Battery cell structure and cylindrical battery

Abstract

The invention relates to the technical field of new energy batteries, in particular to a battery cell structure and a cylindrical battery, the structure comprises a roll core body, a positive electrode tab group and a negative electrode tab group, and the positive electrode tab group and the negative electrode tab group are respectively arranged at two ends of the roll core body; the positive tab groups are connected with the end parts of the positive pole pieces on the same side, the negative tab groups are connected with the end parts of the negative pole pieces on the same side, and the positive tab groups and the negative tab groups are arranged at intervals. Even if the height of the roll core body is increased, electron transmission paths can be reduced, so that the reaction is more uniform, and the high-rate capability of the cylindrical battery is improved; the anode tab and the cathode tab in the height direction of the cylindrical battery are equivalent to parallel shunting, so that heat production is reduced, the direct-current internal resistance of the battery can be effectively reduced, the dynamic voltage difference consistency of the battery pack is improved, and the service life of the battery pack is prolonged; by adopting the mode that the tabs are arranged at intervals, the number of the tabs effectively welded at the two ends of the roll core body is increased, the overcurrent capacity is improved, heat production is reduced, and the cycle performance is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of new energy batteries, and particularly to a core structure and a cylindrical battery. Background Art

[0002] A cylindrical battery is a battery with high capacity, long cycle life, and a wide operating temperature range; with the development of new energy technologies, there are more and more products that use a storage battery as the energy output. For example, new energy vehicles use a storage battery to provide power, eliminating or reducing the use of fuel for power, thus achieving the goal of environmental protection.

[0003] Among them, the structure of the cylindrical battery is also constantly evolving. Compared with the single-tab core structure, the full-tab core structure can reduce the internal resistance of the battery, improve the charge and discharge power, and reduce heat generation by increasing the number of tabs.

[0004] However, in currently common full-tab batteries, one end of the core is the positive tab and the other end is the negative tab; when the height of the full-tab battery is relatively high, the electron transmission path in the height direction is long, resulting in poor electron conductivity, and problems such as uneven reaction, large polarization, poor rate performance, and still an increase in temperature under large current charge and discharge conditions. Summary of the Invention

[0005] To solve at least the above technical problems in the prior art, the present invention provides a core structure and a cylindrical battery.

[0006] On the one hand, the present invention provides a core structure, including a core body, a positive tab group, and a negative tab group. The positive tab group and the negative tab group are respectively arranged at both ends of the core body; the positive tab group is connected to the end of the positive electrode sheet on the same side, the negative tab group is connected to the end of the negative electrode sheet on the same side, and the positive tab group and the negative tab group are arranged at intervals.

[0007] In some embodiments, multiple groups of tab groups are respectively arranged on the long sides of the positive electrode sheet and the negative electrode sheet; along the length direction of the positive electrode sheet and the negative electrode sheet, the multiple groups of tab groups are arranged at intervals.

[0008] In some embodiments, the projection of the tab group on one long side of the positive electrode sheet or the negative electrode sheet onto the other long side is located within the interval.

[0009] In some embodiments, the tab groups on the two long sides of the positive electrode sheet or the negative electrode sheet are symmetrically arranged with respect to the center line in the length direction of the positive electrode sheet or the negative electrode sheet.

[0010] In some embodiments, along the length direction of the positive electrode tab and the negative electrode tab, the number of tabs in the tab group gradually increases.

[0011] In some embodiments, along the length direction of the positive electrode tab and the negative electrode tab, the height of the tab gradually increases.

[0012] In some embodiments, the total length of multiple groups of the tab groups is less than one half of the length of the long side of the connected positive electrode tab or the negative electrode tab.

[0013] In some embodiments, the areas of the positive electrode tab group and the negative electrode tab group are the same, and the area of the positive electrode tab group or the negative electrode tab group is less than one half of the area of the end of the core body; and / or the positive electrode tab group and the negative electrode tab group are symmetrically arranged with the center of the end of the core body as the center.

[0014] In some embodiments, the thicknesses of the positive electrode tab, the negative electrode tab, and the tab are from 0.02 mm to 0.3 mm; and / or the height range of the tab is from 2 mm to 100 mm.

[0015] On the other hand, the present invention also provides a cylindrical battery including the above-mentioned battery cell structure.

