Roll core, battery cell and battery
By setting an annular pole-less ear region in the pole ear region, the problems of long and uneven wetting paths caused by the pole ear blocking end are solved, and the direct inflow and uniform wetting of the electrolyte are achieved, thereby improving the wetting efficiency and reliability of the battery cell.
Patent Information
- Application Number
- CN202422076025.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-26
- Publication Date
- 2025-07-25
- Estimated Expiration
- 2034-08-26
AI Technical Summary
In the prior art, the end of the core is blocked after the extreme ear is smoothed, resulting in a long path of the electrolyte infiltration, poor infiltration efficiency, and uneven infiltration.
An annular non-pole ear region is provided in the pole ear region, the pole ear region is arranged coaxially and the outer diameter is smaller than the outer diameter of the core main body, and an adjacent pole ear region is formed, optimizing the area and position of the pole ear region so that the electrolyte solution flows directly into the core and immerses evenly.
The electrolyte infiltration path is shortened, the wetting efficiency and uniformity are improved, the stress of the heat expansion of the extreme ear is reduced, and the reliability of the battery cell is improved.
Smart Images
Figure CN223156062U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of batteries, and particularly relates to a core, an electrode core and a battery. Background Art
[0002] In the related art, a battery includes a housing and a core disposed inside the housing. The core includes wound positive electrode sheets, negative electrode sheets and separators. Among them, the electrode sheets include a coating area and a bare foil area located at the periphery of the coating area. The coating area is used for coating active substances, and the bare foil area serves as an electrode tab.
[0003] In order to control the height of the electrode tab inside the electrode core, it is necessary to flatten the electrode tab, that is, bend the electrode tab toward the end face of the core so that two adjacent electrode tabs are stacked along the axial direction of the core. However, the flattened electrode tab will block the end of the core, resulting in the electrolyte mainly flowing down through the middle hole of the core to the bottom of the inner cavity of the electrode core, and then adsorbing the electrolyte through the electrode sheet to adsorb the electrolyte to the top of the core to complete the infiltration of the core. In this way, the path of the electrolyte infiltrating the core is long, resulting in poor infiltration efficiency of the core. Summary of the Utility Model
[0004] Embodiments of the present application provide a core, an electrode core and a battery, which can improve the infiltration efficiency of the core.
[0005] In a first aspect, an embodiment of the present application provides a core, which includes a core body and a first electrode tab; the core body includes wound first electrode sheets, separators and second electrode sheets, the separators are located between the first electrode sheets and the second electrode sheets, the polarities of the first electrode sheets and the second electrode sheets are opposite, and along the axial direction of the core, the core body has a first end; the first electrode tab is disposed at the first end and connected to the first electrode sheet; wherein, multiple layers of the first electrode tabs are bent and stacked at the first end to form multiple annular first electrode tab areas, the multiple first electrode tab areas are coaxially arranged, and the outer diameter of the outermost first electrode tab area is smaller than the outer diameter of the core body; there is a first annular space between two adjacent first electrode tab areas, and the first annular space forms a first electrode tab-free area.
[0006] In an embodiment, along the radial direction of the core, the width of the first electrode tab-free area is W1, and the unit thickness of the core body is d0, satisfying: 2d0 ≤ W1 ≤ 8d0, where d0 is the sum of the thickness of a first electrode sheet, the thickness of a separator, the thickness of a second electrode sheet and the thickness of another separator.
[0007] In an embodiment, taking the axial direction of the core as the projection direction and the plane perpendicular to the axial direction of the core as the projection plane, the total area of the multiple first electrode tab areas in the projection plane is S1, and the area of the first end is S, satisfying: 0.5 ≤ S1 / S < 1.
[0008] In one embodiment, the outer diameter of the core body is A, and the outer diameter of the outermost first tab area is B, satisfying: 0.8A ≤ B < A.
[0009] In one embodiment, the outer diameter of the core body is A, and the inner diameter of the innermost first tab area is C, satisfying: 0.02A ≤ C ≤ 0.25A.
[0010] In one embodiment, the first tab includes a plurality of die-cut tabs. The die-cut width of the die-cut tab is u, and the die-cut height of the die-cut tab is W j , satisfying: 0.1 ≤ u / W j ≤ 0.7.
