Roll core, battery cell and battery
By setting the poleless ear area at the end of the core, the electrolyte directly immerses the electrode sheet, the problem of low core wetting efficiency is solved and the battery performance and reliability are improved.
Patent Information
- Application Number
- CN202422076040.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-26
- Publication Date
- 2025-08-15
- Estimated Expiration
- 2034-08-26
AI Technical Summary
In the prior art, the electrolyte has poor wetting efficiency in the core, resulting in a degradation of battery performance.
A pole-less ear area is arranged at the end of the roll core, allowing the electrolyte to flow directly into the inside of the roll core, and infiltrate the pole sheet through the pole-less ear area to increase the contact area between the pole sheet and the electrolyte.
It improves the wetting efficiency of the coil core and the reliability of the battery, reduces the internal stress after the heat expansion of the extreme ear, and improves the connection reliability between the extreme ear and the current collecting disk.
Smart Images
Figure CN223230359U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of battery technology, and in particular to a winding core, a battery cell and a battery. Background Art
[0002] In related technologies, a battery includes a casing and a winding core disposed within the casing. The winding core includes a wound positive electrode sheet, a negative electrode sheet, and a separator. The electrode sheet includes a coated area and a hollow foil area surrounding the coated area. The coated area is used to apply the active material, while the hollow foil area serves as the tab.
[0003] In order to control the height of the tabs inside the battery cell, the tabs need to be flattened, that is, the tabs are bent toward the end face of the core so that two adjacent tabs are stacked along the axial direction of the core. However, the flattened tabs will block the end of the core, causing the electrolyte to mainly flow down from the middle hole of the core to the bottom of the inner cavity of the battery cell, and then the electrolyte is adsorbed by the electrode to the top of the core to complete the infiltration of the core. In this way, the path for the electrolyte to infiltrate the core is longer, resulting in poor infiltration efficiency of the core. Utility Model Content
[0004] The embodiments of the present application provide a winding core, a battery cell, and a battery, which can improve the problem of poor wetting efficiency of the winding core.
[0005] In the first aspect, an embodiment of the present application provides a winding core, which includes a winding core body, a first pole ear and a second pole ear; the winding core body includes a first pole piece, a diaphragm and a second pole piece that are wound together, the diaphragm is located between the first pole piece and the second pole piece, the polarity of the first pole piece and the second pole piece are opposite, and along the axial direction of the winding core, the winding core body has a first end and a second end; the first pole ear is arranged at the first end and connected to the first pole piece, and multiple layers of first pole ears are bent and stacked on the first end to form a first pole ear area; the second pole ear is connected to the second pole piece; the first end is also provided with a first pole-free ear area, and the first pole-free ear area is configured to allow electrolyte to flow into the interior of the winding core body; the midpoint of the radius of the first end is located in the first pole-free ear area.
[0006] In one embodiment, three first tab-free regions are included, and a quarter of the radius, a midpoint of the radius, and a quarter of the radius of the first end portion are respectively located in the three first tab-free regions.
[0007] In one embodiment, the first pole lug region is annular, there are multiple first pole lug regions, the multiple first pole lug regions are coaxially arranged, and the annular space between two adjacent first pole lug regions forms a first pole lug-free region; the second pole lug is arranged at the second end, and multiple layers of second pole lugs are bent and stacked on the second end to form multiple annular second pole lug regions, and the multiple second pole lug regions are coaxially arranged; the annular space between two adjacent second pole lug regions forms a second pole lug-free region; wherein, along the axial direction of the winding core, the first pole lug-free region is at least partially arranged opposite to the second pole lug region.
[0008] In one embodiment, along the radial direction of the winding core, the width of the first tab-free region and the second tab-free region at opposite locations along the axial direction of the winding core is W2, and the width of the first tab-free region is W1, satisfying: 10% W1≤W2.
[0009] In one embodiment, along the axial direction of the winding core, the second tab-free region is at least partially disposed opposite to the first tab region.
