interface stability of the battery cell terminals under harsh conditions such as long-term vibration and temperature cycling.
[0007] Preferably, the extension direction of the protrusion and the groove is perpendicular to the axial direction of the composite pole.
[0008] The design, where the protrusions and grooves extend perpendicular to the axial direction of the composite electrode post, creates a continuous, closed mechanical barrier in the radial direction through the interlocking structure. This directional design effectively resists tensile forces along the electrode post axis and circumferential torsional forces, preventing axial deformation and separation of the copper-aluminum layer during battery charging and discharging. The perpendicular axial texture arrangement optimizes the interface load distribution, ensuring uniform stress transmission along the circumference and preventing microcracks caused by excessive local stress. Simultaneously, this structure facilitates mold processing and forming control during manufacturing, improving production yield. For the battery system, this design enhances the electrode post's resistance to peeling under extreme conditions such as vehicle collisions or mechanical shocks, providing dual protection for cell connection reliability.
[0009] Preferably, the copper part and the aluminum part are mechanically joined only through an interlocking structure, and there is no additional adhesive medium at the joint surface.
[0010] The purely mechanical interlocking bonding method eliminates the risk of interface aging caused by adhesive media (such as glue and solder). Adhesives are susceptible to electrolyte corrosion or high-temperature degradation, leading to a decrease in bond strength; while the stability of mechanical interlocking depends solely on the strength of the material itself. This design avoids curing time and contamination control issues in the bonding process, improving production cycle time. The dielectric-free interface maintains the original conductivity of the metal, avoiding an increase in interface resistance. In long-term use, the performance degradation rate of the mechanical interlocking structure under thermal cycling is lower than that of organic adhesive layers, which helps maintain connection reliability throughout the battery's entire life cycle. This feature also avoids the risk of contamination of the battery's internal environment by volatile organic compounds from adhesives.
[0011] Preferably, a battery cell cover includes a cover body and a composite terminal as described above, wherein the cover body is provided with a terminal mounting hole and the composite terminal passes through the terminal mounting hole.
[0012] By integrating the composite terminal block into the terminal block mounting holes of the cover plate body, this structure achieves integrated physical separation and electrical connection of the internal and external circuits of the cell. The non-planar interlocking feature of the composite terminal block suppresses the risk of interface damage during cover plate assembly. The through-type design ensures the shortest current transmission path, reducing energy loss due to contact resistance. The cover plate body, as a supporting substrate, provides radial constraint for the composite terminal block, reducing the probability of terminal block displacement caused by internal pressure fluctuations in the battery. This integrated solution simplifies the cell packaging process, avoids the additional sealing process required by traditional separate terminal blocks, and is compatible with automated production lines, improving the overall assembly efficiency and structural compactness of the cell.
[0013] Preferably, the aluminum portion of the composite pole penetrates the cover plate body and is exposed on the outside of the cover plate, the copper portion is located on the inside of the cover plate, and the end of the aluminum portion is connected to a light aluminum sheet.
[0014] The exposed aluminum portion meets the conductivity requirements of the negative terminal and facilitates connection to external circuitry; the inner copper portion accommodates the welding requirements of the copper current collector inside the battery. A bare aluminum sheet connects to the end of the aluminum portion, forming an external current collection node. This layout fully utilizes material properties: the aluminum portion resists environmental corrosion on the outside of the cover, while the copper portion avoids oxidation in the low-oxygen environment inside the battery. The introduction of the bare aluminum sheet expands the contact area between the terminal and external conductors, optimizing current transmission efficiency.
[0015] Preferably, an annular laser-welded layer is formed between the light aluminum sheet and the aluminum portion of the composite electrode.
[0016] The annular laser-welded layer forms a continuous, closed metallurgical bond at the interface between the aluminum sheet and the aluminum component. Located on the outside of the cover plate, this structure prevents external moisture and dust from eroding the electrode interface. The annular structure evenly distributes welding thermal stress, preventing micropores or cracks caused by localized overheating. Compared to spot welding or segmented welding, circumferential welding provides a 360° sealing barrier, effectively preventing electrolyte vapor from eroding the electrode interface. The high precision of laser welding avoids thermal impacts on the composite electrode interlocking structure, maintaining the original interface strength. This design also improves the mechanical strength and airtightness of the connection, reduces the probability of weld cracking due to vibration fatigue, and extends the battery's lifespan in humid and hot environments.
