A pure lithium negative tab structure
By employing an embedded groove and protrusion design in the pure lithium anode tab structure, combined with a conductive buffer layer and an anti-overflow protrusion, the relative displacement problem between the pure lithium tab and the metal encapsulation layer during welding is solved, improving welding stability and mechanical strength, and enhancing battery safety and lifespan.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- XINYUAN QINGCAI TECH (BEIJING) CO LTD
- Filing Date
- 2025-06-23
- Publication Date
- 2026-06-26
Smart Images
Figure CN224417984U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of battery technology, and in particular to a pure lithium negative electrode tab structure. Background Technology
[0002] In the field of lithium-ion batteries, the pure lithium anode tab structure is one of the key components of the battery. Its design and manufacturing process have a significant impact on the battery's performance, safety, and lifespan. With the continuous development of battery technology, the performance requirements for the pure lithium anode tab structure are also becoming increasingly stringent.
[0003] In existing technologies, the pure lithium anode tab structure typically includes a pure lithium tab and a metal coating layer. The metal coating layer protects the pure lithium tab and provides mechanical support. However, a significant problem exists in existing technologies: during the welding process, relative displacement can easily occur between the pure lithium tab and the metal coating layer. This relative displacement can lead to instability at the weld joint, thereby affecting the battery's conductivity and structural integrity. Specifically, relative displacement may reduce the contact area at the weld joint, increasing resistance and reducing the battery's charge and discharge efficiency. Furthermore, relative displacement may also cause stress concentration inside the battery, increasing safety risks during use, such as short circuits and thermal runaway.
[0004] To prevent relative displacement, existing technologies typically employ additional securing measures, such as adding mechanical clamping devices or using special adhesives. However, these methods not only increase manufacturing costs and process complexity but may also negatively impact battery performance. Utility Model Content
[0005] Based on the above analysis, the present invention aims to provide a pure lithium negative electrode tab structure to solve the technical problem that relative displacement easily occurs between the pure lithium electrode tab and the metal coating layer in the prior art.
[0006] The objective of this utility model is mainly achieved through the following technical solutions:
[0007] A pure lithium negative electrode tab structure includes: a pure lithium tab, a metal coating layer, and a tab welding area; the metal coating layer wraps around the outside of the pure lithium tab, and the tab welding area is located on the metal coating layer and can weld the pure lithium tab and the metal coating layer through the tab welding area;
[0008] The inner surface of the metal cladding layer is provided with embedding grooves and embedding protrusions, so that the pure lithium electrode tab and the metal cladding layer can be pressed and embedded into each other to reduce relative displacement during welding.
[0009] Furthermore, the metal cladding layer also includes a first stack, a bottom layer, and a second stack connected in sequence, with the second stack overlapping the first stack to form a cladding overlap layer.
[0010] Furthermore, the thickness of the metal cladding layer is 0.05–0.15 mm.
[0011] Furthermore, the pure lithium anode tab structure also includes a conductive buffer layer, which is disposed between the metal encapsulation layer and the pure lithium tab to absorb the expansion stress of the lithium tab.
[0012] Furthermore, the electrode welding area is located on the wrapping overlap layer.
[0013] Furthermore, the edge of the metal coating layer is provided with anti-overflow protrusions to prevent pure lithium from overflowing during welding or charging / discharging.
[0014] Furthermore, the welding area of the electrode welding zone accounts for 60% to 90% of the area of the wrapping overlapping layer.
[0015] Furthermore, the outer surface of the metal coating layer is provided with an anti-oxidation coating to prevent oxidation of the metal coating layer surface.
[0016] Furthermore, the pure lithium negative electrode tab structure also includes a support layer, which is disposed on the outside of the metal encapsulation layer.
[0017] Furthermore, the metal cladding layer is provided with stress relief grooves, which are V-shaped or U-shaped grooves and are distributed at intervals along the length of the tab.
