Battery cell

Abstract

The utility model discloses a battery monomer, and relates to the technical field of batteries. The battery monomer comprises a shell and an inner core module, and the shell has a first direction and a second direction which are perpendicular to each other; the inner core module comprises a plurality of inner cores, the plurality of inner cores are stacked in the shell along a first direction, and at least one end of each inner core in a second direction is connected with a tab group; each single battery body is provided with a folding plane perpendicular to the first direction, the lengths of the tabs in the tab groups are gradually increased group by group in the first direction along the direction far away from the folding plane, and the tab groups are close to and overlapped in the direction close to the folding plane, so that the problems of tab dislocation and tearing are solved, the space occupied by the tabs in the battery is effectively reduced, and the service life of the battery is prolonged. Therefore, the utilization rate of the internal space of the battery is improved, and the energy density and power performance of the battery are improved.

Description

Technical Field

[0001] This application relates to the field of battery technology, and more particularly to a battery cell. Background Technology

[0002] In cores manufactured using existing lamination technology, the tab lengths are all the same because each layer of electrodes is formed using the same die-cutting mold or a die-cutting mold of the same size. For example, in wound cells, to ensure winding efficiency and yield, the tab lengths are all designed to be the same.

[0003] Existing solutions suffer from significant misalignment and low material utilization after the tabs are folded together. Specifically, after multiple inner cores are stacked and the tabs within each inner core are folded together and welded, misalignment occurs between the tabs of the top and bottom inner cores. This misalignment is unusable, requiring longer tabs to ensure sufficient welding width. Furthermore, as the thickness of the inner core module increases, the misalignment length also increases, causing assembly interference. A common solution is to trim the misaligned area; however, this process introduces metal wires, increasing the risk of cell failure. Utility Model Content

[0004] The purpose of this application is to provide a battery cell to solve the technical problem of misalignment of the tabs after multiple inner cores are stacked.

[0005] To achieve the above objectives, this application provides a battery cell, comprising: a housing having a first direction and a second direction perpendicular to each other; an inner core module including a plurality of inner cores stacked within the housing along the first direction, and each inner core having at least one end connected to a tab assembly in the second direction; the battery cell having a convergence plane perpendicular to the first direction, wherein in the first direction and along a direction away from the convergence plane, the length of the tabs in the tab assembly increases progressively, and the tab assembly converges and overlaps towards the convergence plane.

[0006] In some embodiments, the inner core module has a first side and a second side opposite to each other in a first direction, the collapsing plane is disposed close to the first side, and the tabs on the second side move closer to and overlap the collapsing plane.

[0007] In some embodiments, the collapsing plane is located near the center of the inner core module in the first direction, and the tabs on both sides move closer to the collapsing plane and overlap.

[0008] In some embodiments, when the number of multiple inner cores is odd, the length of the tab group connected to the inner core located at the center in the first direction is the shortest, and the length of the tab group away from the two sides of the inner core gradually increases.

[0009] In some embodiments, when the number of multiple inner cores is even, the length of the tabs in the two inner cores connected to the center in the first direction is the shortest and the same, while the length of the tabs in the two inner cores on the sides gradually increases.

[0010] In some embodiments, the folding plane is the plane where the inner core module is located closest to the center position in the first direction, and the tabs on both sides move closer to the folding plane and overlap.

[0011] In some embodiments, when the number of multiple inner cores is odd, the length of the tab group connected to the inner core that is closest to the center in the first direction is the shortest, and the length of the tab group that is far away from the two sides of the inner core gradually increases.

[0012] In some embodiments, when the number of multiple inner cores is even, the length of the tabs in the two inner cores connected to the center in the first direction is the shortest and the same, while the length of the tabs in the two inner cores on the sides away from these two inner cores gradually increases.

[0013] In some embodiments, the inner core includes a plurality of electrodes stacked along a first direction and a diaphragm, the diaphragm being disposed between two adjacent electrodes, and the two adjacent electrodes having different polarities;

[0014] The electrode assembly includes multiple electrodes, which are connected to the electrode plate in the second direction, and all electrodes are of the same length.

