A type of all-electrode lithium-ion battery

Abstract

This application discloses a full-tab lithium-ion battery, including: a shell, a core, a cover structure, and a sealing and insulating component; the shell and the cover structure together enclose an inner cavity, and the core is disposed in the inner cavity; the cover structure includes an upper cover structure and a lower cover structure, which are located at both ends of the core; the sealing and insulating component is an integrally formed sealing and insulating structure, which is installed on the upper end face and outer circular surface of the upper cover structure, and simultaneously realizes the electrical insulation and sealing functions of the upper cover structure.

Description

Technical Field

[0001] This application relates to the field of power lithium-ion battery technology, and more specifically to a full-tab lithium-ion battery. Background Technology

[0002] Currently, in the structural design of all-tab lithium-ion batteries, the sealing performance and electrical insulation performance of the cover structure and the casing are crucial to ensuring the safe operation and lifespan of the battery. In existing technologies, the upper cover structure of all-tab lithium-ion batteries typically requires separate sealing and insulating components: the sealing component is used to block electrolyte leakage paths and ensure the internal sealing of the casing; the insulating component is used to achieve electrical isolation between the upper cover structure and the casing and external circuitry, preventing the risk of short circuits.

[0003] However, separating the sealing and insulating components has significant drawbacks: each component requires a separate installation station and is assembled in stages, which not only increases the variety of parts and inventory management costs but also leads to low production efficiency due to the multi-stage assembly process. Furthermore, tiny gaps can easily form at the joints between the sealing and insulating components, and the assembly tolerances of each component may result in loose fits. These gaps can become potential channels for electrolyte leakage, and incomplete insulation may also cause localized leakage risks.

[0004] Therefore, how to simplify the assembly process of all-tab lithium-ion batteries while improving the integrated reliability of sealing and insulation functions has become a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0005] The purpose of this application is to provide a full-tab lithium-ion battery to improve the integrated reliability of sealing and insulation functions in a full-tab lithium-ion battery.

[0006] To achieve the above objectives, the technical solution adopted in this application is as follows: A full-tab lithium-ion battery is provided, comprising: a casing, a core, a cover structure, and a sealing and insulating component; the casing and the cover structure together form an inner cavity, and the core is disposed within the inner cavity; the cover structure includes an upper cover structure, the core is a wound structure, and one end of the core near the upper cover structure includes a negative electrode aluminum foil full tab, which is shaped to form a negative electrode shaped tab, and the negative electrode shaped tab is welded to the upper cover structure; the sealing and insulating component is an integrally formed sealing and insulating structure, comprising a first end and a second end, the first end being installed on the upper end face of the upper cover structure, and the second end being installed on the outer circular surface of the upper cover structure, wherein the upper end face and the outer circular surface of the upper cover structure are located on two different planes and are respectively disposed on the end face and side wall of the full-tab lithium-ion battery.

[0007] As a preferred embodiment, the upper cover structure includes an upper electrode cover and an upper current collector cover. One side of the upper current collector cover is connected to the negative electrode shaping tab, and the other end is connected to the upper electrode cover. A sealing and insulating element is provided between the upper electrode cover and the housing. The upper electrode cover includes the upper end face and the outer circular face.

[0008] Preferably, the edge of the upper end face extends outward beyond the outer circular surface to form a first clamping part, and the first clamping part clamps the sealing and insulating member with the housing.

[0009] As another preferred embodiment, the upper end face of the upper pole cover forms a groove opposite to the first end, and the cross-section of the groove is an inverted triangle or an inverted trapezoid.

[0010] Further preferably, a square explosion-proof sheet is provided on the side of the housing.

[0011] Further preferably, a second clamping part is provided on the side of the housing near the end of the sealing and insulating member.

[0012] Preferably, the cover structure further includes a lower cover structure, wherein one end of the core near the lower cover structure includes a positive aluminum foil tab, the positive aluminum foil tab being shaped to form a positive shaped tab, and the positive shaped tab being welded to the lower cover structure; the lower cover structure includes a lower electrode cover and a lower current collector cover, one side of the lower current collector cover being connected to the lower electrode cover, the other side of the lower current collector cover being welded to the positive shaped tab, and the lower current collector cover and the housing being integrally formed.

[0013] Further preferably, the lower electrode cover also includes an injection hole for injecting electrolyte into the inner cavity of the housing.

[0014] Preferably, the all-tab lithium-ion battery further includes a rubber stopper and an aluminum stopper, both of which are inserted into the injection hole.

[0015] Preferably, the aluminum plug is a solid structure.

