Bottom shell and cylindrical battery
By setting inclined annular reinforcing ribs on the edge of the cylindrical battery bottom shell, the problem of poor contact between the bottom cover and the tabs or current collectors is solved, achieving high-quality welding and improving the battery's overcurrent capacity and fast charging performance.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-11
- Publication Date
- 2026-04-03
AI Technical Summary
Existing cylindrical batteries have gaps at the contact surfaces between the bottom cover and the tabs or current collectors, leading to poor welding, such as weld explosions, air leaks, and weld depth and width that do not meet requirements.
A first annular reinforcing rib is set at the edge of the bottom shell to form an inclined welding surface that matches the tilt angle of the electrode tab or current collector, thereby increasing the welding area and strength and ensuring welding quality.
It improves welding reliability, avoids welding defects, enhances battery overcurrent capacity and fast charging performance, and reduces cell heat generation.
Smart Images
Figure CN224082525U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of batteries, specifically to a bottom shell and a cylindrical battery. Background Technology
[0002] To improve energy density and fast charging capabilities, the mainstream design for cylindrical batteries currently involves welding the bottom cover and negative electrode side using a through-welding method. This reduces the space required for welding the negative electrode current collector to the bottom cover, thereby improving the utilization of the battery's height space and thus increasing energy density. On the other hand, to enhance current carrying capacity, the welding area is typically maximized, meaning the weld diameter is made as large as possible. However, current slab-laminated electrode tabs have weak edges, creating gaps at the contact surfaces between the bottom cover and the tabs or current collectors. This can easily lead to issues like weld spatter, air leakage, insufficient weld penetration and width, or even complete failure to weld during through-welding. Utility Model Content
[0003] In order to solve the above-mentioned technical problems, or at least partially solve the above-mentioned technical problems, the present invention provides a bottom shell and a cylindrical battery.
[0004] This utility model provides a bottom shell for a cylindrical battery, including a bottom plate and a first annular reinforcing rib disposed on the bottom plate, wherein the first annular reinforcing rib is disposed on the edge of the bottom plate;
[0005] The first annular reinforcing rib protrudes towards one side of the base plate to form a welding surface, and the welding surface is inclined relative to the plane on which the base plate is located.
[0006] Optionally, the angle of inclination of the welding surface relative to the plane of the base plate is 0.5-3°.
[0007] Optionally, the width of the first annular reinforcing rib is 5-15 mm;
[0008] And / or, the depth of the first annular reinforcing rib is 0.3-1.5 mm.
[0009] Optionally, the base plate is further provided with one or more second annular reinforcing ribs, all of which are located inside the first annular reinforcing rib.
[0010] This utility model also provides a bottom shell for a cylindrical battery, including a bottom plate and a first annular reinforcing rib disposed on the bottom plate, wherein the first annular reinforcing rib is disposed on the edge of the bottom plate;
[0011] The first annular reinforcing rib protrudes towards one side of the base plate to form a welding surface, and the welding surface is arc-shaped.
[0012] Optionally, the width of the first annular reinforcing rib is 5-15 mm;
[0013] And / or, the depth of the first annular reinforcing rib is 0.3-1.5 mm.
[0014] Optionally, the base plate is further provided with one or more second annular reinforcing ribs, all of which are located inside the first annular reinforcing rib.
[0015] This utility model provides a cylindrical battery, including a housing, a winding core disposed inside the housing, and the aforementioned bottom shell for the cylindrical battery disposed at the bottom of the housing, wherein the welding surface of the bottom shell is welded to the tabs or current collectors of the winding core.
[0016] Optionally, the outer ring of the first annular reinforcing rib is located on the outside of the tab or current collector of the core in the radial direction.
[0017] Optionally, the outer ring of the first annular reinforcing rib is supported on the inner wall of the housing and connected to the housing.
