Collector plates and battery cells

Abstract

The present invention discloses a current collecting tray and a battery cell, and relates to the technical field of energy storage batteries. A first through hole for the pole ear to pass through is provided on the current collecting tray, and a first groove for accommodating and fixing the pole ear passing through the first through hole is also provided on the current collecting tray. The first groove is arranged in the conductive area of ​​the current collecting tray; the battery cell includes a cell body, a pole ear, and the above-mentioned current collecting tray; the pole ear of the cell passes through the first through hole of the current collecting tray and then bends into the first groove to connect the current collecting tray and tighten the current collecting tray to the end face of the cell. In the current collecting tray and battery cell provided by the present invention, the current collecting tray is tightened and fixed to the end face of the cell by the pole ear, and the current collecting tray contacts and is welded to the side of the pole ear, and the cylindrical cell does not need to be flattened or pre-treated.

Description

Technical Field

[0001] The present invention relates to the technical field of energy storage batteries, and in particular to a current collecting plate and a battery cell. Background Art

[0002] Limited by the precision of modern machining, it is virtually impossible to achieve a completely flat end surface for a fully tabbed cylindrical battery cell formed by winding pole pieces. Because the end surfaces of the wound cylindrical battery cells are uneven, when welding the collector plate, the collector plate can only contact the relatively high part of the cylindrical battery cell end surface. There is a gap between the collector plate and the relatively low part of the cylindrical battery cell end surface, resulting in a small effective contact area between the collector plate and the cylindrical battery cell end surface, and the quality of the collector plate welding fixation is unstable. Furthermore, when the collector plate is further used as the positive and negative tabs of the cylindrical battery, the connection between the collector plate and the tabs also generates severe heat.

[0003] In existing technology, when applying the positive and negative current collectors, a blank area of ​​foil is left at the edge of the current collector. After winding to form a cylindrical cell, the blank area is flattened, thereby aligning the end faces of the cylindrical cell. The current collector plate can be welded closely to the flattened end face, increasing the effective contact area between the collector plate and the end face of the cylindrical cell and ensuring the quality of the collector plate welding. This structure also uses the entire positive and negative current collector as the positive and negative tabs to directly draw current, effectively reducing the internal resistance of the battery.

[0004] The Chinese invention with application number CN202122830826.9 discloses a full-tab cylindrical battery cell including a tab support reinforcement. Its collecting plate is still welded and fixed in contact with the end face of the battery cell. The unevenness of the rear end face after the battery cell is wound and formed will still affect the welding and fixing effect of the collecting plate. It does not fundamentally solve the problem that the poor welding effect of the collecting plate will result from the pre-treatment of the battery cell without flattening. Summary of the Invention

[0005] The object of the present invention is to provide a current collecting plate and a battery cell, in which the current collecting plate is tightly fixed to the end face of the battery cell by the tab, and the current collecting plate contacts and is welded to the side of the tab. The cylindrical battery cell does not need to be flattened for pretreatment, and the current collecting plate and the tab can be in full contact, so as to solve the above-mentioned technical problems.

[0006] In order to solve the above technical problems, the present invention includes:

[0007] A current collecting disk is provided with a first through hole for a pole lug to pass through and a first groove for accommodating the pole lug passing through the first through hole. The first groove is arranged in a conductive area of ​​the current collecting disk.

[0008] Furthermore, at least one first through hole is provided, at least one first groove is provided, and at least one first groove is communicated with an edge of at least one first through hole.

[0009] Furthermore, the current collecting disk is a disk body that is conductive throughout.

[0010] Furthermore, the collecting plate includes an insulating sheet and a busbar, the busbar is arranged on the insulating sheet, the first groove is opened on the busbar, and the first through hole is opened on the insulating sheet.

[0011] Furthermore, the busbar is made of a conductive metal material.

[0012] Furthermore, it also includes a second through hole opened on the insulating sheet and located at the bottom of the busbar, and a third through hole connected to the second through hole is also opened on the busbar.