[0011] In one embodiment, along the winding direction of the first pole piece, the ratio of the die-cut width u to the die-cut height W of each die-cut tab j gradually increases.
[0012] In one embodiment, the core further includes a second tab. The core has a second end portion opposite to the first end portion; the second tab is disposed at the second end portion and connected to the second pole piece; wherein, multiple layers of second tabs are stacked at the second end portion to form a plurality of annular second tab areas. The plurality of second tab areas are coaxially arranged, and there is a second annular space between adjacent two second tab areas. The second annular space forms a second tabless area.
[0013] In one embodiment, with the axial direction of the core as the projection direction and the plane perpendicular to the axial direction of the core as the projection plane, the projection of the first tabless area and the projection of the second tab area partially overlap.
[0014] In one embodiment, along the radial direction of the core, the width of the overlap between the projection of the first tabless area and the projection of the second tab area is W2, and the width of the first tabless area is W1, satisfying: 10% W1 ≤ W2.
[0015] In one embodiment, with the axial direction of the core as the projection direction and the plane perpendicular to the axial direction of the core as the projection plane, the projection of the second tabless area and the projection of the first tab area partially overlap.
[0016] In one embodiment, along the radial direction of the core, the width of the overlap between the projection of the second tabless area and the projection of the first tab area is W4, and the width of the second tabless area is W3, satisfying: 10% W3 ≤ W4.
[0017] In a second aspect, an embodiment of the present application provides an electric core, which includes a housing, a cover plate, and the aforementioned core; the cover plate and the housing are covered to define an accommodation cavity; the core is disposed in the accommodation cavity.
[0018] In a third aspect, an embodiment of the present application provides a battery, which includes the aforementioned electric core.
[0019] Advantages of the embodiments of the present application:
[0020] In the embodiments of the present application, by providing an annular first earless area on the first tab area, on the one hand, the electrolyte can directly flow into the interior of the core through the first earless area, thereby shortening the path of the electrolyte to infiltrate the core, and further improving the infiltration efficiency of the core; on the other hand, the electrolyte can uniformly infiltrate the core circumferentially, thereby improving the uniformity of the core infiltration, and further enhancing the infiltration efficiency. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For those skilled in the art, without creative efforts, other drawings can be obtained based on these drawings.
[0022] Figure 1 is a schematic structural diagram of a core provided by an embodiment of the present application;
[0023] Figure 2 is a schematic structural diagram of a first end provided by an embodiment of the present application;
[0024] Figure 3 is a schematic structural diagram of a tab provided by an embodiment of the present application;
[0025] Figure 4 is a schematic structural diagram of a second end provided by an embodiment of the present application;
[0026] Figure 5 is a schematic diagram of the projection relationship between the first earless area and the second tab area provided by an embodiment of the present application;
[0027] Figure 6 is a schematic diagram of the projection relationship between the second earless area and the first tab area provided by an embodiment of the present application;
[0028] Figure 7 is a schematic structural diagram of a battery cell provided by an embodiment of the present application;
[0029] Figure 8 is a schematic structural diagram of a battery provided by an embodiment of the present application.
[0030] Description of the reference numerals:
[0031] 001 - Core;
[0032] 011 - Core body;
[0033] 111 - First end; 1111 - First earless area;
[0034] 112 - Second end portion; 1121 - Second tabless region;
[0035] 113 - Intermediate hole;
[0036] 012 - First tab region; 121 - First tab;
[0037] 013 - Second tab region; 131 - Second tab;
[0038] 002 - Battery cell; 021 - Housing; 022 - Cover plate;
[0039] 003 - Battery; 031 - Box body. Detailed implementation manners
[0040] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present application.
[0041] In addition, it should be understood that 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 one or more features. In the description of the present application, "a plurality" means two or more, unless otherwise specifically defined.
[0042] In the description of the present application, it should be noted that unless otherwise clearly defined and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection, an electrical connection, or a communication with each other; it may be directly connected, or indirectly connected through an intermediate medium, and it may be the communication inside two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific situations.
