Collecting plate and cylindrical battery

Abstract

The collector plate comprises an upper plate body and a lower plate body, the upper plate body is opposite to a first tab, one surface of the upper plate body is used for welding the first tab, and the other surface of the upper plate body is conducted with a pole of the cylindrical battery; the lower plate body is opposite to the second tab, one surface of the lower plate body is used for welding the second tab, and the other surface of the lower plate body is conducted with the other pole of the cylindrical battery; at least one of the upper plate body and the lower plate body comprises a tab welding part and a collector plate welding part which are detachably connected. According to the utility model, at least one of the upper plate body and the lower plate body is divided into the collector plate welding part and the tab welding part which are detachably connected, so that when the collector plate is welded, the thinner tab welding part and the tab are welded together, the laser power required by welding can be reduced, and the welding efficiency is improved under the condition that the current guiding capability of the collector plate is maintained. And the area of the tab and the roll core affected by heat during welding is reduced, the probability of damage to the diaphragm is reduced, and the yield of cylindrical battery preparation is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of lithium-ion batteries, in particular to a current collecting plate and a cylindrical battery. Background Art

[0002] Lithium-ion batteries, the leading secondary battery, have dominated the portable electronics and electric vehicle markets and, in recent years, have also entered the energy storage sector. Lithium-ion batteries offer advantages over single-electrode batteries due to their short electron transmission paths, low local resistance, and more uniform temperature and current density distribution. During the lithium-ion battery manufacturing process, current collector plates are welded to conduct the electrical energy from the cell to the battery, making them crucial to the success of lithium-ion battery manufacturing.

[0003] The collector plates and tabs of lithium-ion batteries are usually welded together using laser welding. However, to ensure that lithium-ion batteries have a high energy density, the tab area of ​​the battery cell is relatively thin, which makes the welding interface close to the diaphragm. The heat generated during laser welding can easily be transferred to the diaphragm, causing it to shrink or even burn, thereby affecting the yield of the lithium-ion battery. Utility Model Content

[0004] The main purpose of the utility model is to provide a current collecting plate, aiming to solve the problem that the existing current collecting plate easily affects the diaphragm during welding.

[0005] To achieve the above objectives, the present invention provides a current collecting plate for welding tabs of cylindrical batteries, wherein the tabs include a first tab and a second tab with opposite polarities, the first tab and the second tab being disposed at both ends of a winding core of the cylindrical battery. The current collecting plate comprises:

[0006] An upper plate, the upper plate being opposite to the first electrode tab, having one surface for welding the first electrode tab and the other surface being connected to a pole of the cylindrical battery;

[0007] A lower plate body, the lower plate body is opposite to the second pole tab, one side of the lower plate body is used for welding the second pole tab, and the other side is connected to the other pole column of the cylindrical battery; at least one of the upper plate body and the lower plate body includes a detachably connected pole tab welding portion and a current collecting plate welding portion.

[0008] In some embodiments, the upper disk body includes a first tab welding portion and a first current collecting disk welding portion, and the first tab welding portion and the first current collecting disk welding portion are constructed with a matching first concave-convex structure for interlocking the two.

[0009] In some embodiments, the lower plate body includes a second tab welding portion and a second current collecting plate welding portion, and the second tab welding portion and the second current collecting plate welding portion are configured with a matching second concave-convex structure for interlocking the two.

[0010] In some embodiments, a first liquid injection hole is opened at the center of the first tab welding portion, and the first liquid injection hole is used to inject electrolyte.

[0011] In some embodiments, a second liquid injection hole is opened at the center of the second tab welding portion, and the second liquid injection hole is the same size as the first liquid injection hole.

[0012] In some embodiments, the first concave-convex structure includes first protrusions uniformly distributed along the circumference of the surface of the first tab welding portion, and first grooves uniformly distributed along the circumference of the surface of the first collecting plate welding portion.

[0013] In some embodiments, the second concave-convex structure includes second protrusions uniformly distributed along the circumference of the surface of the second tab welding portion, and second grooves uniformly distributed along the circumference of the surface of the second collecting plate welding portion.

