Thin battery cell and thin battery

Abstract

The utility model discloses a thin battery cell which comprises a battery cell body, the battery cell body comprises a first pole piece group and a second pole piece group, the length of the first pole piece group is larger than that of the second pole piece group, the second pole piece group is stacked on the first pole piece group, and a staggered area is formed between the second pole piece group and the first pole piece group; the first pole piece group and the second pole piece group are connected with a tab group, the tab group is provided with a first reverse folding part, the tab group is reversely folded to enable the first reverse folding part to be arranged in the dislocation area, a first distance is formed between the first reverse folding part and the first pole piece group, and the height of the first reverse folding part is smaller than that of the second pole piece group. Meanwhile, the utility model also provides a thin battery. According to the utility model, the problem that the packaging and the appearance are influenced by the ultrahigh tab group after the tab group of the thin laminated structure battery is welded and bent is effectively improved, and the problem that the energy sealing is low due to the overlarge occupied edge sealing size caused by the straight welding of the tab group is avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a thin battery cell and a thin battery. Background Art

[0002] Currently, laminated batteries on the market are those in which the individual pole pieces produced during the die-cutting process are stacked together to form a battery cell. In the lithium battery manufacturing process, cell assembly is a mid-stage production step, primarily including winding or lamination, cell pre-packaging, and cell injection. Compared to winding, the lamination process is more common in the production of prismatic and pouch cells.

[0003] like Figure 1 As shown in FIG, conventional thin laminated batteries basically use direct welding to lead out the tabs for assembly and packaging, which results in an excessively large top packaging area of ​​the battery, reducing battery size utilization and energy density; Figure 2 As shown, the use of bent tab groups will cause the tabs to be too high, affecting battery assembly and appearance, and there is a risk of puncturing the packaging film; therefore, it is necessary to improve how to effectively utilize the size space of thin laminated batteries and thereby improve the energy density of the batteries. Utility Model Content

[0004] The purpose of the present invention is to overcome the above-mentioned defects in the prior art and to provide a thin battery cell and a thin battery, which can effectively improve the problem of excessive height of the tab group after welding and bending of the tab group of a thin laminated structure battery, affecting the packaging and appearance, and avoid the problem of excessive edge sealing size caused by direct welding of the tab group, thereby reducing energy sealing.

[0005] To achieve the above-mentioned object, the present invention provides a thin battery cell, characterized by comprising:

[0006] A battery cell body, the battery cell body comprising a first electrode group and a second electrode group, the first electrode group being longer than the second electrode group, the second electrode group being stacked on the first electrode group to form an offset region between the second electrode group and the first electrode group;

[0007] The first pole piece group and the second pole piece group are connected with a pole lug group, and the pole lug group is provided with a first folded portion. The pole lug group is folded so that the first folded portion is placed in the dislocation area, and a first distance is formed between the first folded portion and the first pole piece group. The height of the first folded portion is less than the height of the second pole piece group.

[0008] Furthermore, the tab group sequentially forms a lead portion, a first bent portion, a first straight portion, and a second bent portion, the lead portion is connected to the first electrode group and the second electrode group respectively, and the second bent portion is connected to the first inverted portion.

[0009] Furthermore, the length of the first pole piece group is greater than the sum of the length of the second pole piece group and the length of the first inflected portion located in the dislocation area.

[0010] Furthermore, a second distance is formed between the lower end of the first inflected portion and the upper end of the first electrode group.

[0011] A thin battery comprises a packaging shell and the above-mentioned thin battery cell, wherein the thin battery cell is accommodated in the packaging shell, the tab group of the thin battery cell comprises a positive tab group and a negative tab group, and the packaging shell is provided with a positive tab and a negative tab respectively connected to the positive tab group and the negative tab group.

[0012] Furthermore, the packaging shell is a packaging soft film, and the end of the packaging shell extends to form an electrode lead-out terminal, and the positive and negative tabs both pass through the electrode lead-out terminal. Tab glue is provided on the positive and negative tabs to insulate them from the electrode lead-out terminal.

[0013] Furthermore, the packaging shell is a steel shell, and the packaging shell includes a main shell and a cover body that are connected to each other.

[0014] Furthermore, the main shell is a cylindrical structure, the cover is fixed to the upper end of the main shell, and a first opening and a first pole are provided on the cover or the main shell. The first pole is fixed to the first opening by an insulating glue provided, the first pole is connected to the positive electrode ear, and the main shell or the cover is connected to the negative electrode ear.