[0016] For a battery cell structure and a cylindrical battery provided by the present invention, positive electrode tabs and negative electrode tabs are provided at both ends of the core body. Even if the height of the core body increases, the electron transmission path can be reduced, the reaction can be made more uniform, and the high-rate performance of the cylindrical battery can be improved; and the positive electrode tabs and negative electrode tabs in the height direction of the cylindrical battery are equivalent to parallel shunt, reducing heat generation, effectively reducing the DC internal resistance of the battery, improving the dynamic pressure difference consistency of the battery pack, and improving the service life of the battery pack; and by adopting the tab spacing arrangement method, the number of effectively welded tabs at both ends of the core body is increased, the overcurrent capacity is improved, the heat generation is reduced, and the cycle performance is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] By reading the following detailed description with reference to the accompanying drawings, the above and other objects, features, and advantages of the exemplary embodiments of the present invention will become readily understood. In the drawings, several embodiments of the present invention are shown in an exemplary rather than restrictive manner, wherein:

[0018] In the drawings, the same or corresponding reference numerals represent the same or corresponding parts.

[0019] Figure 1 is a schematic structural diagram of the battery cell structure provided by the embodiment of the present invention;

[0020] Figure 2 is a front view of one end of the battery cell structure provided by the embodiment of the present invention;

[0021] Figure 3 The front view of a positive electrode tab in a cell structure provided by an embodiment of the present invention;

[0022] Figure 4 The front view of a negative electrode tab in a cell structure provided by an embodiment of the present invention;

[0023] Figure 5 The front view of another positive electrode tab in a cell structure provided by an embodiment of the present invention;

[0024] Figure 6 The front view of another negative electrode tab in a cell structure provided by an embodiment of the present invention.

[0025] In the figure:

[0026] 10: Core body; 20: Positive electrode tab group; 30: Negative electrode tab group;

[0027] 11: Positive electrode tab; 12: Negative electrode tab; 13: Tab group; 14: Spacing. Detailed implementation manners

[0028] To make the objectives, features, and advantages of the present invention more obvious and understandable, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts fall within the protection scope of the present invention.

[0029] An embodiment of the present invention provides a cell structure, including a core body, a positive electrode tab group, and a negative electrode tab group. Among them, the positive electrode tab group and the negative electrode tab group are respectively arranged at both ends of the core body. When electrons are transmitted in the core body, there is no need to cross the entire height of the core body, which can reduce the electron transmission path, make the reaction more uniform, and can effectively increase the number of welded tabs, improve the current-carrying capacity, reduce heat generation, and improve the cycle performance.

[0030] The following will describe in detail each structure, the positional relationship and connection relationship between each structure in the cell structure provided by the embodiment of the present invention with reference to the accompanying drawings.

[0031] As Figures 1 to 6 shown, in the embodiment of the present invention, the positive electrode tab group 20 and the negative electrode tab group 30 are respectively arranged at both ends of the core body 10. The positive electrode tab group 20 is connected to the end of the positive electrode tab 11 on the same side, and the negative electrode tab group 30 is connected to the end of the negative electrode tab 12 on the same side, and the positive electrode tab group 20 and the negative electrode tab group 30 are arranged at intervals.

[0032] In the existing all-tab structure, generally, one end of the core body 10 is the positive tab and the other end is the negative tab, that is, one end of the existing core body 10 only contains one type of tab with the same polarity. In the embodiments of the present invention, the positive tab group 20 and the negative tab group 30 are simultaneously arranged at both ends of the core body 10, and the specific structure is as follows:

[0033] In the embodiments of the present invention, the core body 10 includes a positive electrode plate 11, a negative electrode plate 12, and a separator (not shown in the figure). Multiple groups of tab groups 13 are respectively arranged on the long side sides of the positive electrode plate 11 and the negative electrode plate 12; along the length direction of the positive electrode plate 11 and the negative electrode plate 12, the multiple groups of tab groups 13 are arranged at intervals. During the winding forming process, as the positive electrode plate 11 and the negative electrode plate 12 are wound, the intervals 14 are used to avoid tabs with opposite polarities to meet the partitioning of the positive tab group 20 and the negative tab group 30. That is, after the core body 10 is wound and formed, the positive tab group 20 and the negative tab group 30 on the same side will not come into contact either, ensuring that the formed core body 10 can be used normally.

[0034] Taking the positive electrode plate 11 as an example, after the first group of tab groups 13 of the positive electrode plate 11 is wound, as the positive electrode plate 11 continues to be wound, the interval 14 between the first group of tab groups and the second group of tab groups bypasses the tab group 13 of the negative electrode plate 12, and then the second group of tab groups is superimposed on the outside of the first group of tab groups. Through continuous winding operations, the subsequent tab groups 13 are all superimposed on the outside of the previous group of tab groups 13, so that the tab groups 13 of the positive electrode plate 11 form a positive tab group 20 occupying a certain area at one end of the core body 10. When the positive electrode plate 11 is wound, the negative electrode plate 12 is wound synchronously. The tab groups 13 on the negative electrode plate 12 form a negative tab group 30 occupying a certain area at one end of the core body 10, wherein the positive tab group 20 and the negative tab group 30 are arranged at intervals.