[0013] Furthermore, the busbar includes a busbar body and an extension portion, and the extension portion is integrally connected to the busbar body; when the busbar is disposed on the insulating sheet, the extension portion extends out of the insulating sheet.

[0014] Furthermore, the insulating sheet is further provided with a second groove capable of accommodating the extension portion, and the second groove is communicated with the second through hole.

[0015] Furthermore, the second through hole has a cavity capable of accommodating the busbar body, and a limiting flange for limiting the busbar is provided on the hole wall of the second through hole.

[0016] Furthermore, the bottom surface of the second groove is flush with the upper surface of the limiting flange, and the depth of the second groove is greater than the thickness of the extension portion.

[0017] Furthermore, a connecting through hole is provided at one end of the extension portion located outside the insulating sheet.

[0018] A battery cell, comprising a current collecting plate as described above, a cell body, and a pole ear arranged at the end face of the cell body, characterized in that the pole ear passes through the first through hole of the current collecting plate and then bends into the first groove to connect the current collecting plate and tighten the current collecting plate to the end face of the battery cell.

[0019] Furthermore, the hollow foil is in a sheet shape; and along the winding direction of the pole piece, the sum of the lengths of the plurality of hollow foils is less than the length of the pole piece.

[0020] Furthermore, at least one tab is provided at each end of the battery cell body.

[0021] Beneficial effects of the present invention:

[0022] 1. The tabs at the ends of the battery cells pass through the current collecting disc and the current collecting disc is clamped and fixed to the end face of the battery cells. The ends of the battery cells do not need to be flattened or pre-processed, and the current collecting disc can also be stably fixed to the end face of the battery cells.

[0023] Second, the gaps at both ends of the wound battery cell will not be blocked by the flattened tabs, thus retaining the end face gaps of the battery cell, and the electrolyte can quickly penetrate into the battery cell.

[0024] 3. When the collector plate is connected to the tab, the tab lies on the collector plate, and the direct contact area between the collector plate and the tab is large. When the collector plate serves as the battery tab, it can effectively reduce the internal resistance of the battery, reduce battery heat and reduce charge and discharge energy loss.

[0025] Fourth, the tabs are formed by the bare foil on the side of the electrode sheet during winding. In this application, except for the bare foil directly opposite the first through hole, which is used to form the tab and passes through the first through hole, the bare foil in other areas of the end face of the battery cell can be left unused, thereby reducing the weight of the battery cell and preventing the excess bare foil from pressing against the current collecting plate, which would increase the overall volume of the cylindrical battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The accompanying drawings, which are incorporated into and constitute a part of the specification, illustrate embodiments of the present invention and, together with the description, serve to explain the principles of the present invention. In the drawings, similar reference numerals are used to represent similar elements. The drawings described below are some embodiments of the present invention, but not all. It is clear that those skilled in the art can derive other drawings from these drawings without inventive effort.

[0027] Figure 1 This is a schematic structural diagram of the current collecting plate of Example 1;

[0028] Figure 2 This is a schematic structural diagram of a battery cell according to Example 1;

[0029] Figure 3 Schematic diagram of the structure of the cylindrical battery of Example 1;

[0030] Figure 4 Schematic diagram of the structure of the busbar of Example 1;

[0031] Figure 5 This is a schematic structural diagram of the insulating sheet of Example 1;

[0032] Figure 6 This is a schematic structural diagram of the current collecting plate of Example 2;

[0033] Figure 7 This is a schematic structural diagram of a battery cell according to Example 2;

[0034] Figure 8 This is a schematic structural diagram of a cylindrical battery according to Example 2;

[0035] Figure 9This is a schematic structural diagram of the current collecting plate of Example 3;

[0036] Figure 10 This is a schematic structural diagram of a battery cell according to Example 3;

[0037] 1-collecting plate, 11-busbar, 111-busbar body, 112-extension portion, 113-third through hole, 12-insulating sheet, 121-second through hole, 122-limiting flange, 123-second groove, 13-first through hole, 14-first groove, 2-connecting through hole, 3-battery cell, 31-ear, 4-cylindrical battery. DETAILED DESCRIPTION

[0038] The present invention will be further described in detail below with reference to the accompanying drawings and implementation examples.