[0017] Preferably, the aluminum sheet has an axially protruding sealing flange on the side facing the cover plate body, and the sealing flange is parallel to the inner surface of the cover plate body.
[0018] The axially protruding sealing flange forms a mechanical sealing barrier facing the inside of the battery. Its design, parallel to the inner surface of the cover plate, ensures uniform pressure on the sealing surface, generating stable surface contact pressure during battery encapsulation. After the cell is filled with electrolyte, this flange acts as a dam against electrolyte leakage, preventing liquid from climbing up the terminals. The parallel arrangement avoids stress concentration during assembly, improving sealing reliability. The flange structure can adaptively adjust the clamping force during thermal expansion, compensating for differences in thermal deformation between different materials. Compared to traditional O-rings, this integrated metal flange avoids the failure risk caused by rubber aging, providing a maintenance-free, long-term sealing solution for the cell.
[0019] Preferably, the electrode mounting hole is provided with an integrally injection-molded insulator, which covers the sidewall and part of the end face of the composite electrode.
[0020] The one-piece injection-molded insulator integrates the composite terminal and cover plate body into a triple function: electrical isolation, mechanical fixation, and secondary sealing. The design of the covered sidewalls blocks short-circuit paths between the terminal and the metal cover plate; the covered end face prevents short-circuit risks caused by external metal foreign objects overlapping. The injection molding process creates a microscopic interlock between the insulator, the terminal, and the mounting holes, improving tensile strength. This structure eliminates the assembly tolerances required by traditional insulating gaskets, avoiding seal failure due to component misalignment. The continuous wrapping characteristic of the insulator adapts to cover plate deformation, maintaining long-term insulation resistance stability, making it particularly suitable for high-voltage battery systems.
[0021] Preferably, the insulator extends to the contact interface between the composite pole and the cover plate body, forming a radial sealing barrier.
[0022] The extension of the insulator towards the contact interface constructs a radial sealing barrier, superimposing a fluid sealing function on top of electrical insulation. This barrier blocks the capillary permeation path of the electrolyte along the electrode-cap gap, preventing electrochemical corrosion. The radial seal and the axial sealing flange form an orthogonal sealing system, improving multi-directional sealing redundancy. The extended structure fills manufacturing tolerance gaps, compensating for component assembly deviations. For systems prone to mechanical deformation, such as prismatic batteries, this design can absorb some structural stress, preventing seal separation caused by rigid contact. This feature significantly enhances the cell's leakage prevention capability under tilting and vibration conditions without adding additional components.
[0023] Preferably, the exposed end of the aluminum portion of the composite pole is provided with an external thread structure.
[0024] The exposed threaded structure at the aluminum end provides a standardized circuit connection interface. The threaded connection enables high-pressure contact, reducing contact resistance and heat loss, while resisting loosening caused by mechanical vibration. This design is compatible with industry-standard connectors, simplifying battery system integration. The threaded lead structure generates axial clamping force during tightening, optimizing the interface conductivity between the terminals and the electrode post. Compared to welding or crimping solutions, the threaded connection allows for non-destructive disassembly during equipment maintenance, facilitating battery reuse. This feature expands the cell's adaptability in energy storage systems, power tools, and other scenarios without compromising the strength of the electrode post itself.
[0025] The advantages of this utility model compared to the prior art are: The core innovation of this utility model lies in the non-planar interlocking structure design of the composite pole joint surface, which achieves multiple technical advantages through geometric innovation: 1. Improved interface mechanical stability Three-dimensional interlocking effect: The continuous alternating protrusions and grooves form a topological interlock ( Figure 3 This structure creates mechanical constraints between the copper and aluminum components in multiple directions. Compared to traditional planar interfaces, this structure transforms point / line contact into spatial curved surface contact, significantly increasing the effective load-bearing area. Stress dispersion mechanism: The continuous distribution of protrusions and grooves allows interfacial stress to be transmitted along the surface gradient (rather than concentrated at the edge), reducing the probability of microcrack initiation caused by local stress exceeding the limit. Anti-separation performance: When subjected to axial tensile force, the groove sidewalls form a radial barrier against the protrusions; when subjected to torsional force, the interlocking texture generates meshing resistance. This multi-directional constraint mechanism helps suppress interlayer separation caused by battery charging and discharging expansion or vehicle vibration.