[0015] In some embodiments, the battery cell further includes: a side cover plate connected to the housing; an electrode post including a main body portion and a connecting portion, the main body portion extending through the side cover plate in a second direction, and the connecting portion connected to one end of the main body portion near the inner core module; and an insulating member disposed between the side cover plate and the connecting portion.

[0016] The technical advantages of this application are as follows: A battery cell is provided, including a casing and an inner core module. The casing has a first direction and a second direction perpendicular to each other. The inner core module includes multiple inner cores stacked within the casing along the first direction. At least one end of each inner core is connected to a tab assembly in the second direction. The battery cell has a convergence plane perpendicular to the first direction. In the first direction and along the direction away from the convergence plane, the length of the tabs in the tab assembly increases progressively. The tab assemblies converge and overlap towards the convergence plane to improve the problems of tab misalignment and tearing, and effectively reduce the space occupied by the tabs inside the battery, thereby improving the utilization rate of the battery's internal space and thus improving the battery's energy density and power performance. Furthermore, by rationally allocating the length of each tab assembly, multiple tab assemblies are converged and overlapped to form a smaller misalignment, improving material utilization and reducing costs. Moreover, there is no need to cut the tabs, reducing manufacturing costs and minimizing the source of foreign matter generated by cutting the tabs, thus improving the cell's safety performance. Attached Figure Description

[0017] The technical solution and other beneficial effects of this application will become apparent from the following detailed description of specific embodiments in conjunction with the accompanying drawings.

[0018] Figure 1 This is a schematic diagram of the structure of a battery cell provided in an embodiment of this application.

[0019] Figure 2 for Figure 1 The provided schematic diagram of the stacking of the inner core modules mainly shows that the tab lengths of each inner core are different.

[0020] Figure 3 for Figure 1 A schematic diagram of the structure where the tabs connected to the inner cores converge at the folding plane.

[0021] Figure 4 The schematic diagram of the stacking of an odd number of inner cores provided in the embodiments of this application mainly shows that the tab lengths of each inner core are different.

[0022] Figure 5 The location of the convergence plane of the odd number of inner cores provided in the embodiments of this application.

[0023] Figure 6 The diagram shows an even number of inner cores stacked in an embodiment of this application, mainly illustrating that the tab lengths of each inner core are different.

[0024] Figure 7 A structural schematic diagram showing the location of the convergence plane of an even number of inner cores provided in the embodiments of this application. Figure 1 .

[0025] Figure 8 A structural schematic diagram showing the location of the convergence plane of an even number of inner cores provided in the embodiments of this application. Figure 2 .

[0026] Figure 9 This is a schematic diagram of the electrode structure of a certain inner core provided in an embodiment of this application.

[0027] The components in the attached diagram are labeled as follows:

[0028] 1-Shell; 2-Inner core module; 21-Inner core; 211-First side; 212-Second side; 3-Taper assembly; 31-Positive electrode plate; 32-Negative electrode plate; 33-Separator; 34-Positive electrode tab; 35-Negative electrode tab; 4-Side cover plate; 5-Electrical post; 51-Main body; 52-Connecting part; 6-Insulating component; O-Collapse plane; Z-First direction; X-Second direction. Detailed Implementation

[0029] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0030] To address the technical problem of misalignment of tabs after multiple inner cores are stacked, this application provides a battery cell including a housing and an inner core module. The housing has a first direction and a second direction perpendicular to each other. The inner core module includes multiple inner cores stacked within the housing along the first direction, and each inner core has a tab assembly connected to at least one end in the second direction. The battery cell has a convergence plane perpendicular to the first direction. Along the direction away from the convergence plane, the length of the tabs in the tab assembly increases progressively, and the tab assemblies converge and overlap towards the convergence plane to improve the problems of tab misalignment and tearing, and effectively reduce the space occupied by the tabs inside the battery, thereby improving the utilization rate of the battery's internal space and thus improving the battery's energy density and power performance. Furthermore, by rationally allocating the length of each tab assembly, the multiple tab assemblies form a smaller misalignment after convergence and overlap, improving material utilization and reducing costs. Moreover, there is no need to cut the tabs, reducing manufacturing costs and minimizing the source of foreign matter generated by cutting the tabs, thus improving the cell's safety performance.