[0039] In this specification, directional terms such as up, down, left, right, front, back, front, back, top, and bottom, which are mentioned or may be mentioned, are defined relative to the configurations shown in the accompanying drawings. The terms "inside" and "outside" refer to directions toward or away from the geometric center of a specific component, respectively. These are relative concepts and may vary depending on the location and usage of the component. Therefore, these or other directional terms should not be construed as restrictive.

[0040] Example 1:

[0041] See also Figures 1 to 5 In this embodiment, the collecting plate 1 is provided with a first through hole 13 for the pole lug 31 to pass through, and the collecting plate 1 is also provided with a first groove 14 for accommodating and fixing the pole lug 31 passing through the first through hole 13.

[0042] Specifically, there are two first through holes 13 and two first grooves 14. The two first through holes 13 are centrally symmetrically arranged on the circular collecting plate 1, and the two first grooves 14 are also centrally symmetrically arranged on the circular collecting plate 1. The edges of one first through hole 13 and one first groove 14 are connected to each other.

[0043] In this embodiment, the collecting plate 1 includes an insulating sheet 12 and a busbar 11 made of conductive metal. The busbar 11 is arranged in the middle of the insulating sheet 12. Two first through holes 13 are both opened on the insulating sheet 12, and two first grooves 14 are both opened on the busbar 11.

[0044] In this embodiment, the busbar 11 includes a busbar body 111 for connecting to the tab 31 and an extension portion 112 connecting the external structure and the busbar body 111; when the busbar body 111 is arranged in the middle of the insulating sheet 12, the extension portion 112 extends to an area outside the insulating sheet 12 to facilitate its connection with external equipment.

[0045] In this embodiment, in order to facilitate the connection of the extension portion 112 to the external structure, a connecting through hole 2 is further provided on the outer extension end of the extension portion 112. In addition, the extension portion 112 and the conduit body 111 are integrally formed.

[0046] In this embodiment, the busbar 11 is glued and fixed to the insulating sheet 12. To enhance the bonding between the insulating sheet 12 and the busbar 11, a second through-hole 121 is provided in the middle of the insulating sheet 12. The second through-hole 121 has a cavity that can accommodate the busbar body 111. A limiting flange 122 is provided on the wall of the second through-hole 121 to restrict the busbar body 111 from passing through the second through-hole 121. The limiting flange 122 is an annular protrusion, and the upper surface of the limiting flange 122 is flush with the bottom surface of a second groove 123 provided in the insulating sheet 12 and is in communication with each other.

[0047] The busbar body 111 is embedded in the second through-hole 121, and part of the extension 112 is located in the second groove 123. A technician can apply glue to the contact surfaces between the busbar body 111 and the limiting flange 122, and between the extension 112 and the second groove 123, to adhere and secure the busbar 11 to the insulating sheet 12. The second through-hole 121 and the second groove 123 prevent the busbar 11 from rotating relative to the insulating sheet 12 and separating from it.

[0048] In this embodiment, the busbar body 111 is further provided with a third through-hole 113, which communicates with the second through-hole 121 to facilitate the entry of electrolyte into the battery cells 3 through the third through-hole 113 and the second through-hole 121. Furthermore, the depth of the second groove 123 is greater than the thickness of the extension 112, thereby minimizing the overall thickness of the collecting tray 1 when the busbar 11 is secured to the insulating sheet 12.

[0049] In this embodiment, the current collecting plate 1 is installed at the end surface of the battery cell 3 .