[0018] The technical solution provided by this utility model has the following advantages compared with the prior art:
[0019] The bottom shell provided by this utility model is provided with a first annular reinforcing rib to increase the structural strength of the bottom shell. The first annular reinforcing rib is located at the edge of the bottom shell to increase the area of the welding surface, thereby increasing the welding area and ensuring the welding strength. The extension method of the welding surface matches the tilt angle of the tab or current collector, and makes the welding surface fit with the edge of the tab or current collector. This ensures that the bottom shell can be effectively fitted with the tab or current collector during laser penetration welding, avoiding situations such as weld explosion, air leakage, weld depth and weld width not meeting requirements, or even failure to weld. This ensures the reliability of the welding quality, increases the diameter of the penetration weld, improves the battery current carrying capacity, thereby improving the fast charging capacity and reducing cell heat generation. Attached Figure Description
[0020] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present invention and, together with the description, serve to explain the principles of the present invention.
[0021] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0022] Figure 1This is a schematic diagram of the cylindrical battery described in an embodiment of the present invention;
[0023] Figure 2 for Figure 1 A magnified view of a section at point A in the middle;
[0024] Figure 3 This is a diagram showing the positional relationship between the first annular reinforcing rib and the core with the current collecting plate in an embodiment of this utility model.
[0025] Figure 4 This is a diagram showing the positional relationship between the first annular reinforcing rib and the core without a current collector in an embodiment of the present invention.
[0026] Figure 5 This is a cross-sectional view of a portion of a cylindrical battery with an arc-shaped welding surface, as described in an embodiment of this utility model.
[0027] Explanation of reference numerals in the attached figures
[0028] 1. Base plate; 11. First annular reinforcing rib; 111. Welding surface; 112. Inner ring; 113. Outer ring; 114. Welding ring; 12. Second annular reinforcing rib; 2. Shell; 21. Core; 211. Electrode lug; 212. Current collector; 213. Connecting piece. Detailed Implementation
[0029] To better understand the above-mentioned objectives, features, and advantages of this utility model, the solution of this utility model will be further described below. It should be noted that, unless otherwise specified, the embodiments and features of this utility model can be combined with each other.
[0030] The following description sets forth many specific details to provide a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein; obviously, the embodiments described in the specification are only some embodiments of the present invention, and not all embodiments.
[0031] Combination Figures 1 to 5As shown, the bottom shell for a cylindrical battery provided in this embodiment of the present invention includes a bottom plate 1 and a first annular reinforcing rib 11 disposed on the bottom plate 1. The bottom plate 1 is circular, and the first annular reinforcing rib 11 is annular and coincides with the axis of the bottom plate 1. The first annular reinforcing rib 11 is disposed at the edge of the bottom plate 1, specifically close to the outer peripheral edge of the bottom plate 1, to increase the circumference and area of the first annular reinforcing rib 11. The first annular reinforcing rib 11 protrudes towards the bottom plate 1 to form a welding surface 111. Specifically, the first annular reinforcing rib 11 protrudes towards the core 21, so that the side of the first annular reinforcing rib 11 facing the core 21 forms a welding surface 111 for welding to the tabs 211 or current collectors 212 of the core 21.
[0032] Combination Figure 3 and Figure 4 As shown, the welding surface 111 is inclined relative to the plane of the base plate 1. Specifically, the first annular reinforcing rib 11 has an inner ring 112, an outer ring 113, and a welding ring 114 connected to the ends of the inner ring 112 and the outer ring 113. The welding surface 111 is formed on the welding ring 114. The height of the inner ring 112 of the first annular reinforcing rib 11 is less than the height of the outer ring 113 of the first annular reinforcing rib 11, so that the welding ring 114 gradually tilts towards the core 21 from the inside to the outside. The tilt angle of the welding surface 111 matches the tilt angle of the tab 211 or the current collector 212. This matching means that the tilt angle of the welding surface 111 is the same as or close to the tilt angle of the tab 211 or the current collector 212, so that the welding surface 111 can fit against the tab 211 or the current collector 212, and the edge of the welding surface 111 fits against the edge of the tab 211 or the current collector 212, thereby ensuring sufficient contact area to ensure welding quality.
