Battery cell shell assembly and battery cell

Abstract

The utility model relates to a battery cell shell assembly and a battery cell. The battery cell shell assembly comprises a connecting sheet and an insulating part, the insulating part is arranged between the connecting sheet and the pole group, a pole lug penetrating hole groove is formed in the insulating part, and a pole lug on the pole group can penetrate through the pole lug penetrating hole groove and is connected with the connecting sheet. The tab insulating part is additionally arranged between the connecting sheet and the pole group, so that the pole group can be insulated from the connecting sheet, and the problem that welding slag is easy to fall into the battery cell in the welding process of the tab and the connecting sheet in the assembling process of the battery cell can be avoided.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, and in particular to a cell housing assembly and the manufacture of a cell. Background Technology

[0002] With the increasing global demand for renewable energy and new energy vehicles, battery technology, especially the design and manufacturing of battery cells, is becoming increasingly important. As the core component of a battery system, the performance of the battery cell directly affects the energy density, safety, and lifespan of the entire battery system. In existing technologies, the cell's cover shell plays a crucial role, not only protecting the internal electrical components but also contributing to the cell's conductivity, insulation, and sealing functions.

[0003] Currently, battery cell end caps and housings generally adopt a separate structure. During assembly, the end cap and electrode assembly are electrically connected via connecting tabs before being assembled together into the housing. In existing technologies, during the battery cell assembly and welding process, after the electrode tabs and connecting tabs are ultrasonically welded, the connecting tabs are then laser-welded to the bottom of the electrode post on the end cap. Because the laser weld marks are located inside the battery cell, the resulting weld slag may pose a risk of internal short circuits within the battery cell. Utility Model Content

[0004] The purpose of this utility model is to provide a battery cell housing assembly and a battery cell, which solves the problem that existing battery cell laser welding marks are located inside the battery cell, and there is a risk of short circuit caused by the introduction of welding slag.

[0005] To achieve the above objectives, this utility model provides a battery cell housing assembly, including a connecting piece and an insulating component; the insulating component is disposed between the connecting piece and the electrode assembly, and the insulating component is provided with a tab insertion slot, through which the tabs on the electrode assembly can pass and connect with the connecting piece.

[0006] Furthermore, it also includes an end cap and a housing, the housing comprising an integrated intermediate portion and a base plate, an opening at one end opposite the base plate, the end cap being mounted at the opening; the end cap having a pole post with a pole post hole exposing the connecting piece; the tabs on the pole assembly extending through the tab insertion slot to the space between the end cap and the insulating member, and connecting to the connecting piece; the connecting piece being located between the insulating member and the end cap.

[0007] Furthermore, it also includes end caps and a housing, the housing including a middle portion, with openings at opposite ends of the middle portion, and two end caps correspondingly installed at the two openings; the end caps have pole posts, with pole post holes on the pole posts, the pole post holes exposing the connecting piece; the tabs on the pole assembly can extend through the tab insertion slots to the space between the end caps and the insulating member, and connect with the connecting piece; the connecting piece is located between the insulating member and the end caps.

[0008] Furthermore, the insulating component includes an insulating body and a first side, a second side, and a third side; the first side and the third side are located on opposite sides of the insulating body, and the second side is disposed at one end of the insulating body and respectively connects the adjacent ends of the first side and the third side; a tab insertion groove is provided between the first side and the insulating body and between the third side and the insulating body.

[0009] Furthermore, the insulating member includes an open end, which is disposed opposite to the second side and exposes one end of the tab insertion slot.

[0010] Furthermore, the connecting piece includes a positive electrode connecting piece and a negative electrode connecting piece, and the positive electrode connecting piece and the negative electrode connecting piece maintain a predetermined distance.

[0011] On the other hand, this utility model also proposes a battery cell, including the battery cell housing assembly described above, and also including an electrode assembly. The electrode assembly is installed inside the battery cell housing assembly. The electrode tabs of the electrode assembly pass through the electrode tab insertion slots and are connected to the connecting piece. The bottom of the electrode post is connected to the connecting piece through the electrode post hole in the battery cell housing assembly.

