Winding battery cell and battery with same

Abstract

The invention provides a winding battery cell and a battery with the winding battery cell. The winding battery cell comprises a first pole piece, a second pole piece and a diaphragm, wherein the first pole piece, the diaphragm and the second pole piece are laminated and are wound along the winding direction to form the winding battery cell; the inner ring and the outer ring of the first pole piece are respectively provided with a plurality of first tabs and at least one second tab, and the number of the first tabs is greater than that of the second tabs; and a third tab is arranged on the second pole piece. According to the winding battery cell provided by the embodiment of the invention, the plurality of first tabs and the at least one second tab are respectively arranged on the inner ring and the outer ring of the first pole piece, and the number of the first tabs is larger than that of the second tabs, so that the internal resistance of the inner ring of the first pole piece is smaller than that of the outer ring of the first pole piece; the heating rate of the inner ring of the first pole piece is smaller than that of the outer ring of the first pole piece. Therefore, the winding battery cell provided by the embodiment of the invention has the effect of balancing the temperature rise rate of each internal region.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to a wound battery core and a battery having the same. Background Art

[0002] The battery including the wound cell in the related art generates heat during use. Since the heat dissipation capacity of the inner ring of the wound cell is smaller than that of the outer ring of the wound cell, the temperature rise rate of the inner ring of the wound cell is greater than that of the outer ring of the wound cell, resulting in an unbalanced temperature rise rate (temperature rise) in the wound cell, which leads to a low safety performance of the wound cell. Summary of the invention

[0003] In view of the problem of unbalanced internal temperature rise rate of wound battery cells in the related art, an embodiment of the present invention provides a wound battery cell and a battery having the same.

[0004] The wound battery cell of the embodiment of the present invention comprises a first pole piece, a second pole piece and a separator, wherein the first pole piece, the separator and the second pole piece are stacked and wound along a winding direction to form the wound battery cell; The inner circle and the outer circle of the first pole piece are respectively provided with a plurality of first pole lugs and at least one second pole lug, and the number of the first pole lugs is greater than the number of the second pole lugs; The second pole piece is provided with a third pole lug.

[0005] It can be understood that a dividing line can be assumed on the first pole piece to separate the inner circle and the outer circle of the first pole piece. In the winding direction, the first pole piece between the starting end of the first pole piece and the dividing line serves as the inner circle of the first pole piece, and the first pole piece between the tail end of the first pole piece and the dividing line serves as the outer circle of the first pole piece. As for the position of the dividing line on the first pole piece, it can be determined according to actual needs.

[0006] The wound battery cell of the embodiment of the present invention is provided with multiple first pole ears and at least one second pole ear on the inner circle and outer circle of the first pole piece, respectively, and the number of first pole ears is set to be greater than the number of second pole ears. As a result, the internal resistance of the inner circle of the first pole piece is smaller than the internal resistance of the outer circle of the first pole piece, so that the heating rate of the inner circle of the first pole piece is smaller than the heating rate of the outer circle of the first pole piece.

[0007] It can be understood that the heat dissipation rate of the inner circle of the first pole piece is lower than the heat dissipation rate of the outer circle of the first pole piece. Based on this, the temperature rise rate of the inner circle of the first pole piece can be balanced with the temperature rise rate of the outer circle of the first pole piece, thereby making the temperature rise rates of the inner and outer circles of the battery cell equal, thereby achieving the effect of balancing the internal temperature rise rate of the battery cell.

[0008] Therefore, the wound battery cell of the embodiment of the present invention has the effect of balancing the temperature increase rate of each internal region.

[0009] In some embodiments, in the winding direction, the ratio of the length of the outer circle of the first pole piece to the length of the inner circle of the first pole piece is 3-1.

[0010] In some embodiments, a plurality of the first pole tabs are spaced apart along the length direction of the first pole piece.

[0011] In some embodiments, the first electrode tab and the second electrode tab are connected to form a first polarity electrode tab.

[0012] In some embodiments, the third electrode tab is single or multiple, and the single or multiple third electrode tabs form a second polarity electrode tab.