[0015] Furthermore, the main shell is a square structure, the cover is fixed to the main shell, a second opening and a second pole are provided on the cover, the second pole is fixed to the second opening by an insulating glue, the second pole is connected to the positive electrode ear, and the main shell or the cover is connected to the negative electrode ear.

[0016] Furthermore, the cover is fixed to the upper end or side wing of the main shell.

[0017] Compared with the existing technology, the utility model has the following advantages: the utility model can effectively improve the problem of excessive height of the tab group after welding and bending of the thin laminated structure battery tab group, which affects the packaging and appearance, and avoid the problem of excessive edge sealing size caused by direct welding of the tab group, resulting in low energy sealing. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 This is a schematic diagram of the structure of the lead-out tab by direct welding in the prior art;

[0020] Figure 2 This is a schematic diagram of the structure of bending the tab group to lead out the tab in the prior art;

[0021] Figure 3 This is a schematic structural diagram of a thin battery cell of the present invention;

[0022] Figure 4 yes Figure 3 A schematic diagram comparing the length / height of each component in;

[0023] Figure 5 It is a top view schematic diagram of the battery cell of the utility model;

[0024] Figure 6 This is a schematic structural diagram of Example 1 of a thin battery of the present utility model;

[0025] Figure 7 yes Figure 6 Schematic diagram of the lead-out of the negative electrode tab group;

[0026] Figure 8 This is a schematic structural diagram of Example 2 of a thin battery of the present utility model;

[0027] Figure 9 Schematic diagram of the structure of the negative electrode tab group lead-out of Example 2;

[0028] Figure 10 2 is a schematic top view of the battery cell of Example 2;

[0029] Figure 11 This is a schematic structural diagram of Example 3 of a thin battery of the present utility model;

[0030] Figure 12 Schematic diagram of different installation positions of the second pole of embodiment 3;

[0031] Figure 13 It is a schematic diagram of the structure of the negative electrode tab group lead-out of Example 3.

[0032] Included in the diagram are:

[0033] 1. Cell body; 11. First electrode group; 12. Second electrode group; 13. Offset area; 2. Tab group; 21. Lead-out portion; 22. First bending portion; 23. First straight portion; 24. Second bending portion; 25. First inflection portion; 26. First spacing; 27. Second spacing; 28. Positive tab group; 29. ​​Negative tab group; 3. Packaging shell; 31. Electrode lead-out terminal; 32. Main shell; 33. Cover; 331. First opening; 332. Second opening; 34. First pole; 35. Second pole; 4. Positive tab; 5. Negative tab; 6. Tab glue; 7. Insulating glue. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in this embodiment of the present invention to clearly and completely describe the technical solution in this embodiment of the present invention. Obviously, the embodiment described is only one embodiment of the present invention, not all embodiments of the present invention. Based on this embodiment of the present invention, all other embodiments of the present invention obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this utility model.

[0035] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as described in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0036] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features.

[0037] See also Figures 3 to 11 , embodiments of the present invention provide a thin battery cell and a thin battery.