[0026] 2. Manufacturing cost optimization Simplified process: The interlocking structure can be formed in one step through plastic deformation processes such as cold forging and extrusion (without the need for high-precision laser welding or vacuum rolling equipment). Improved yield: Geometric interlocking requires less interface cleanliness than welding processes, reducing scrap rates caused by surface oxide layers; Material savings: Pure mechanical bonding eliminates the need for auxiliary materials such as solder and adhesive.
[0027] 3. Enhanced long-term reliability Thermal fatigue resistance: The curved contact of the interlocking structure allows the copper-aluminum layer to produce slight slip compensation during thermal expansion, reducing the accumulation of residual stress at the interface; Environmental tolerance: The design without organic adhesive layers avoids interface degradation caused by electrolyte erosion, making it suitable for the highly corrosive environment of high-nickel battery systems; Vibration condition adaptation: The strength decay rate of mechanical interlock under high-frequency vibration is lower than that of welded joint surfaces, which helps to extend the service life of power batteries in vehicle operation.
[0028] 4. Auxiliary improvements to electrical performance Maintaining low interface resistance: direct metal interlocking avoids additional contact resistance of the adhesive layer, and the bump-groove structure increases the effective conductive area. Current distribution optimization: The three-dimensional interlocking interface enables the current lines to diffuse uniformly along the curved surface (compared to the edge skin effect of the planar interface), reducing the risk of local overheating. Attached Figure Description
[0029] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.
[0030] Figure 1 This is a structural diagram of the composite pole of Embodiment 1 of this utility model.
[0031] Figure 2 This is an exploded view of the composite pole of Embodiment 1 of this utility model.
[0032] Figure 3 This is a structural diagram of the composite pole of Embodiment 2 of this utility model.
[0033] Figure 4 This is a structural diagram of the battery cell cover plate in Embodiment 3 of this utility model.
[0034] Figure 5 This is a structural diagram of the battery cell cover plate from another perspective in Embodiment 3 of this utility model.
[0035] Figure 6 This is a cross-sectional view of the battery cell cover plate in Embodiment 3 of this utility model.
[0036] Figure 7 This is a schematic diagram of the structure of the battery cell cover plate in Embodiment 3 of this utility model.
[0037] Figure 8 This is a schematic diagram of the structure of an existing battery cell cover in the background art.
[0038] Labeling Explanation: 1 Composite pole, 11 Copper part, 12 Aluminum part, 13 Interlocking structure, 131 Protrusion, 132 Groove, 2 Cover plate body, 21 Pole mounting hole, 3 Light aluminum sheet, 31 Annular laser welded layer, 32 Sealing flange, 4 Insulator, 01 Copper plate, 02 Aluminum plate. Detailed Implementation
[0039] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.
[0040] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.
[0041] It should be noted that similar reference numerals and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. In the description of the embodiments of this application, it should be understood that the terms "upper," "lower," "left," "right," "vertical," "horizontal," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the figures, or the orientation or positional relationship commonly used when the product of this application is in use, or the orientation or positional relationship commonly understood by those skilled in the art. They are only for the convenience of describing this application 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. Therefore, they should not be construed as limitations on this application.
[0042] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.
[0043] The technical solutions in this application will now be described with reference to the accompanying drawings. Example
[0044] This embodiment provides a composite pole 1, including a copper part 11 and an aluminum part 12. The joint surfaces of the copper part 11 and the aluminum part 12 form a non-planar interlocking structure 13. The interlocking structure 13 includes mutually cooperating protrusions 131 and grooves 132, forming a mortise and tenon structure.