[0013] In some embodiments, the first electrode tab and the second electrode tab are stacked in a thickness direction of the wound battery core; The third electrode tab is staggered with the first electrode tab and the second electrode tab in the width direction of the wound battery core.

[0014] In some embodiments, the first electrode sheet is a positive electrode sheet or a negative electrode sheet.

[0015] In some embodiments, the first electrode tab is a die-cut electrode tab or a welded electrode tab, and / or, The second pole tab is a die-cut pole tab or a welded pole tab.

[0016] In some embodiments, the first pole tab is a die-cut pole tab, and the second pole tab is a welded pole tab. The first pole tab is bent toward the second pole tab, and a free end of the first pole tab is connected to the second pole tab.

[0017] An embodiment of the present invention further provides a battery, comprising the wound battery cell as described in the above embodiment. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

[0019] Figure 1 is a schematic structural diagram of a wound battery cell according to an embodiment of the present invention; Figure 2 is a schematic diagram of the expansion of the first pole piece of an embodiment of the present invention; Figure 3Schematic diagram of the connection between the first electrode tab and the second electrode tab in an embodiment of the present invention.

[0020] In the figure: 1. The first pole piece; 2. The second pole piece; 3. Diaphragm; 4. The first tab; 5. Second pole ear; 6. The third pole ear. DETAILED DESCRIPTION

[0021] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0022] In the description of the present invention, it should be understood that the terms "longitudinal", "radial", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0023] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be glue injection inside two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0024] The following attached Figure 1-2 A wound battery cell according to an embodiment of the present invention is described.

[0025] like Figure 1 As shown, the wound battery cell of the embodiment of the present invention comprises a first pole piece 1, a second pole piece 2 and a separator 3, and the first pole piece 1, the separator 3 and the second pole piece 2 are stacked and wound along a winding direction to form a wound battery cell; like Figure 1 As shown, the inner circle and the outer circle of the first pole piece 1 are respectively provided with a plurality of first pole tabs 4 and at least one second pole tab 5, and the number of the first pole tabs 4 is greater than the number of the second pole tabs 5; like Figure 1 As shown, a third pole lug 6 is provided on the second pole piece 2 .

[0026] It can be understood that a dividing line can be assumed on the first pole piece 1 to separate the inner circle and the outer circle of the first pole piece 1. In the winding direction, the portion of the first pole piece 1 between the starting end of the first pole piece 1 and the dividing line serves as the inner circle of the first pole piece 1, and the portion of the first pole piece 1 between the tail end of the first pole piece 1 and the dividing line serves as the outer circle of the first pole piece 1. As for the position of the dividing line on the first pole piece 1, it can be determined according to actual needs.

[0027] The wound battery cell of the embodiment of the present invention is provided with a plurality of first pole ears 4 and at least one second pole ear 5 on the inner circle and the outer circle of the first pole piece 1, respectively, and the number of the first pole ears 4 is set to be greater than the number of the second pole ears 5. Thus, the internal resistance of the inner circle of the first pole piece 1 is smaller than the internal resistance of the outer circle of the first pole piece 1, so that the heating rate of the inner circle of the first pole piece 1 is smaller than the heating rate of the outer circle of the first pole piece 1.

[0028] It can be understood that the heat dissipation rate of the inner circle of the first pole piece 1 is lower than the heat dissipation rate of the outer circle of the first pole piece 1. Based on this, the temperature rise rate of the inner circle of the first pole piece 1 can be balanced with the temperature rise rate of the outer circle of the first pole piece 1, thereby making the temperature rise rates of the inner circle and the outer circle of the battery cell equal, thereby achieving the effect of balancing the internal temperature rise rate of the battery cell.

[0029] Therefore, the wound battery cell of the embodiment of the present invention has the effect of balancing the temperature increase rate of each internal region.

[0030] In some embodiments, in the winding direction, the ratio of the length of the outer circle of the first pole piece 1 to the length of the inner circle of the first pole piece 1 is 3-1. In other words, in the winding direction, the ratio of the distance between the end of the first pole piece 1 and the dividing line to the distance between the starting end of the first pole piece 1 and the dividing line is 3-1.