[0012] Furthermore, the electrode assembly is provided with an L-shaped electrode tab, a portion of which passes through the electrode tab into the slot and is welded to the connecting piece.

[0013] Furthermore, the electrode tabs include positive electrode tabs and negative electrode tabs spaced apart, which are ultrasonically welded to the positive electrode connecting piece and the negative electrode connecting piece, respectively.

[0014] Furthermore, the electrode group includes two sub-electrode groups arranged in parallel. Each sub-electrode group is provided with a positive electrode tab and a negative electrode tab. A positive electrode connecting piece and a negative electrode connecting piece are respectively connected to the positive electrode tab and the negative electrode tab in the two sub-electrode groups.

[0015] Compared with the prior art, the present invention has at least the following beneficial effects:

[0016] By setting an insulating component between the electrode assembly and the connecting piece, and providing a tab insertion slot on the insulating component, the tabs on the electrode assembly pass through the tab insertion slot and are welded to the connecting piece above the insulating component. This not only ensures insulation between the battery cell and the connecting piece, but also prevents welding slag from falling into the battery cell during the welding process of the tabs and the connecting piece.

[0017] Furthermore, a terminal hole is provided on the terminal post of the end cap. During the laser welding process of connecting the bottom of the terminal post to the connecting piece through the terminal hole, since the welding is performed from the outside of the cell, the laser weld mark is located on the outside of the cell. The welding slag only falls into the terminal hole and will not remain inside the cell, thereby reducing the risk of short circuit caused by welding slag being introduced into the cell. Attached Figure Description

[0018] Figure 1 This is an exploded view of the battery cell cover housing assembly in one embodiment of the present invention;

[0019] Figure 2 This is a schematic diagram of the structure of the end cover and housing assembly in a battery cell cover housing assembly according to an embodiment of the present invention;

[0020] Figure 3 This is a schematic diagram of the assembled electrode assembly in a cell cover housing assembly according to an embodiment of the present invention;

[0021] Figure 4 This is an exploded view of the assembled electrode assembly in the cell cover housing assembly according to an embodiment of the present invention;

[0022] Figure 5 This is a schematic diagram of the structure of the middle electrode lug of the middle electrode group in an embodiment of the present invention, without folding;

[0023] Figure 6 This is a front view of the middle assembly of the battery cell cover housing assembly according to an embodiment of the present invention;

[0024] Figure 7 This is a side view of the end cover and housing assembly in a battery cell cover housing assembly according to an embodiment of the present invention;

[0025] Figure 8 This is a top view of the end cover and housing assembly in a battery cell cover housing assembly according to an embodiment of the present invention.

[0026] The components are as follows: 1. Shell; 101. Base plate; 102. Middle part; 11. Pole post; 12. Pole post hole; 14. Laser welding mark; 2. Connecting piece; 21. Positive electrode connecting piece; 22. Negative electrode connecting piece; 3. Insulating component; 31. Insulating body; 32. First side; 33. Second side; 34. Third side; 35. Pole tab insertion groove; 36. Open end; 4. End cap; 5. Pole group; 51. Pole tab; 511. Positive electrode tab; 512. Negative electrode tab. Detailed Implementation

[0027] The following is a more detailed description of a battery cell housing assembly and its battery cell according to the present invention, with reference to the accompanying drawings, which illustrate preferred embodiments of the present invention. It should be understood that those skilled in the art can modify the present invention described herein while still achieving its advantageous effects. Therefore, the following description should be understood as being of general knowledge to those skilled in the art and is not intended to limit the present invention.

[0028] For clarity, not all features of the actual embodiments are described. In the following description, well-known functions and structures are not detailed in detail, as they would confuse the present invention with unnecessary detail. It should be understood that in the development of any actual embodiment, numerous implementation details must be made to achieve the developer's specific goals, such as changes from one embodiment to another according to limitations related to the system or business. Furthermore, it should be understood that such development work may be complex and time-consuming, but is merely routine work for those skilled in the art.