[0018] The technical solution of this utility model can achieve at least one of the following effects:
[0019] (1) The pure lithium negative electrode tab structure of this utility model includes a pure lithium tab, a metal coating layer and a tab welding area. The inner surface of the metal coating layer is provided with an embedding groove and an embedding protrusion. Through the embedding groove and the embedding protrusion, the metal coating layer and the pure lithium tab are inter-embedded. The pure lithium tab and the metal coating layer can fit tightly together during the welding process, reducing relative displacement, improving the stability and reliability of the welding, ensuring the welding quality, and solving the technical problems existing in the prior art. In addition, the inter-embedded structure can further enhance the mechanical strength between the metal coating layer and the pure lithium tab when under pressure, preventing loosening due to volume expansion during charging and discharging. Thus, the mechanical stability of the entire tab structure is enhanced.
[0020] (2) The pure lithium negative electrode tab structure of this utility model includes a metal coating layer comprising a coating body, one end of which overlaps with the other end of the coating body to form a coating overlap layer. The electrode tab welding area is located on the coating overlap layer. During the welding process, heat and pressure are concentrated on the coating overlap layer. Since the coating overlap layer has a double metal structure, it can withstand higher welding energy without deformation. The double structure of the coating overlap layer also increases the welding contact area, making the welding point stronger. This effectively reduces the relative displacement between the pure lithium electrode tab and the metal coating layer. The double metal structure disperses the welding stress, which avoids the deformation problem of a single metal layer and improves the connection stability by increasing the welding contact area.
[0021] (3) The pure lithium negative electrode tab structure of this utility model has an anti-overflow protrusion on the edge of the metal coating layer. During the welding process, the lithium metal may soften or melt in the contact area between the metal coating layer and the pure lithium tab due to high temperature. The anti-overflow protrusion can effectively limit the flow path of molten lithium by forming a continuous blocking boundary. During the charging and discharging process, the lithium metal undergoes volume changes due to repeated insertion and extraction. The structure design of the anti-overflow protrusion can adapt to the expansion and contraction of the pure lithium tab, while continuously playing a blocking role to prevent lithium metal from seeping out from the edge of the coating layer due to mechanical stress. Thus, the risk of pure lithium overflow during high-temperature welding and battery cycling is suppressed, and the internal short circuit or electrode structure damage caused by lithium metal overflow is avoided, thereby improving the safety and service life of the battery.
[0022] In this invention, the above-described technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of this invention will be set forth in the following description, and some advantages will become apparent from the description or be learned by practicing the invention. The objectives and other advantages of this invention can be realized and obtained from the description and accompanying drawings, which are particularly pointed out. Attached Figure Description
[0023] The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of the invention. Throughout the drawings, the same reference numerals denote the same parts.
[0024] Figure 1 This is a schematic diagram of the pure lithium negative electrode tab structure in an embodiment of this utility model;
[0025] Figure 2 This is a schematic diagram showing the unfolded structure of the pure lithium negative electrode tab in an embodiment of this utility model;
[0026] Figure 3 This is a schematic diagram of the electrode tab welding area in an embodiment of the present invention;
[0027] Figure 4This is a schematic diagram of the conductive buffer layer in an embodiment of the present invention;
[0028] Figure 5 This is a schematic diagram of the structure of the metal coating layer in an embodiment of this utility model.
[0029] Figure label:
[0030] 1-Pure lithium tab, 2-Metal coating layer, 21-Embedded groove, 22-Embedded protrusion, 23-Coating body, 231-First stack, 232-Bottom layer, 233-Second stack, 3-Taper welding area, 4-Conductive buffer layer, 5-Anti-overflow protrusion, 6-Antioxidant coating, 8-Stress relief groove, 9-Support layer. Detailed Implementation
[0031] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which constitute a part of the present invention and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.
[0032] The technical solution of this application and how the technical solution of this application solves the above-mentioned technical problems are described in detail below with specific embodiments.