[0031] Please see Figure 1 This application provides a battery cell, which is a side-mounted (side-placed) battery cell including a housing 1 and an inner core module 2. The housing 1 has a first direction Z and a second direction X that are perpendicular to each other. The inner core module 2 includes a plurality of inner cores 21, which are stacked in the housing 1 along the first direction Z. Each inner core 21 is connected to at least one end of a tab group 3 in the second direction X. The battery cell has a convergence plane O perpendicular to the first direction Z. In the first direction Z and along the direction away from the convergence plane O, the length of the tabs in the tab group 3 increases in sequence, and the tab group 3 moves closer to the convergence plane O and stacks together.

[0032] It is understood that the first direction Z is the thickness direction of the housing 1, and the second direction X is the length direction of the housing 1. The housing 1 has a receiving cavity, which provides a good working environment for the inner core module 2 and other important structures in the battery. The housing 1 plays a certain protective role for these structures, preventing them from being damaged by external factors. In this embodiment, along the first direction Z and away from the convergence plane O, the length of the tabs in the tab group 3 increases in each group, and the tab group 3 moves closer to and overlaps with the convergence plane O. The increasing length of the tabs in the tab group 3 can effectively reduce the space occupied by the tabs inside the battery, thereby improving the utilization rate of the battery's internal space. The arrangement of the tab group 3 moving closer to and overlapping with the convergence plane O helps to distribute the current more evenly, thereby reducing the risk of local overheating and improving the battery's thermal management performance. Furthermore, the approach and overlap of the tab group 3 can increase the overall stability of the battery structure and reduce the risk of tab loosening or damage due to vibration or impact during use.

[0033] Please see Figure 2 and Figure 3 The inner core module 2 has a first side 211 and a second side 212 in the first direction Z. The convergence plane O is set close to the first side 211, and the tab group 3 of the second side 212 moves closer to the convergence plane O and overlaps. This allows all the tabs of the tab group 3 to be converged at the convergence plane O, which reduces the lateral space occupied by the tabs in the module, increases the proportion of the effective active material area of ​​the cell, and helps to improve the volumetric energy density of the battery.

[0034] Please see Figure 4 , Figure 5 , Figure 6 and Figure 7 The convergence plane O is located near the center of the inner core module 2 in the first direction Z, and the tabs 3 on both sides converge and overlap towards the convergence plane O. The two tabs converge symmetrically to the convergence plane O at the center of the inner core module 2, forming a bidirectional current path. This shortens the current transmission distance from the active material to the tabs, reduces the lateral resistance difference of the current collector (such as copper foil / aluminum foil), improves the symmetry of current distribution during charging and discharging, and reduces the risk of local polarization. Compared with a single-sided convergence design, the convergence of the two tabs towards the center of the inner core module 2 reduces the space redundancy on both sides of the module, further improves the active material filling rate of the inner core 21, and optimizes the module volume utilization.

[0035] Please see Figure 4 and Figure 5 When the number of multiple inner cores 21 is odd, the length of the tab group 3 connected to the inner core 21 located at the center in the first direction Z is the shortest, and the length of the tab group 3 on both sides away from the inner core 21 gradually increases. Figure 5The diagram illustrates that the inner core module 2 comprises three stacked inner cores 21, with the convergence plane O located at the center of the inner core module 2, i.e. Figure 5 At the center of the inner core 2, the length of the electrode in the electrode group 3 connected to the inner core 2 is the shortest, while the length of the electrode in the other electrode groups 3 connected to the inner core 21 gradually increases in the direction away from the inner core 2.

