Conductive current-collecting assembly structure and battery

Abstract

The present application relates to the technical field of batteries. Disclosed is a conductive current-collecting assembly structure and a battery. The conductive current-collecting assembly structure comprises an electrode column, a connecting piece and a protective portion, wherein the connecting piece comprises a connecting body and a protrusion, the protrusion being provided with an accommodating recess, the connecting body surrounding the periphery of the protrusion and being connected to an open end of the accommodating recess, and the protrusion being welded to the electrode column to form a first weld mark, which is located on an inner wall of the accommodating recess; and the protective portion comprises a protective layer and a first insulating portion, the protective layer being filled in the accommodating recess and covering the first weld mark, the first insulating portion being attached to the side of the connecting body away from the electrode column and covering the open end of the accommodating recess, and the first insulating portion being provided with a through hole directly facing the open end of the accommodating recess.

Description

Conductive current collector assembly structure and battery

[0001] This application claims priority to Chinese Patent Application No. 202521269285.9, filed on June 19, 2025, the entire contents of which are incorporated herein by reference.

[0002] Technical Field

[0003] This application relates to the field of battery technology, specifically to a conductive current collector assembly structure and a battery comprising the conductive current collector assembly structure.

[0004] Background Technology

[0005] In battery manufacturing, some terminals have recessed grooves that face away from the battery cell. For this terminal structure, a convex connector is typically used for welding to the terminal. Before welding, the terminal is flipped so that the groove opening faces upwards. Then, the convex connector is placed on the terminal with its convex portion aligned with the groove. During welding, a solder mark is formed on the inside of the convex portion.

[0006] Technical issues

[0007] Currently, to reduce the risk of welding slag falling into the battery and causing safety hazards, insulating sheets are generally attached to the convex connecting pieces. While this can prevent welding slag from falling into the core pack to some extent, insulating sheets such as PET film (Polyethylene Terephthalate Film) and PI film (Polyimide Film) are prone to softening or carbonization at temperatures above 150°C (for example, PI film begins to decompose above 250°C), which may lead to insulation failure, allowing welding slag to fall into the core pack and cause battery safety hazards.

[0008] Technical solutions

[0009] Firstly, a conductive current collector assembly structure is provided, comprising:

[0010] pole;

[0011] The connecting piece includes a connecting body and a protrusion, the protrusion having a receiving groove, the connecting body being circumferentially disposed around the outer periphery of the protrusion and connected to the open end of the receiving groove; the protrusion is welded to the pole to form a first weld mark, the first weld mark being located on the inner wall of the receiving groove;

[0012] The protective part includes a protective layer and a first insulating part. The protective layer fills the receiving groove and covers the first solder mark. The first insulating part is attached to the side of the connecting body away from the pole post and covers the opening end of the receiving groove. The first insulating part has a through hole facing the opening end of the receiving groove.

[0013] In a second aspect, a battery is provided, comprising a core pack, tabs, a cover plate, and the aforementioned conductive current collector assembly structure. The core pack is connected to the cover plate, and the terminal post of the conductive current collector assembly structure is fixed to the cover plate. The tabs are inserted into the core pack and welded to the connecting body of the conductive current collector assembly structure. Correspondingly, a second solder mark is formed on the connecting body. Along the axial direction of the terminal post, the second solder mark is located on the side of the connecting body opposite to the terminal post, and the first insulating portion of the conductive current collector assembly structure covers the second solder mark.

[0014] Beneficial effects

[0015] This application fills the receiving groove with a protective layer and covers the first solder mark. Since the protective layer is simultaneously connected to the bottom and sidewalls of the receiving groove, it can improve the stability of the protective layer's coverage of the first solder mark compared to conventional single-sided connection. By opening through holes in the first insulating part, the heat generated by the pole is transferred to the protective layer through the bump and then dissipated through the through holes. This reduces the probability of the protective layer falling off due to heat, causing the solder slag generated by the welding between the bump and the pole to fall into the core package, thus reducing the risk of short circuit inside the core package.