[0033] Example 1
[0034] like Figure 1 and Figure 2 As shown, this utility model embodiment provides a pure lithium negative electrode tab structure, including: a pure lithium tab 1, a metal coating layer 2, and a tab welding area 3; the metal coating layer 2 wraps around the outside of the pure lithium tab 1, and the tab welding area 3 is located on the metal coating layer 2 and can weld the pure lithium tab 1 and the metal coating layer 2 through the tab welding area 3; the inner surface of the metal coating layer 2 is provided with an embedding groove 21 and an embedding protrusion 22, so that the pure lithium tab 1 and the metal coating layer 2 can be pressed and embedded into each other to reduce the relative displacement during welding.
[0035] The pure lithium tab 1 is the main storage and transport medium for lithium ions, responsible for storing and releasing lithium ions during battery charging and discharging. The metal coating layer 2 protects the pure lithium tab 1, preventing it from directly contacting the external environment and thus avoiding lithium oxidation and corrosion. It forms a physical barrier on the outside of the pure lithium tab 1 to prevent lithium from directly contacting air. For example, the metal coating layer 2 can be made of nickel or nickel-plated copper, and its shape can be rectangular. The tab welding area 3 is located on the metal coating layer 2, providing a welding position to fix the pure lithium tab 1 and the metal coating layer 2 together by welding. Specifically, the inner surface of the metal coating layer 2 is provided with an embedding groove 21 and an embedding protrusion 22. The embedding groove 21 is used to allow the pure lithium tab 1 to be embedded during pre-pressing. The embedded protrusion 22 is used to embed the metal coating layer 2 into the pure lithium electrode 1 during pre-pressing. Through the mutual embedding of the metal coating layer 2 and the pure lithium electrode 1, the pure lithium electrode 1 and the metal coating layer 2 can be tightly attached during the welding process, reducing relative displacement, improving the stability and reliability of the welding, ensuring the welding quality, and solving the technical problems existing in the prior art. In addition, the mutual embedding structure can further enhance the mechanical strength between the metal coating layer 2 and the pure lithium electrode 1 under pressure, preventing loosening due to volume expansion during charging and discharging. Thus, the mechanical stability of the entire electrode structure is enhanced. Furthermore, the mutual embedding structure makes the contact between the pure lithium electrode 1 and the metal coating layer 2 tighter, improving the conductivity.
[0036] In a preferred embodiment of the present invention, the metal cladding layer 2 further includes a first stack 231, a bottom layer 232, and a second stack 233 connected in sequence, wherein the second stack 233 overlaps the first stack 231 to form a cladding overlap layer.
[0037] The metal coating layer 2 comprises three parts: a first stack 231, a bottom layer 232, and a second stack 233. The first stack 231 and the second stack 233 are folded and overlapped on the bottom layer 232 to cover the outer surface of the pure lithium electrode 1 and provide mechanical support. The overlapping layer refers to the overlapping area of the first stack 231 and the second stack 233. The overlapping layer increases the contact area between the metal coating layer 2 and the pure lithium electrode 1, and also improves the overall stability of the coating structure. The overlapping layer formed by the first stack 231 and the second stack 233 allows the metal coating layer 2 to wrap the pure lithium electrode 1 without relying on external clamping devices or adhesives. The overlapping layer is tightly bonded by the ductility and compression of the metal material itself, which restricts the relative sliding between the metal coating layer 2 and the pure lithium electrode 1 during the welding process, thereby avoiding welding misalignment. This improves the contact stability of the welding point and reduces the process complexity and manufacturing cost caused by additional fixing measures.
[0038] Based on this, such as Figure 3As shown, the electrode welding area 3 is located on the wrapping overlapping layer.
[0039] The electrode welding area 3 refers to the area where the pure lithium electrode 1 and the metal coating layer 2 are fixed by welding, for example, by laser welding or ultrasonic welding. During the welding process, heat and pressure are concentrated on the overlapping coating layer. Since the overlapping coating layer has a double-layer metal structure, it can withstand higher welding energy without deformation. In addition, the double-layer structure of the overlapping coating layer also increases the welding contact area, making the welding point stronger, thereby effectively reducing the relative displacement between the pure lithium electrode 1 and the metal coating layer 2. In the prior art, the welding area is usually set in a single-layer area of the metal coating layer. Single-layer metal is prone to deformation due to heat concentration during welding, which in turn causes displacement. However, this utility model embodiment sets the welding area on the overlapping coating layer, using the double-layer metal structure to disperse the welding stress, which not only avoids the deformation problem of single-layer metal, but also improves the connection stability by increasing the welding contact area.