[0014] In some embodiments, the thickness of the upper plate or the lower plate is 0.1 to 0.5 mm.

[0015] In some embodiments, the first tab welding portion includes a welding surface, the welding surface is used for welding the first tab, and a tab groove is configured on the welding surface, the tab groove is used to accommodate the first tab.

[0016] The utility model further proposes a cylindrical battery, comprising a winding core, tabs and a current collecting plate, wherein the tabs include a first tab and a second tab with opposite polarities, the first tab and the second tab are respectively arranged at both ends of the winding core of the cylindrical battery, and the current collecting plate is any one of the current collecting plates described in the aforementioned embodiments.

[0017] The utility model splits at least one of the upper disk body and the lower disk body into a detachably connected current collecting disk welding part and a tab welding part, so that when welding the current collecting disk, only the thinner tab welding part needs to be welded together with the tab, which can reduce the laser power required for welding. While maintaining the current guiding ability of the current collecting disk, the area of ​​the tab and the winding core affected by heat during welding is reduced, the probability of damaging the diaphragm is reduced, and the yield rate of cylindrical battery preparation is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a cross-sectional view of the collector plate and winding core of the utility model;

[0019] Figure 2 This is a cross-sectional view of the upper plate body of the current collecting plate of the present invention;

[0020] Figure 3 It is a top view of the first tab welding portion in the current collecting disk of the present invention;

[0021] Figure 4It is a top view of the welding portion of the first current collecting disc in the current collecting disc of the present invention;

[0022] Figure 5 It is a bottom view of the first tab welding portion in the current collecting disk of the present invention.

[0023] Reference numerals:

[0024] 100, upper disk body; 110, first electrode tab welding part; 111, first liquid injection hole; 112, first protrusion; 113, welding surface; 114, electrode tab groove; 120, first current collecting disk welding part; 121, first groove; 122, third liquid injection hole; 130, limiting part; 200, lower disk body; 210, second electrode tab welding part; 220, second current collecting disk welding part; 300, winding core. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the schemes in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0026] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0027] It should also be noted that when an element is referred to as being "fixed on" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or there may be an intermediate element.

[0028] In addition, the descriptions of "first," "second," etc. in this utility model are for descriptive purposes only and should not be understood as indicating or implying their relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions between the various embodiments can be combined with each other, but this must be based on the fact that they can be implemented by ordinary technicians in this field. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by this utility model.

[0029] The utility model proposes a collector plate for welding the tabs of cylindrical batteries. The tabs include a first tab and a second tab with opposite polarities. The first tab and the second tab are respectively arranged at both ends of the winding core of the cylindrical battery. Figure 1 , the collecting plate includes:

[0030] The upper plate 100 is opposite to the first tab, one side of the upper plate 100 is used for welding the first tab, and the other side is connected to a pole of the cylindrical battery;

[0031] The lower plate 200 is opposite to the second pole tab, one side of the lower plate 200 is used for welding the second pole tab, and the other side is connected to the other pole of the cylindrical battery; at least one of the upper plate 100 and the lower plate 200 includes a pole tab welding part and a current collecting plate welding part that can be interlocked.

[0032] The material of the current collecting plate can be a highly conductive and corrosion-resistant metal, such as copper or aluminum, to ensure that the current collecting plate has good electrical conductivity and durability. The materials of the upper plate body 100 and the lower plate body 200 can be the same or different. The shape and size of the current collecting plate are usually determined according to the model and type of the cylindrical battery. For example, it can be set to a cylindrical or prismatic shape to meet the needs of different cylindrical batteries. The present invention does not limit this. Preferably, the material used for the upper plate body 100 is the same as that for the first pole ear, and the material used for the lower plate body 200 is the same as that for the second pole ear, so as to facilitate welding and conduction.