[0016] Preferably, the aluminum plug is fitted to the rubber plug, and an extension is provided on the side of the aluminum plug near the rubber plug. The extension protrudes outward relative to the end face of the rubber plug, so that the cross-sectional area of ​​the aluminum plug is larger than that of the rubber plug, and the aluminum plug can completely cover the rubber plug. The aluminum plug and the rubber plug form a stepped structure with different heights in the injection hole.

[0017] Compared with the prior art, the beneficial effects of this application are as follows:

[0018] The one-piece molded sealing and insulating component can complete the installation of the upper end face and outer circular face of the upper cover structure in one go, avoiding secondary assembly, reducing assembly processes and parts inventory costs, while reducing the risk of process defects caused by improper assembly of multiple parts, and significantly improving production efficiency and assembly stability.

[0019] Meanwhile, the one-piece molded structure covers the upper surface and outer circular surface of the cover with a continuous material form, avoiding gaps caused by splicing multiple parts, and forming a seamless protective system for sealing and insulation functions. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the exploded structure of a full-tab lithium-ion battery.

[0021] Figure 2 This is a schematic diagram of a type of all-tab lithium-ion battery.

[0022] Figure 3 For along Figure 2 Sectional view along the middle AA direction;

[0023] Figure 4 for Figure 3 A magnified view of the area along the B direction;

[0024] Figure 5 for Figure 3 A magnified view of the area along the C-axis;

[0025] Figure 6 This is a structural diagram of the bottom of the shell.

[0026] In the diagram: 100, full-tab lithium-ion battery; 1, casing; 11, second clamping part; 2, core; 30, upper cover structure; 40, lower cover structure; 3, lower electrode cover; 4, upper electrode cover; 41, groove; 42, upper end face; 43, outer circular surface; 44, first clamping part; 5, sealing and insulating component; 51, first end; 52, second end; 6, upper current collector cover; 7, rubber plug; 8, aluminum plug; 81, extension part; 9, square explosion-proof sheet; 10, lower current collector cover. Detailed Implementation

[0027] The present application will be further described below with reference to specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0028] In the description of this application, it should be noted that the directional terms such as "center", "lateral", "longitudinal", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", and "counterclockwise" indicate the orientation and positional relationship based on the orientation or positional relationship shown in the accompanying drawings. 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. They should not be construed as limiting the specific protection scope of this application.

[0029] It should be noted that the terms "first," "second," etc., in the specification and claims of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0030] The terms “comprising” and “having”, and any variations thereof, in the specification and claims of this application are intended to cover non-exclusive inclusion, for example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product, or device.

[0031] In a preferred embodiment, see Figures 1 to 6 This application provides a full-tab lithium-ion battery 100, including: a shell 1, a core 2, a cover structure, and a sealing and insulating component 5; the shell 1 and the cover structure together form an inner cavity, and the core 2 is disposed in the inner cavity; the cover structure includes an upper cover structure 30 and a lower cover structure 40, which are located at both ends of the core 2; the sealing and insulating component 5 is an integrally formed sealing and insulating structure, which includes a first end 51 and a second end 52. The first end 51 is installed on the upper end face 42 of the upper cover structure 30, and the second end 52 is installed on the outer circular surface 43 of the upper cover structure 30. The upper end face 42 and the outer circular surface 43 of the upper cover structure 30 are located on two different planes and are respectively disposed on the end face and side wall of the full-tab lithium-ion battery 100. The first end 51 and the second end 52 cooperate to simultaneously realize the electrical insulation and sealing functions of the upper cover structure 30.

[0032] The welding of the core 2 and the shell 1 can be achieved by first fixing the spatial position of the core 2 and the shell 1 with a tooling fixture, then pressing the core 2 into the shell and ensuring that the positive end face of the core 2 is in reliable contact with the lower end face of the shell 1, and then fixing the core 2 and the shell 1 with the beam emitted by the laser welding machine. The core 2 is a wound structure. The end of the core 2 near the upper cover structure 30 includes a negative aluminum foil (copper foil) full electrode tab. After being shaped, the negative aluminum foil full electrode tab forms a negative shaped electrode tab, which is welded to the upper cover structure 30. Similarly, the end of the core 2 near the lower cover structure 40 includes a positive aluminum foil full electrode tab. After being shaped, the positive aluminum foil full electrode tab forms a positive shaped electrode tab, which is welded to the lower cover structure 40.

[0033] In related technologies, sealing and insulation functions are often achieved by independent components, such as separate sealing rings and insulating gaskets. These require separate installation positions and step-by-step assembly, which not only increases the number of parts but may also increase assembly complexity due to the tolerances of multiple components. In contrast, the one-piece molded sealing and insulating component 5 can complete the installation of the upper end face 42 and outer circular face 43 of the upper cover structure 30 in one go, avoiding secondary assembly, reducing assembly steps and parts inventory costs, and reducing the risk of process defects caused by improper assembly of multiple components, thus significantly improving production efficiency and assembly stability.