[0031] For example, the ratio of the length of the outer circle of the first pole piece 1 to the length of the inner circle of the first pole piece 1 is 1, that is, the length of the outer circle of the first pole piece 1 is equal to the length of the inner circle of the second pole piece 2 .

[0032] For example, the ratio of the length of the outer circle of the first pole piece 1 to the length of the inner circle of the first pole piece 1 is 3, the length of the outer circle of the first pole piece 1 accounts for 3 / 4 of the length of the first pole piece 1, and the length of the inner circle of the first pole piece 1 accounts for 1 / 4 of the length of the second pole piece 2.

[0033] It can be understood that the ratio of the length of the outer circle of the first pole piece 1 to the length of the inner circle of the first pole piece 1 can be set according to actual needs.

[0034] In some embodiments, Figure 2 As shown, a plurality of first pole tabs 4 are arranged at intervals along the length direction of the first pole piece 1 .

[0035] It can be understood that the first pole piece 1 is wound along a winding direction, that is, the winding direction is from the starting end of the first pole piece 1 to the end of the first pole piece 1 .

[0036] In order to enable the first pole tabs 4 to be spaced apart in the thickness direction of the wound battery cell after the first pole sheet 1 is wound to form a wound battery cell, the spacing between adjacent first pole tabs 4 can be set to gradually increase along the winding direction of the first pole sheet 1 in the length direction of the first pole sheet 1.

[0037] In some embodiments, the first electrode tab 4 and the second electrode tab 5 are connected to form a first polarity electrode tab.

[0038] Further, the first pole tab 4 is a die-cut pole tab or a welded pole tab, and / or the second pole tab 5 is a die-cut pole tab or a welded pole tab.

[0039] In other words, when the first electrode tab 4 is a die-cut electrode tab, the second electrode tab 5 can be a die-cut electrode tab or a welded electrode tab.

[0040] When the first electrode tab 4 is a welded electrode tab, the second electrode tab 5 may be a die-cut electrode tab or a welded electrode tab.

[0041] Therefore, the first pole tab 4 and the second pole tab 5 of the wound battery cell of the embodiment of the present invention may be arranged in any of the following ways.

[0042] First, the first pole ear 4 is a die-cut pole ear, and the second pole ear 5 is a die-cut pole ear; Second, the first pole ear 4 is a die-cut pole ear, and the second pole ear 5 is a welded pole ear; Third, the first pole ear 4 is a welded pole ear, and the second pole ear 5 is a die-cut pole ear; Fourthly, the first pole tab 4 is a welded pole tab, and the second pole tab 5 is a welded pole tab.

[0043] Furthermore, the first pole tab 4 is a die-cut pole tab, and the second pole tab 5 is a welded pole tab.

[0044] By using the first electrode tab 4 as a die-cut electrode tab, the internal resistance of the first electrode tab 4 can be further reduced, and thus the internal resistance of the first electrode sheet 1 can be further reduced.

[0045] The winding structure of the embodiment of the present invention is described below by assuming that the first pole tab 4 is a die-cut pole tab and the second pole tab 5 is a welded pole tab.

[0046] like Figure 3 As shown, the first pole tab 4 is bent toward the second pole tab 5 , and the free end of the first pole tab 4 is connected to the second pole tab 5 , thereby the first pole tab 4 and the second pole tab 5 form a first polarity pole tab.

[0047] Preferably, the first pole tab 4 and the second pole tab 5 are connected by welding.

[0048] In some embodiments, the third electrode tab 6 is single or multiple, and the single or multiple third electrode tabs 6 form a second polarity electrode tab.

[0049] In some embodiments, Figure 1 As shown, the first pole tab 4 and the second pole tab 5 are stacked in the thickness direction of the wound battery cell; the third pole tab 6 is staggered with the first pole tab 4 and the second pole tab 5 in the width direction of the wound battery cell.