[0033] The tab 211 or current collector 212 here refers to:
[0034] like Figure 3 As shown, when a current collector 212 is connected to the tab 211, the tab 211 is welded to the bottom shell through the current collector 212. First, the tab 211 is flattened so that it is stacked at the end of the core 21. At this time, due to the different number of stacked layers of the tab 211 from the outside to the inside, the flattened tab 211 at the edge of the end of the core 21 has a gradually increasing thickness from the outside to the inside, so that the tab 211 forms a slope. At this time, the current collector 212 is welded to the flattened tab 211 through the connecting piece 213. The slope of the current collector 212 is consistent with that of the tab 211. At this time, the current collector 212 is in a state of waiting to be welded. The current collector 212 is then welded to the welding surface 111 of the first annular reinforcing rib 11 on the bottom shell. During welding, the tilt angle of the welding surface 111 matches the tilt angle of the current collector 212 to increase the welding area.
[0035] like Figure 4 As shown, when the tab 211 is not connected to the current collector 212, the tab 211 is directly welded to the bottom shell. First, the tab 211 is flattened so that it is stacked at the end of the core 21. At this time, due to the different number of stacked layers of the tab 211 from the outside to the inside, the flattened tab 211 at the edge of the end of the core 21 has a gradually increasing thickness from the outside to the inside, so that the tab 211 forms a slope. At this time, the tab 211 is in a state to be welded. The tab 211 with the slope is then welded to the welding surface 111 of the first annular reinforcing rib 11 on the bottom shell. During welding, the tilt angle of the welding surface 111 matches the slope of the tab 211 to increase the welding area.
[0036] The bottom shell provided by this utility model is provided with a first annular reinforcing rib 11 to increase the structural strength of the bottom shell. The first annular reinforcing rib 11 is located at the edge of the bottom shell, increasing the area of the welding surface 111, thereby increasing the welding area and ensuring the welding strength. The extension method of the welding surface 111 matches the tilt angle of the tab 211 or current collector 212, and makes the welding surface 111 fit with the edge of the tab 211 or current collector 212 in the state to be welded. This ensures that the bottom shell can be effectively fitted with the tab 211 or current collector 212 during laser penetration welding, avoiding situations such as weld explosion, air leakage, failure to meet the requirements of weld depth and weld width, or even failure to weld. This ensures the reliability of the welding quality, increases the diameter of the penetration weld, improves the battery overcurrent capacity and thus improves the fast charging capacity, and reduces the heat generation of the battery cell.
[0037] In some embodiments, the tilt angle of the welding surface 111 relative to the plane of the base plate 1 is 0.5-3°. The specific tilt angle is designed according to the tilt angle of the tab 211 or current collector 212 in the state to be welded, so as to ensure that the welding surface 111 is in contact with the tab 211 or current collector 212 in the state to be welded.
[0038] In some embodiments, the welding surface 111 is extended in such a way that it is in contact with the tab 211 or the current collector 212.
[0039] In this design, since the welding surface 111 is in contact with the tab 211 or current collector 212 in the state to be welded, there is a sufficient contact area between the welding surface 111 and the tab 211 or current collector 212 in the state to be welded, thereby further increasing the welding quality, increasing the diameter of the through weld, and improving the battery current carrying capacity.
[0040] In some embodiments, the width of the first annular reinforcing rib 11 is 5-15 mm. Specifically, the distance between the inner ring 112 and the outer ring 113 of the first annular reinforcing rib 11 is 5-15 mm.
[0041] In some embodiments, the depth of the first annular reinforcing rib 11 is 0.3-1.5 mm.
[0042] The welding surface 111 of the first annular reinforcing rib 11 at this size can effectively increase the fit between the electrode tab 211 or current collector 212 of the core 21, meet the welding requirements of the electrode tab 211 or current collector 212, and make the weld diameter large enough.
