Battery roll core with low internal resistance and double-tab structure and battery
By adopting a bitab structure and optimizing the tab design in the battery core, the problems of high internal resistance and complex assembly of traditional single-tab battery cores are solved, resulting in reduced internal resistance, reduced heat generation, and improved assembly efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- JIANGMEN ZETA POWER SUPPLY TECH CO LTD
- Filing Date
- 2025-05-09
- Publication Date
- 2026-04-28
AI Technical Summary
Traditional single-tab battery cores have high internal resistance. When assembling multiple cores, it is necessary to distinguish between core A and core B, which makes welding inconvenient and poses a risk of short circuit in the cells.
The design adopts a full tab design, with the positive and negative electrode sheets die-cut into a bitab structure. Each layer of the core retains one positive tab and one negative tab, and the alignment and welding quality of the tabs are ensured by optimizing the tab angle and the shape of the connection.
It reduces internal resistance, decreases heat generation, improves the uniformity and safety of the current transmission path, and simplifies the multi-core assembly process, thereby improving assembly efficiency.
Smart Images
Figure CN224177533U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of battery cell manufacturing technology, and more specifically, it relates to a battery core and battery with a low internal resistance bipolar structure. Background Technology
[0002] With the rapid development of the electric vehicle and energy storage system industries, higher requirements are being placed on the energy density, charging and discharging speed, and safety of batteries. Traditional single-tab battery cores (see...) Figures 1-2 During high-current charging and discharging, the long conduction distance and high resistance of the tabs can lead to severe heat generation, which limits the performance and safety of the battery.
[0003] Furthermore, when assembling multiple cores in a traditional single-tab battery, it is necessary to distinguish between core A and core B, and weld one core A together with one core B (see...). Figure 3 In this context, "A-type core" refers to a core with the positive electrode on the left and the negative electrode on the right; "B-type core" refers to a core with the positive electrode on the right and the negative electrode on the left. If single-electrode cores are not differentiated, there will be a large gap between the core electrodes (see...). Figure 4 During welding, the tabs are prone to weld spatter. To avoid this problem, the tabs can only be assembled back-to-back (see...). Figure 5 Soldering in this way will cause the battery cell to short-circuit. Utility Model Content
[0004] To address the shortcomings of existing technologies, the purpose of this utility model is to provide a battery core with a low internal resistance bipolar tab structure, which solves the technical problems of high internal resistance in existing single-tab battery cores and the need to distinguish between core A and core B when assembling multiple cores.
[0005] The above-mentioned technical objective of this utility model is achieved through the following technical solution:
[0006] A battery core with a low internal resistance bipolar tab structure includes a positive electrode sheet, a separator, and a negative electrode sheet stacked sequentially; the positive electrode sheet is die-cut with a plurality of positive tabs to form a bipolar tab structure, and the negative electrode sheet is die-cut with a plurality of negative tabs to form a bipolar tab structure; the positive electrode sheet, separator, and negative electrode sheet are wound to form a core with a multi-layer structure, wherein each layer of the core retains one positive tab and one negative tab.
[0007] Preferably, the positive tabs of each layer of the core have their orthogonal projections in the XZ plane coincide and are located at one end of the core; the negative tabs of each layer of the core have their orthogonal projections in the XZ plane coincide and are located at the other end of the core.
[0008] Preferably, the angle between the positive electrode tab and the positive electrode plate, and the angle between the negative electrode tab and the negative electrode plate are both 94°-105°.
[0009] Preferably, the connection between the positive electrode tab and the positive electrode plate, and the connection between the negative electrode tab and the negative electrode plate are both rounded, with a radius of 2.5mm-3mm.
[0010] Another object of this invention is to provide a battery comprising the battery core as described above.
[0011] Preferably, the battery is a ternary lithium battery or a lithium iron phosphate battery.
[0012] Preferably, the battery is a square battery or a cylindrical battery.
[0013] In summary, this invention offers the following advantages: By employing a full-tab design for both the positive and negative electrode sheets and die-cutting them into a bitab structure, each layer of the core retains one tab after the positive and negative electrode sheets are wound into a core, thus doubling the number of tabs. Compared to a single-tab battery core, the current transmission path is shortened by half, thereby reducing internal resistance and heat generation. Furthermore, there is no need to distinguish between A and B cores; multiple cores can be randomly assembled, significantly reducing the time spent by assembly line workers in identifying cores and improving assembly efficiency. Attached Figure Description
[0014] Figure 1 This is a schematic diagram of the first structure of a single-tab battery core, specifically a schematic diagram of the structure of core A.
[0015] Figure 2 This is a schematic diagram of the second structure of a single-tab battery core, specifically a schematic diagram of the structure of core B.
[0016] Figure 3 This is a diagram showing the arrangement of core A and core B during welding.
[0017] Figure 4 This is the first layout diagram when two A-core coils are welded together;
[0018] Figure 5 This is the second row layout diagram when two A-core coils are welded together;
[0019] Figure 6 This is a schematic diagram of the structure of the battery core with low internal resistance bipolar tab structure in this utility model;
[0020] Figure 7 yes Figure 6 The main view;
[0021] Figure 8 yes Figure 6 Side view;
[0022] Figure 9 This is a diagram showing the arrangement of two low-internal-resistance bipolar battery cores during welding.
[0023] Figure 10 This is a comparison image of the die-cut tabs in single-tab battery cores and dual-tab battery cores. Detailed Implementation
[0024] To make the objectives, features, and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model are described in detail below with reference to the accompanying drawings. Several embodiments of this utility model are shown in the drawings. However, this utility model can be implemented in many different forms and is not limited to the embodiments described herein.