[0050] The battery cell 3 corresponding to the current collecting disk 1 of this embodiment is formed by winding a pole piece. Before winding, the edge of the pole piece is reserved for multiple hollow foils to form the pole lugs 31. After the pole piece is wound to form the battery cell 3, the multiple hollow foils at the edge of the pole piece overlap with each other, forming two pole lugs 31 protruding from the end face of the battery cell 3 at each end of the battery cell 3. The two pole lugs 31 located on the same end face of the battery cell 3 are also centrally symmetrical, and the cross-section of each pole lug 31 is comparable to the size of its corresponding first through hole 13, ensuring that each pole lug 31 can pass through a corresponding first through hole 13 and bend and fall into a corresponding first groove 14.

[0051] The tabs 31 are formed by overlapping multiple hollow foils. After passing through the first through-holes 13, the tabs 31 can be bent and inverted one by one into the first grooves 14 on the busbar 11, thereby tightening and fixing the current collecting plate 1 to the end face of the battery cell 3. Furthermore, technicians can also weld the inverted tabs 31 to the busbar 11 to further secure the current collecting plate 1 to the end face of the battery cell 3.

[0052] In this embodiment, multiple hollow foils of specific shapes and sizes at the edge of the pole piece are formed by laser cutting, and the operation of cutting excess hollow foil at the edge of the pole piece to form a pole ear 31 that can be completely overlapped during winding can be performed before the pole piece is wound or after the pole piece is wound. The latter is relatively more convenient and simple.

[0053] The cylindrical battery 4 of this embodiment includes a battery cell 3 and two current collecting plates 1 fixed at both ends of the battery cell 3. The two current collecting plates 1 are both tightened and fixed by the tabs 31 of the battery cell 3 passing through the first through hole 13 and falling into the first groove 14 connected to the first through hole 13; technicians can also further weld the tabs 31 and the busbar 11 in the first groove 14.

[0054] Example 2:

[0055] See also Figures 6 to 8 In this embodiment, the current collecting plate 1 is provided with only one first through hole 13 for the pole tab 31 to pass through, and one first groove 14 for accommodating and fixing the pole tab 31 passing through the first through hole 13 .

[0056] In this embodiment, the entire current collecting plate 1 is made of a conductive metal material, which improves the conductivity of the current collecting plate 1 and further reduces the internal resistance of the battery. The edge of the current collecting plate 1 is integrally provided with an extension portion 112. The outer end of the extension portion 112 is provided with a connecting through-hole 2. The current collecting plate 1 is connected to the external structure through the extension portion 112.

[0057] In this embodiment, the current collecting plate 1 is provided with a third through hole 113 to facilitate the electrolyte to enter the battery cell 3 through the third through hole 113 .

[0058] In this embodiment, there is only one pole lug 31 at each end of the battery cell 3, and the cross-section of each pole lug 31 is comparable to the size of its corresponding first through hole 13, so as to ensure that each pole lug 31 can pass through a corresponding first through hole 13 and bend and fall into a corresponding first groove 14.

[0059] In this embodiment, the number of empty foils corresponding to the overlapping tabs 31 is smaller than that in the first embodiment, but the length of each empty foil is longer than that in the first embodiment, which can increase the contact area between the current collecting plate 1 and the tab 31 to further reduce the internal resistance of the battery.

[0060] Apart from this, everything else is the same as in the first embodiment.

[0061] Example 3:

[0062] See also Figures 9 and 10 In this embodiment, the current collecting disk 1 is provided with only four first through holes 13 for the pole lugs 31 to pass through, and two first grooves 14 for accommodating and fixing the pole lugs 31 passing through the first through holes 13. The four first through holes 13 are centrally symmetrically arranged on the current collecting disk 1, and the two first grooves 14 are centrally symmetrically arranged on the current collecting disk 1.

[0063] The current collecting plate 1 of this embodiment adopts the same separated structure of the insulating sheet 12 and the busbar 11 as that of the first embodiment.

[0064] The current collecting plate 1 may also adopt a conductive metal structure as described in the second embodiment.

[0065] An extension portion 112 is integrally provided on the edge of the collecting plate 1 . A connecting through hole 2 is provided at the outer end of the extension portion 112 . The collecting plate 1 is connected to an external structure through the extension portion 112 .