[0016] Attached Figure Description

[0017] Figure 1 is a side view of the connecting piece described in this application;

[0018] Figure 2 is a cross-sectional schematic diagram of the conductive current collector assembly structure described in this application;

[0019] Figure 3 is a cross-sectional schematic diagram of the connecting piece described in this application;

[0020] Figure 4 is a second cross-sectional view of the connecting piece described in this application;

[0021] Figure 5 is a schematic diagram of the battery described in this application.

[0022] In the picture:

[0023] 1. Connecting piece; 11. Connecting body; 12. Protrusion; 121. Receiving groove; 122. First connecting sidewall; 123. Second connecting sidewall; 2. Protective layer; 3. First insulating part; 31. Through hole; 4. First solder mark; 5. Limiting part;

[0024] 100, Core package; 200, Tab; 300, Cover plate; 400, Conductive current collector assembly structure; 410, Terminal post; 500, Second solder mark; 600, Second insulation part.

[0025] Embodiments of the present invention

[0026] To make the technical problems solved by this application, the technical solutions adopted, and the technical effects achieved clearer, the technical solutions of the embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0027] In the description of this application, unless otherwise expressly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0028] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0029] In the description of this embodiment, the terms "upper," "lower," "left," and "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used solely for ease of description and simplification of operation, 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. Furthermore, the terms "first," "second," etc., are merely used for descriptive distinction and have no special meaning.

[0030] As shown in Figures 1-3, an embodiment of this application provides a conductive current collector assembly structure, including a terminal post, a connecting piece 1, and a protective portion. The connecting piece 1 includes a connecting body 11 and a protrusion 12. The connecting body 11 is circumferentially disposed around the outer periphery of the protrusion 12. The protrusion 12 has a receiving groove 121. The connecting body 11 is connected to the open end of the receiving groove 121. The protrusion 12 is welded to the terminal post to form a first solder mark 4, which is located on the inner wall of the receiving groove 121. The protective portion includes a protective layer 2 and a first insulating portion 3. The protective layer 2 fills the receiving groove 121 and covers the first solder mark 4. The first insulating portion 3 is attached to the side of the connecting body 11 away from the terminal post and covers the open end of the receiving groove 121. The first insulating portion 3 has a through hole 31 directly opposite the open end of the receiving groove 121.

[0031] In this embodiment, the inner wall of the receiving groove 121 includes a bottom and a sidewall. The protective layer 2 filling the receiving groove 121 means that the protective layer 2 is simultaneously connected to both the bottom and the sidewall of the receiving groove 121.

[0032] In this embodiment, the connecting body 11, which is arranged around the outer periphery of the convex shroud 12, is connected to the open end of the receiving groove 121 of the convex shroud 12. After the convex shroud 12 is welded to the pole, a first weld mark 4 is formed on the inner wall of the receiving groove 121, and a protective layer 2 is filled in the receiving groove 121, so that the protective layer 2 is adhered and fixed in the receiving groove 121 and covers the first weld mark 4. Since the protective layer 2 is connected to the bottom and side wall of the receiving groove 121 at the same time, compared with the conventional single-sided connection, the coverage stability of the protective layer 2 on the first weld mark 4 is improved. In this embodiment, by attaching the first insulating part 3 to the side of the connecting body 11 away from the pole, and by opening a through hole 31 in the area of ​​the first insulating part 3 facing the open end of the receiving groove 121, the heat generated by the pole is transferred to the protective layer 2 through the convex shroud 12 and then dissipated through the through hole 31, reducing the probability that the weld slag generated during the welding of the convex shroud 12 and the pole will fall into the core package due to the protective layer 2 falling off due to heat, and reducing the risk of short circuit inside the core package.

[0033] In this embodiment, the first insulating part 3 has an adhesive surface that is bonded to the connecting body 11. The adhesive surface corresponds to the connecting body 11, that is, the adhesive surface is completely covered with a layer of adhesive. The first insulating part 3 is stably bonded to the connecting body 11 through the adhesive layer. As for the area of ​​the first insulating part 3 facing the receiving groove 121, no adhesive layer needs to be pasted.