[0043] To facilitate understanding of the solution of the present application, the spline curves and arrows used for the reference numerals in the accompanying drawings are described herein: For the components indicated by the spline curves without arrows, they are physical components, that is, components with a physical structure; for the components indicated by the spline curves with arrows, they are virtual components, that is, components without a physical structure.
[0044] Please refer to Figure 1 and Figure 2 , Figure 1It is a schematic structural diagram of a core 001 provided by an embodiment of the present application. Figure 2 It is a schematic structural diagram of a first end portion 111 provided by an embodiment of the present application. An embodiment of the present application provides a core 001, which includes a core 001 body and a first tab 121. The core 001 body includes a first electrode tab, a separator, and a second electrode tab that are wound. The separator is located between the first electrode tab and the second electrode tab. The polarities of the first electrode tab and the second electrode tab are opposite. Along the axial direction of the core 001, the core 001 body has a first end portion 111. The first tab 121 is disposed on the first end portion 111 and connected to the first electrode tab. Among them, multiple layers of the first tab 121 are bent and stacked on the first end portion 111 to form a plurality of annular first tab regions 012. The plurality of first tab regions 012 are coaxially arranged. The outer diameter of the outermost first tab region 012 is smaller than the outer diameter of the core 001 body. There is a first annular space between two adjacent first tab regions 012, and the first annular space forms a first tabless region 1111.
[0045] It can be understood that the inner diameter and the outer diameter are the diameters of the relevant parts. Before being bent, the tab is parallel to the axial direction of the core 001. After the tab is bent, the tabs are stacked in sequence along the axial direction of the core 001 to form a tab region.
[0046] The tabless region is an area where no tab is provided on the end face of the core 001.
[0047] Among them, the first electrode tab includes a coating area coated with active material and an uncoated area not coated with active material. The first tab 121 can be integrally provided as at least a part of the uncoated area. In other embodiments, the first tab 121 can be separately welded to the first electrode tab.
[0048] In addition, the first tab 121 can be a positive tab or a negative tab.
[0049] Exemplarily, the number of the first tabless regions 1111 is n, satisfying: 1 ≤ n ≤ 4. The n first tabless regions 1111 are evenly spaced in sequence along the radial direction of the core 001. Optionally, there are three first tabless regions 1111. Correspondingly, the number of the first tab regions 012 is four. The first annular space between two radially adjacent first tab regions 012 is a first tabless region 1111. The three first tabless regions 1111 are sequentially provided at 1 / 4, 1 / 2, and 3 / 4 of the radius of the core 001.
[0050] In this embodiment, by providing an annular first tabless region 1111 on the first tab region 012, on the one hand, the electrolyte can directly flow into the interior of the core 001 through the first tabless region 1111, thereby shortening the path of the electrolyte to infiltrate the core 001, and further improving the infiltration efficiency of the core 001; on the other hand, the electrolyte can be evenly infiltrated along the circumferential direction of the core 001, thereby improving the uniformity of the infiltration of the core 001, and further enhancing the infiltration efficiency.
[0051] Moreover, the first tabless region 1111 can also provide a space for thermal expansion for the first tab regions 012 on both sides thereof, thereby reducing the stress borne by the first tab 121 after thermal expansion, and further enhancing the reliability of the battery cell.
[0052] In addition, by setting the outer diameter of the outermost first tab region 012 to be smaller than the outer diameter of the core 001 body, the outermost first tab region 012 can be spaced from the outer periphery of the core 001 body. In this way, not only can the electrolyte infiltrate from the circumferential direction of the core 001, but also the size of the end portion of the core 001 can be controlled to facilitate the insertion of the core 001 into the case.
[0053] Please refer to Figure 2 , in one embodiment, along the radial direction of the core 001, the width of the first tabless region 1111 is W1. The unit thickness of the core 001 body is d0, and it satisfies: 2d0 ≤ W1 ≤ 8d0.
[0054] Among them, the unit thickness d0 of the core 001 body is the sum of the thickness of a first electrode tab, the thickness of a separator, the thickness of a second electrode tab, and the thickness of another separator.
[0055] It can be understood that W1 includes but is not limited to: 2d0, 2.8d0, 3d0, 3.5d0, 4d0, 4.6d0, 5d0, 5.2d0, 6d0, 7.4d0, 7.6d0, 7.8d0, 8d0.