[0038] Example 1

[0039] The thin battery cell of this embodiment, such as Figures 3 to 5As shown, the thin battery cell includes: a battery cell body 1, the battery cell body 1 includes a first electrode group 11 and a second electrode group 12, wherein the length L1 of the first electrode group 11 is greater than the length L2 of the second electrode group 12, and the second electrode group 12 is stacked on the first electrode group 11, wherein the right end of the second electrode group 12 is flush with the right end of the first electrode group 11, so that the left end of the second electrode group 12 and the left end of the first electrode group 11 form a misalignment area 13; the first electrode group 11 and the second electrode group 12 are connected to the pole ear group 2, specifically, in this embodiment, the first electrode group 11 and the second electrode group 12 are both composed of a positive electrode sheet and a negative electrode sheet stacked with an insulating space, that is, the pole ear leading out of the positive electrode sheet constitutes the positive pole ear group 2, and the pole ear group leading out of the negative electrode sheet The negative electrode tab group 2; in this embodiment, the structures of the positive electrode tab group 2 and the negative electrode tab group 2 are the same, and the above-mentioned tab group 2 is sequentially connected to form a lead-out portion 21, a first bent portion 22, a first straight portion 23, a second bent portion 24 and a first reversed portion 25, wherein the lead-out portion 21 is connected to the first electrode group 11 and the second electrode group 12, specifically, the lead-out portion 21 is led out from the first electrode group 11 and the second electrode group from top to bottom to form a trapezoidal structure that gradually thickens from top to bottom, and the end of the lead-out portion 21 is flatly folded to form a first bent portion 22, and the bottom of the first bent portion 22 is flush with the bottom of the first electrode group 11, so that the bottom of the tab group 2 does not exceed the bottom of the first electrode group 11 to ensure that the tab group 2 will not exceed the bottom of the battery body 1 , the tab group 2 is folded back through the first bending portion 22 to form a first straight portion 23, and the first straight portion 23 is arranged in parallel with the right end of the cell body 1, so that the cell as a whole is flat without any protruding parts affecting the subsequent packaging. The end of the first straight portion 23 continues to fold back to form a first folded portion 25, so that the first folded portion 25 is placed in the dislocation area 13, and a first spacing 26 is formed between the first folded portion 25 and the first electrode group 11, so that the first folded portion 25 is spaced apart from the second electrode group 12 when placed in the dislocation area 13; furthermore, the height of the second electrode group 12 is greater than the height H3 of the first folded portion 25. In this embodiment, a second spacing 27 is set between the lower end of the first folded portion 25 and the upper end of the first electrode group 11, so that the two Separated, at the same time, the upper end of the first inflected portion 25 is flush with the upper end of the second electrode group 12. Of course, the lower end of the first inflected portion 25 can also be close to or even tightly attached to the upper end of the first electrode group 11, so that the upper end of the first inflected portion 25 is slightly lower than the upper end of the second electrode group 12. The above arrangement can ensure that the height H1 of the battery cell body 1 is greater than the sum of the height H3 of the first inflected portion 25 and the height H2 of the first electrode group 11; the length L1 of the first electrode group 11 is greater than the sum of the length L2 of the second electrode group 12 and the length L3 of the first inflected portion 25 placed in the dislocation area 13, and thus the first inflected portion 25 will not exceed the height of the second electrode group 12, resulting in the problem of excessive edge sealing size and low energy sealing.

[0040] This embodiment also provides a thin battery, such as Figure 6 and Figure 7 The thin battery includes a packaging shell 3 and the above-mentioned thin battery cell, and the thin battery cell is accommodated in the packaging shell 3. In this embodiment, the above-mentioned packaging shell 3 is a packaging soft film, which completely wraps the above-mentioned thin battery cell. An electrode lead-out terminal 31 is formed by extending from the end of the packaging shell 3. The tab group 2 of the thin battery cell includes a positive tab group 28 and a negative tab group 29. A positive tab 4 and a negative tab 5 connected to the positive tab group 28 and the negative tab group 29 are respectively provided on the packaging shell 3. The positive tab 4 and the negative tab 5 both pass through the electrode lead-out terminal 31. Tab glue 6 is provided on the positive tab 4 and the negative tab 5 to insulate them from the electrode lead-out terminal 31.

[0041] This is a brief description of the working principle of the utility model: the utility model forms a staggered area 13 by arranging a first electrode group 11 and a second electrode group 12 of different lengths to overlap, and the staggered area 13 is used to accommodate the electrode tab group 2 led out of the first electrode group 11 and the second electrode group 12, so that the electrode tab group 2 of the battery cell body 1 of the utility model will not be too high after bending to affect the packaging and appearance, and avoid the problem of excessive edge sealing size occupied by direct welding of the electrode tab group 2, thereby avoiding the problem of low energy sealing.

[0042] Example 2

[0043] The difference between this embodiment and embodiment 1 is that Figures 8 to 10 As shown, the packaging shell 3 of this embodiment is a steel shell, and the packaging shell 3 includes a main shell 32 and a cover body 33 connected to each other. In this embodiment, the main shell 32 is a cylindrical structure, and the cover body 33 is fixed to the upper end of the main shell 32 by welding. A first opening 331 and a first pole 34 are provided on the cover body 33. The first pole 34 is fixed to the first opening 331 by an insulating glue 7. The first pole 34 is connected to the positive ear 4 to form the positive electrode of this embodiment, and the main shell 32 or the cover body 33 is connected to the negative ear 5 to form the negative electrode of this embodiment. The rest is the same as in Example 1, and the technical effect of Example 1 is also achieved.