[0033] The above disk body 100 includes a pole ear welding part and a current collecting plate welding part as an example, wherein there are multiple ways of detachably connecting the pole ear welding part and the current collecting plate welding part. For example, a side wall extending toward the pole ear welding part can be provided on the outer edge of the current collecting plate welding part, and a thread is constructed on the inner surface of the side wall, so that the current collecting plate welding part forms a structure similar to a bottle cap, and the outer edge of the pole ear welding part is correspondingly provided with an external thread, so that the current collecting plate welding part and the pole ear welding part are threadedly connected; the current collecting plate welding part and the pole ear welding part can also be connected by bolts, specifically: a number of screw holes are respectively provided on the current collecting plate welding part and the pole ear welding part. When the pole ear welding part and the pole ear are welded, the screw holes of the current collecting plate welding part are aligned with the screw holes of the pole ear welding part, and then the bolts are inserted and tightened to complete the connection between the current collecting plate welding part and the pole ear welding part; similarly, the current collecting plate welding part and the pole ear welding part can also be connected by a pin structure, which is not limited by the present invention.

[0034] The present invention splits at least one of the upper disk body 100 and the lower disk body 200 into a detachably connected current collecting plate welding portion and a tab welding portion, so that when welding the current collecting plate, only the thinner tab welding portion needs to be welded together with the tab, thereby reducing the laser power required for welding. While maintaining the current collecting plate's ability to conduct current, the area of ​​the tab and the winding core 300 affected by heat during welding is reduced, thereby reducing the probability of damaging the diaphragm and improving the yield rate of cylindrical battery preparation.

[0035] like Figure 1 and Figure 2 As shown, in some embodiments, the upper disk body 100 includes a first tab welding portion 110 and a first current collecting plate welding portion 120 , and the first tab welding portion 110 and the first current collecting plate welding portion 120 are configured with a matching first concave-convex structure for interlocking the two.

[0036] The first concave-convex structure can be a notch provided on the first tab welding portion 110 and a convex portion provided on the first collecting disk welding portion 120 corresponding to the notch, wherein the shape of the notch and the convex portion can be curved, cylindrical, or other shapes, and multiple convex portions and notches can be provided, and their setting positions can be selected according to actual needs. The notch of the first tab welding portion provides stable positioning and support for the convex portion of the first collecting disk welding portion, ensuring that the first tab welding portion and the first collecting disk welding portion can be accurately docked during the assembly process, which can prevent the first collecting disk welding portion and the first tab welding portion from being displaced or loosened during use. The notch on the first tab welding portion 110 can also further reduce the thickness of the first tab welding portion, thereby reducing the heat-affected zone generated during welding and reducing the probability of damage to the diaphragm.

[0037] In actual operation, the first tab weld is first welded to the first tab. A notch is then provided at the weld between the first tab weld and the first tab to reduce the thickness of the weld. Subsequently, the protrusion of the first current collecting plate weld is aligned with the notch of the first tab weld and the protrusion is inserted into the notch, thereby completing the clamping connection between the first current collecting plate weld and the first tab weld. In this embodiment, the first concave-convex structure achieves a detachable connection between the current collecting plate weld and the tab weld. This not only reduces the probability of the diaphragm absorbing excessive heat during welding, but also simplifies the assembly process between the first current collecting plate weld and the first tab weld, thereby improving production efficiency.

[0038] In some embodiments, the lower plate 200 includes a second tab welding portion 210 and a second current collecting plate welding portion 220. The second tab welding portion 210 and the second current collecting plate welding portion 220 are configured with a second concave-convex structure for interlocking the two. The second concave-convex structure is configured similarly to the first concave-convex structure and will not be further described here.

[0039] like Figure 3 As shown, in some embodiments, a first liquid injection hole 111 is opened at the center of the first tab welding portion 110, and the first liquid injection hole 111 is used to inject electrolyte.

[0040] The shape of the first injection hole 111 can be circular, oval, square or other shapes, and its size can be set according to the injection speed of the electrolyte. Placing the first injection hole 111 in the center of the first electrode welding portion 110 can improve the accuracy of the electrolyte injection process and make the electrolyte smoother during the injection process of the cylindrical battery. During use, the electrolyte is injected from the first injection hole 111 through an external device, and then the electrolyte passes through the channel of the first injection hole 111 in sequence and enters the internal space of the cylindrical battery. Preferably, refer to Figure 4 A third liquid injection hole 122 can be opened in the center of the first collecting plate welding part 120, so that the liquid injection process can be completed after the first tab welding part 110 and the first collecting plate welding part 120 are matched, avoiding the electrolyte from affecting the matching process between the two.