[0056] In this embodiment, through the above settings, on the one hand, W1 can have an appropriate size to facilitate the flow of the electrolyte in the first tabless region 1111 and cover more electrode tabs in the radial direction of the core 001; on the other hand, it can be avoided that W1 is too large resulting in a smaller area of the first tab region 012, so that the total area of the first tabs 121 can meet the current collection requirements of the core 001, and the core 001 can have an appropriate internal resistance.
[0057] In one embodiment, taking the axial direction of the core 001 as the projection direction and the plane perpendicular to the axial direction of the core 001 as the projection plane, the total area of the multiple first tab regions 012 in the projection plane is S1, and the area of the first end portion 111 is S, and it satisfies: 0.5 ≤ S1 / S < 1.
[0058] Exemplarily, the ratio of the total area S1 of the first tab area 012 in the projection plane to the area S of the first end portion 111 includes but is not limited to: 0.5, 0.52, 0.55, 0.58, 0.6, 0.62, 0.63, 0.64, 0.66, 0.66, 0.68, 0.7, 0.72, 0.76, 0.78, 0.8, 0.85, 0.9, 0.95.
[0059] Furthermore, 0.5 ≤ S1 / S ≤ 0.8.
[0060] In this embodiment, through the above limitations, on the one hand, the first tab area 012 can have a sufficient total area to meet the current collection requirements of the core 001; on the other hand, it can be avoided that the total area of the first tab area 012 is too large, resulting in too small an area of the tabless area, so as to ensure the wetting speed of the core 001 and facilitate improving the wetting efficiency of the core 001.
[0061] Please refer to Figure 2 , in an embodiment, the outer diameter of the core 001 body is A, and the outer diameter of the outermost first tab area 012 is B, satisfying: 0.8A ≤ B < A.
[0062] It can be understood that B includes but is not limited to: 0.8A, 0.81A, 0.81.5A, 0.82A, 0.83A, 0.84A, 0.85A, 0.86A, 0.88A, 0.9A, 0.92A, 0.95A, 0.99A.
[0063] Exemplarily:
[0064] When A is 44.6 mm, 35.68 mm ≤ B < 44.6 mm;
[0065] When A is 45 mm, 36 mm ≤ B < 45 mm;
[0066] When A is 45.2 mm, 36.16 mm ≤ B < 45.2 mm.
[0067] Furthermore, 0.8A ≤ B ≤ 0.95A.
[0068] In this embodiment, through the above limitations, on the one hand, it can be avoided that the outer diameter of the first tab area 012 is too large, resulting in too small a spacing between its outer periphery and the outer periphery of the core 001 body, so as to ensure that there is a space for the first tab 121 to thermally expand between the outer periphery of the first tab area 012 and the outer periphery of the core 001 body, and further avoid a large stress on the first tab 121 after thermal expansion; on the other hand, it can be avoided that the outer diameter of the first tab area 012 is too small, resulting in a small area of the first tab 121, so as to ensure the area of the first tab 121 to meet the requirements of the current collection capacity of the first tab.
[0069] Please refer to Figure 2 , in one embodiment, the inner diameter of the innermost first tab area 012 is C, satisfying: 0.02A ≤ C ≤ 0.25A.
[0070] It can be understood that C includes but is not limited to: 0.02A, 0.06A, 0.08A, 0.1A, 0.11A, 0.12A, 0.15A, 0.18A, 0.2A, 0.4A, 0.25A.
[0071] Exemplarily:
[0072] When A is 44.6 mm, 0.892 mm ≤ C ≤ 11.5 mm;
[0073] When A is 45 mm, 0.9 mm ≤ C ≤ 11.25 mm;
[0074] When A is 45.2 mm, 0.904 mm ≤ C ≤ 11.3 mm.
[0075] Further, 0.1A ≤ C ≤ 0.25A.
[0076] In this embodiment, through the above limitations, on the one hand, it can be avoided that the inner diameter of the first tab area 012 is too small, resulting in too small a spacing between its inner circumference and the inner circumference of the core 001 body, so that a space for the first tab 121 to thermally expand can be ensured on the inner circumferential side of the first tab area 012, and further, it can be avoided that the expanded first tab 121 blocks the middle hole 113 of the core 001 or interferes at the center of the core 001; on the other hand, it can be avoided that the inner diameter of the first tab area 012 is too large, resulting in a small area of the first tab 121, so that the area of the first tab 121 can be ensured to meet the requirements of the current collection ability of the first tab.
