Battery cell structure, battery module, and battery pack

Abstract

To provide a battery cell structure which achieves improvement of a connection method between a pin and a tab to improve energy density.SOLUTION: A battery cell structure, a battery module, and a battery pack are provided. The battery cell structure includes a housing 26, an electrode assembly, a top cover assembly 12, and a pin part 13. The electrode assembly is disposed in the housing. The electrode assembly includes: a battery cell body 10; and tabs 11 extending from the battery cell body. The top cover assembly includes: a top cover; and an electrode terminal disposed on the top cover. The top cover body is connected to the housing. The pin part includes a terminal connection part and a tab guide part which are connected with each other. The terminal connection part is connected to the electrode terminal. The tab guide part is connected to the tab. The terminal connection part is connected to the tab guide part. One side of the tab guide part, which is apart from the electrode assembly, is an outer surface.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to the field of battery cell structures, and in particular to battery cell structures, battery modules, and battery packs. [Background technology]

[0002] There are tabs and pins inside the battery, and the pins are electrically connected to the tabs. The existing technological process for welding the tabs and pins is as follows: first, the tabs are ultrasonically flat-welded, then the tabs are cut, and finally the tabs and pins are laser-welded.

[0003] The pin and tab welding method has many problems. First, the tab cutting process generates a large amount of metal fragments, which are difficult to clean and remain inside the battery core, easily causing insulation failure. Second, the two tabs of the battery cell are wrapped around the pin from both sides. Due to limitations of the existing pin structure, the tabs partially overlap with the pin. If the tabs are not cut, the thickness of the overlapping area increases, not only occupying the battery's internal space but also reducing the battery's energy density. Summary of the Invention [Problem to be solved by the invention]

[0004] The technical problem to be solved by the present invention is to overcome the drawback of the prior art, which is the irrational pin-to-tab connection method, which requires a large space because the tab overlaps the pin, resulting in a decrease in the energy density of the battery.

[0005] To solve the above technical problems, the present invention provides a battery cell structure, a battery module, and a battery pack. [Means for solving the problem]

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is a battery cell structure including a housing, an electrode assembly, a top cover assembly, and a pin portion. The electrode assembly is disposed within the housing, and the electrode assembly includes a battery cell body and a tab extending from the battery cell body. The top cover assembly includes a top cover body and an electrode terminal disposed on the top cover body. The top cover body is connected to the housing. The pin portion includes a terminal connection portion and a tab guide portion that are connected to each other. The terminal connection portion is connected to the electrode terminal. The tab guide portion is connected to the tab. The terminal connection portion is connected to the tab guide portion. One surface of the tab guide portion away from the electrode assembly is an outer surface, and a portion of the outer surface is recessed to form a groove, and the tab is partially received in the groove.

[0007] In this solution, the tab protrudes from the battery cell body and is attached to the outer surface of the tab guide. Because part of the tab is housed in the groove, it is hidden within the thickness of the tab guide, reducing the space occupied by the end of the tab and contributing to improving the energy density of the battery cell. Furthermore, because there is no need to cut off the terminal end of the tab, no metal fragments are generated, ensuring insulation within the battery cell.

[0008] Preferably, the tab is partially received within the groove.

[0009] Preferably, the bottom of the groove has a bottom wall surface, and the bottom wall surface is recessed in a direction approaching the electrode assembly to form a through groove.

[0010] Preferably, the through groove extends from a position close to the top cover assembly in a direction away from the top cover assembly.

[0011] Preferably, the through groove extends from a position close to the top cover assembly in a direction away from the top cover assembly until it passes through the pin portion.

[0012] Preferably, the tab is bent outward from one side of the tab guide portion.

[0013] Preferably, the end of the tab extends toward the center of the tab guide portion, and the end of the tab is received in the groove.

[0014] Preferably, the end of the tab is not received in the groove.

[0015] Preferably, the electrode assembly includes a first electrode assembly and a second electrode assembly, a first tab extending from the first electrode assembly, a second tab extending from the second electrode assembly, and the first and second tabs respectively extending from webs on opposite sides of the tab guide portion to a center of the tab guide portion.

[0016] Preferably, the ends of the first tab and the second tab intersect with each other and the intersecting portion is received within the groove.

[0017] Preferably, the ends of the first tab and the second tab do not intersect with each other.

[0018] Preferably, at least a portion of the tabs overlap one another and the overlapping portions are received within the grooves.

[0019] In this technical solution, the excess length of the tabs overlaps and is accommodated in the groove, thereby reducing the space occupied by the overlapping portions of the tabs in the thickness direction of the tab guide portion, thereby improving the energy density of the battery cell.