[0010] In one embodiment, along the radial direction of the winding core, the width of the second tab-free region and the first tab-free region at the portion opposite to each other along the axial direction of the winding core is W4, and the width of the second tab-free region is W3, satisfying: 10% W4≤W3.
[0011] In one embodiment, a midpoint of the radius of the second end portion is located in a second tab-free region.
[0012] In one embodiment, three second tab-free regions are included, and a quarter of the radius, a midpoint of the radius, and a quarter of the radius of the second end are respectively located in the three second tab-free regions.
[0013] In one embodiment, along the radial direction of the winding core, the width of the second tab-free area is W3, and the unit thickness of the winding core body is d0, satisfying: 2d0≤W3≤8d0, where d0 is the sum of the thickness of a first pole piece, the thickness of a diaphragm, the thickness of a second pole piece, and the thickness of another diaphragm.
[0014] In one embodiment, the diameter of the middle hole of the winding core is φ, the inner diameter of the innermost first tab region is C, satisfying: C≤φ; and / or the inner diameter of the innermost second tab region is C', satisfying: C'≤φ.
[0015] In one embodiment, the outer diameter of the winding core body is A, the outer diameter of the outermost first tab region is B, and the following conditions are met: B<A; and / or the outer diameter of the outermost second tab region is B', and the following conditions are met: B'<A.
[0016] In one embodiment, the second tab is disposed at the first end, multiple layers of second tabs are bent and stacked on the first end to form a second tab region, and the first tab-free region is located between the first tab region and the second tab region.
[0017] In one embodiment, along the radial direction of the winding core, the width of the first tab-free area is W1, and the unit thickness of the winding core body is d0, satisfying: 2d0≤W1≤8d0, where d0 is the sum of the thickness of a first pole piece, the thickness of a diaphragm, the thickness of a second pole piece, and the thickness of another diaphragm.
[0018] In a second aspect, an embodiment of the present application provides a battery cell, comprising a shell, a cover plate, and the aforementioned winding core; the cover plate is covered with the shell to define a accommodating cavity; and the winding core is disposed in the accommodating cavity.
[0019] In a third aspect, an embodiment of the present application provides a battery comprising the aforementioned battery cell.
[0020] Beneficial effects of the embodiments of the present application:
[0021] In the embodiments of the present application, by providing a first tab-free region and a second tab-free region, the electrolyte can directly penetrate the electrode through the first tab-free region, and the electrolyte that falls to the bottom of the winding core can directly penetrate the electrode through the second tab-free region, thereby increasing the area of direct contact between the electrode and the electrolyte. In this way, the wetting efficiency of the winding core can be improved. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.
[0023] Figure 1 Schematic diagram of the structure of the winding core provided in an embodiment of the present application;
[0024] Figure 2 is a structural schematic diagram of the first end portion provided in an embodiment of the present application;
[0025] Figure 3 is a structural schematic diagram of the second end provided in an embodiment of the present application;
[0026] Figure 4 is a structural schematic diagram of another first end portion provided by an embodiment of the present application;
[0027] Figure 5 Schematic diagram of the projection relationship between the first tab-free area and the second tab area provided in an embodiment of the present application;
[0028] Figure 6 Schematic diagram of the projection relationship between the second tab-free region and the first tab region provided in an embodiment of the present application;
[0029] Figure 7 is a structural schematic diagram of another second end portion provided in an embodiment of the present application;
[0030] Figure 8 is a schematic structural diagram of a battery cell provided in an embodiment of the present application;
[0031] Figure 9It is a schematic structural diagram of a battery provided in an embodiment of the present application.
[0032] Description of reference numerals:
[0033] 001- core;
[0034] 011- core body;
[0035] 111-first end portion; 1111-first tab-free region;
[0036] 112- second end portion; 1121- second tab-free region;
[0037] 113-middle hole;
[0038] 012-first tab region; 121-first tab;
[0039] 013-second tab area; 131-second tab;
[0040] 002-battery cell; 021-housing; 022-cover;
[0041] 003-battery; 031-box. DETAILED DESCRIPTION
[0042] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without making creative efforts are within the scope of protection of this application.