[0077] Please refer to Figure 3 , Figure 3 is a schematic structural diagram of the tab provided by the embodiment of the present application. Figure 3 The figure shows a partial structural schematic diagram of the tab in the unfolded state. In one embodiment, the first tab 121 includes a plurality of die-cut tabs. The die-cut width of the die-cut tab is u. The die-cut height of the die-cut tab is W j . Satisfying: 0.1 ≤ u / W j ≤ 0.7.
[0078] It can be understood that the die-cut tab refers to a tab with a required shape cut out in the non-coated area of the current collector using a mold and a cutting tool, such as a laser cutter.
[0079] Among them, the die-cut width u of each die-cut tab and its die-cut height W jThe ratios include but are not limited to: 0.1, 0.12, 0.15, 0.16, 0.18, 0.2, 0.26, 0.3, 0.38, 0.42, 0.45, 0.5, 0.52, 0.55, 0.58, 0.6, 0.65, 0.66, 0.67, 0.68, 0.7.
[0080] In this embodiment, through the above limitations, on the one hand, it is possible to avoid the die-cutting width of the first tab 121 being too small, so that the first tab 121 has an appropriate connection length with the coating area, thereby ensuring the reliability of the connection between the first tab 121 and the coating area; on the other hand, it is possible to avoid a large die-cutting width of the first tab 121 resulting in a large resistance to flattening the first tab 121, thereby improving the ease of operation of flattening the tab.
[0081] In one embodiment, along the winding direction of the first pole piece, the die-cutting width u of each die-cut tab and its die-cutting height W j The ratio gradually increases.
[0082] Generally, the die-cutting height W on the same pole piece j is a fixed value. Therefore, as the ratio of the die-cutting width u of the die-cut tab to its die-cutting height W j gradually increases, correspondingly, the die-cutting width u of the die-cut tab gradually increases.
[0083] It can be understood that the pole piece is wound around the center of the winding core, and the side line in the length direction of the pole piece is a curve, specifically a helix. As the distance from the center of the winding core increases, the radius of the tab gradually increases. And the curvature k of any point on the tab = 1 / R, where R is the radius of that point. Therefore, as the winding diameter increases, the curvature of the first tab 121 gradually decreases. Correspondingly, as the curvature gradually decreases, the root of the first tab 121, that is, the connection part between the first tab 121 and the coating area, has less resistance to bending the first tab 121.
[0084] Based on this, in this embodiment, through the above settings, as the winding diameter increases, the die-cutting width u of the first tab 121 gradually increases. In this way, on the one hand, the spiral length of the first tab 121 with a large curvature is smaller to reduce the resistance to its bending, thereby facilitating its flattening and bending inward; on the other hand, since the resistance to bending of the first tab 121 with a smaller curvature is smaller, the spiral length of the first tab 121 with a smaller curvature can be larger, so that the first tab 121 with a smaller curvature has a larger connection part with the coating area, thereby improving the connection reliability between the first tab 121 near the outer periphery of the winding core 001 and the coating area.
[0085] Please refer to Figure 4 , Figure 4It is a schematic structural diagram of the second end portion 112 provided by an embodiment of the present application. In one embodiment, the core 001 further includes a second tab 131. The core 001 has a second end portion 112 disposed opposite to the first end portion 111. The second tab 131 is disposed on the second end portion 112 and connected to the second electrode plate. Among them, multiple second tabs 131 are stacked on the second end portion 112 to form multiple annular second tab regions 013. The multiple second tab regions 013 are coaxially arranged. There is a second annular space between adjacent two second tab regions 013. The second annular space forms a second tabless region 1121.
[0086] Among them, the second electrode plate includes a coated region coated with active material and an uncoated region not coated with active material. The second tab 131 can be integrally provided as at least a part of the uncoated region. In other embodiments, the second tab 131 can be separately welded to the second electrode plate.
[0087] In addition, the first tab 121 can be a positive tab, and the second tab 131 is a negative tab.