[0050] For example, when the third pole tab 6 is single, the third pole tab 6 can be arranged on any side of the first pole tab 4 and the second pole tab 5 in the width direction of the wound battery cell. Thus, the wound battery cell of the embodiment of the present invention can be manufactured into a battery with a two-pole tab structure.

[0051] For example, when there are two third pole tabs 6, the two third pole tabs 6 can be arranged on both sides of the first pole tab 4 and the second pole tab 5 in the width direction of the wound battery cell. Thus, the wound battery cell of the embodiment of the present invention can be manufactured into a battery with a three-pole tab structure.

[0052] In some embodiments, the first electrode sheet 1 is a positive electrode sheet or a negative electrode sheet.

[0053] When the first electrode sheet 1 is a positive electrode sheet, the first electrode sheet 1 is provided with a first electrode ear 4 and a second electrode ear 5 so that the internal resistance of the first electrode sheet 1 is smaller than the internal resistance of the second electrode sheet 2, that is, the internal resistance of the positive electrode sheet is smaller than the internal resistance of the negative electrode sheet, thereby greatly improving the fast discharge performance of the battery cell, so that the battery cell can meet the use scenario of high-power discharge.

[0054] When the first electrode sheet 1 is a negative electrode sheet, the first electrode sheet 1 is provided with a first electrode ear 4 and a second electrode ear 5 so that the internal resistance of the first electrode sheet 1 is smaller than the internal resistance of the second electrode sheet 2, that is, the internal resistance of the negative electrode sheet is smaller than the internal resistance of the positive electrode sheet, thereby greatly improving the fast charging performance of the battery cell, so that the battery cell can meet the usage scenario of fast charging.

[0055] An embodiment of the present invention further provides a battery, comprising the wound battery cell described in the above embodiment.

[0056] The embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included in the protection scope of the present invention.

Claims

1. A wound battery cell, characterized in that: The wound battery cell comprises a first pole piece (1), a second pole piece (2) and a diaphragm (3), wherein the first pole piece (1), the diaphragm (3) and the second pole piece (2) are stacked and wound along a winding direction to form the wound battery cell; The inner ring and the outer ring of the first pole piece (1) are respectively provided with a plurality of first pole lugs (4) and at least one second pole lug (5), and the number of the first pole lugs (4) is greater than the number of the second pole lugs (5); The second pole piece (2) is provided with a third pole lug (6).

2. The wound battery cell according to claim 1, characterized in that: In the winding direction, the ratio of the length of the outer circle of the first pole piece (1) to the length of the inner circle of the first pole piece (1) is 3-1.

3. The wound battery cell according to claim 1, characterized in that: A plurality of the first pole tabs (4) are arranged at intervals along the length direction of the first pole piece (1).

4. The wound battery cell according to claim 1, characterized in that: The first pole tab (4) and the second pole tab (5) are connected to form a first polarity pole tab.

5. The wound battery cell according to claim 1, characterized in that: The third pole lug (6) is single or multiple, and the single or multiple third pole lugs (6) form a second polarity pole lug.

6. The wound battery cell according to claim 1, characterized in that: The first pole tab (4) and the second pole tab (5) are stacked in a thickness direction of the wound battery core; The third pole tab (6) is arranged staggered with the first pole tab (4) and the second pole tab (5) in the width direction of the wound battery cell.

7. The wound battery cell according to claim 1, characterized in that: The first electrode (1) is a positive electrode or a negative electrode.

8. The wound battery cell according to claim 1, characterized in that: The first electrode tab (4) is a die-cut electrode tab or a welded electrode tab, and / or, The second pole tab (5) is a die-cut pole tab or a welded pole tab.

9. The wound battery cell according to claim 6, characterized in that: The first pole lug (4) is a die-cut pole lug, and the second pole lug (5) is a welded pole lug. The first pole lug (4) is bent towards the second pole lug (5), and a free end of the first pole lug (4) is connected to the second pole lug (5).

10. A battery, characterized in that: It comprises a wound battery cell as described in any one of claims 1 to 9.

Images