[0034] Optionally, the first solder mark 4 is located at the bottom of the receiving groove 121, the through hole 31 is directly opposite the bottom of the groove, the protective layer 2 covers the bottom of the groove and extends to connect with the side wall of the receiving groove 121, and the heat of the protective layer 2 is dissipated through the through hole 31, which can shorten the heat dissipation path of the protective layer 2 and improve the heat dissipation effect.

[0035] In some embodiments, along the axial direction of the convex hull 12 (i.e., the direction of axis L in FIG3), the maximum thickness of the protective layer 2 is less than or equal to the depth of the receiving groove 121.

[0036] Optionally, the protective layer 2 can be a conical structure along the axial direction of the convex hull 12. The maximum thickness of the conical structure can be equal to or less than the depth of the receiving groove 121. In other embodiments, the protective layer 2 can also be a cylindrical structure, the height of which can be equal to or less than the depth of the receiving groove 121.

[0037] In some embodiments, along the axial direction of the bulge 12, the side of the protective layer 2 facing the first insulating portion 3 is flush with the side of the first insulating portion 3 facing the connecting body 11.

[0038] In this embodiment, the protective layer 2 refers to the cured protective layer 2. In this embodiment, the maximum thickness of the protective layer 2 is designed to be equal to the depth of the receiving groove 121. This avoids the protective layer 2 pressing against the first insulating part 3 and affecting the adhesion stability of the first insulating part 3. Simultaneously, the first insulating part 3 provides a certain supporting force for the protective layer 2, reducing the risk of the protective layer 2 falling off. In other embodiments, along the axial direction of the protrusion 12, the maximum thickness of the protective layer 2 is less than the depth of the receiving groove 121. When using the dispensing process, the maximum thickness of the formed protective layer 2 is located at the axis of the protrusion 12. It only needs to satisfy that the maximum thickness of the protective layer 2 is less than the depth of the receiving groove 121, meaning the protective layer 2 does not completely fill the receiving groove 121. In this case, the first insulating part 3 acts as the final barrier; even if the protective layer 2 falls off, it will fall onto the first insulating part 3.

[0039] For example, along the axial direction of the convex hull 12, the ratio of the maximum thickness of the protective layer 2 to the depth of the receiving groove 121 is 0.5-0.75. By controlling the ratio of the maximum thickness of the protective layer 2 to the depth of the receiving groove 121 to 0.5-0.75, a certain degree of connection stability can be achieved between the protective layer 2 and the inner wall of the receiving groove 121.

[0040] Optionally, in this embodiment, the ratio of the maximum thickness of the protective layer 2 along the axial direction of the convex bulge 12 to the depth of the receiving groove 121 is 0.5, 0.55, 0.6, 0.65, 0.7 or 0.75.

[0041] For example, for a convex bulge 12 with a diameter (inner diameter) of 35.1 mm and a depth of 2.7 mm, the amount of adhesive applied is about 2.2 g.

[0042] However, it should be noted that even if the protective layer 2 does not fill the entire receiving groove 121, it is still necessary to ensure that the covering surface of the protective layer 2 can completely cover the first weld mark 4. Only in this way can the weld slag be prevented from falling off.

[0043] For example, the axis of the through hole 31 coincides with the center line of the protective layer 2 along the axis of the through hole 31. Optionally, the bulge 12 is cylindrical, and the first solder mark 4 is located at the bottom of the receiving groove 121. Correspondingly, the protective layer 2 completely covers the first solder mark 4 and is connected to the side wall of the receiving groove 121. In this embodiment, by designing the axis of the through hole 31 to coincide with the axis of the bulge 12, that is, coinciding the axis of the through hole 31 with the center line of the protective layer 2, not only can the heat dissipation effect of the protective layer 2 be improved, but it also has a positioning function for the mounting of the first insulating part 3. When mounting the first insulating part 3, the through hole 31 can be aligned with the center of the protective layer 2, which improves the consistency of the adhesive layer bonding position on the first insulating part 3. The effective area of ​​the insulation of the tab (the tab is welded to the connecting body 11) is ensured by positioning the adhesive through the through hole 31.