[0088] In this embodiment, by providing the second tab region 013 at the second end portion 112, the part where the bottom of the electrode plate is in direct contact with the electrolyte can be increased, and thus the efficiency of the electrolyte infiltrating the core 001 can be improved.
[0089] Please refer to Figure 5 , Figure 5 It is a schematic diagram of the projection relationship between the first tabless region 1111 and the second tab region 013 provided by an embodiment of the present application. Figure 5 The end face of the shown core 001 is the second end portion 112 of the core 001, and the thick dashed line shows the first tabless region 1111. In one embodiment, taking the axial direction of the core 001 as the projection direction and the plane perpendicular to the axial direction of the core 001 as the projection plane, the projection of the first tabless region 1111 coincides with the projection of the second tab region 013 in part.
[0090] Among them, two radially adjacent first tabless regions 1111 can respectively coincide with the inner and outer parts of the same second tab region 013, or the second tab region 013 coincides with at most one first tabless region 1111 in part.
[0091] In this embodiment, through the above limitation, when the electrode liquid entering the core 001 from the first tabless region 1111 is discharged from the second end portion 112, the discharge of this part of the electrolyte is slowed down due to the obstruction of the second tab region 013, so that more electrolyte can be retained in the core 001, and thus the electrolyte infiltration efficiency is improved.
[0092] Specifically, along the radial direction of the core 001, the width of the overlapping projection of the first tabless region 1111 and the second tab region 013 is W2, and the width of the first tabless region 1111 is W1, satisfying: 10% W1 ≤ W2.
[0093] It can be understood that W2 includes but is not limited to 10% W1, 12% W1, 13.6% W1, 15% W1, 18% W1, 28% W1, 30% W1, 35% W1, 40% W1, 42% W1, 45% W1, 50% W1.
[0094] Furthermore, 10% W1 ≤ W2 ≤ 50% W1.
[0095] In this embodiment, through the above limitations, it is possible to avoid the overlapping part of the projection of the first tabless region 1111 and the projection of the second tab region 013 from being too small, so that the obstruction of the second tab region 013 to the electrolyte entering from the first tabless region 1111 is more obvious. Furthermore, more electrolyte can be retained inside the core 001, and finally the electrolyte infiltration efficiency can be improved.
[0096] Please refer to Figure 6 , Figure 6 which is a schematic diagram of the projection relationship between the second tabless region 1121 and the first tab region 012 provided by the embodiment of the present application. Figure 6 The end face of the shown core 001 is the first end portion 111 of the core 001, and the thick dashed line shows the second tabless region 1121. In one embodiment, taking the axial direction of the core 001 as the projection direction and the plane perpendicular to the axial direction of the core 001 as the projection plane, the projection of the second tabless region 1121 and the projection of the first tab region 012 partially overlap.
[0097] Among them, two radially adjacent second tabless regions 1121 can respectively overlap with the inner and outer parts of the same first tab region 012, or the first tab region 012 can overlap with at most one second tabless region 1121 partially.
[0098] In this embodiment, through the above limitations, the second tabless region 1121 and the first tabless region 1111 are arranged in a staggered manner, so that the electrolyte can infiltrate more electrode sheets in the radial direction of the core 001, and further improve the infiltration efficiency at the center of the thickness of the core 001.
[0099] Please refer to Figure 6 , in one embodiment, along the radial direction of the core 001, the width of the overlapping projection of the second tabless region 1121 and the first tab region 012 is W4. The width of the second tabless region 1121 is W3, satisfying: 10% W3 ≤ W4. Among them, 2d0 ≤ W3 ≤ 8d0.
[0100] It can be understood that W4 includes but is not limited to 10% W3, 12% W3, 13.6% W3, 15% W3, 18% W3, 28% W3, 30% W3, 35% W3, 40% W3, 42% W3, 45% W3, 50% W3.
[0101] Furthermore, 10% W3 ≤ W4 ≤ 50% W3.
[0102] In this embodiment, through the above limitations, it is possible to avoid the situation where the overlapping part of the projection of the second tabless area 1121 and the projection of the second tab area 013 is too small, so that the area of the part of the first tabless area 1111 opposite to the second tabless area 1121 can be made smaller, making the obstruction of the electrolyte entering the first tabless area 1111 by the second tab area 013 more obvious. As a result, more electrolyte can be retained inside the core 001, ultimately improving the electrolyte infiltration efficiency.