[0040] In a preferred embodiment of this utility model, the thickness of the metal cladding layer 2 is 0.05 to 0.15 mm.
[0041] A preferred embodiment of this utility model is as follows: Figure 4 As shown, the pure lithium anode tab structure also includes a conductive buffer layer 4, which is disposed between the metal wrapping layer 2 and the pure lithium tab 1 to absorb the expansion stress of the lithium tab 1.
[0042] The conductive buffer layer 4 can be made of porous metal foam, conductive elastomer, or graphene composite material. The conductive buffer layer 4 can be pre-attached to the inside of the metal wrapping layer 2. The conductive buffer layer 4 absorbs the stress generated by the volume change of the lithium tab 1 during charging and discharging through elastic deformation. The conductive buffer layer 4 is sandwiched between the metal wrapping layer 2 and the pure lithium tab 1. When the pure lithium tab 1 expands in volume, the conductive buffer layer 4 absorbs the expansion stress through its own elastic deformation, while maintaining the conductive contact between the metal wrapping layer 2 and the pure lithium tab 1, without affecting their mutual embedding. By setting the conductive buffer layer 4, the conductive buffer layer 4 is deformed under pressure. Under the premise of maintaining conductivity, the rigid wrapping and flexible buffer are combined, which avoids welding fixation failure and reduces structural damage caused by stress accumulation.
[0043] A preferred embodiment of this utility model is as follows: Figure 5 As shown, the edge of the metal coating layer 2 is provided with an anti-overflow protrusion 5 to prevent pure lithium from overflowing during welding or charging and discharging.
[0044] The anti-overflow protrusion 5 is used to prevent pure lithium from overflowing during welding or charging and discharging. For example, the anti-overflow protrusion 5 is formed by stamping. The anti-overflow protrusion 5 restricts the outward flow of pure lithium material when heated or compressed by physical blocking, thereby preventing lithium metal from overflowing from the edge of the coating layer. During welding, the lithium metal may soften or melt in the contact area between the metal coating layer 2 and the pure lithium tab 1 due to high temperature. The anti-overflow protrusion 5 can effectively restrict the flow path of molten lithium by forming a continuous blocking boundary. During charging and discharging, the lithium metal undergoes volume changes due to repeated insertion and extraction. The structural design of the anti-overflow protrusion 5 can adapt to the expansion and contraction of the pure lithium tab 1, while continuously playing a blocking role to prevent lithium metal from seeping out from the edge of the coating layer due to mechanical stress. Thus, it suppresses the risk of pure lithium overflow during high-temperature welding and battery cycling, avoids internal short circuits or electrode structure damage caused by lithium metal overflow, and improves battery safety and service life.
[0045] In a preferred embodiment of this utility model, the welding area of the tab welding area 3 accounts for 60% to 90% of the area of the wrapping overlapping layer.
[0046] The welding area is controlled within 60% to 90% of the area of the overlapping layer. This ensures sufficient welding strength to fix the pure lithium tab 1 and the metal coating layer 2, while also retaining some unwelded areas to alleviate the thermal stress generated during the welding process.
[0047] Example 2
[0048] Embodiment 2 of this utility model is a further improvement based on Embodiment 1, such as... Figure 5 As shown, the outer surface of the metal coating layer 2 is provided with an anti-oxidation coating 6 to prevent oxidation of the surface of the metal coating layer 2.
[0049] An anti-oxidation coating 6 covers the outer surface of the metal encapsulation layer 2. For example, the anti-oxidation coating 6 may be an aluminum oxide or silicon nitride coating, which can be formed by chemical vapor deposition or spraying process to isolate the outer surface of the metal encapsulation layer 2 from the outside world to avoid oxidation reaction.