[0029] The present invention will be described more specifically by way of example in the following paragraphs with reference to the accompanying drawings. The advantages and features of the present invention will become clearer from the following description and claims. It should be noted that the drawings are in a very simplified form and use non-precise proportions, and are only used to facilitate and clarify the illustration of the embodiments of the present invention.

[0030] As mentioned in the background section, the cell cover and casing of alkali metal ion batteries (taking lithium-ion batteries as an example) generally adopt a separate structure. In this structure, the electrode assembly, made of active materials such as lithium cobalt oxide / graphite, is internally electrically connected by copper / aluminum connecting pieces and then assembled with aluminum alloy terminals into a stainless steel or aluminum casing. In the lithium-ion battery manufacturing process, the laser welding process between the connecting pieces and the bottom of the terminals presents significant technical challenges. Since lithium-ion batteries are filled with carbonate electrolytes and lithium hexafluorophosphate, if the metal particles (such as Al and Cu oxides) generated by laser welding are not completely captured, they may penetrate the polyethylene / polypropylene composite separator, causing obstruction of the lithium-ion migration path or dendrite short circuits.

[0031] In view of this, such as Figures 1-4 As shown, this utility model provides a battery cell housing assembly, including a connecting piece 2 and an insulating member 3; the insulating member 3 is disposed between the connecting piece 2 and the electrode group, and the insulating member 3 is provided with a tab insertion groove 35, and the tabs 51 on the electrode group can pass through the tab insertion groove 35 and be connected to the connecting piece 2.

[0032] In one embodiment, such as Figure 2As shown, the battery cell housing assembly further includes an end cap 4 and a housing 1. The housing 1 includes an integrated intermediate portion 102 and a base plate 101. An opening is provided at one end opposite to the base plate 101, and the end cap 4 is installed at the opening. The end cap 4 has a pole post 11, and a pole post hole 12 is provided on the pole post 11, which exposes the connecting piece 2. The tab 51 on the pole group 5 can extend through the tab insertion slot 35 to the space between the end cap 4 and the insulating member 3, and connect with the connecting piece 2. The connecting piece 2 is located between the insulating member 3 and the end cap 4.

[0033] Specifically, the middle part 102 has a hollow structure, and the end cap 4 and the base plate 101 are respectively disposed at both ends of the middle part 102. The base plate 101 and the middle part 102 can be integrated by welding or integral molding.

[0034] In addition, the end cap 4 is provided with a pole post 11. Figure 2 The diagram schematically shows two terminals 11, labeled positive and negative respectively, to facilitate alignment with the positive and negative terminals of the connecting piece 2 during the subsequent installation of the electrode assembly 5 into the casing. Each terminal 11 has a terminal hole 12, which exposes the connecting piece 2. Through the terminal hole 12, the bottom of the terminal 11 can be laser-welded to the connecting piece 2 from the outside of the cell. The resulting laser weld mark 14 is located on the outside of the cell, while the weld slag falls into the terminal hole 12, thereby reducing the risk of short circuits caused by weld slag entering the cell.

[0035] In this embodiment, as Figure 4 As shown, the connecting piece 2 includes a positive electrode connecting piece 21 and a negative electrode connecting piece 22, which maintain a predetermined distance. The connecting piece 2, as an electrical conductor, is responsible for connecting the positive and negative electrodes in the electrode group 5 to the external circuit of the battery, ensuring that current can flow smoothly into and out of the cell.

[0036] Furthermore, such as Figure 4 As shown, the insulating component 3 includes an insulating body 31 and a first side 32, a second side 33 and a third side 34. The first side 32 and the third side 34 are located on opposite sides of the insulating body 31. The second side 33 is disposed at one end of the insulating body 31 and connects the adjacent ends of the first side 32 and the third side 34 respectively. A tab insertion groove 35 is provided between the first side 32 and the insulating body 31 and between the third side 34 and the insulating body 31.

[0037] Furthermore, the insulating member 3 includes an open end 36, which is disposed opposite to the second side 33 and exposes one end of the tab insertion groove 35.