[0020] Preferably, the at least two tabs are bent outward from both sides of the tab guide portion, respectively, with the ends of the at least two tabs overlapping each other and the overlapping portions being accommodated in the grooves.

[0021] In this solution, at least two tabs are bent from the side closer to the electrode assembly toward the outer surface, and the overlapping portions of the ends of the at least two tabs are accommodated in a groove, thereby reducing the space occupied by the overlapping portions of the tab ends and contributing to improving the energy density of the battery cell.

[0022] Preferably, the groove extends along the length of the tab guide portion, and the length of the groove is equal to or greater than the length of the tab.

[0023] In this solution, the length of the tab is less than or equal to the length of the groove, so that the tab can be positioned completely within the groove without leaving any excess part exposed outside the groove, thereby reducing the space occupied by the tab.

[0024] Preferably, the groove is centrally located on the outer surface.

[0025] In this solution, the groove is positioned at the center of the outer surface, so the distance between the groove and both sides of the tab guide portion is the same. Therefore, two tabs of the same length can surround the tab guide portion from both sides. The overlapping areas of the two tabs are located exactly opposite the groove position that defines the positions of the two electrode assemblies. Furthermore, because the tabs of the two electrode assemblies are the same length, there is no need to consider the assembly order of the two electrode assemblies, and the situation where the overlapping portions of the tabs cannot be aligned with the groove due to incorrect operation is avoided, resulting in a good foolproof effect.

[0026] Preferably, a smooth transition is formed between the sidewall surface and the outer surface of the groove, forming the first arcuate portion.

[0027] In this solution, the tab extends from the outer surface to the groove and is bent at a first arc to prevent the tab from breaking when pressed against a sharp corner.

[0028] Preferably, the bottom of the groove has a bottom wall surface, and the height difference between the bottom wall surface and the outer surface is at least the thickness of a single tab.

[0029] In this solution, two tabs surround the tab guide portion from both sides. The end of the first tab is recessed into the groove and is formed from a high level to a low level. The second tab is at a low level and is limited by the height difference between the bottom wall surface and the outer surface, which is at least the thickness of a single tab. Therefore, the top surface of the second tab does not protrude from the top surface of the first tab.

[0030] Preferably, the bottom of the groove has a bottom wall surface, and the bottom wall surface is recessed in a direction approaching the electrode assembly to form a through groove. The tab passes through the through groove and enters the groove by the electrode assembly, and the end of the tab is bent and overlaps the bottom wall surface.

[0031] In this solution, the tab passes through the groove from the center of the tab guide portion, and the end of the tab extends into the groove and rests on the bottom wall surface. In this way, the end of the tab does not protrude from the outer surface, which contributes to improving the energy density of the battery cell.

[0032] The battery module includes the battery cell structure described above.

[0033] In this solution, the above battery cell structure is applied to a battery module, which can save the internal space of the battery module and thereby increase the energy density of the entire battery module.

[0034] A battery pack includes the battery cell structure or the battery module.

[0035] In this solution, the above cell structure or battery module is applied within a battery pack, which reduces the amount of dead space within the battery pack, thereby increasing the power contained in the battery per unit volume.

[0036] Based on common knowledge in the art, the above-mentioned preferred conditions can be freely combined to obtain preferred examples of the present invention. [Effects of the Invention]

[0037] The advantageous effects of the present invention are that the tab protrudes from the battery cell body and is attached to the outer surface of the tab guide, and part of the tab is housed in the groove, so that part of the tab is hidden within the thickness space of the tab guide, reducing the space occupied by the end of the tab and contributing to improving the energy density of the battery cell. In addition, since there is no need to cut off the terminal end of the tab, no metal pieces are generated and insulation within the battery cell is ensured. [Brief explanation of the drawings]

[0038] [Figure 1] 1 is a schematic diagram showing an exploded structure of a battery cell structure according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a schematic structural diagram of the top cover assembly and pin portion of FIG. 1. [Figure 3] FIG. 3 is an enlarged schematic view of the structure of the pin portion of FIG. 2. [Figure 4] 3 is a schematic diagram of a tab surrounding a tab guide portion in the battery cell structure according to the first embodiment of the present invention. FIG. [Figure 5] 10 is a schematic structural diagram of a pin portion in a battery cell structure according to a second embodiment of the present invention. FIG. [Figure 6] FIG. 6 is a schematic diagram showing the structure of the outer surface of FIG. 5. [Figure 7] 10 is a schematic diagram of a tab surrounding a tab guide portion in a battery cell structure according to a second embodiment of the present invention. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0039] The present invention will be described more clearly and completely below using embodiments in conjunction with the accompanying drawings, but the present invention is not limited to the scope of the embodiments.