[0034] When independent seals and insulators are assembled, tiny gaps can easily exist between them and at the contact points with the cover structure, potentially leading to electrolyte leakage or localized leakage due to insulation failure at these gaps. The one-piece molded structure, by covering the upper surface 42 and outer circular surface 43 of the cover with a continuous material form, avoids gaps caused by splicing multiple components, creating a seamless sealing and insulation protection system. On one hand, it allows for a tighter fit to the cover structure surface, enhancing the barrier against electrolyte; on the other hand, it ensures the continuity of insulation between the cover and other components, reducing the risk of short circuits due to insulation failure and improving battery safety and reliability from the structural root.

[0035] Meanwhile, the unibody structure eliminates the need for additional space to accommodate independent seals and insulation components, allowing for a more compact design that reduces the space occupied inside the battery. In scenarios where high energy density is pursued in all-tab lithium-ion batteries, this space optimization allows for more room to be reserved for core energy storage components such as the core.

[0036] As a preferred embodiment, the upper cover structure 30 includes an upper electrode cover 4 and an upper current collector cover 6. One side of the upper current collector cover 6 is connected to the negative electrode shaping tab, and the other end is connected to the upper electrode cover 4. A sealing and insulating element 5 is provided between the upper electrode cover 4 and the housing 1. The upper electrode cover 4 includes an upper end face 42 and an outer circular face 43. The sealing and insulating element 5 covers the upper end face 42 and the outer circular face 43 of the upper electrode cover 4.

[0037] Furthermore, the lower cover structure 40 includes a lower electrode cover 3 and a lower current collector cover 10. One side of the lower current collector cover 10 is connected to the lower electrode cover 3, and the other side of the lower current collector cover 10 is welded to the positive electrode shaping tab. See [reference needed]. Figure 6 The lower flow cover 10 and the housing 1 are integrated into one structure.

[0038] The welding of the upper current collector cover 6 to the negative electrode of the battery core 2 facilitates charge discharge. The spatial position of the battery core 2 and the upper current collector cover 6 can be fixed first using a tooling fixture, and then the beam emitted by the laser welding machine can reliably fix the negative end face of the battery core 2 to the lower end face of the upper current collector cover 6. The welding of the upper electrode cover 4 to the upper current collector cover 6 facilitates the flow of current to the electrical appliance. The spatial position of the upper electrode cover 4 and the upper current collector cover 6 can be fixed first using a tooling fixture, and then the tooling can drive the upper current collector cover 6 and the core 2 to rotate together around their own axis. Then the beam emitted by the laser welding machine can reliably fix the outer circular surface 43 at the connection between the upper electrode cover 4 and the upper current collector cover 6.

[0039] The shell 1 and the lower current collector 10, which are integrally formed, are fused into a single component through an integral molding process, eliminating the connection interface and making the shell 1 and the lower current collector 10 form a rigid whole that is seamlessly connected. This significantly improves the vibration and impact resistance of the bottom structure of the battery and further ensures the long-term safety of the battery.

[0040] Preferred, see Figure 4 The edge of the upper end face 42 extends outward beyond the outer circular face 43 to form a first pressing part 44. The first pressing part 44 clamps the sealing and insulating part 5 with the housing 1, thereby further improving the assembly reliability of the sealing and insulating part 5.

[0041] As another preferred option, see Figure 4 The upper end face 42 of the upper pole cover 4 has a recessed groove 41 on the side near the sealing and insulating component 5. The cross-section of the groove 41 is an inverted triangle or an inverted trapezoid.

[0042] According to this application, the first end 51 of the sealing insulation member 5 is the core area for achieving electrical insulation between the upper electrode cover 4 and external components. Its insulation effect depends on the tight fit with the surface of the upper electrode cover 4. The concave groove 41 provides precise assembly guidance for the first end 51 of the sealing insulation member 5: on the one hand, the angle of the bevel can complement the edge shape of the sealing insulation member 5, guiding the sealing insulation member 5 to be quickly positioned during assembly and avoiding uneven fit of the insulation surface due to installation offset; on the other hand, the concave shape of the bevel can increase the contact area between the sealing insulation member 5 and the upper electrode cover 4, and the pressure transmission through the bevel makes the two fit more tightly, reducing the risk of insulation failure caused by gaps and ensuring the stable performance of the insulation function of the first end 51.