[0038] In another embodiment, the cell housing assembly further includes an end cap 4 and a housing 1. The housing 1 includes a middle portion 102, with openings at opposite ends of the middle portion 102. Two end caps 4 are correspondingly installed at the two openings. Each end cap 4 has a pole post with a pole post hole that exposes the connecting piece. The tabs on the pole assembly can extend through the tab insertion slot to the space between the end cap 4 and the insulating member, and connect with the connecting piece. The connecting piece is located between the insulating member and the end cap 4.

[0039] It should be noted that the structural design of the opening must meet the process requirements of electrode assembly. Its shape can be adapted to the size of the electrode assembly, either circular or rectangular, and flanges or reinforcing structures can be set at the edges of the opening to improve the strength of the casing. This opening not only serves as an electrode assembly channel but can also integrate functions such as an electrolyte injection port or a heat dissipation channel. The specific configuration is adjusted according to the battery type and process requirements. When the positive and negative electrode tabs of the electrode assembly are located at opposite ends of the casing, the openings at both ends must be equipped with matching end cap structures, achieving dual protection of electrical connection and sealing performance through different sealing methods (such as welding or threaded connection).

[0040] Furthermore, in another aspect of this embodiment, a battery cell is also provided, including the battery cell housing assembly described above, and also including an electrode group 5.

[0041] Specifically, such as Figure 5 As shown, the electrode group 5 is provided with L-shaped tabs 51. Each tab 51 includes a positive tab 511 and a negative tab 512 spaced apart, which are ultrasonically welded to the positive connecting piece 21 and the negative connecting piece 22, respectively. The positive tab 511 and the negative tab 512 connect the internal and external circuits of the battery cell, allowing the cell to be charged or discharged. This ensures a balanced current path between the positive and negative electrodes, which helps maintain the consistency and stability of the cell's performance during charging and discharging. Furthermore, the tabs 51 also help maximize the use of the internal space of the cell, allowing it to store more energy within a limited space and increasing its energy density.

[0042] In this embodiment, the tab 51 is folded because it is made of a metal material, such as copper or aluminum. These materials have good conductivity and a certain degree of flexibility, allowing the tab 51 to be folded. Additionally, during the assembly of the battery cell, the tab 51 needs to be folded to fit a specific assembly space or to connect with the connecting piece 2. The number of tabs 51 is... Figure 5 The diagram schematically shows four electrodes, including two positive electrode tabs 511 and two negative electrode tabs 512.

[0043] In this embodiment, the pole group 5 includes multiple sub-pole groups arranged in parallel. Figure 2 The diagram schematically shows two neutron electrode groups, each equipped with a positive electrode tab 511 and a negative electrode tab 512. A positive electrode connecting piece 21 and a negative electrode connecting piece 22 connect the positive electrode tab 511 and the negative electrode tab 512 of each of the two sub-electrode groups, respectively. Specifically, the positive electrode connecting piece 21 of the connecting piece 2 is ultrasonically welded to the positive electrode tab 511 of the electrode 51, and the negative electrode connecting piece 22 of the connecting piece 2 is ultrasonically welded to the negative electrode tab 512 of the electrode 51.

[0044] In this embodiment, the pole group 5 is installed inside the housing 1, wherein, as... Figure 3 As shown, the tab 51 of the electrode group 5 is connected to the connecting piece 2 in the cell housing assembly, the insulating member 3 is located between the connecting piece 2 and the electrode group 5, and the assembly methods of the insulating member 3, the connecting piece 2 and the electrode group 5 include the following two:

[0045] Assembly method 1: The plurality of electrode tabs 51 of the electrode group 5 are first ultrasonically welded to the connecting piece 2, and then horizontally inserted from the opening end 36 on the insulating member 3 until the insulating member 3 is assembled between the connecting piece 2 and the electrode group 5.

[0046] Assembly method 2: A portion of the electrode lug 51 of the electrode group 5 is vertically inserted into the electrode lug insertion slot 35 and folded inward, and ultrasonically welded to the connecting piece 2. At this time, the insulating member 3 is located between the connecting piece 2 and the electrode group 5.