[0035] In the embodiments of the present invention, when forming the positive electrode plate 11 and the negative electrode plate 12, the positive and negative electrode slurries are coated on the current collector, and then slit, so that there are empty foil areas on both sides of the coating area on the current collector; then the empty foil areas are cut to form the tab structure.

[0036] For example, the current collectors used for the positive electrode plate 11 and the negative electrode plate 12 are metals such as aluminum foil and copper foil, and their thicknesses are between 0.02 mm and 0.30 mm, which can be adjusted according to the actual current-carrying requirements. Among them, cutting and forming tabs in the empty foil areas can reduce burr generation, reduce the short-circuit rate, improve the production yield, and reduce the production manufacturing cost.

[0037] Such as Figure 3 and Figure 4As shown, a way of arranging the electrode tabs is presented. Among them, the vertical projection of the tab group 13 on one long side of the positive electrode tab 11 or the negative electrode tab 12 onto the other long side is located within the interval 14. That is to say, the opposite side of the tab group 13 is the interval 14, and no tab group 13 is provided. As shown in the perspective view in the figure, if the tab group 13 is provided at the top, the opposite side is the interval 14; if the top is the interval 14, the opposite side is provided with the tab group 13. For example, when the positive electrode tab 11 and the negative electrode tab 12 are stacked, the tab group 13 of the positive electrode tab 11 is stacked with the position of the interval 14 of the negative electrode tab 12, and the tab group 13 of the negative electrode tab 12 is stacked with the position of the interval 14 of the positive electrode tab 11.

[0038] As Figure 5 and Figure 6 shown, another way of arranging the electrode tabs is presented. Among them, the tab groups 13 on the two long sides of the positive electrode tab 11 or the negative electrode tab 12 are symmetrically arranged with the center line in the length direction of the positive electrode tab 11 or the negative electrode tab 12 as the center. That is to say, the opposite side of the tab group 13 is also the tab group 13, and the opposite side of the interval 14 is also the interval 14. As shown in the perspective view in the figure, if the tab group 13 is provided at the top, the opposite side is also provided with the tab group 13; if the top is the interval 14, the opposite side is provided with the interval 14. For example, when the positive electrode tab 11 and the negative electrode tab 12 are stacked, the starting position of one electrode tab is the tab group 13, and the starting position of the other electrode tab is the interval 14. Therefore, the tab group 13 of the positive electrode tab 11 is stacked with the position of the interval 14 of the negative electrode tab 12, and the tab group 13 of the negative electrode tab 12 is stacked with the position of the interval 14 of the positive electrode tab 11.

[0039] By adopting the above two ways of arranging the electrode tabs, symmetric positive electrode tab groups 20 and negative electrode tab groups 30 can be formed on both sides of the core body 10.

[0040] Continuing to refer to Figures 1 to 6 shown, in the embodiment of the present invention, along the length direction of the positive electrode tab 11 and the negative electrode tab 12, the number of tabs in the tab group 13 gradually increases. As the winding operation of the positive electrode tab 11 and the negative electrode tab 12 progresses, the diameter of the formed core body 10 becomes larger and larger. Correspondingly, it is necessary to appropriately increase the number of tabs in the tab group 13 to meet the coverage between the tab groups 13 and ensure the area of the formed positive electrode tab group 20 or negative electrode tab group 30.

[0041] Correspondingly, as the diameter of the core body 10 increases, if the tabs are to be wound at the set positions, it is necessary to appropriately increase the length of the interval 14. That is to say, along the length direction of the electrode tab, the length of the interval 14 gradually increases, and the increasing range of the interval 14 only needs to meet the coverage between the tab groups 13.

[0042] For example, the height of the tabs gradually increases along the length direction of the positive electrode sheet 11 and the negative electrode sheet 12. Similarly, as the diameter of the winding core body 10 increases, if the area covered by the tabs is to be repeated, the height of the tabs of the outer ring needs to be set slightly higher. Therefore, the height of the tabs is gradually increased along the length direction of the tabs.

[0043] For example, the end of the pole lug can be horizontal, and multiple pole lugs can be stepped, or the end of the pole lug can be inclined, and a continuous inclined structure is formed between multiple pole lugs. When the length of the outer ring pole lug increases, after the winding core body 10 is wound and formed, when the pole lugs are bent and fallen, the contact area between the pole lugs can be effectively increased.

[0044] For example, the height of the tab ranges from 2 mm to 100 mm; preferably, the height of the tab ranges from 2 mm to 20 mm.