[0103] In one embodiment, taking the axial direction of the core 001 as the projection direction and the plane where the second end 112 is located as the projection plane, the total area of the second tab area 013 in the projection plane is S2, and the area of the second end 112 is S, satisfying: 0.5 ≤ S2 / S < 1. Furthermore, 0.5 ≤ S2 / S ≤ 0.8.
[0104] It can be understood that the areas at both ends of the core 001 are equal, so the area of the second end 112 is also S.
[0105] Exemplarily, the ratio between the total area S2 of the second tab area 013 in the projection plane and the area S of the second end 112 includes but is not limited to: 0.5, 0.52, 0.55, 0.58, 0.6, 0.62, 0.63, 0.64, 0.66, 0.66, 0.68, 0.7, 0.72, 0.76, 0.78, 0.8, 0.85, 0.9, 0.95.
[0106] Furthermore, 0.5 ≤ S2 / S ≤ 0.8.
[0107] In this embodiment, through the above limitations, on the one hand, it is possible to make the second tab area 013 have a sufficient total area to meet the current collection requirements of the core 001; on the other hand, it is possible to avoid the situation where the total area of the second tab area 013 is too large, resulting in too small an area of the tabless area, thus ensuring the infiltration speed at the center of the thickness of the core 001 and facilitating the improvement of the infiltration efficiency of the core 001.
[0108] In addition, the outer diameter of the outermost second tab area 013 and the inner diameter of the innermost second tab area 013 are respectively the same as the outer diameter of the outermost first tab area 012 and the inner diameter of the innermost first tab area 012. Specifically, the outer diameter of the second tab area 013 is D, satisfying: 0.8A ≤ D < A, and further, 0.8A ≤ D ≤ 0.95A. The inner diameter of the second tab area 013 is F, satisfying: 0.02A ≤ F ≤ 0.25A, and further, 0.1A ≤ F ≤ 0.25A.
[0109] Among them, the width of the second tabless area 1121 is W3, which is the same as the width of the first tabless area 1111. Specifically, 2d0 ≤ W3 ≤ 8d0. The second tab is a die-cut tab, and the ratio of its die-cut width u to the die-cut height W j satisfies: 0.1 ≤ u / W j ≤ 0.7.
[0110] Please refer to Figure 7 , Figure 7 which is a schematic structural diagram of the battery cell 002 provided by the embodiment of the present application. Correspondingly, the embodiment of the present application provides a battery cell 002, which includes a housing 021, a cover plate 022, and the aforementioned winding core 001; the cover plate 022 is covered with the housing 021 to define a receiving cavity; the winding core 001 is disposed in the receiving cavity.
[0111] In this embodiment, by adopting the aforementioned winding core 001, on the one hand, the electrolyte can directly flow into the inside of the winding core 001 through the top of the winding core 001, thereby shortening the path of the electrolyte to infiltrate the winding core 001, and further improving the infiltration efficiency of the battery cell 002; on the other hand, multiple liquid inlet parts can be provided on the first end portion 111 of the winding core 001, and the multiple liquid inlets are respectively infiltrated along the radial direction of the winding core 001, which can improve the uniformity of the infiltration of the winding core 001, thereby further improving the infiltration efficiency of the battery cell 002.
[0112] Please refer to Figure 8 , Figure 8 which is a schematic structural diagram of the battery 003 provided by the embodiment of the present application. The embodiment of the present application provides a battery 003, which includes the aforementioned battery cell 002.
[0113] It can be understood that the battery 003 may further include a box body or a bottom plate, the battery cell 002 is disposed in the box body, or the battery cell 002 is mounted on the bottom plate.
[0114] In this embodiment, by using the aforementioned battery cell 002, on the one hand, the electrolyte can directly flow into the interior of the wound core 001 through the top of the wound core 001, thereby shortening the path of the electrolyte to infiltrate the wound core 001, and further improving the manufacturing efficiency of the battery 003; on the other hand, multiple liquid inlet parts can be provided on the first end portion 111 of the wound core 001, and the multiple liquid inlet parts infiltrate the wound core 001 along the radial direction of the wound core 001, which can improve the uniformity of the infiltration of the wound core 001, and further improve the manufacturing efficiency of the battery 003.