[0043] Furthermore, it should be understood that the specific embodiments described herein are intended only to illustrate and explain the present application and are not intended to limit the present application. In this application, unless otherwise indicated, directional terms such as "upper" and "lower" generally refer to the upper and lower positions of the device in actual use or operation, specifically the directions of the drawings in the accompanying drawings; whereas "inner" and "outer" refer to the outline of the device.
[0044] The terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the specified features. In the description of this application, "plurality" means two or more, unless otherwise specifically specified.
[0045] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections, electrical connections, or mutual communication; they can refer to direct connections or indirect connections through an intermediate medium; they can refer to internal communication between two components or the interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.
[0046] To facilitate understanding of the solution of the present application, the spline curves and arrows used in the drawings are explained here: the components indicated by the spline curves without arrows are solid components, that is, components with solid structures; the components indicated by the spline curves with arrows are virtual components, that is, components without solid structures.
[0047] See also Figures 1 to 3 , Figure 1 This is a schematic diagram of the structure of the winding core 001 provided in an embodiment of the present application. Figure 2 is a structural diagram of the first end portion 111 provided in an embodiment of the present application. Figure 3 : is a structural schematic diagram of the second end 112 provided in an embodiment of the present application. An embodiment of the present application provides a winding core 001, which includes a winding core body 011, a first pole lug 121 and a second pole lug 131. The winding core body 011 includes a first pole piece, a diaphragm and a second pole piece that are wound. The diaphragm is located between the first pole piece and the second pole piece. The polarity of the first pole piece and the second pole piece are opposite. Along the axial direction of the winding core 001, the winding core body 011 has a first end 111 and a second end 112. The first pole lug 121 is provided at the first end 111 and connected to the first pole piece. Multiple layers of the first pole lug 121 are bent and stacked on the first end 111 to form a first pole lug region 012. The second pole lug 131 is connected to the second pole piece. The first end 111 is also provided with a first pole lug-free region 1111. The first pole lug-free region 1111 is configured to allow electrolyte to flow into the interior of the winding core body 011. There is no bent and stacked first electrode tab 121 and second electrode tab 131. The midpoint of the radius of the first end portion 111 is located in the first electrode tab-free region 1111.
[0048] Furthermore, the middle ring of the first tab-free region 1111 coincides with the ring where the midpoint of the radius of the first end portion 111 is located.
[0049] It can be understood that the tabs are parallel to the axial direction of the winding core 001 before being bent. After being bent, the tabs are stacked in sequence along the axial direction of the winding core 001 to form a tab area.
[0050] In addition, the first tab-free region 1111 is not provided with at least one of the bent first tab 121 , the second tab 131 , and the separator.
[0051] The first and second electrode sheets include a coated area coated with an active material and an uncoated area uncoated with the active material. The first and second electrode tabs 121, 131 may be integrally formed to form at least a portion of the uncoated area. In other embodiments, the first electrode tab 121 may be separately welded to the first electrode sheet, and the second electrode tab 131 may be separately welded to the second electrode sheet.
[0052] Specifically, one of the first electrode sheet and the second electrode sheet is a positive electrode sheet, and the other is a negative electrode sheet. For example, the first electrode sheet is a positive electrode sheet, and the second electrode sheet is a negative electrode sheet. Correspondingly, the first electrode tab 121 is a positive electrode tab, and the second electrode tab 131 is a negative electrode tab.
[0053] In this embodiment, the first tab-free region 1111 is provided so that the electrolyte can directly penetrate the electrode through the first tab-free region 1111, thereby increasing the area of direct contact between the electrode and the electrolyte. This improves the wetting efficiency of the winding core 001.
[0054] Furthermore, by providing the first tab-free region 1111 , expansion space can be provided for the first tab 121 that expands due to heat, thereby reducing the internal stress of the first tab 121 after thermal expansion, thereby improving the reliability of the battery.