[0045] This structure employs a non-planar interlocking design, forming continuous alternating protrusions and grooves at the interface between the copper portion 11 and the aluminum portion 12, resulting in a geometric interlocking effect between the two metals during the composite process. This interlocking structure significantly increases the effective contact area while dispersing interfacial stress through mechanical interlocking. Compared to traditional planar bonding, this design can resist multi-directional external impacts and reduce the risk of interlaminar shearing due to differences in thermal expansion coefficients. The non-planar interlocking structure disperses interfacial stress through the geometric fit of protrusions and grooves, enhancing the overall structural integrity. Furthermore, this design eliminates the need for high-precision welding or expensive composite processes, reducing processing difficulty and manufacturing costs, while ensuring the interface stability of the battery cell terminals under harsh conditions such as long-term vibration and temperature cycling.
[0046] In this embodiment, the extension direction of the protrusion and the groove is perpendicular to the axial direction of the composite pole 1.
[0047] The design of the protrusions and grooves extending perpendicular to the axial direction of the composite electrode post 1 creates a continuous, closed mechanical barrier in the radial direction for the interlocking structure 13. This directional design effectively resists tensile forces and circumferential torsional forces along the electrode post axial direction, preventing axial deformation and separation of the copper-aluminum layer during battery charging and discharging. The textured pattern perpendicular to the axial direction optimizes the interface load distribution, ensuring uniform stress transmission along the circumference and preventing microcracks caused by excessive local stress. Simultaneously, this structure facilitates mold processing and forming control during manufacturing, improving production yield. For the battery system, this design enhances the electrode post's resistance to peeling under extreme scenarios such as vehicle collisions or mechanical shocks, providing dual protection for the reliability of cell connections.
[0048] In this embodiment, the copper part 11 and the aluminum part 12 are mechanically joined only by the interlocking structure 13, and there is no additional adhesive medium at the joint surface.
[0049] The purely mechanical interlocking connection eliminates the risk of interface aging caused by adhesive media (such as glue and solder). Adhesives are susceptible to electrolyte corrosion or high-temperature degradation, leading to a decrease in bond strength; while the stability of mechanical interlocking depends solely on the strength of the material itself. This design avoids curing time and contamination control issues in the bonding process, improving production cycle time. The dielectric-free interface maintains the original conductivity of the metal, avoiding an increase in interface resistance. In long-term use, the mechanical interlocking structure 13 exhibits a lower performance degradation rate under thermal cycling than organic adhesive layers, which helps maintain connection reliability throughout the battery's entire lifespan. This feature also mitigates the risk of contamination of the battery's internal environment by volatile organic compounds from adhesives. Example
[0050] The core difference between this embodiment and Embodiment 1 is that the interlocking structure uses a combination of periodically arranged protrusions and grooves. (See [link to previous embodiment]). Figure 3This design forms spatial topological interlocks through repeating geometric units, further optimizing the interface mechanical properties and manufacturing adaptability while maintaining the basic structural features described in Example 1.
[0051] Detailed description of structural characteristics Geometric distribution characteristics: The protrusions and grooves are arranged in a regular array along the mating surface, forming a continuous and repeating interlocking unit, such as a geometric array arranged in parallel or concentric directions; in each unit, the protrusions are embedded into the corresponding grooves to generate multi-directional mechanical constraints, forming an interlocking effect in the axial, radial and circumferential directions.
[0052] Mechanical transmission mechanism: Periodic distribution ensures that the interface load is evenly distributed to each interlocking unit, avoiding local stress concentration; the synergistic effect of multiple protrusions enhances torsional resistance: When the pole is subjected to external torque, the sidewalls of adjacent grooves form distributed barriers to the protrusions, inhibiting relative slippage between layers.
[0053] Process adaptation advantages: Regular repeating patterns can be formed in one step by stamping or cold forging with standard molds, reducing processing complexity; periodic design allows the cumulative error of manufacturing tolerances to be digested within a single unit, avoiding overall engagement failure.
[0054] Performance enhancement mechanism Vibration adaptability: The periodic interlocking units can disperse high-frequency vibration energy, reducing the risk of fretting wear caused by resonance. Each unit independently absorbs vibration energy, reducing the probability of interface fatigue crack initiation.
[0055] Thermal deformation compatibility: Under the effect of the thermal expansion difference between copper and aluminum, each interlocking unit can undergo micro-scale slippage to compensate for the difference in material expansion and reduce the accumulation of residual stress at the interface.