[0045] Continue to refer Figures 1 to 6 As shown, in the embodiment of the present invention, the total length of the multiple groups of tab groups 13 is less than half of the length of the long side of the connected positive electrode sheet 11 or the negative electrode sheet 12; that is, on the long side of the positive electrode sheet 11 or the negative electrode sheet 12, the length occupied by the interval 14 (the portion of the tab) is greater than the length occupied by the tab; similarly, the positive tab group 20 and the negative tab group 30 have the same area or the same region, and the area of ​​the positive tab group 20 or the negative tab group 30 is less than half of the area of ​​the end of the winding core body 10;

[0046] A positive electrode tab group 20 and a negative electrode tab group 30 are arranged on both side ends of the winding core body 10. The two tab groups need to be arranged independently without contact. Therefore, by limiting the length occupied by the pole piece and the area occupied by the tab group, it can be ensured that the two tab groups are without contact after forming.

[0047] For example, the positive electrode tab group 20 and the negative electrode tab group 30 are symmetrically arranged with the center of the circle at the end of the core body 10 as the center. The symmetrical structure has the same area, which is conducive to the uniformity of charging and discharging. The regular symmetrical structure is also conducive to the design and connection of structures such as current collectors.

[0048] An embodiment of the present invention provides a cylindrical battery, including the above-mentioned battery cell structure, the battery cell structure has a certain height, and both ends of the battery cell structure include a positive electrode tab group 20 and a negative electrode tab group 30. For example, the height of the battery cell structure can be one or more times that of the existing common battery cell structure, and the performance of the cylindrical battery will not be reduced when the battery cell height is increased.

[0049] A core structure and a cylindrical battery provided by the present invention are provided with a positive electrode tab and a negative electrode tab at both ends of the core body 10. Even if the height of the core body 10 increases, the electron transmission path can be reduced, the reaction can be made more uniform, and the high-rate performance of the cylindrical battery can be improved; and the positive electrode tab and the negative electrode tab in the height direction of the cylindrical battery are equivalent to parallel shunt, reducing heat generation, effectively reducing the DC internal resistance of the battery, improving the consistency of the dynamic pressure difference of the battery pack, and improving the service life of the battery pack; and by adopting the method of arranging the tabs at intervals, the number of effectively welded tabs at both ends of the core body 10 increases, the overcurrent capacity is improved, the heat generation is reduced, and the cycle performance is improved.

[0050] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. Moreover, the specific features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0051] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, "a plurality" means two or more unless otherwise specifically defined.

[0052] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, and all of them should be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. A battery cell structure, characterized in that: It comprises a winding core body (10), a positive electrode tab group (20) and a negative electrode tab group (30), wherein the positive electrode tab group (20) and the negative electrode tab group (30) are respectively arranged at two ends of the winding core body (10); The positive electrode tab group (20) is connected to the end of the positive electrode sheet (11) on the same side, and the negative electrode tab group (30) is connected to the end of the negative electrode sheet (12) on the same side, and the positive electrode tab group (20) and the negative electrode tab group (30) are arranged at intervals.

2. The battery cell structure according to claim 1, characterized in that: A plurality of electrode tab groups (13) are respectively arranged on the long sides of the positive electrode sheet (11) and the negative electrode sheet (12); Along the length direction of the positive electrode sheet (11) and the negative electrode sheet (12), a plurality of electrode tab groups (13) are arranged at intervals.

3. The battery cell structure according to claim 2, characterized in that: A vertical projection of the tab group (13) on one long side of the positive electrode sheet (11) or the negative electrode sheet (12) to the other long side is located within the gap (14).

4. The battery cell structure according to claim 2, characterized in that: The tab groups (13) on the two long sides of the positive pole sheet (11) or the negative pole sheet (12) are symmetrically arranged with the center line of the length direction of the positive pole sheet (11) or the negative pole sheet (12) as the center.

5. The battery core structure according to claim 3 or 4, characterized in that: Along the length direction of the positive electrode sheet (11) and the negative electrode sheet (12), the number of electrode tabs in the electrode tab group (13) gradually increases.

6. The battery cell structure according to claim 5, characterized in that: Along the length direction of the positive electrode sheet (11) and the negative electrode sheet (12), the height of the electrode tab gradually increases.

7. The battery cell structure according to claim 5, characterized in that: The total length of the plurality of electrode tab groups (13) is less than half the length of the long side of the connected positive electrode sheet (11) or the negative electrode sheet (12).

8. The battery cell structure according to claim 7, characterized in that: The positive electrode tab group (20) and the negative electrode tab group (30) have the same area, and the area of ​​the positive electrode tab group (20) or the negative electrode tab group (30) is less than half of the area of ​​the end of the winding core body (10); and / or The positive electrode tab group (20) and the negative electrode tab group (30) are symmetrically arranged with the center of the end of the winding core body (10) as the center.

9. The battery cell structure according to claim 5, characterized in that: The thickness of the positive electrode sheet (11), the negative electrode sheet (12) and the electrode tab is 0.02 mm to 0.3 mm; and / or The height of the tab ranges from 2 mm to 100 mm.

10. A cylindrical battery, characterized in that: The invention comprises a battery core structure as claimed in any one of claims 1 to 9.

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