[0055] Furthermore, because the outer periphery of core 001 is in direct contact with the electrolyte, the electrolyte can infiltrate the electrode radially inward from the outer periphery of core 001. Simultaneously, electrolyte entering central hole 113 of core 001 can also infiltrate the electrode radially outward from the inner periphery of core 001. However, because the outer periphery has a larger area than the inner periphery, and the circumference of the electrode gradually decreases as it approaches the axis of core 001, the infiltration rate in the radial direction of the outer periphery is greater than that in the radial direction of the inner periphery.
[0056] Based on this, in this embodiment, by positioning the midpoint of the radius of the first end portion 111 within a first tab-free area 1111, the first tab-free area 1111 is arranged closer to the inner periphery of the core 001; in this way, not only can the pole piece wound more tightly in the middle of the core 001 be directly wetted, but the radial direction of the core 001 can also be wetted more evenly, thereby further improving the wet efficiency of the core 001.
[0057] See also Figure 4 , Figure 41 is a schematic diagram of another structure of the first end portion 111 provided in an embodiment of the present application. In one embodiment, the winding core 001 includes three first tab-free regions 1111, and the first end portion 111 is located within the three first tab-free regions 1111 at 1 / 4 of the radius, the midpoint of the radius, and 3 / 4 of the radius, respectively.
[0058] It can be understood that the circumference at 1 / 4 of the radius of the first end 111 , the circumference at the midpoint of the radius, and the circumference at 3 / 4 of the radius are located in the corresponding first tab-free area 1111 .
[0059] Furthermore, the middle rings of the three first tab-free regions 1111 respectively coincide with the circumference at 1 / 4 of the radius of the first end portion 111 , the circumference at the midpoint of the radius, and the circumference at 3 / 4 of the radius.
[0060] In this embodiment, through the above arrangement, the plurality of first tab-free regions 1111 can be evenly distributed, thereby improving the uniformity of the wetting of the core 001 and further improving the wetting efficiency of the core 001 .
[0061] In one embodiment, the first pole lug region 012 is annular. Multiple first pole lug regions 012 are coaxially arranged. The annular space between two adjacent first pole lug regions 012 forms a first pole lug-free region 1111. The second pole lug 131 is arranged at the second end 112. Multiple layers of second pole lugs 131 are bent and stacked on the second end 112 to form multiple annular second pole lug regions 013. Multiple second pole lug regions 013 are coaxially arranged. The annular space between two adjacent second pole lug regions 013 forms a second pole lug-free region 1121. In the axial direction of the winding core 001, the first pole lug-free region 1111 is at least partially arranged opposite the second pole lug region 013.
[0062] In this embodiment, the second tab-free region 1121 is provided so that the electrolyte that falls onto the bottom of the winding core 001 can directly penetrate the electrode through the second tab-free region 1121, thereby increasing the area of direct contact between the electrode and the electrolyte. This improves the wetting efficiency of the winding core 001.
[0063] Furthermore, by providing the second tab-free region 1121 , expansion space can be provided for the second tab 131 that expands due to heat, thereby reducing the internal stress of the second tab 131 after thermal expansion, thereby improving the reliability of the battery.
[0064] In addition, by arranging the first tab-free area 1111 at least partially opposite to the second tab area 013, the second tab area 013 can more obviously hinder the electrolyte entering from the first tab-free area 1111, thereby allowing more electrolyte to be retained in the core 001, and ultimately improving the electrolyte infiltration efficiency.
[0065] Setting the first tab area 012 and the second tab area 013 as an annular structure can make the force center of the end face of the core 001 symmetrical, thereby improving the force state of the end face of the core 001, so as to improve the reliability of the connection between the tab and the collecting plate.
[0066] Among them, two radially adjacent first tab-free regions 1111 can respectively overlap with the inner and outer parts of the same second tab region 013 , or the second tab region 013 can overlap with at most one first tab-free region 1111 .