[0043] Furthermore, the second end 52 (side position) of the sealing insulation member 5 undertakes the main sealing function, while the groove 41 forms a secondary sealing function by cooperating with the first end 51 in the sealing insulation member 5, playing a secondary sealing role. This is equivalent to adding an extra sealing defense line on the basis of the main seal (outer circular surface 43 position), which greatly improves the overall sealing reliability.

[0044] For further optimization, see [link to relevant documentation]. Figure 2 A square explosion-proof sheet 9 is provided on the side of the housing 1 to ensure the safety of compression.

[0045] The explosion-proof structures in related technologies (such as circular orifice explosion-proof sheets) have limited venting area. When a large amount of gas is generated inside the battery due to thermal runaway, short circuits, or other problems, the narrow venting channel may prevent the pressure from being released quickly, leading to serious safety accidents such as casing rupture and explosion. However, the square explosion-proof sheet 9 in this application can form a larger venting area through planar laying, with an effective venting area far greater than that of a point-type structure. When the internal pressure reaches the opening threshold of the explosion-proof sheet, the square area can rupture or open entirely, providing a smoother release path for the gas, significantly shortening the duration of the pressure peak, rapidly reducing the internal pressure of the battery, and fundamentally reducing the risk of severe runaway caused by pressure accumulation.

[0046] For further optimization, see [link to relevant documentation]. Figure 4 The side of the housing 1 near the end of the sealing and insulating member 5 is provided with a second pressing part 11. Specifically, the housing 1 is provided with a second pressing part 11 at a position opposite to the second end 52 of the sealing and insulating member 5. The second pressing part 11 clamps the second end 52 with the outer circular surface 43.

[0047] Specifically, the fully automated assembly equipment relies on the precise gripping of robotic arms or clamps to complete the handling, positioning and assembly of batteries. The contour of the recessed area on the housing 1 can complement and adapt to the clamping end of the equipment clamp. The clamp achieves stable clamping of the battery by embedding the second pressing part 11, avoiding relative sliding caused by the smooth surface of the housing 1, and ensuring the stability of the battery posture during the clamping process. Therefore, the second pressing part 11 also provides the function of being clamped.

[0048] In a further preferred embodiment, the lower electrode cover 3 also includes an injection hole for injecting electrolyte into the inner cavity of the housing 1. The full-tab lithium-ion battery 100 also includes a rubber stopper 7 and an aluminum stopper 8, both of which are inserted into the injection hole to prevent battery leakage.

[0049] Furthermore, in the related technology, the hollow aluminum plug 8 has an internal cavity, which causes uneven heat distribution when heated. It is prone to local deformation due to differences in thermal expansion, such as the edge lifting. This leads to a decrease in the fitting accuracy between the aluminum plug 8 and the injection hole. During welding, the laser can easily penetrate the aluminum plug 8 directly, resulting in a very high battery leakage rate and a low welding yield.

[0050] In this application, the aluminum plug 8 is preferably a solid structure. The solid aluminum plug 8 has a uniform material composition, allowing laser heat to be uniformly conducted through the solid material during welding, thus avoiding the localized stress concentration problems caused by the cavity in a hollow structure. This ensures that the aluminum plug 8 maintains a tight fit with the injection hole after heating, reducing edge warping and morphological distortion, providing a stable structural foundation for subsequent welding processes, ensuring precise relative positioning between the aluminum plug 8 and the injection hole, and reducing the risk of welding deviations due to deformation.

[0051] Meanwhile, the solid aluminum plug 8 has no internal cavity, and the overall structural strength is uniform and higher. It can effectively resist the energy impact during laser welding and avoid energy concentration breakdown caused by cavity defects. This ensures that a complete and dense fusion layer is formed in the welding area, significantly reducing the risk of leakage and improving the sealing reliability of the injection hole.

[0052] Preferred, see Figure 1 and Figure 5 The end face of the rubber stopper 7 is fitted to the end face of the aluminum stopper 8. An extension 81 is provided on the side of the aluminum stopper 8 near the rubber stopper 7. The extension 81 protrudes outward relative to the end face of the rubber stopper 7, so that the cross-sectional area of ​​the aluminum stopper 8 is larger than the cross-sectional area of ​​the rubber stopper 7, and the aluminum stopper 8 can completely cover the rubber stopper 7. The aluminum stopper 8 and the rubber stopper 7 form a stepped structure with different heights in the injection hole.