[0041] In some embodiments, a second injection hole is defined in the center of the second tab weld 210. The second injection hole is the same size as the first injection hole 111. The second injection hole is configured similarly to the first injection hole 111 and will not be further described here. The fact that the first and second injection holes are the same size simplifies the alignment of the first collector plate weld 120 with the first tab weld 110, making fabrication more convenient and reducing production costs.

[0042] like Figure 2-Figure 4 As shown, in some embodiments, the first concave-convex structure includes first protrusions 112 uniformly distributed along the circumference of the surface of the first tab welding portion 110, and first grooves 121 uniformly distributed along the circumference of the surface of the first collecting plate welding portion 120. The first tab welding portion 110 and the first collecting plate welding portion 120 can be connected together through the cooperation between the first protrusions 112 and the first grooves 121. Preferably, the first protrusions 112 and the first grooves 121 can be configured as annular. The contact area between the annular first protrusions 112 and the first grooves 121 is larger, thereby increasing friction and improving the strength and stability of the connection between the first collecting plate welding portion 120 and the first tab welding portion 110.

[0043] In some embodiments, the second concave-convex structure includes second protrusions uniformly distributed along the circumference of the surface of the second tab welding portion 210, and second grooves uniformly distributed along the circumference of the surface of the second collecting plate welding portion 220. The arrangement of the second protrusions and the second grooves is similar to that of the previous embodiment and will not be repeated here.

[0044] In some embodiments, the thickness of the upper plate 100 or the lower plate 200 is 0.1-0.5 mm.

[0045] Taking the upper disc 100 as an example, if the thickness of the upper disc 100 is greater than 0.5 mm, the upper disc 100 is too thick, and the weight of the upper disc 100 increases, affecting the portability and ease of use of the cylindrical battery. Furthermore, more raw materials are required to prepare the upper disc 100, increasing production costs. Thicker materials tend to slow heat dissipation, affecting the heat dissipation performance of the cylindrical battery. If the thickness of the upper disc 100 is less than 0.1 mm, the structural strength of the upper disc 100 itself is insufficient, making it prone to deformation or breakage during assembly or use. Furthermore, an overly thin upper disc 100 has a high electrical resistance, thereby reducing the charge and discharge rate of the cylindrical battery. Preferably, in this embodiment, the thickness of the upper disc 100 is set to 0.2 mm, which ensures that the upper disc 100 has sufficient structural strength while avoiding the use of excessive raw materials, thereby keeping the weight of the cylindrical battery within a relatively small range. The lower disc 200 is similar to the upper disc 100 and will not be described in detail here.

[0046] like Figure 2 and Figure 5 As shown, in some embodiments, the first tab welding portion 110 includes a welding surface 113 , which is used to weld the first tab. A tab groove 114 is configured on the welding surface 113 , which is used to accommodate the first tab.

[0047] The tab slot 114 provides reliable positioning and support, thereby ensuring a stable and precise welding process between the entire first tab and the first tab welding portion 110. The tab slot 114 can be rectangular, U-shaped, semicircular, or other shapes, and can be specifically configured according to the shape and size of the first tab to ensure that the first tab fits tightly within the tab slot 114. During welding, the first tab is first placed within the tab slot 114, and then the first tab and the first tab welding portion 110 are welded together using methods such as laser welding or resistance welding.

[0048] The tab groove 114 provided on the first tab welding portion 110 effectively improves the accuracy and reliability of welding, avoids positional deviation of the first tab during the welding process, and ensures a stable connection between the cylindrical battery and the upper plate 100. Furthermore, the provision of the tab groove 114 further reduces the thickness of the welding position, improving welding efficiency while reducing the power required for welding, thereby reducing the heat-affected zone of the weld and further reducing the probability of the separator being affected during the welding process. It is understood that the lower plate 200 can be provided with a similar structure with reference to the upper plate 100, and no further details will be given here.