[0067] See also Figure 5 , Figure 5 It is a schematic diagram of the projection relationship between the first tab-free area 1111 and the second tab area 013 provided in an embodiment of the present application. Figure 5 The end face of the winding core 001 is shown as the second end portion 112 of the winding core 001, and the thick dashed line indicates the first tab-free region 1111. In one embodiment, along the radial direction of the winding core 001, the width of the first tab-free region 1111 and the second tab region 013 at the locations opposite to each other along the axial direction of the winding core 001 is W2, and the width of the first tab-free region 1111 is W1, satisfying the following condition: 10% W1≤W2.
[0068] 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, and 50% W1.
[0069] Further, 10% W1≤W2≤50% W1.
[0070] In this embodiment, through the above-mentioned limitation, it is possible to avoid the overlapping area between the projection of the first tab-free area 1111 and the projection of the second tab area 013 being too small, so that the second tab area 013 can more obviously hinder the electrolyte entering from the first tab-free area 1111, thereby allowing more electrolyte to be retained in the core 001, and ultimately improving the electrolyte infiltration efficiency.
[0071] See also Figure 6 , Figure 6 It is a schematic diagram of the projection relationship between the second tab-free region 1121 and the first tab region 012 provided in an embodiment of the present application. Figure 6 The end face of the winding core 001 is the first end 111 of the winding core 001, and the thick dashed line shows the second tab-free area 1121. In one embodiment, along the axial direction of the winding core 001, the second tab-free area 1121 is at least partially disposed opposite to the first tab area 012.
[0072] Among them, two radially adjacent second tab-free 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 tab-free region 1121.
[0073] In this embodiment, through the above-mentioned limitation, the second tab-free area 1121 and the first tab-free area 1111 can be staggered, so that the electrolyte can infiltrate more pole pieces at the center of the thickness of the core 001, thereby further improving the infiltration efficiency at the center of the thickness of the core 001.
[0074] See also Figure 6 In one embodiment, along the radial direction of the winding core 001, the width of the second tab-free region 1121 and the first tab region 012 at the portion opposite to each other along the axial direction of the winding core 001 is W4, and the width of the second tab-free region 1121 is W3, satisfying: 10% W4≤W3.
[0075] 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, and 50% W3.
[0076] Further, 10% W3≤W4≤50% W3.
[0077] In this embodiment, through the above-mentioned limitation, it is possible to avoid the overlapping portion of the projection of the second tab-free area 1121 and the projection of the second tab-free area 013 being too small, so that the relative portion of the first tab-free area 1111 and the second tab-free area 1121 can be made smaller, so that the second tab area 013 can more obviously hinder the electrolyte from entering the first tab-free area 1111, thereby allowing more electrolyte to be retained in the core 001, and ultimately improving the electrolyte infiltration efficiency.
[0078] Specifically, the number of the first non-polarized lug areas 1111 is consistent with the number of the second non-polarized lug areas 1121. Along the radial direction of the core 001, the first non-polarized lug areas 1111 and the second non-polarized lug areas 1121 correspond one to one. The inner diameter of the first non-polarized lug area 1111 is larger than the inner diameter of the corresponding second non-polarized lug area 1121, and the outer diameter of the first non-polarized lug area 1111 is larger than the outer diameter of the corresponding second non-polarized lug area 1121, or the inner diameter of the first non-polarized lug area 1111 is smaller than the inner diameter of the corresponding second non-polarized lug area 1121, and the outer diameter of the first non-polarized lug area 1111 is smaller than the outer diameter of the corresponding second non-polarized lug area 1121. In this way, the layout of the first end 111 and the layout of the second end 112 are simple, and the uniformity of the arrangement of each non-polarized lug area on the same end face can be improved.
[0079] See also Figure 3 In one embodiment, the midpoint of the radius of the second end portion 112 is located in a second tab-free region 1121 .
[0080] Furthermore, the middle ring of the second tab-free region 1121 coincides with the ring where the midpoint of the radius of the second end portion 112 is located.
[0081] In this embodiment, the midpoint of the radius of the second end portion 112 is located within a second tab-free area 1121, so that the second tab-free area 1121 is arranged closer to the inner periphery of the core 001; in this way, not only can the pole piece wound more tightly in the middle of the core 001 be directly wetted, but the radial direction of the core 001 can also be wetted more evenly, thereby further improving the wet efficiency of the core 001.