[0036] Please see Figure 6 and Figure 7 When the number of inner cores 21 is even, the length of the tabs in the two inner cores 21 connected to the pole group 3 located near the center in the first direction Z is the shortest and the same, while the length of the tab group 3 located away from the two inner cores 21 gradually increases. Figure 7 The diagram illustrates that the inner core module 2 comprises four stacked inner cores 21, with the convergence plane O located at the center of the inner core module 2, i.e. Figure 7 In the layered surface between "inner core 2" and "inner core 3", the length of the electrode in the electrode group 3 connected to "inner core 2" is the shortest, while the length of the electrode in the other electrode group 3 connected to "inner core 3" gradually increases in the direction away from "inner core 2" and "inner core 3".

[0037] Please see Figure 8 The folding plane O is the plane containing the inner core module 2 closest to the center position in the first direction Z. The tabs 3 on both sides move closer to the folding plane O and overlap. In some embodiments, the inner core module 2 includes four stacked inner cores 21, the center position of which is the stacking surface between "inner core 2" and "inner core 3", and the folding plane O is the plane containing either "inner core 2" or "inner core 3" closest to the center position. Figure 8 The convergence plane O is shown as the "inner core 3" near the center. Therefore, the tabs connected to the other inner cores 21 converge toward the plane where the "inner core 3" is located, and the length of the tabs in the tab group 3 connected to these inner cores 21 gradually increases in the direction away from the "inner core 3".

[0038] Please see Figure 5 In conjunction with the above embodiments, in some embodiments, when the number of multiple inner cores 21 is odd, the length of the tab group 3 connected to the inner core 21 that is closest to the center in the first direction Z is the shortest, and the length of the tab group 3 that is far away from the two sides of the inner core 21 gradually increases.

[0039] Please see Figure 7 and Figure 8In conjunction with the above embodiments, in some embodiments, when the number of multiple inner cores 21 is even, the length of the tabs in the two inner cores 21 that are closest to the center in the first direction Z is the shortest and the same, while the length of the tabs 3 that are far away from the two inner cores 21 gradually increases.

[0040] Therefore, by reasonably allocating the length of each tab group 3, multiple tab groups 3 can be stacked together to form a small misalignment, thereby improving material utilization and reducing costs. Furthermore, there is no need to cut the tabs, which reduces manufacturing costs and also reduces the source of foreign matter generated by cutting the tabs, thus improving the safety performance of the battery cell.

[0041] Please see Figure 9 In conjunction with the above embodiments, in some embodiments, the inner core 21 includes a plurality of electrode sheets stacked along the first direction Z and a diaphragm 33, the diaphragm 33 being disposed between two adjacent electrode sheets, and the polarities of the two adjacent electrode sheets being different; the tab group 3 includes a plurality of tabs, including a positive tab 34 and a negative tab 35, each tab being connected to an electrode sheet in the second direction X, and each tab having the same length.

[0042] In some embodiments, the tab assembly 3 includes a positive tab assembly and a negative tab assembly, and one end of the inner core 21 in the second direction X is simultaneously connected to the positive tab assembly and the negative tab assembly, which are spaced apart. Alternatively, the two ends of the inner core 21 in the second direction X are respectively connected to the positive tab assembly and the negative tab assembly.

[0043] Please see Figure 9 In conjunction with the above embodiments, in some embodiments, the battery cell further includes: a side cover plate 4, an electrode post 5, and an insulating component 6.

[0044] The housing 1 has an opening (not shown) in the second direction X that communicates with the interior of the housing 1. A side cover 4 is connected to the housing 1 to close the opening. The design of the opening makes it easier to insert the inner core module 2 into the housing 1 during assembly, simplifying the assembly process. In addition, maintenance or replacement of the inner core 21 can be achieved by opening the side cover 4, increasing the maintainability of the battery.