[0056] Mass production economics: Standardized repeating patterns are adapted to high-speed continuous stamping production lines, improving the production cycle of poles and reducing unit costs. Example
[0057] In this embodiment, a battery cell cover plate includes a cover plate body 2 and a composite electrode post 1 as a negative electrode post, as in embodiment 1 or 2. The cover plate body 2 is provided with an electrode post mounting hole 21, and the composite electrode post 1 passes through the electrode post mounting hole 21.
[0058] By integrating the composite terminal 1 into the terminal mounting hole 21 of the cover plate body 2, this structure achieves integrated physical separation and electrical connection of the internal and external circuits of the battery cell. The non-planar interlocking feature of the composite terminal 1 suppresses the risk of interface damage during cover plate assembly. The through-type design ensures the shortest current transmission path, reducing energy loss due to contact resistance. The cover plate body 2, as a supporting substrate, provides radial constraint for the composite terminal 1, reducing the probability of terminal displacement caused by internal pressure fluctuations in the battery. This integrated solution simplifies the battery cell packaging process, avoids the additional sealing process required by traditional separate terminals, and is compatible with automated production lines, improving the overall assembly efficiency and structural compactness of the battery cell.
[0059] In this embodiment, the composite electrode 1 is used as a negative electrode. The aluminum part 12 of the composite electrode 1 penetrates through the cover plate body and is exposed on the outside of the cover plate. The copper part 11 is located on the inside of the cover plate, and the end of the aluminum part 12 is connected to a light aluminum sheet 3.
[0060] The exposed aluminum portion meets the conductivity requirements of the negative terminal and facilitates connection to external circuitry; the inner copper portion accommodates the welding requirements of the copper current collector inside the battery. A bare aluminum sheet connects to the end of the aluminum portion, forming an external current collection node. This layout fully utilizes material properties: the aluminum portion resists environmental corrosion on the outside of the cover, while the copper portion avoids oxidation in the low-oxygen environment inside the battery. The introduction of the bare aluminum sheet expands the contact area between the terminal and external conductors, optimizing current transmission efficiency.
[0061] In this embodiment, an annular laser welding layer 31 is formed between the light aluminum sheet 3 and the aluminum part 12 of the composite pole 1.
[0062] The annular laser-welded layer forms a continuous, closed metallurgical bond at the interface between the aluminum sheet and the aluminum portion. This structure, located on the outside of the cover plate, prevents external moisture and dust from eroding the electrode interface. The annular structure evenly distributes welding thermal stress, preventing micropores or cracks caused by localized overheating. Compared to spot welding or segmented welding, circumferential welding provides a 360° sealing barrier, effectively preventing electrolyte vapor from eroding the electrode interface. The high precision of laser welding avoids thermal impact on the interlocking structure 13 of the composite electrode 1, maintaining the original interface strength. This design also improves the mechanical strength and airtightness of the connection, reduces the probability of weld cracking due to vibration fatigue, and extends the battery's lifespan in humid and hot environments.
[0063] In this embodiment, the aluminum sheet 3 has an axially protruding sealing flange 32 on the side facing the cover plate body 2, and the sealing flange 32 is parallel to the inner surface of the cover plate body 2.
[0064] The axially protruding sealing flange 32 forms a mechanical sealing barrier facing the inside of the battery. Its design, parallel to the inner surface of the cover body 2, ensures uniform pressing of the sealing surface, generating stable surface contact pressure during battery encapsulation. After the cell is filled with electrolyte, this flange acts as a dam against electrolyte leakage, preventing liquid from climbing up the electrode posts. The parallel arrangement avoids stress concentration during assembly, improving sealing reliability. The flange structure can adaptively adjust the clamping force during thermal expansion, compensating for differences in thermal deformation between different materials. Compared to traditional O-rings, this integrated metal flange avoids the failure risk caused by rubber aging, providing a maintenance-free, long-term sealing solution for the cell.
[0065] In this embodiment, an integrally injection-molded insulator 4 is provided in the electrode mounting hole 21, and the insulator 4 covers the side wall and part of the end face of the composite electrode 1.