[0082] See also Figure 7 , Figure 7 Schematic diagram of another second end portion 112 provided in an embodiment of the present application. In one embodiment, the winding core 001 includes three second tab-free regions 1121. The third and fourth points of the radius of the second end portion 112 are located within the three second tab-free regions 1121.
[0083] It can be understood that the circumference at 1 / 4 of the radius of the second end portion 112 , the circumference at the midpoint of the radius, and the circumference at 3 / 4 of the radius are located in the corresponding second tab-free region 1121 .
[0084] Furthermore, the middle rings of the three second tab-free regions 1121 respectively coincide with the circumference at 1 / 4 of the radius of the second end portion 112 , the circumference at the midpoint of the radius, and the circumference at 3 / 4 of the radius.
[0085] In this embodiment, through the above arrangement, the plurality of second tab-free regions 1121 can be evenly distributed, thereby improving the uniformity of the wetting of the core 001 and further improving the wetting efficiency of the core 001 .
[0086] See also Figure 3 In one embodiment, along the radial direction of the winding core 001, the width of the second tab-free area 1121 is W3, and the unit thickness of the winding core body 011 is d0, satisfying: 2d0≤W3≤8d0, wherein d0 is the sum of the thickness of a first electrode piece, the thickness of a diaphragm, the thickness of a second electrode piece, and the thickness of another diaphragm.
[0087] It can be understood that W3 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, and 8d0.
[0088] In this embodiment, through the above-mentioned setting, on the one hand, W3 can be made to have an appropriate size to facilitate the flow of electrolyte in the second non-electrode lug area 1121 and to cover more pole pieces in the radial direction of the core 001; on the other hand, it can avoid W3 being too large, resulting in a smaller total area of the second electrode lug area 013, so that the total area of the second electrode lug 131 can meet the current collection requirements of the core 001, and the core 001 can have an appropriate internal resistance.
[0089] See also Figure 2 or Figure 3 In one embodiment, the aperture of the middle hole 113 of the winding core 001 is φ, the inner diameter of the first tab region 012 located at the innermost side is C, and the following conditions are satisfied: C≤φ; and / or the inner diameter of the second tab region 013 located at the innermost side is C', and the following conditions are satisfied: C'≤φ.
[0090] Specifically, the inner diameter of the first pole lug area 012 located at the innermost side is C, satisfying: C≤φ, or, the inner diameter of the second pole lug area 013 located at the innermost side is C', satisfying: C'≤φ, or, the inner diameter of the first pole lug area 012 located at the innermost side is C, satisfying: C≤φ, and the inner diameter of the second pole lug area 013 located at the innermost side is C', satisfying: C'≤φ.
[0091] It can be understood that the inner diameter and outer diameter are the diameters of the relevant parts.
[0092] In this embodiment, through the above-mentioned arrangement, on the one hand, the first pole lug area 012 and the second pole lug area 013 can be prevented from blocking the middle hole 113 of the winding core 001, thereby improving the smoothness of the electrode liquid flowing into or out of the middle, thereby improving the infiltration efficiency of the winding core 001; on the other hand, there can be space for thermal expansion on the inner peripheral side of the first pole lug area 012 and the inner side of the second pole lug area 013, thereby reducing the stress on the first pole lug 121 and the second pole lug 131 after thermal expansion, thereby improving the reliability of the battery cell.
[0093] See also Figure 2 or Figure 3 In one embodiment, the outer diameter of the winding core 001 body is A, the outer diameter of the first tab region 012 located on the outermost side is B, satisfying: B<A; and / or, the outer diameter of the second tab region 013 located on the outermost side is B', satisfying: B'<A.
[0094] Specifically, the outer diameter of the first pole lug area 012 located at the outermost side is B, satisfying: B<A, or, the outer diameter of the second pole lug area 013 located at the outermost side is B', satisfying: B'<A, or, the outer diameter of the first pole lug area 012 located at the outermost side is B, satisfying: B<A, and the outer diameter of the second pole lug area 013 located at the outermost side is B', satisfying: B'<A.