[0025] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances. The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature.
[0026] In this invention, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" of the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature. The terms "vertical," "horizontal," "left," "right," "above," "below," and similar expressions are for illustrative purposes only and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed or operated in a specific orientation, and therefore should not be construed as limiting the invention.
[0027] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.
[0028] This utility model provides a battery core with a low internal resistance bipolar tab structure, comprising a positive electrode sheet, a separator, and a negative electrode sheet stacked sequentially; the positive electrode sheet is die-cut with a plurality of positive tabs 1 to form a bipolar tab structure, and the negative electrode sheet is die-cut with a plurality of negative tabs 2 to form a bipolar tab structure; the positive electrode sheet, separator, and negative electrode sheet are wound together to form a core, wherein each layer of the core retains one positive tab 1 and one negative tab 2.
[0029] Specifically, the lengths of the positive and negative electrode sheets are designed, and during the die-cutting process, the distance between the electrodes is shortened (e.g., ...). Figure 10 As shown in section B, where section A is the die-cut diagram of the tabs of a single-tab battery core, and section B is the die-cut diagram of the tabs of a double-tab battery core, the core is wound so that each layer retains one positive tab 1 and one negative tab 2, resulting in the following... Figure 6 The battery core with the structure shown.
[0030] This invention utilizes a bipolar die-cutting scheme, increasing the number of positive tabs 1 and negative tabs 2 to increase the internal electron migration area. Compared to single-tab cells, this halves the current transmission path, thereby reducing internal resistance. Simultaneously, the bipolar structure ensures a more uniform current distribution within the cell, avoiding the localized resistance increase problem caused by current concentration at one end in single-tab cells. This further reduces the overall internal resistance of the cell and prevents localized overheating, resulting in a more balanced overall temperature and improved safety and stability.
[0031] Furthermore, since the bipolar battery core provided by this utility model has tabs on each layer, it does not require a "back-to-back" method for assembling multiple cells. The arrangement of multiple battery cores during assembly is as follows: Figure 9 As shown in the diagram. In other words, the aforementioned bipolar battery cores do not require differentiation between core A and core B; multiple cores can be randomly combined for assembly, greatly reducing the time spent by assembly line workers in distinguishing cores and improving assembly efficiency.
[0032] Furthermore, the alignment of the bipolar tabs is subsequently fine-tuned to ensure it meets the specified process standards. Specifically, as follows... Figure 7-8 As shown, the positive electrode tab 1 of each layer of the core has its orthographic projection in the XZ plane coincides and is located at one end (left end) of the core; the negative electrode tab 2 of each layer of the core has its orthographic projection in the XZ plane coincides and is located at the other end (right end) of the core. This ensures the welding quality between the multiple electrodes.
[0033] Furthermore, the angle between positive electrode tab 1 and the positive electrode plate, and the angle between negative electrode tab 2 and the negative electrode plate, are both 94°-105°, with the specific positions of the angles being as follows: Figure 7 Position θ is shown in the middle; this structural arrangement ensures the welding quality between multiple tabs.
[0034] Furthermore, the connection points between the positive electrode tab 1 and the positive electrode plate, and between the negative electrode tab 2 and the negative electrode plate, are all rounded, with a radius of 2.5mm-3mm. The specific locations of the rounded corners are as follows: Figure 7 The position indicated by R in the middle; this structural arrangement ensures the welding quality between multiple electrode tabs.
[0035] This utility model also provides a battery including the aforementioned battery core and other accessories. The other accessories include a protective shell for housing the battery core, a top cover for sealing the protective shell, and positive and negative terminals mounted on the top cover. Based on the active material, the battery types include, but are not limited to, ternary lithium batteries and lithium iron phosphate batteries. Based on shape, the battery types include, but are not limited to, prismatic batteries or cylindrical batteries.
[0036] The above description is merely a preferred embodiment of this utility model. The protection scope of this utility model is not limited to the above embodiments. All technical solutions falling within the scope of this utility model's concept are protected. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principle of this utility model should also be considered within the protection scope of this utility model.
Claims
1. A battery core with a low internal resistance bipolar tab structure, comprising a positive electrode sheet, a separator, and a negative electrode sheet stacked sequentially; characterized in that, The positive electrode sheet is die-cut with a plurality of positive tabs to form a bipolar tab structure, and the negative electrode sheet is die-cut with a plurality of negative tabs to form a bipolar tab structure; the positive electrode sheet, the separator and the negative electrode sheet are wound to form a multi-layered core, wherein each layer of the core retains a positive tab and a negative tab.
2. The battery core according to claim 1, characterized in that, The positive tabs of each layer of the core coincide in the orthographic projection of the XZ plane and are located at one end of the core; the negative tabs of each layer of the core coincide in the orthographic projection of the XZ plane and are located at the other end of the core.
3. The battery core according to claim 1, characterized in that, The angle between the positive electrode tab and the positive electrode plate, and the angle between the negative electrode tab and the negative electrode plate are both 94°-105°.
4. The battery core according to claim 3, characterized in that, The connection between the positive electrode tab and the positive electrode plate, and the connection between the negative electrode tab and the negative electrode plate, are all rounded with a radius of 2.5mm-3mm.
5. A battery, characterized in that, Includes the battery core as described in any one of claims 1-4.
6. The battery according to claim 5, characterized in that, The battery is a ternary lithium battery or a lithium iron phosphate battery.
7. The battery according to claim 5, characterized in that, The battery is either a square battery or a cylindrical battery.