[0040] Embodiment 1

[0041] 1 to 4 show an embodiment of a battery cell structure of the present invention. As shown in Figures 1 and 2, it includes a housing 26, an electrode assembly, a top cover assembly 12, and a pin portion 13. The electrode assembly is provided inside the housing 26, and the electrode assembly includes a battery cell body 10 and a tab 11 extending from the battery cell body 10.

[0042] The battery cell body 10 may be a laminate or a winding core.

[0043] The top cover assembly 12 includes a top cover body 14 and an electrode terminal 15 disposed on the top cover body 14, and the top cover body 14 is connected to the housing 26.

[0044] The pin portion 13 includes a terminal connection portion 16 and a tab guide portion 17, which are connected to each other. The terminal connection portion 16 is connected to the electrode terminal 15, and the tab guide portion 17 is connected to the tab 11.

[0045] The surface of the tab guide portion 17 facing away from the electrode assembly is an outer surface 18, a portion of which is recessed to form a groove 19 within which a portion of the tab 11 is accommodated.

[0046] In this embodiment, a portion of the tab 11 is accommodated in the groove 19, and thus the tab 11 is partially hidden within the thickness space of the tab guide portion 17, reducing the space occupied by the tab 11 and thereby improving the energy density of the battery cell. Furthermore, because the excess portion of the tab 11 can be accommodated within the groove 19, there is no need to cut off the excess portion at the end of the tab 11. This prevents the generation of metal fragments, and the presence of the metal fragments does not damage the insulation within the battery cell. In this way, the safety of the battery cell can be improved.

[0047] Preferably, at least a portion of the tabs 11 overlap one another, and the overlapping portions are received within the grooves 19 .

[0048] In some embodiments, the end of tab 11 is folded and housed in groove 19. In other embodiments, the center portion of tab 11 is folded and housed in groove 19. In either of the above two embodiments, tab 11 can be hidden within the thickness space of tab guide portion 17, and the space occupied by tab 11 can be reduced.

[0049] Preferably, at least two tabs 11 are bent from both sides of tab guide portion 17 toward outer surface 18 , with the ends of at least two tabs 11 overlapping each other and the overlapping portions being housed in groove 19 .

[0050] In this embodiment, the two tabs 11 are bent from either side of the tab guide portion 17 toward the outer surface 18, and the overlapping portions at the ends of the two tabs 11 are housed in the groove 19. This reduces the space occupied by the overlapping portions at the ends of the tabs, thereby improving the energy density of the battery cell.

[0051] In another embodiment of the present invention, multiple tabs 11 are bent from one side of tab guide portion 17 to outer surface 18, and multiple tabs 11 are bent from the other side of tab guide portion 17 toward outer surface 18. The multiple tabs 11 on both sides overlap at outer surface 18, and the overlapping portions are received in grooves 19.

[0052] Preferably, the groove 19 extends along the length of the tab guide portion 17 and the length of the groove 19 is equal to or greater than the length of the tab 11 .

[0053] In some embodiments, the length of groove 19 is longer than the length of tab 11. Because the length of tab 11 is shorter than the length of groove 19, tab 11 can be positioned completely within groove 19 without leaving any excess portion exposed outside the groove, thereby reducing the space occupied by tab 11.

[0054] In some other embodiments, the length of groove 19 is equal to the length of tab 11 so that tab 11 can be seated precisely and perfectly within groove 19 .

[0055] 4, in some embodiments, the number of electrode assemblies is two, and the two electrode assemblies are stacked on top of each other, with two tabs 11 surrounding the tab guide portion 17 from both sides thereof. The two tabs 11 overlap each other on the outer surface 18, and the overlapping portions are disposed in grooves 19. This reduces the space occupied by the overlapping portions of the tabs 11, improving space utilization.

[0056] The number of electrode assemblies is not limited to two. In another embodiment of the present invention, the number of electrode assemblies is one, and one tab 11 surrounds the tab guide portion 17 from one side of the tab guide portion 17. The excess portion of the end of the tab 11 is folded and placed in the groove 19, thereby preventing the excess tab 11 from being cut off and reducing the space occupied by the end of the tab 11.

[0057] As shown in FIG. 3, in some embodiments, the groove 19 is located in the center of the outer surface 18 .