[0047] In this embodiment, as Figure 6 or Figure 7 As shown, by integrating the end cap 4 and the housing 102, the internal space layout of the battery cell can be optimized. The tabs 51 and connecting pieces 2 of the electrode assembly 5 do not need to be folded inside the battery cell after welding, reducing the required space and thus improving the space utilization rate of the electrode assembly 5 inside the battery cell, thereby increasing the volumetric energy density of the battery cell. Furthermore, the integrated design of the end cap 4 and the housing 102 eliminates the need for pre-assembly of the end cap 4 and electrode assembly 5 when inserting the electrode assembly 5 into the housing, reducing assembly difficulty and improving assembly efficiency. Additionally, the bottom of the electrode post 11 is connected to the connecting piece 2 via the electrode post hole 12 in the battery cell housing assembly, eliminating the need for complex positioning and operations inside the battery cell, thus simplifying the assembly process. The bottom of the electrode post 11 is laser-welded to the connecting piece 2, and the resulting laser weld mark 14 is located on the outside of the battery cell. Simultaneously, the weld slag falls into the electrode post hole 12, reducing the risk of short circuits caused by weld slag being introduced into the battery cell.

[0048] The battery cell housing assembly and the battery cell assembly method are as follows:

[0049] Preparation of S1 and pole group 5:

[0050] like Figure 5 As shown, electrode group 5 includes two sub-electrode groups arranged side by side. Each sub-electrode group is provided with a positive electrode tab 511 and a negative electrode tab 512. The positive electrode tabs 511 and 512 are spaced apart and can be connected to the connecting piece 2 respectively. One positive electrode connecting piece 21 and one negative electrode connecting piece 22 respectively connect the positive electrode tab 511 and the negative electrode tab 512 in the two sub-electrode groups.

[0051] S2, Configuration of Insulator 3:

[0052] Prepare insulating component 3, such as Figure 4 As shown, the insulating member 3 includes an insulating body 31 and a first side 32, a second side 33, and a third side 34. The first side 32 and the third side 34 are located on opposite sides of the insulating body 31. The second side 33 is disposed at one end of the insulating body 31 and connects the adjacent ends of the first side 32 and the third side 34. A tab insertion groove 35 is provided between the first side 32 and the insulating body 31, and between the third side 34 and the insulating body 31. An open end 36 is provided on the side opposite to the second side 33, and the open end 36 can expose one end of the tab insertion groove 35.

[0053] S3. Assembly of connecting piece 21 and pole group 5:

[0054] Assembly method 1: The positive electrode connecting piece 21 and the negative electrode connecting piece 22 are ultrasonically welded to the positive electrode tab 511 and the negative electrode tab 512 of the two sub-electrode groups, respectively, and then horizontally inserted from the opening end 36 on the insulating member 3 until the insulating member 3 is assembled between the connecting piece 2 and the electrode group 5.

[0055] Assembly method 2: A portion of the positive electrode tab 511 and the negative electrode tab 512 in the two sub-electrode groups are vertically inserted into the tab insertion slot 35, and folded inward, and then ultrasonically welded to the positive electrode connecting piece 21 and the negative electrode connecting piece 22 respectively. At this time, the insulating component 3 is located between the connecting piece 2 and the electrode group 5.

[0056] S4, Inserting the casing:

[0057] The electrode assembly 5, after being assembled with the connecting piece 2, is inserted into the housing 1 through the opening. At this time, the connecting piece 2 is exposed through the electrode post hole 12.

[0058] S5, Welding connecting piece 2 and pole post 11:

[0059] The bottom of the electrode 11 is connected to the connecting piece 2 by laser welding through the electrode hole 12 in the cell housing assembly. For example... Figure 8 As shown, during the welding process, welding is performed from the outside of the cell. The laser weld mark 14 is located outside the cell housing assembly. The weld slag only falls into the electrode hole 12 and will not remain inside the cell, which can reduce the risk of short circuit caused by the weld slag being introduced into the cell.

[0060] S6. Final Inspection and Testing:

[0061] The assembled battery cells undergo visual inspection and performance testing, including electrical and mechanical strength tests, to ensure that each cell meets quality and safety standards.