[0053] In some related technologies, the small welding surface can easily lead to problems such as the aluminum plug 8 warping and insufficient welding, increasing the risk of leakage. However, the stepped structure in this application, with the aluminum plug 8 completely covering the rubber plug 7, creates a larger welding contact area. On the one hand, the larger contact area can disperse welding stress, reducing warping of the aluminum plug 8 due to uneven local stress, and ensuring a tight fit between the aluminum plug 8 and the edge of the injection hole. On the other hand, the ample welding surface provides a more stable working area for laser welding, reducing the probability of incomplete or weak welds caused by an insufficient welding surface, resulting in a more complete and uniform weld fusion layer, structurally ensuring the initial sealing effect of the injection hole.

[0054] In related technologies, the welding area of ​​the aluminum plug 8 is relatively small, and during welding, the laser can easily irradiate the rubber plug 7 below, causing the rubber plug 7 to burst due to high temperature and lose its sealing function. However, the stepped structure in this application, through the aluminum plug 8 covering the rubber plug 7 and the staggered step, makes the aluminum plug 8 the sole target of laser irradiation. The aluminum plug 8, as the lower structure, completely blocks the rubber plug 7, thereby further reducing the risk of leakage.

[0055] Meanwhile, in terms of production efficiency, the stable welding effect reduces rework rates caused by edge warping, incomplete welding, and damage to the rubber stopper. The larger welding surface makes laser welding parameters easier to control, shortening the welding time per battery and improving production efficiency. The reduced rework rate decreases the additional investment in manpower and materials, and the lower defect rate also reduces scrap losses, providing better economic and stability support for the large-scale production of all-tab lithium-ion batteries.

[0056] The basic principles, main features, and advantages of this application have been described above. Those skilled in the art should understand that this application is not limited to the above embodiments. The embodiments and descriptions in the specification are merely the principles of this application. Various changes and modifications can be made to this application without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claims. The scope of protection claimed by this application is defined by the appended claims and their equivalents.

Claims

1. A full tab lithium-ion battery, comprising: A shell, a core, and a cover structure, wherein the shell and the cover structure together enclose an inner cavity, the core is disposed in the inner cavity, the cover structure includes an upper cover structure, the core includes a negative electrode shaping tab, and the negative electrode shaping tab is connected to the upper cover structure, characterized in that: The all-tab lithium-ion battery further includes a sealing and insulating component disposed between the housing and the upper cover structure. The sealing and insulating component is an integrally formed structure and includes a first end and a second end. The upper cover structure includes an upper end face and an outer circular surface that is not the same as the upper end face. The first end is located between the upper end face and the housing, and the second end is located between the outer circular surface and the housing.

2. The all-tab lithium-ion battery as described in claim 1, characterized in that, The upper cover structure includes an upper electrode cover and an upper current collector cover. One side of the upper current collector cover is connected to the negative electrode shaping tab, and the other end is connected to the upper electrode cover. The sealing and insulating element is provided between the upper electrode cover and the housing. The upper electrode cover includes the upper end face and the outer circular face.

3. The full tab lithium ion battery of claim 2, wherein, The edge of the upper end face extends outward beyond the outer circular surface to form a first clamping part, which clamps the sealing and insulating member with the housing.

4. The full-tab lithium-ion battery as described in claim 2, wherein the upper end face of the upper electrode cover forms a groove opposite to the first end face, and the cross-section of the groove is an inverted triangle or an inverted trapezoid.

5. The all-tab lithium-ion battery as described in claim 1, characterized in that, A square explosion-proof plate is provided on the side of the housing.

6. The all-tab lithium-ion battery as described in any one of claims 1-5, characterized in that, The housing is provided with a second clamping part at a position opposite to the second end of the sealing and insulating member, and the second clamping part clamps the second end with the outer circular surface.

7. The all-tab lithium-ion battery as described in claim 1, characterized in that, The cover structure also includes a lower cover structure, and the end of the core near the lower cover structure includes a positive electrode shaping tab, which is connected to the lower cover structure. The lower cover structure includes a lower electrode cover and a lower current collector cover. One side of the lower current collector cover is connected to the lower electrode cover, and the other side of the lower current collector cover is connected to the positive electrode shaping tab. The lower current collector cover and the housing are integrally formed.

8. The full tab lithium ion battery of claim 7, wherein, The lower electrode cap also includes a liquid injection hole and a rubber plug and an aluminum plug disposed in the liquid injection hole, wherein the aluminum plug is welded to the lower electrode cap.

9. The all-tab lithium-ion battery as described in claim 8, characterized in that, The end face of the rubber stopper is fitted to the end face of the aluminum stopper. An extension is provided on the side of the aluminum stopper near the rubber stopper. The extension protrudes outward relative to the end face of the rubber stopper, so that the cross-sectional area of ​​the aluminum stopper is larger than that of the rubber stopper.

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