[0043] In some implementations, combined Figure 1 and Figure 2 As shown, the base plate 1 is also provided with one or more second annular reinforcing ribs 12, all of which are located inside the first annular reinforcing rib 11. The second annular reinforcing ribs 12 are circular in shape and coincide with the axes of the first annular reinforcing rib 11 and the base plate 1. The number and location of the second annular reinforcing ribs 12 are not limited, as long as the strength requirements of the base shell are met. The design of the first annular reinforcing rib 11 and the second annular reinforcing rib 12 gives the base plate 1 a concave-convex structure, ensuring the structural strength of the base plate 1.
[0044] This utility model also provides a bottom shell for a cylindrical battery, including a bottom plate 1 and a first annular reinforcing rib 11 disposed on the bottom plate 1. The bottom plate 1 is circular, and the first annular reinforcing rib 11 is annular and coincides with the axis of the bottom plate 1. The first annular reinforcing rib 11 is disposed at the edge of the bottom plate 1, specifically close to the outer peripheral edge of the bottom plate 1, to increase the circumference and area of the first annular reinforcing rib 11. The first annular reinforcing rib 11 protrudes towards the bottom plate 1 to form a welding surface 111. Specifically, the first annular reinforcing rib 11 protrudes towards the core 21, so that the side of the first annular reinforcing rib 11 facing the core 21 forms a welding surface 111 for welding to the tabs 211 or current collectors 212 of the core 21.
[0045] like Figure 5 As shown, the welding surface 111 is arc-shaped. Specifically, the arc surface of the welding surface 111 matches the tilt angle of the tab 211 or the current collector 212. This matching means that before welding, when the core 21 is pressed towards the bottom shell, the tab 211 or the current collector 212 at the edge of the core 21 can fit against the arc-shaped welding surface 111, thereby ensuring the welding effect.
[0046] The bottom shell provided by this utility model is provided with a first annular reinforcing rib 11 to increase the structural strength of the bottom shell. The first annular reinforcing rib 11 is located at the edge of the bottom shell, increasing the area of the welding surface 111, thereby increasing the welding area and ensuring the welding strength. The extension method of the welding surface 111 matches the tilt angle of the tab 211 or current collector 212, so that the tab 211 or current collector 212 at the edge of the core 21 can fit with the arc-shaped welding surface 111. This ensures that the bottom shell can be effectively fitted with the tab 211 or current collector 212 during laser penetration welding, avoiding situations such as weld explosion, air leakage, weld depth and weld width not meeting requirements, or even failure to weld. This ensures the reliability of the welding quality, increases the diameter of the penetration weld, improves the battery current carrying capacity, thereby improving the fast charging capacity and reducing cell heat generation.
[0047] In some embodiments, the width of the first annular reinforcing rib 11 is 5-15 mm. Specifically, the distance between the inner ring 112 and the outer ring 113 of the first annular reinforcing rib 11 is 5-15 mm.
[0048] In some embodiments, the depth of the first annular reinforcing rib 11 is 0.3-1.5 mm.
[0049] The welding surface 111 of the first annular reinforcing rib 11 at this size can effectively increase the fit between the tab 211 or current collector 212 of the core 21, satisfying the welding requirements of the tab 211 or current collector 212, so that the weld diameter is large enough.
[0050] In some implementations, combined Figure 1 and Figure 2 As shown, the base plate 1 is also provided with one or more second annular reinforcing ribs 12, all of which are located inside the first annular reinforcing rib 11. The second annular reinforcing ribs 12 are circular in shape and coincide with the axes of the first annular reinforcing rib 11 and the base plate 1. The number and location of the second annular reinforcing ribs 12 are not limited, as long as the strength requirements of the base shell are met. The design of the first annular reinforcing rib 11 and the second annular reinforcing rib 12 gives the base plate 1 a concave-convex structure, ensuring the structural strength of the base plate 1.
[0051] like Figure 1 As shown, this utility model provides a cylindrical battery, which includes a housing 2, a winding core 21 disposed inside the housing 2, and a bottom shell for the cylindrical battery disposed at the bottom of the housing 2, wherein the bottom shell includes all the technical features of the aforementioned bottom shell. The welding surface 111 of the bottom shell is welded to the tabs 211 or current collectors 212 of the winding core 21. The bottom through-welding process also ensures the utilization rate of the battery's height space.