[0095] In this embodiment, through the above-mentioned arrangement, on the one hand, the outer diameters of the first pole lug area 012 and the second pole lug area 013 can be controlled to facilitate the entry of the core 001 into the shell; on the other hand, the electrolyte can infiltrate the electrode through the outer diameter side of the first pole lug area 012 and the outer diameter of the second pole lug area 013, thereby further increasing the area of direct contact between the electrolyte and the electrode, and further improving the infiltration efficiency of the core 001.
[0096] In addition, through the above arrangement, there can be space for thermal expansion on the outer peripheral side of the first tab area 012 and the outer side of the second tab area 013, thereby reducing the stress on the first tab 121 and the second tab 131 after thermal expansion, thereby improving the reliability of the battery cell.
[0097] In another embodiment, the second tab 131 is disposed at the first end 1111. Multiple layers of second tabs 131 are bent and stacked at the first end 1111 to form a second tab region 013. The first tab-free region 1121 is located between the first tab region 012 and the second tab region 013.
[0098] In one embodiment, along the radial direction of the winding core 001 , the width of the first tab-free region 1111 is W1 , and the unit thickness of the winding core body 011 is d0 , which satisfies the following relationship: 2d0 ≤ W1 ≤ 8d0 .
[0099] The unit thickness d0 of the winding core body 011 is the sum of the thickness of a first electrode piece, the thickness of a diaphragm, the thickness of a second electrode piece, and the thickness of another diaphragm.
[0100] 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, and 8d0.
[0101] In this embodiment, through the above-mentioned setting, on the one hand, W1 can be made to have an appropriate size to facilitate the flow of electrolyte in the first tab-free area 1111 and to cover more pole pieces in the radial direction of the core 001; on the other hand, it can avoid W1 being too large, resulting in a smaller total area of the first tab area 012, so that the total area of the first tab 121 can meet the current collection requirements of the core 001, and the core 001 can have an appropriate internal resistance.
[0102] See also Figure 8 , Figure 8 Schematic diagram of the structure of a battery cell 002 provided in an embodiment of the present application. Accordingly, an embodiment of the present application provides a battery cell 002 comprising a housing 021, a cover plate 022, and the aforementioned winding core 001; the cover plate 022 and the housing 021 are combined to define a receiving cavity; the winding core 001 is disposed within the receiving cavity.
[0103] In this embodiment, by adopting the aforementioned winding core 001, the electrolyte can directly penetrate the electrode at the center of the winding core thickness through the first tab-free area 1111, thereby improving the wetting efficiency of the electrode at the center of the winding core thickness, and further improving the wetting efficiency of the battery cell 002.
[0104] See also Figure 9 , Figure 9 003 is a schematic diagram of the structure of a battery 003 provided in an embodiment of the present application. The embodiment of the present application provides a battery 003, and the battery 003 includes the aforementioned battery cell 002.
[0105] It can be understood that the battery 003 may also include a box or a base plate, and the battery cell 002 is arranged in the box, or the battery cell 002 is installed on the base plate.
[0106] In this embodiment, by using the aforementioned battery cell 002, the electrolyte can directly penetrate the electrode sheet at the center of the core thickness through the first tab-free region 1111, thereby improving the wetting efficiency of the electrode sheet at the center of the core thickness, and further improving the wetting efficiency of the battery cell 002. As a result, the wetting efficiency of the battery 003 can be improved.
[0107] The above is a detailed introduction to the embodiments of the present application. Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method and core idea of the present application. At the same time, for those skilled in the art, based on the ideas of the present application, there may be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.