[0045] The pole post 5 includes a main body 51 and a connecting part 52. The main body 51 penetrates the side cover plate 4 along the second direction X, and the connecting part 52 is connected to one end of the main body 51 near the inner core module 2.

[0046] Understandably, the main body 51 penetrates the side cover plate 4, allowing current to be directly conducted from the inner core module 2 to the external circuit, and enhancing the overall structural stability of the battery. This reduces the risk of the terminal post 5 becoming loose or damaged due to vibration or impact during use. The outer edge dimension of the connecting part 52 in the first direction Z is larger than the outer edge dimension of the main body 51 in the first direction Z, thereby increasing the connection area between the terminal post 5 and the connecting piece or tab.

[0047] An insulating element 6 is disposed between the side cover plate 4 and the connecting part 52 to prevent the current from forming an unnecessary current path between the side cover plate 4 and the connecting part 52, thereby avoiding the occurrence of a short circuit.

[0048] This application also provides a battery module comprising multiple battery cells as described above, which are connected in series or in parallel. By connecting multiple battery cells in series or in parallel, the battery module can flexibly adjust voltage and capacity, improve reliability and safety, optimize energy and thermal management, and adapt to various application requirements.

[0049] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0050] The above provides a detailed description of a battery cell provided in the embodiments of this application. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the technical solutions and core ideas of this application. Those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A battery cell, characterized by, Comprising: a housing having a first direction and a second direction perpendicular to each other; a core module comprising a plurality of cores, the plurality of cores being arranged in the housing in a stack along the first direction, each of the cores being connected with a tab group at at least one end in the second direction; the battery cell having a folding plane perpendicular to the first direction, in the first direction and in a direction away from the folding plane, the length of the tabs in the tab groups increases gradually from one group to another, and the tab groups are folded and overlapped towards the folding plane.

2. The battery cell of claim 1, wherein the core module has opposite first and second sides in the first direction, the folding plane is arranged close to the first side, and the tab groups on the second side are folded and overlapped towards the folding plane.

3. The battery cell of claim 1, wherein the folding plane is arranged close to a center position of the core module in the first direction, and the tab groups on both sides are folded and overlapped towards the folding plane.

4. The battery cell of claim 3, wherein when the number of the plurality of cores is odd, the length of the tabs in the tab group connected to the core at the center position in the first direction is the shortest, and the length of the tabs in the tab groups away from the core on both sides gradually increases.

5. The battery cell of claim 3, wherein when the number of the plurality of cores is even, the length of the tabs in the tab groups connected to the two cores close to the center position in the first direction is the shortest and the same, and the length of the tabs in the tab groups away from the two cores on both sides gradually increases.

6. The battery cell of claim 1, wherein the folding plane is the plane of the core closest to the center position of the core module in the first direction, and the tab groups on both sides are folded and overlapped towards the folding plane.

7. The battery cell of claim 6, wherein when the number of the plurality of cores is odd, the length of the tabs in the tab group connected to the core closest to the center position in the first direction is the shortest, and the length of the tabs in the tab groups away from the core on both sides gradually increases.

8. The battery cell of claim 6, wherein when the number of the plurality of cores is even, the length of the tabs in the tab groups connected to the two cores closest to the center position in the first direction is the shortest and the same, and the length of the tabs in the tab groups away from the two cores on both sides gradually increases.

9. The battery cell of claim 1, wherein the core comprises a plurality of pole pieces and a separator arranged between adjacent pole pieces in a stack along the first direction, and the adjacent pole pieces have different polarities; the tab group comprises a plurality of tabs connected to the pole pieces in the second direction, and the length of each of the tabs is the same.

10. The battery cell of claim 1, wherein, Further comprising: a side cover plate connected to the housing. The pole includes a main body part penetrating the side cover plate along the second direction and a connecting part connected to the main body part near one end of the inner core module. An insulating part is arranged between the side cover plate and the connecting part.

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