[0049] Preferably, Figure 5As shown, a limiting portion 130 can be protruded at the edge of the welding surface 113 to limit the core 300 so that the core 300 is always within the coverage of the collecting disk, reducing the probability of the core 300 or the composite collecting disk being offset, and avoiding welding misalignment or radial displacement of the collecting disk that causes the core 300 to be unable to enter the shell.

[0050] The present invention further provides a cylindrical battery comprising a winding core 300, tabs, and a current collecting plate. The specific structure of the current collecting plate is similar to that of the above-described embodiment. The tabs include a first tab and a second tab of opposite polarity, which are disposed at opposite ends of the winding core 300 of the cylindrical battery. Because this cylindrical battery utilizes all the technical solutions of all the above-described embodiments, it at least possesses all the technical effects brought about by the technical solutions of the above-described embodiments, and therefore will not be further elaborated here.

[0051] The above description is only part or preferred embodiments of the present invention. Neither the text nor the drawings can limit the scope of protection of the present invention. All equivalent structural transformations made by using the contents of the present invention specification and drawings under the overall concept of the present invention, or direct / indirect application in other related technical fields are included in the scope of protection of the present invention.

Claims

1. A current collecting plate for welding tabs of cylindrical batteries, wherein the tabs include a first tab and a second tab with opposite polarities, the first tab and the second tab being disposed at both ends of a winding core of the cylindrical battery, characterized in that: The collecting plate comprises: An upper plate, the upper plate being opposite to the first electrode tab, having one surface for welding the first electrode tab and the other surface being connected to a pole of the cylindrical battery; A lower plate body, the lower plate body is opposite to the second pole tab, one side of the lower plate body is used for welding the second pole tab, and the other side is connected to the other pole column of the cylindrical battery; at least one of the upper plate body and the lower plate body includes a detachably connected pole tab welding portion and a current collecting plate welding portion.

2. The collecting plate according to claim 1, characterized in that: The upper plate body includes a first tab welding portion and a first current collecting plate welding portion, and the first tab welding portion and the first current collecting plate welding portion are configured with a matching first concave-convex structure for interlocking the two.

3. The collecting plate according to claim 2, characterized in that: The lower plate body includes a second pole tab welding portion and a second current collecting plate welding portion, and the second pole tab welding portion and the second current collecting plate welding portion are configured with a matching second concave-convex structure for interlocking the two.

4. The collecting plate according to claim 3, characterized in that: A first liquid injection hole is opened at the center of the first tab welding portion, and the first liquid injection hole is used to inject electrolyte.

5. The collecting plate according to claim 4, characterized in that: A second liquid injection hole is opened at the center of the second tab welding portion, and the second liquid injection hole is the same size as the first liquid injection hole.

6. The collecting plate according to claim 2, characterized in that: The first concave-convex structure includes first protrusions uniformly distributed along the circumference of the surface of the first tab welding portion, and first grooves uniformly distributed along the circumference of the surface of the first collecting plate welding portion.

7. The collecting plate according to claim 3, characterized in that: The second concave-convex structure includes second protrusions uniformly distributed along the circumference of the surface of the second tab welding portion, and second grooves uniformly distributed along the circumference of the surface of the second current collecting plate welding portion.

8. The collecting plate according to any one of claims 1 to 7, characterized in that: The thickness of the upper plate or the lower plate is 0.1-0.5 mm.

9. The collecting plate according to claim 2, characterized in that: The first tab welding portion includes a welding surface, the welding surface is used for welding the first tab, and a tab groove is configured on the welding surface, the tab groove is used for accommodating the first tab.

10. A cylindrical battery comprising a winding core, tabs, and a current collecting plate, wherein the tabs comprise a first tab and a second tab with opposite polarities, the first tab and the second tab being disposed at opposite ends of the winding core of the cylindrical battery, characterized in that: The collecting plate is the collecting plate according to any one of claims 1 to 9.

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