[0044] Optionally, the through-hole 31 can be elliptical, circular, or polygonal. The polygonal structure can be a regular polygon such as an equilateral triangle, a square, a rectangle, a regular pentagon, or a regular hexagon, or an irregular polygon such as a right triangle or a trapezoid. Of course, the structure of the through-hole 31 in this embodiment is not limited to this; it only needs to prevent the protective layer 2 from falling out of the through-hole 31 while providing sufficient heat dissipation. The number of through-holes 31 in this embodiment is also not limited to one. In addition to providing a through-hole 31 at the center of the first insulating part 3, multiple holes can be arranged circumferentially around the central through-hole 31 to assist in heat dissipation and improve the heat dissipation effect.

[0045] In this embodiment, the cross-sectional area of ​​the through hole 31 along its radial direction is not less than 1 square millimeter, so that the through hole 31 has sufficient heat dissipation effect. The inner diameter of the through hole 31 does not exceed the inner diameter of the convex 12, so as to prevent the protective layer 2 from passing through.

[0046] For example, the protective layer 2 is a hot melt adhesive protective layer. In actual operation, the hot melt adhesive is heated to 190±10℃ and melted, and is in a flowable state. A dispensing gun is used to apply the adhesive to the bottom of the receiving tank 121, ensuring that the bottom of the receiving tank 121 is completely covered by the hot melt adhesive protective layer, and that the outer periphery of the hot melt adhesive protective layer is bonded to the sidewall of the receiving tank 121. The hot melt adhesive protective layer formed by dispensing can seamlessly cover the uneven surface of the first solder mark 4, avoiding air bubbles and uncovered areas, blocking the electrolyte penetration path, preventing metal corrosion, and solving the problem of the first insulating part 3 easily falling off due to uneven bonding surfaces when the first insulating part 3 is bonded to the first solder mark 4, thereby reducing solder slag falling off.

[0047] When the hot melt adhesive protective layer is heated to a molten state, the through hole 31 on the first insulating part 3 also has an overflow function for the molten hot melt adhesive protective layer, preventing the hot melt adhesive protective layer from expanding due to heat and pushing the protective layer 2 out to separate from the connecting piece 1, thus causing insulation failure.

[0048] The hot melt adhesive protective layer in this embodiment can better adapt to thermal expansion and contraction, avoiding edge cracking caused by temperature cycling; during battery charging and discharging, the elastic modulus of the hot melt adhesive protective layer can buffer the deformation stress of the terminal post, reducing the risk of fatigue fracture of the solder joint, while traditional adhesive application to the insulation part can usually only provide a single insulation function.

[0049] Specifically, after the convex bulge 12 is welded to the pole post, an adhesive dispensing operation is performed in the receiving groove 121. The specific steps are as follows:

[0050] (1) Provide hot melt adhesive, heat the hot melt adhesive to a molten state, and set the dispensing head movement trajectory (moving spirally from the outside to the inside to the center).

[0051] (2) Spray hot melt adhesive from the outlet onto the first weld mark 4 on the welding surface of the protrusion 12 and the pole post (bottom of the receiving groove 121), and completely fill the entire receiving groove 121;

[0052] (3) During the dispensing process, the dispensing position is blown with air to make the hot melt adhesive evenly distributed on the surface of the first solder mark 4 and to accelerate the cooling and curing of the hot melt adhesive.

[0053] (4) The hot melt adhesive is cured and bonded to the surface of the first solder mark 4 to form a protective layer 2.

[0054] After prolonged use, the adhesion between the protective layer 2 and the inner wall of the receiving groove 121 weakens. When the protective layer 2 fills the entire protrusion 12, the first insulating part 3 can provide a certain lifting force to the protective layer 2, reducing the risk of the protective layer 2 falling off.

[0055] In this embodiment, the term "filled" means that the maximum thickness of the protective layer 2 is equal to the depth of the receiving groove 121.

[0056] In some other embodiments, the protective layer 2 may also be a thermally conductive adhesive, which fills the receiving groove 121 and is bonded to the first insulating part 3. The thermally conductive adhesive transfers heat to the first insulating part 3 for heat dissipation. When the first insulating part 3 has a through hole 31, the heat of the protective layer 2 is dissipated through the through hole 31.