Claims
1. A winding core, characterized in that: include: A winding core body, comprising a first pole piece, a diaphragm, and a second pole piece wound together, wherein the diaphragm is located between the first pole piece and the second pole piece, the first pole piece and the second pole piece have opposite polarities, and the winding core body has a first end and a second end along the axial direction of the winding core; A first electrode tab is provided at the first end portion and connected to the first electrode piece, wherein multiple layers of the first electrode tabs are bent and stacked at the first end portion to form a first electrode tab region; a second pole lug connected to the second pole piece; The first end portion is further provided with a first tab-free area, and the first tab-free area is configured to allow electrolyte to flow into the interior of the winding core body; A midpoint of the radius of the first end portion is located within the first tab-free region.
2. The winding core according to claim 1, characterized in that The first electrode-free lug region comprises three first electrode-free lug regions, and a 1 / 4 point of the radius, a midpoint of the radius, and a 3 / 4 point of the radius of the first end portion are respectively located in the three first electrode-free lug regions.
3. The winding core according to claim 1, characterized in that The first tab region is annular, and there are a plurality of the first tab regions, which are coaxially arranged, and the annular space between two adjacent first tab regions forms the first tab-free region; The second tab is disposed at the second end portion, and multiple layers of the second tab are bent and stacked on the second end portion to form a plurality of annular second tab regions, wherein the plurality of second tab regions are coaxially disposed; and an annular space between two adjacent second tab regions forms a second tab-free region; Wherein, along the axial direction of the winding core, the first tab-free region is at least partially arranged opposite to the second tab region.
4. The winding core according to claim 3, characterized in that Along the radial direction of the winding core, the width of the first tab-free region and the second tab-free region at opposite locations along the axial direction of the winding core is W2, and the width of the first tab-free region is W1, satisfying: 10% W1≤W2.
5. The winding core according to claim 3, characterized in that Along the axial direction of the winding core, the second tab-free region is at least partially arranged opposite to the first tab region.
6. The winding core according to claim 5, characterized in that Along the radial direction of the winding core, the width of the second tab-free region and the first tab-free region at the portion opposite to each other along the axial direction of the winding core is W4, and the width of the second tab-free region is W3, satisfying: 10% W4≤W3.
7. The winding core according to claim 3, characterized in that A midpoint of the radius of the second end portion is located in the second tab-free region.
8. The winding core according to claim 3, characterized in that The second end portion comprises three second tab-free regions, and a 1 / 4 point of the radius, a midpoint of the radius, and a 3 / 4 point of the radius of the second end portion are respectively located in the three second tab-free regions.
9. The winding core according to claim 3, characterized in that Along the radial direction of the winding core, the width of the second tab-free area is W3, and the unit thickness of the winding core body is d0, satisfying: 2d0≤W3≤8d0, wherein d0 is the sum of the thickness of the first pole piece, the thickness of the diaphragm, the thickness of the second pole piece and the thickness of another diaphragm.
10. The winding core according to claim 3, characterized in that The diameter of the middle hole of the winding core is φ, and the inner diameter of the first tab region located on the innermost side is C, satisfying: C≤φ; And / or, the inner diameter of the second tab region located at the innermost side is C', satisfying: C'≤φ.
11. The winding core according to claim 3, characterized in that The outer diameter of the winding core body is A, and the outer diameter of the first tab region located on the outermost side is B, satisfying: B<A; And / or, the outer diameter of the second tab region located at the outermost side is B', satisfying: B'<A.
12. The winding core according to claim 1, characterized in that The second tab is disposed at the first end portion, and multiple layers of the second tab are bent and stacked on the first end portion to form a second tab region. The first tab-free region is located between the first tab region and the second tab region.
13. The winding core according to any one of claims 1 to 12, characterized in that: Along the radial direction of the winding core, the width of the first tab-free area is W1, and the unit thickness of the winding core body is d0, satisfying: 2d0≤W1≤8d0, wherein d0 is the sum of the thickness of the first pole piece, the thickness of the diaphragm, the thickness of the second pole piece and the thickness of another diaphragm.
14. A battery cell, characterized in that: include: case; a cover plate, covering the shell to define a receiving cavity; And, the winding core according to any one of claims 1 to 13 is arranged in the accommodating cavity.
15. A battery, characterized in that: Comprising the battery cell as claimed in claim 14.