[0066] The integrally injection-molded insulator 4 integrates the composite terminal 1 and the cover plate body 2, providing triple functionality: electrical isolation, mechanical fixation, and secondary sealing. The design of the covered sidewalls blocks short-circuit paths between the terminal and the metal cover plate; the covered end face prevents short-circuit risks caused by external metal foreign objects overlapping. The injection molding process creates a microscopic interlock between the insulator 4, the terminal, and the mounting holes, improving tensile strength. This structure eliminates the assembly tolerances required by traditional insulating gaskets, avoiding seal failure due to component misalignment. The continuous wrapping characteristic of the insulator 4 adapts to cover plate deformation, maintaining long-term insulation resistance stability, making it particularly suitable for high-voltage battery systems.
[0067] In this embodiment, the insulator 4 extends to the contact interface between the composite pole 1 and the cover plate body 2, forming a radial sealing barrier.
[0068] The extension of the insulator's four-way contact interface constructs a radial sealing barrier, superimposing a fluid sealing function on top of electrical insulation. This barrier blocks the capillary penetration path of electrolyte along the electrode-cap gap, preventing electrochemical corrosion. The radial seal and the axial sealing flange 32 form an orthogonal sealing system, improving multi-directional sealing redundancy. The extended structure fills manufacturing tolerance gaps, compensating for component assembly deviations. For systems prone to mechanical deformation, such as prismatic batteries, this design can absorb some structural stress, preventing seal separation caused by rigid contact. This feature significantly enhances the cell's leakage prevention capability under tilting and vibration conditions without adding additional components.
[0069] In this embodiment, the exposed end of the aluminum part 12 of the composite pole 1 is provided with an external thread structure.
[0070] The exposed threaded structure of the aluminum section 12 provides a standardized circuit connection interface. The threaded connection enables high-pressure contact, reducing contact resistance and heat loss, while resisting loosening caused by mechanical vibration. This design is compatible with industry-standard connectors, simplifying battery system integration. The threaded lead structure generates axial clamping force during tightening, optimizing the interface conductivity between the terminals and the electrode post. Compared to welding or crimping solutions, the threaded connection allows for non-destructive disassembly during equipment maintenance, facilitating the reuse of batteries. This feature expands the cell's adaptability in energy storage systems, power tools, and other scenarios without compromising the strength of the electrode post itself.
[0071] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.
Claims
1. A composite electrode, characterized in that, It includes a copper part (11) and an aluminum part (12). The joint surfaces of the copper part (11) and the aluminum part (12) form a non-planar interlocking structure. The interlocking structure includes at least one protrusion and at least one groove that cooperate with each other. The extension direction of the protrusion and the groove is perpendicular to the axial direction of the composite pole. The copper part (11) and the aluminum part (12) are mechanically joined only by the interlocking structure, and there is no additional adhesive medium on the joint surface.
2. A battery cell cover plate, characterized in that, It includes a cover plate body (2) and a composite pole (1) as described in claim 1; the cover plate body (2) is provided with a pole mounting hole (21), and the composite pole (1) passes through the pole mounting hole (21).
3. The cell cover plate according to claim 2, characterized in that, The aluminum part (12) of the composite pole (1) penetrates the cover plate body and is exposed on the outside of the cover plate, the copper part (11) is located on the inside of the cover plate, and the end of the aluminum part (12) is connected to a light aluminum sheet (3).
4. The cell cover plate according to claim 3, characterized in that, An annular laser welding layer (31) is formed between the light aluminum sheet (3) and the aluminum part (12) of the composite pole (1).
5. The cell cover plate according to claim 4, characterized in that, The aluminum sheet (3) has an axially protruding sealing flange (32) on the side facing the cover plate body (2), and the sealing flange (32) is parallel to the inner surface of the cover plate body (2).
6. The cell cover plate according to claim 2, characterized in that, An integrally injection-molded insulator (4) is provided inside the pole mounting hole (21), and the insulator (4) covers the side wall and part of the end face of the composite pole (1).
7. The cell cover plate according to claim 6, characterized in that, The insulator (4) extends to the contact interface between the composite pole (1) and the cover plate body (2) to form a radial sealing barrier.
8. The cell cover plate according to claim 3, characterized in that, The exposed end of the aluminum part (12) of the composite pole (1) is provided with an external thread structure.