[0057] Optionally, the conductive current collection assembly structure of this embodiment further includes a limiting part 5, which is arranged around the side wall of the receiving groove 121. There is a gap between the limiting part 5 and the bottom of the receiving groove 121. The limiting part 5 has a clearance hole for the welding head to pass through. The limiting part 5 is embedded in the protective layer 2, or the protective layer 2 is located on the side of the limiting part 5 away from the opening end.

[0058] It is understandable that the limiting part 5 is arranged around the side wall of the receiving groove 121. After the protective layer 2 is made by dispensing or applying glue, the protective layer 2 can be located on the side of the limiting part 5 away from the opening end or the limiting part 5 can be embedded in the protective layer 2. The limiting part 5 provides a certain support force to the protective layer 2, which can improve the bonding stability between the protective layer 2 and the first solder mark 4.

[0059] Optionally, as shown in Figure 3, the sidewall of the convex hull 12 is bent inward to form the limiting part 5. In this embodiment, the connecting body 11, the convex hull 12 and the limiting part 5 are integrally formed, which can improve the connection stability between the connecting body 11 and the pole post and the pole tab (the pole tab is electrically connected to the pole post through the connecting body 11).

[0060] The limiting part 5 can be perpendicular to the side wall of the receiving groove 121, or it can be set at an angle of less than 180° with the side wall of the receiving groove 121, which can also provide support for the protective layer 2.

[0061] Specifically, the sidewall of the convex bulge 12 includes a first connecting sidewall 122 and a second connecting sidewall 123 spaced apart along the axial direction of the convex bulge 12. One end of the second connecting sidewall 123 is an open end. The limiting part 5 includes two tightly fitted limiting plates. The ends of the two limiting plates away from the sidewall are connected to each other. The other end of one limiting plate is connected to the first connecting sidewall 122, and the other end of the other limiting plate is connected to the second connecting sidewall 123.

[0062] Taking the annular limiting part 5 as an example, the radial width of the limiting part 5 should not be too large. That is, the center of the limiting part 5 has a clearance hole to avoid interference with laser welding and dispensing (or applying glue). The size of the clearance hole is determined according to the size of the convex hull 12, and will not be described in detail here.

[0063] In other embodiments, as shown in FIG4, the receiving groove 121 has a conical structure, and the diameter of the opening end of the receiving groove 121 is smaller than the diameter of the bottom wall of the receiving groove 121. The protective layer 2 is filled in the receiving groove 121. Even if the adhesive surface between the protective layer 2 and the side wall of the receiving groove 121 separates due to heat and / or the first insulating part 3 ages and fails to maintain insulation, the side wall of the conical receiving groove 121 can still provide support for the protective layer 2, preventing the protective layer 2 from falling off. This can prevent the welding slag generated by welding the pole and the protrusion 12 from falling into the core package.

[0064] The conductive current collector assembly structure in this embodiment is particularly suitable for poles with a groove. When the pole has a groove, the protrusion 12 is located in the groove, and the outer wall of the protrusion 12 fits against the inner wall of the groove, which further improves the welding stability between the protrusion 12 and the pole.

[0065] This embodiment also provides a battery, as shown in FIG5. The battery includes a core pack 100, tabs 200, a cover plate 300, and a conductive current collector assembly structure 400 according to any embodiment of this application. The core pack 100 is connected to the cover plate 300, and the terminal post 410 of the conductive current collector assembly structure 400 is fixed on the cover plate 300. The tabs 200 are inserted into the core pack 100 and welded to the connecting body 11 of the conductive current collector assembly structure 400. Correspondingly, a second solder mark 500 is formed on the connecting body 11. Along the axial direction of the terminal post 410, the second solder mark 500 is located on the side of the connecting body 11 away from the terminal post 410. The first insulating part 3 of the conductive current collector assembly structure 400 covers the second solder mark 500. By using this conductive current collector assembly structure 400, the risk of the first solder mark 4 caused by the welding of the protrusion 12 and the terminal post 410 due to the heat-induced peeling of the protective layer 2 falling into the core pack 100 and causing a short circuit can be reduced.