[0058] In this embodiment, the two tabs 11 have the same length, and are bent from both sides toward the outer surface 18 of the tab guide portion 17, with the two tabs 11 overlapping in the center of the outer surface 18, and the overlapping portion directly facing the position of the groove 19.

[0059] The groove 19 is disposed in the center of the outer surface 18 so that the distance between the groove 19 and both sides of the tab guide portion 17 is the same, and therefore two tabs 11 of the same length can surround the tab guide portion 17 from both sides thereof. The overlapping area of ​​the two tabs 11 is exactly opposite the position of the groove 19 that defines the positions of the two electrode assemblies.

[0060] Furthermore, since the tabs 11 of the two electrode assemblies are the same length, there is no need to consider the order in which the two electrode assemblies are assembled. This avoids the situation in which the overlapping portions of the tabs 11 cannot be aligned with the grooves 19 due to incorrect operation, resulting in a good foolproof effect.

[0061] It should be noted that the position of the groove 19 is not limited to the central position described above. In other embodiments of the present invention, the groove 19 may be shifted from the central position of the tab guide portion 17 according to actual needs in order to accommodate different lengths of the two tabs 11.

[0062] As shown in FIG. 3, the first arcuate portion 20 is preferably formed by a smooth transition between the sidewall surface of the groove 19 and the outer surface 18 .

[0063] In this embodiment, the tab 11 extends from the outer surface 18 to the groove 19 and is bent at the first arc portion 20. The smooth surface of the first arc portion 20 prevents the tab 11 from being damaged by being pressed against a sharp corner.

[0064] Preferably, the bottom of the groove 19 has a bottom wall 21 and the difference in height between the bottom wall 21 and the outer surface 18 is at least the thickness of a single tab 11 .

[0065] As shown in FIG. 4, in some embodiments, first tab 24 is bent from one side of tab guide portion 17 and surrounds tab guide portion 17, and the end of first tab 24 is bent and recessed into groove 19 to form high and low levels.

[0066] A second tab 25 is bent from the other side of the tab guide portion 17, surrounds the tab guide portion 17, extends above the outer surface 18 and rests at a lower level.

[0067] The first tab 24 is attached to the outer surface 18 and bottom wall surface 21 of the groove 19, and the height difference between the bottom wall surface 21 and the outer surface 18 is the thickness of the single tab 11, and the height difference between the high level and the low level is also the thickness of the single tab 11. Therefore, the upper surface of the second tab 25 is kept flush with the upper surface of the first tab 24, thereby reducing the protruding thickness of the tab 11.

[0068] In another embodiment of the present invention, the height difference between the bottom wall surface 21 and the outer surface 18 is greater than the thickness of a single tab 11. In this case, the second tab 25 is recessed in the groove 19 so that its upper surface does not protrude beyond the upper surface of the first tab 24, achieving a similar effect.

[0069] Preferably, the terminal connection portion 16 and the tab guide portion 17 form an L-shaped bent plate. The L-shaped bent plate is attached to the side of the electrode assembly, and since the bent plate itself is a plate, the space occupied by the bent plate is small.

[0070] Embodiment 2

[0071] 5 to 7 show a second embodiment of the battery cell structure of the present invention. This includes a housing 26, an electrode assembly, a top cover assembly 12, and a pin portion 13. The housing 26, the electrode assembly, and the top cover assembly 12 are similar to those of the first embodiment, but the pin portion 13 has features that differ from those of the first embodiment, as will be described below.

[0072] 5 and 6, in this embodiment, the bottom of the groove 19 of the tab guide portion 17 has a bottom wall surface 21, which is recessed in a direction approaching the electrode assembly to form a through groove 22. The through groove 22 is formed by removing a central region of the bottom wall surface 21, so that the remaining bottom wall surface 21 surrounds the edge of the through groove 22.

[0073] As shown in FIG. 7, the tab 11 passes through the through groove 22 from the electrode assembly and enters the groove 19 , and the end of the tab 11 is bent and overlaps the bottom wall surface 21 .

[0074] The tab 11 employs the above-described connection method, and the end of the tab 11 does not protrude from the outer surface 18, but is hidden within the groove 19. Therefore, it occupies the space within the thickness of the tab guide portion 17, but does not occupy the outer surface of the tab guide portion 17. This reduces the space occupied by the tab in the internal space of the battery cell, contributing to improving the energy density of the battery cell.

[0075] As shown in FIG. 5, preferably, the second arcuate portion 23 is formed by a smooth transition between the side wall surface of the through groove 22 and the bottom wall surface 21 of the groove 19 .