[0052] In some implementations, combined Figure 3 and Figure 4 As shown, the outer ring 113 of the first annular reinforcing rib 11 is located radially outside the tab 211 or current collector 212 of the core 21.
[0053] In this design, the weld marks of the first annular reinforcing rib 11 and the tab 211 or current collector 212 can extend beyond the edge of the tab 211 or current collector 212 to ensure the welding effect between the edge of the tab 211 or current collector 212 and the first annular reinforcing rib 11.
[0054] In some implementations, reference continues. Figure 3 and Figure 4 The outer ring 113 of the first annular reinforcing rib 11 is supported on the inner wall of the shell 2 and connected to the shell 2.
[0055] In this design direction, a stepped surface is formed between the outer ring 113 of the first annular reinforcing rib 11 and the base plate 1, so as to cooperate with the end of the shell 2 and increase the tightness of the connection between the base plate 1 and the shell 2.
[0056] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.
[0057] The above description is merely a specific embodiment of this utility model, enabling those skilled in the art to understand or implement it. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this utility model. Therefore, this utility model is not to be limited to the embodiments described herein, but is to be accorded the widest scope consistent with the principles and novel features of the utility model described herein.
Claims
1. A bottom casing for a cylindrical battery, characterized in that, It includes a base plate (1) and a first annular reinforcing rib (11) disposed on the base plate (1), the first annular reinforcing rib (11) being disposed at the edge of the base plate (1); The first annular reinforcing rib (11) protrudes towards the side of the base plate (1) to form a welding surface (111), and the welding surface (111) is inclined relative to the plane of the base plate (1).
2. The bottom casing for a cylindrical battery according to claim 1, characterized in that, The angle of inclination of the welding surface (111) relative to the plane of the base plate (1) is 0.5-3°.
3. The bottom casing for a cylindrical battery according to claim 1, characterized in that, The width of the first annular reinforcing rib (11) is 5-15 mm; And / or, the depth of the first annular reinforcing rib (11) is 0.3-1.5 mm.
4. The bottom casing for a cylindrical battery according to claim 1, characterized in that, The base plate (1) is also provided with one or more second annular reinforcing ribs (12), and the one or more second annular reinforcing ribs (12) are all located inside the first annular reinforcing rib (11).
5. A bottom casing for a cylindrical battery, characterized in that, It includes a base plate (1) and a first annular reinforcing rib (11) disposed on the base plate (1), the first annular reinforcing rib (11) being disposed at the edge of the base plate (1); The first annular reinforcing rib (11) protrudes towards the side of the base plate (1) to form a welding surface (111), and the welding surface (111) is arc-shaped.
6. The bottom casing for a cylindrical battery according to claim 5, characterized in that, The width of the first annular reinforcing rib (11) is 5-15 mm; And / or, the depth of the first annular reinforcing rib (11) is 0.3-1.5 mm.
7. The bottom casing for a cylindrical battery according to claim 5, characterized in that, The base plate (1) is also provided with one or more second annular reinforcing ribs (12), and the one or more second annular reinforcing ribs (12) are all located inside the first annular reinforcing rib (11).
8. A cylindrical battery, characterized in that, The device includes a housing (2), a core (21) disposed inside the housing (2), and a bottom shell for a cylindrical battery as described in any one of claims 1 to 7 disposed at the bottom of the housing (2), wherein the welding surface (111) of the bottom shell is welded to the tab (211) or current collector (212) of the core (21).
9. The cylindrical battery according to claim 8, characterized in that, The outer ring (113) of the first annular reinforcing rib (11) is located on the outside of the tab (211) or collector plate (212) of the core (21) in the radial direction.
10. The cylindrical battery according to claim 8, characterized in that, The outer ring (113) of the first annular reinforcing rib (11) is supported on the inner wall of the housing (2) and connected to the housing (2).