[0066] The first insulating part 3 covers the second solder mark 500, which effectively forms an insulating structure between the tab 200 and the core pack 100, reducing the occurrence of the tab 200 breaking and being inserted into the core pack 100 in reverse, and reducing the probability of micro short circuit or high voltage breakdown caused by lack of insulation during battery assembly.

[0067] The battery of this embodiment includes two conductive current collector assembly structures 400, one of which serves as a positive conductive current collector assembly structure and the other as a negative conductive current collector assembly structure. The connecting body 11 of each conductive current collector assembly structure 400 has four welding areas for welding to the positive or negative electrode tab, and the four welding areas are arranged circumferentially around the bulge 12.

[0068] The battery in this embodiment also includes a second insulating part 600, which is bonded to the tab 200 to increase the effective insulation area of ​​the tab 200.

[0069] Of course, in other embodiments, the second insulating part 600 can be removed and the area of ​​the first insulating part 3 can be increased, which is equivalent to combining the first insulating part 3 and the second insulating part 600 into one, and only one pasting is required.

Claims

1. A conductive current collector assembly structure, comprising: pole; The connecting piece includes a connecting body and a protrusion, the protrusion having a receiving groove, the connecting body being circumferentially disposed around the outer periphery of the protrusion and connected to the open end of the receiving groove; the protrusion is welded to the pole to form a first weld mark, the first weld mark being located on the inner wall of the receiving groove; The protective part includes a protective layer and a first insulating part. The protective layer fills the receiving groove and covers the first solder mark. The first insulating part is attached to the side of the connecting body away from the pole post and covers the opening end of the receiving groove. The first insulating part has a through hole facing the opening end of the receiving groove.

2. The electrically conductive current collecting assembly structure of claim 1, wherein, The first solder mark is located at the bottom of the receiving groove, and the through hole is directly opposite the bottom of the groove.

3. The electrically conductive current collecting assembly structure of claim 2, wherein, The axis of the through hole coincides with the center line of the protective layer along the axis of the through hole.

4. The electrically conductive current collecting assembly structure of claim 2, wherein, Along the axial direction of the convex hull, the maximum thickness of the protective layer is less than or equal to the depth of the receiving groove.

5. The electrically conductive current collecting assembly structure of claim 2, wherein, Along the axial direction of the convex bulge, the side of the protective layer facing the first insulating part is flush with the side of the first insulating part facing the connecting body.

6. The electrically conductive current collecting assembly structure of claim 2, wherein, Along the axial direction of the convex hull, the ratio of the maximum thickness of the protective layer to the depth of the receiving groove is 0.5-0.

75.

7. The conductive current collection assembly structure according to any one of claims 1 to 6 further includes a limiting part, the limiting part being circumferentially disposed on the side wall of the receiving groove, the limiting part having a gap with the bottom of the receiving groove, and the limiting part having a clearance hole for the welding head to pass through; the limiting part being embedded in the protective layer, or the protective layer being located on the side of the limiting part away from the opening end.

8. The electrically conductive current collecting assembly structure of claim 7, wherein, The sidewall of the convex bulge bends inward to form the limiting portion.

9. The electrically conductive current collecting assembly structure according to any one of claims 1 to 6, wherein, The receiving groove has a conical structure, and the diameter of the opening end of the receiving groove is smaller than the diameter of the bottom wall of the receiving groove.

10. A battery comprising a core pack, tabs, a cover plate, and a conductive current-collecting assembly structure according to any one of claims 1 to 9, wherein the core pack is connected to the cover plate, and the terminal of the conductive current-collecting assembly structure is fixed to the cover plate; the tabs are inserted into the core pack and welded to the connecting body of the conductive current-collecting assembly structure, and a second solder mark is formed on the connecting body correspondingly, the second solder mark being located on the side of the connecting body away from the terminal along the axial direction of the terminal, and the first insulating portion of the conductive current-collecting assembly structure covering the second solder mark.

Images