[0050] An optional solution of this utility model embodiment is as follows: Figure 5 As shown, the pure lithium anode tab structure also includes a support layer 9, which is disposed on the outside of the metal encapsulation layer 2.
[0051] The support layer 9 refers to an additional layer used to enhance the structural stability of the metal cladding layer 2. For example, the support layer 9 can be made of metal or polymer materials, such as stainless steel, nickel alloy or polyimide film. The support layer 9 reduces the deformation of the metal cladding layer 2 caused by external force or internal stress during welding or charging and discharging through physical support, thereby maintaining the integrity of the tab structure.
[0052] An optional solution of this utility model embodiment is as follows: Figure 5 As shown, the metal cladding layer 2 is provided with stress relief grooves 8, which are V-shaped or U-shaped grooves and are distributed at intervals along the length of the tab.
[0053] After forming V-shaped or U-shaped grooves on the surface of the metal coating layer 2, when the tab is stressed due to temperature changes or lithium expansion during welding or charging and discharging, the groove structure can absorb some of the stress through deformation, and at the same time disperse the concentrated stress to the area around the groove, so as to avoid excessive stress accumulation in a single location, which would cause the metal coating layer 2 to crack or deform. The grooves are distributed at intervals along the length direction to further ensure that the stress release effect covers the entire tab area, while maintaining the continuity and mechanical support capacity of the metal coating layer 2.
[0054] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present utility model should be included within the protection scope of the present utility model.
Claims
1. A pure lithium negative tab structure, characterized by, include: A pure lithium electrode (1), a metal coating layer (2), and an electrode welding area (3); the metal coating layer (2) wraps around the outside of the pure lithium electrode (1), and the electrode welding area (3) is located on the metal coating layer (2) and the pure lithium electrode (1) and the metal coating layer (2) can be welded through the electrode welding area (3); The inner surface of the metal cladding layer (2) is provided with an embedding groove (21) and an embedding protrusion (22), so that the pure lithium electrode (1) and the metal cladding layer (2) can be pressed and embedded into each other to reduce the relative displacement during welding.
2. The pure lithium negative tab structure of claim 1, wherein, The metal cladding layer (2) further includes a first stack (231), a bottom layer (232), and a second stack (233) connected in sequence, wherein the second stack (233) overlaps the first stack (231) to form a cladding overlap layer.
3. The pure lithium negative tab structure of claim 1, wherein, The pure lithium negative electrode tab structure also includes a conductive buffer layer (4), which is disposed between the metal wrapping layer (2) and the pure lithium tab (1) to absorb the expansion stress of the pure lithium tab (1).
4. The pure lithium negative tab structure of claim 2, wherein, The electrode welding area (3) is located on the wrapping overlapping layer.
5. The pure lithium negative tab structure of claim 1, wherein, The edge of the metal coating layer (2) is provided with an anti-overflow protrusion (5) to prevent pure lithium from overflowing during welding or charging and discharging.
6. The pure lithium negative tab structure of claim 4, wherein, The welding area of the electrode welding area (3) accounts for 60% to 90% of the area of the wrapping overlapping layer.
7. The pure lithium negative tab structure of claim 1, wherein, The outer surface of the metal coating layer (2) is provided with an anti-oxidation coating (6) to prevent oxidation of the surface of the metal coating layer (2).
8. The pure lithium negative tab structure of claim 1, wherein, The pure lithium negative electrode tab structure also includes a support layer (9), which is disposed on the outside of the metal encapsulation layer (2).
9. The pure lithium negative tab structure of claim 1, wherein, The metal cladding layer (2) is provided with stress relief grooves (8), which are V-shaped or U-shaped grooves and are distributed at intervals along the length of the tab.
10. The pure lithium negative tab structure of claim 1, wherein, The thickness of the metal cladding layer (2) is 0.05 to 0.15 mm.