[0044] Example 3

[0045] The difference between this embodiment and embodiment 1 is that Figures 10 to 12 As shown, the encapsulation shell 3 of this embodiment is a steel shell, and the encapsulation shell 3 includes a main shell 32 and a cover 33 connected to each other. The above-mentioned main shell 32 is a square structure, and the cover 33 is fixed to the main shell 32 by welding. The cover 33 can be welded to the upper end of the main shell 32. In some embodiments, the cover 33 can also be welded to the side of the main shell 32 (not shown in the figure). It can be selected according to actual needs; Figure 12As shown, the cover 33 is provided with a second opening 332 and a second pole 35, which can also be as shown in FIG. Figure 11 As shown, the second opening 332 and the second pole 35 are provided on the main shell 32. The specific setting positions of the second opening 332 and the second pole 35 can be selected according to actual needs. In this embodiment, the second pole 35 is fixed to the second opening 332 by the insulating glue 7 provided. The second pole 35 is connected to the positive ear 4 to form the positive electrode of this embodiment, and the main shell 32 or the cover 33 is connected to the negative ear 5 to form the negative electrode of this embodiment. The rest is the same as that of Example 1, and the effect of Example 1 is also achieved.

[0046] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A thin battery cell, characterized in that: include: A battery cell body (1), the battery cell body (1) comprising a first pole piece group (11) and a second pole piece group (12), the first pole piece group (11) being longer than the second pole piece group (12), the second pole piece group (12) being superimposed on the first pole piece group (11), so that a dislocation region (13) is formed between the second pole piece group (12) and the first pole piece group (11); The first pole piece group (11) and the second pole piece group (12) are connected to a pole tab group (2), the pole tab group (2) is provided with a first folded portion (25), the pole tab group (2) is folded so that the first folded portion (25) is placed in the dislocation area (13), and a first spacing (26) is formed between the first folded portion (25) and the first pole piece group (11), and the height of the first folded portion (25) is less than the height of the second pole piece group (12).

2. The thin battery cell according to claim 1, characterized in that: The tab group (2) sequentially forms a lead-out portion (21), a first bent portion (22), a first straight portion (23), and a second bent portion (24); the lead-out portion (21) is respectively connected to the first pole piece group (11) and the second pole piece group (12); and the second bent portion (24) is connected to the first inverted portion (25).

3. The thin battery cell according to claim 2, characterized in that: The length of the first pole piece group (11) is greater than the sum of the length of the second pole piece group (12) and the length of the first folded portion (25) located in the dislocation area (13).

4. The thin battery cell according to claim 2, characterized in that: A second distance (27) is formed between the lower end of the first folded portion (25) and the upper end of the first electrode group (11).

5. A thin battery, characterized in that: The invention comprises a packaging shell (3) and a thin battery cell according to any one of claims 1 to 4, wherein the thin battery cell is accommodated in the packaging shell (3), the tab group (2) of the thin battery cell comprises a positive tab group (28) and a negative tab group (29), and the packaging shell (3) is provided with a positive tab (4) and a negative tab (5) respectively connected to the positive tab group (28) and the negative tab group (29).

6. The thin battery according to claim 5, characterized in that The packaging shell (3) is a packaging soft film, and the end of the packaging shell (3) extends to form an electrode lead-out terminal (31), and the positive electrode tab (4) and the negative electrode tab (5) both pass through the electrode lead-out terminal (31). Tab glue (6) is provided on the positive electrode tab (4) and the negative electrode tab (5) to insulate the positive electrode tab (4) and the negative electrode tab (5) from the electrode lead-out terminal (31).

7. The thin battery according to claim 1, wherein: The encapsulating shell (3) is a steel shell, and comprises a main shell (32) and a cover (33) that are connected to each other.

8. The thin battery according to claim 7, characterized in that The main shell (32) is a cylindrical structure. The cover (33) is fixed to the upper end of the main shell (32). A first opening (331) and a first pole (34) are provided on the cover (33). The first pole (34) is fixed to the first opening (331) through an insulating glue (7). The first pole (34) is connected to the positive electrode ear (4). The main shell (32) or the cover (33) is connected to the negative electrode ear (5).

9. The thin battery according to claim 7, wherein: The main shell (32) is a square structure, the cover (33) is fixed to the main shell (32), a second opening (332) and a second pole (35) are provided on the cover (33) or the main shell (32), the second pole (35) is fixed to the second opening (332) by means of an insulating glue (7), the second pole (35) is connected to the positive electrode ear (4), and the main shell (32) or the cover (33) is connected to the negative electrode ear (5).

10. The thin battery according to claim 9, characterized in that The cover (33) is fixed to the upper end portion or the side wing of the main shell (32).

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