[0115] The embodiments of the present application have been introduced in detail above. Specific examples are used in this article to elaborate on the principle and implementation manner of the present application. The description of the above embodiments is only used to help understand the method and its core idea of the present application; at the same time, for those skilled in the art, according to the idea of the present application, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present application.
Claims
1. A core, characterized in that, Comprising: A core body, including a first pole piece, a separator, and a second pole piece wound around, the separator being located between the first pole piece and the second pole piece, the polarities of the first pole piece and the second pole piece being opposite, along the axial direction of the core, the core body having a first end; A first pole tab, disposed at the first end and connected to the first pole piece; Wherein, multiple layers of the first pole tabs are bent and stacked at the first end to form a plurality of annular first pole tab regions, the plurality of first pole tab regions being coaxially arranged, and the outer diameter of the outermost first pole tab region being smaller than the outer diameter of the core body; There is a first annular space between two adjacent first pole tab regions, and the first annular space forms a first tabless region.
2. The core according to claim 1, characterized in that, Along the radial direction of the core, the width of the first tabless region is W1, and the unit thickness of the core body is d0, satisfying: 2d0 ≤ W1 ≤ 8d0, where d0 is the sum of the thickness of one first pole piece, the thickness of one separator, the thickness of one second pole piece, and the thickness of another separator.
3. The core according to claim 1, wherein Taking the axial direction of the core as the projection direction and the plane perpendicular to the axial direction of the core as the projection plane, the total area of the plurality of first pole tab regions in the projection plane is S1, and the area of the first end is S, satisfying: 0.5 ≤ S1 / S < 1.
4. The core according to claim 1, characterized in that, The outer diameter of the core body is A, and the outer diameter of the outermost first pole tab region is B, satisfying: 0.8A ≤ B < A.
5. The core according to claim 1, characterized in that, The outer diameter of the core body is A, and the inner diameter of the innermost first pole tab region is C, satisfying: 0.02A ≤ C ≤ 0.25A.
6. The core according to any one of claims 1-5, characterized in that, The first tab includes a plurality of die-cut tabs, the die-cut width of the die-cut tab is u, and the die-cut height of the die-cut tab is W j , satisfying: 0.1 ≤ u / W j ≤ 0.7 7. The core according to claim 6, characterized in that, Along the winding direction of the first pole piece, the ratio of the die-cut width u to the die-cut height W of each die-cut tab j gradually increases.
8. The core according to any one of claims 1-5, characterized in that, The core further includes a second pole tab, and the core has a second end opposite to the first end; the second pole tab is disposed at the second end and connected to the second pole piece; Wherein, multiple layers of the second pole tabs are stacked at the second end to form a plurality of annular second pole tab regions, the plurality of second pole tab regions being coaxially arranged, and there is a second annular space between two adjacent second pole tab regions, and the second annular space forms a second tabless region.
9. The core according to claim 8, characterized in that, Taking the axial direction of the core as the projection direction and the plane perpendicular to the axial direction of the core as the projection plane, the projection of the first tabless region and the projection of the second pole tab region partially overlap.
10. The core according to claim 9, characterized in that, Along the radial direction of the core, the width of the overlap between the projection of the first tabless region and the projection of the second pole tab region is W2, and the width of the first tabless region is W1, satisfying: 10%W1 ≤ W2.
11. The core according to claim 8, characterized in that, Taking the axial direction of the core as the projection direction and the plane perpendicular to the axial direction of the core as the projection plane, the projection of the second tabless region and the projection of the first pole tab region partially overlap.
12. The core according to claim 11, characterized in that, Along the radial direction of the core, the width of the overlap between the projection of the second tabless region and the projection of the first pole tab region is W4, and the width of the second tabless region is W3, satisfying: 10%W3 ≤ W4.
13. A battery cell, characterized in that, Comprising: A housing; A cover plate, covering the housing to define a receiving cavity; And, the core as described in any one of claims 1 - 12, disposed in the receiving cavity.
14. A battery, characterized in that, Comprising the battery cell as described in claim 13.