[0062] In summary, in the battery cell housing assembly and battery cell provided in this utility model embodiment, by providing an insulating component between the electrode group and the connecting piece, and providing a tab insertion slot on the insulating component, the tabs on the electrode group pass through the tab insertion slot and are welded to the connecting piece above the insulating component. This not only ensures the insulation between the battery cell and the connecting piece, but also prevents welding slag from falling into the battery cell during the welding process of the tabs and the connecting piece.

[0063] Furthermore, a terminal hole is provided on the terminal post of the end cap. During the laser welding process of connecting the bottom of the terminal post to the connecting piece through the terminal hole, since the welding is performed from the outside of the cell, the laser weld mark is located on the outside of the cell. The welding slag only falls into the terminal hole and will not remain inside the cell, thereby reducing the risk of short circuit caused by welding slag being introduced into the cell.

[0064] The above are merely preferred embodiments of this utility model and do not constitute any limitation on this utility model. Any equivalent substitutions or modifications made by those skilled in the art to the technical solutions and contents disclosed in this utility model without departing from the scope of the technical solutions of this utility model shall still fall within the protection scope of this utility model.

Claims

1. A battery cell housing assembly, characterized in that, It includes a connecting piece and an insulating component; the insulating component is disposed between the connecting piece and the electrode assembly, and the insulating component has a tab insertion slot, through which the tabs on the electrode assembly can pass and connect with the connecting piece.

2. The cell housing assembly according to claim 1, characterized in that, It also includes an end cap and a housing, the housing comprising an integrated middle section and a base plate, an opening at one end opposite to the base plate, the end cap being mounted at the opening; the end cap having a pole post with a pole post hole exposing the connecting piece; the tabs on the pole assembly extending through the tab insertion slot to the space between the end cap and the insulator, and connecting to the connecting piece; The connecting piece is located between the insulating element and the end cap.

3. The cell housing assembly according to claim 1, characterized in that, It also includes end caps and a housing, the housing including a middle part, with openings at opposite ends of the middle part, and two end caps correspondingly installed at the two openings; the end caps have pole posts with pole post holes that expose the connecting piece; the tabs on the pole group can pass through the tab insertion slots and extend to the space between the end caps and the insulating member, and connect with the connecting piece; The connecting piece is located between the insulating element and the end cap.

4. The cell housing assembly according to claim 1, characterized in that, The insulating component includes an insulating body and a first side, a second side, and a third side; the first side and the third side are located on opposite sides of the insulating body, and the second side is disposed at one end of the insulating body and connects to the adjacent ends of the first side and the third side respectively; a tab insertion groove is provided between the first side and the insulating body and between the third side and the insulating body.

5. The cell housing assembly according to claim 4, characterized in that, The insulating element includes an open end, which is disposed opposite to the second side and exposes one end of the tab insertion slot.

6. The cell housing assembly according to claim 1, characterized in that, The connecting piece includes a positive electrode connecting piece and a negative electrode connecting piece, and the positive electrode connecting piece and the negative electrode connecting piece maintain a predetermined distance.

7. A battery cell, characterized in that, The battery cell housing assembly as described in any one of claims 1-6 further includes an electrode assembly, which is installed inside the battery cell housing assembly. The electrode tabs of the electrode assembly pass through the electrode tab insertion slots and are connected to the connecting piece. The bottom of the electrode post is connected to the connecting piece through the electrode post holes in the battery cell housing assembly.

8. The battery cell according to claim 7, characterized in that, The electrode assembly is provided with an L-shaped electrode tab, a portion of which passes through the electrode tab into a slot and is welded to the connecting piece.

9. The battery cell according to claim 7, characterized in that, The electrode tabs include positive electrode tabs and negative electrode tabs spaced apart, which are ultrasonically welded to the positive electrode connecting piece and the negative electrode connecting piece, respectively.

10. The battery cell according to claim 7, characterized in that, The electrode group includes two sub-electrode groups arranged in parallel. Each sub-electrode group is provided with a positive electrode tab and a negative electrode tab. A positive electrode connecting piece and a negative electrode connecting piece are respectively connected to the positive electrode tab and the negative electrode tab in the two sub-electrode groups.

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