[0076] In this embodiment, the tab 11 protrudes from the through groove 22 and is bent to overlap the bottom wall surface 21, and the tab 11 is bent at the second arc portion 23. The second arc portion 23 has a smooth transition surface, which prevents the tab 11 from being damaged by being pressed at a sharp angle.

[0077] As shown in FIG. 6, the through groove 22 is a U-shaped groove, and the opening of the U-shaped groove is spaced apart from the terminal connection portion 16 .

[0078] In this embodiment, the pin portion 13 is attached to a jig using a U-shaped groove, and the pin portion 13 is fixed by the jig, thereby welding the tab 11 and the tab guide portion 17 together.

[0079] Embodiment 3

[0080] The battery module includes the battery cell structure in the above embodiment.

[0081] In this embodiment, the battery cell structure is applied to the battery module, which can save the internal space of the battery module and thereby increase the energy density of the entire battery module.

[0082] Embodiment 4

[0083] A battery pack includes the battery cell structure and / or the battery module.

[0084] In this embodiment, the battery cell structure or battery module is applied within a battery pack, which reduces the amount of dead space within the battery pack, thereby increasing the power contained in the battery per unit volume.

[0085] Although specific implementations of the present invention have been described above, those skilled in the art can understand that these are merely examples, and the protection scope of the present invention is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principle and essence of the present invention, and all such changes and modifications are included within the protection scope of the present invention. [Industrial Applicability]

[0086] The battery cell structure, battery module, and battery pack provided by the present invention overcome the drawbacks of the unreasonable connection between the pins and tabs, in that the tabs overlap the pins, requiring a large space and reducing the energy density of the battery. [Explanation of symbols]

[0087] 10: Battery cell body 11: Tab 12: Top cover assembly 13: Pin section 14: Top cover body 15: Electrode terminal 16: Terminal connection 17: Tab guide part 18: Exterior 19: Groove 20: First arc 21: Bottom wall 22: Through groove 23: Second arc 24: First tab 25: Second tab 26: Housing

Claims

1. Housing and an electrode assembly disposed in the housing and including a battery cell body and a tab extending from the battery cell body; a top cover assembly including a top cover body and an electrode terminal disposed on the top cover body, the top cover body being connected to the housing; a pin portion including a terminal connection portion and a tab guide portion, the terminal connection portion being connected to the tab guide portion, the terminal connection portion being connected to the electrode terminal, and the tab guide portion being connected to the tab, one surface of the tab guide portion away from the electrode assembly being an outer surface, and a portion of the outer surface being recessed to form a groove; Equipped with the groove is located inside the tab guide portion, the tab is partially received within the groove; The tab is bent from one side of the tab guide portion to the outer surface, A battery cell structure in which an end of the tab extends toward a center of the tab guide portion, the tabs are plural, and the end of at least one of the tabs is received in the groove.

2. The battery cell structure according to claim 1 , wherein the bottom of the groove has a bottom wall surface, and the bottom wall surface is recessed in a direction approaching the electrode assembly to form a through groove.

3. The battery cell structure according to claim 2 , wherein the through groove extends from a position close to the top cover assembly in a direction away from the top cover assembly.

4. The battery cell structure according to claim 3 , wherein the through groove penetrates the pin portion from a position close to the top cover assembly in a direction away from the top cover assembly.

5. The battery cell structure of claim 1 , wherein at least a portion of the tabs overlap each other, and the overlapping portions formed by the overlapping tabs are received within the groove.

6. 6. The battery cell structure according to claim 5, wherein at least two of the tabs are bent from opposite sides of the tab guide portion toward the outer surface, and end portions of the at least two of the tabs overlap, and the overlapping portions formed by the overlapping terminal ends are housed in the groove.

7. 2. The battery cell structure according to claim 1, wherein the groove extends along the length direction of the tab guide portion, and the length of the groove in the length direction of the tab guide portion is equal to or greater than the length of the tab in the length direction of the tab guide portion.

8. The battery cell structure of claim 1 , wherein the groove is centrally located on the outer surface.

9. The battery cell structure of claim 1 , wherein a smooth transition is formed between the sidewall surface of the groove and the outer surface, forming a first arcuate portion.

10. 2. The battery cell structure of claim 1, wherein the bottom of the groove has a bottom wall surface, and the height difference between the bottom wall surface and the outer surface is at least the thickness of a single one of the tabs.

11. A battery module comprising the battery cell structure according to any one of claims 1 to 10.

12. A battery pack comprising the battery cell structure according to any one of claims 1 to 10.

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