[0066] In this embodiment, the four first through holes 13 are divided into two groups of two first through holes 13 , wherein the two first through holes 13 in one group are both connected to one first groove 14 , and the two first through holes 13 in the other group are also both connected to another first groove 14 .

[0067] In this embodiment, four tabs 31 are provided at each end of the battery cell 3, and the cross-section of each tab 31 is comparable to the size of a corresponding first through hole 13, so as to ensure that each tab 31 can pass through a corresponding first through hole 13 and bend and fall into a corresponding first groove 14.

[0068] When a current collecting plate 1 is provided at one end of the battery cell 3, the four pole tabs 31 at one end of the battery cell 3 pass through their respective corresponding first through holes 13 at the same time, and two pole tabs 31 are bent and fall into the same first groove 14, and the other two pole tabs 31 are bent and fall into another first groove 14 to tighten and fix the current collecting plate 1 to the end face of the battery cell 3, and the fixing effect of the current collecting plate 1 is better than that of the first embodiment.

[0069] Apart from this, everything else is the same as in the first embodiment.

[0070] In other embodiments, the plurality of first through holes 13 on the current collecting plate 1 may also be asymmetrically distributed on the current collecting plate 1 , and the plurality of first grooves 14 may also be asymmetrically distributed on the current collecting plate 1 .

[0071] Furthermore, a plurality of first grooves 14 may be connected to one first through hole 13 at the same time.

[0072] Any matters not mentioned above are applicable to the prior art.

[0073] Finally, it should be noted that the above embodiments are intended only to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art will appreciate that modifications may be made to the technical solutions described in the above embodiments, or that some of the technical features may be replaced with equivalents; such modifications or replacements do not deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A collecting plate, characterized in that: The collecting disk (1) is provided with a first through hole (13) for the pole ear (31) to pass through, and a first groove (14) for accommodating the pole ear (31) passing through the first through hole (13), wherein the first groove (14) is provided in a conductive area of ​​the collecting disk (1); the collecting disk (1) comprises a busbar (11) and an insulating sheet (12), wherein the busbar (11) is provided on the insulating sheet (12), the first groove (14) is provided on the busbar (11), and the first through hole (13) is provided on the insulating sheet (12); the busbar (11) is provided in the middle of the insulating sheet (12); and the collecting disk further comprises a second through hole (121) provided on the insulating sheet (12) and located at the bottom of the busbar (11), and the busbar (11) is further provided with a third through hole (113) communicating with the second through hole (121).

2. The collecting tray according to claim 1, wherein: At least one first through hole (13) is provided, at least one first groove (14) is provided, and at least one first groove (14) is communicated with at least one first through hole (13).

3. The collecting tray according to claim 1, wherein: The busbar (11) comprises a busbar body (111) and an extension portion (112), wherein the extension portion (112) is integrally connected to the busbar body (111); when the busbar (11) is arranged on the insulating sheet (12), the extension portion (112) extends outside the insulating sheet (12).

4. The collecting tray according to claim 3, wherein: The insulating sheet (12) is further provided with a second groove (123) capable of accommodating the extension portion (112), and the second groove (123) is communicated with the second through hole (121).

5. The collecting tray according to claim 4, wherein: The second through hole (121) has a cavity capable of accommodating the busbar body (111), and a limiting flange (122) for limiting the busbar (11) is provided on the hole wall of the second through hole (121).

6. The collecting tray according to claim 5, wherein: The bottom surface of the second groove (123) is flush with the upper surface of the limiting flange (122), and the depth of the second groove (123) is greater than the thickness of the extension portion (112).

7. A battery cell, comprising a current collecting plate (1) according to any one of claims 1 to 6, a cell body, and a tab (31) arranged at an end surface of the cell body, characterized in that: The pole lug (31) passes through the first through hole (13) of the current collecting plate (1) and then bends into the first groove (14) to connect the current collecting plate (1) and clamp the current collecting plate (1) to the end face of the battery cell.

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