Battery cell and battery

Abstract

The invention discloses a battery cell and a battery, and relates to the technical field of batteries. The battery cell comprises a shell, a roll core, a first tab group and a second tab group, and the roll core comprises a positive plate, a diaphragm and a negative plate; the first tab group comprises a first positive tab and a first negative tab, one end of the first positive tab is electrically connected with the positive plate, the other end of the first positive tab is located outside the shell, one end of the first negative tab is electrically connected with the negative plate, and the other end of the first negative tab is located outside the shell; the winding core comprises a plurality of winding layers which are stacked in the thickness direction; the second tab group comprises at least one of a second positive tab and a second negative tab, and under the condition that the second tab group comprises the second positive tab, the first positive tab and the second positive tab are positioned on different winding layers of the plurality of winding layers; and under the condition that the second tab group comprises the second negative tab, the first negative tab and the second negative tab are positioned on different winding layers of the plurality of winding layers.

Description

Technical Field

[0001] This application relates to the field of battery technology, specifically to a battery cell and a battery. Background Technology

[0002] With the development of electronic products, the capacity of batteries in these products is increasing. A major way to increase battery capacity is to increase the length of the electrode plates. However, this also leads to thicker battery cells, resulting in poor heat dissipation. Existing battery cells typically include one positive and one negative electrode. As the electrode plates become longer, uneven current distribution within the battery can easily occur, leading to longer charging times and higher charging temperatures. Summary of the Invention

[0003] This application provides a battery cell and a battery that can solve the problems of long charging time and large charging temperature rise caused by uneven current distribution in related technologies.

[0004] Firstly, a battery cell is provided, comprising:

[0005] A housing, wherein a receiving cavity is provided within the housing;

[0006] A core, wherein the core is disposed within the accommodating cavity, the core comprising a positive electrode sheet, a separator and a negative electrode sheet stacked sequentially, and the core is in a wound shape;

[0007] The first electrode group includes a first positive electrode and a first negative electrode. One end of the first positive electrode is electrically connected to the positive electrode sheet, and the other end of the first positive electrode is located outside the housing. One end of the first negative electrode is electrically connected to the negative electrode sheet, and the other end of the first negative electrode is located outside the housing. The winding core includes a plurality of winding layers stacked along the thickness direction.

[0008] The second tab group includes at least one of a second positive tab and a second negative tab. When the second tab group includes a second positive tab, one end of the second positive tab is electrically connected to the positive electrode plate, and the other end of the second positive tab is located outside the housing. The first positive tab and the second positive tab are located in different winding layers of the plurality of winding layers. When the second tab group includes a second negative tab, one end of the second negative tab is electrically connected to the negative electrode plate, and the other end of the second negative tab is located outside the housing. The first negative tab and the second negative tab are located in different winding layers of the plurality of winding layers.

[0009] In a second aspect, a battery is provided, comprising the cell described in the first aspect.

[0010] In this embodiment, by including a first tab group and a second tab group in the battery cell, the battery cell can be charged and discharged simultaneously through both groups, thus improving the uniformity of current distribution within the cell. Furthermore, by positioning the first positive tab and the second positive tab at different winding layers of the plurality of winding layers when the second tab group includes the second positive tab, and the first negative tab and the second negative tab at different winding layers when the second tab group includes the second negative tab, the distance between two tabs of the same polarity can be avoided. This helps reduce the overall internal resistance of the winding core, thereby reducing the charging time and temperature rise during charging. Attached Figure Description

[0011] Figure 1 This is one of the structural schematic diagrams of a battery cell provided in this application;

[0012] Figure 2 yes Figure 1 A schematic diagram of the internal winding structure of the battery cell;

[0013] Figure 3 yes Figure 1 Top view of point A in the diagram;

[0014] Figure 4 yes Figure 1 Side view;

[0015] Figure 5 yes Figure 4 A magnified view of point B in the diagram;

[0016] Figure 6 This is the second schematic diagram of the structure of a battery cell provided in this application;

[0017] Figure 7 yes Figure 6 A schematic diagram of the internal winding structure of the battery cell;

[0018] Figure 8 yes Figure 6 Top view at point C;

[0019] Figure 9 yes Figure 6 Side view;

[0020] Figure 10 yes Figure 9 A magnified view of point D in the diagram. Detailed Implementation

[0021] The technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.

[0022] The terms "first," "second," etc., used in this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first" and "second" are generally of the same class, not limited in number; for example, the first object can be one or more. Furthermore, "or" in this application indicates at least one of the connected objects. For example, the scope of protection for "A or B" covers at least three scenarios: Scenario 1: including A but not B; Scenario 2: including B but not A; Scenario 3: including both A and B. In addition, the terms "A and / or B," "at least one of A and B," and "at least one of A or B" also cover at least the above three scenarios. The character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0023] The following description, in conjunction with the accompanying drawings, details the battery cells and batteries provided in the embodiments of this application through some examples and application scenarios.

[0024] Please see Figures 1 to 10 This application provides a battery cell, including a housing 200, wherein the housing 200 has a receiving cavity 210.

[0025] The core 100 is disposed in the accommodating cavity 210. The core 100 includes a positive electrode sheet 110, a separator 120 and a negative electrode sheet 130 stacked in sequence, and the core 100 is in a wound shape.

[0026] The first tab group 300 includes a first positive tab 310 and a first negative tab 320. One end of the first positive tab 310 is electrically connected to the positive electrode plate 110, and the other end of the first positive tab 310 is located outside the housing 200. One end of the first negative tab 320 is electrically connected to the negative electrode plate 130, and the other end of the first negative tab 320 is located outside the housing 200. The core 100 includes a plurality of winding layers 140 stacked along the thickness direction.

[0027] A second tab assembly 400 includes at least one of a second positive tab 410 and a second negative tab 420. When the second tab assembly 400 includes the second positive tab 410, one end of the second positive tab 410 is electrically connected to the positive electrode 110, and the other end of the second positive tab 410 is located outside the housing 200. The first positive tab 310 and the second positive tab 410 are located in different winding layers 140 of the plurality of winding layers 140. When the second tab assembly 400 includes the second negative tab 420, one end of the second negative tab 420 is electrically connected to the negative electrode 130, and the other end of the second negative tab 420 is located outside the housing 200. The first negative tab 320 and the second negative tab 420 are located in different winding layers 140 of the plurality of winding layers 140.

[0028] The aforementioned battery cell can be used as a battery cell in various electronic devices. The aforementioned housing 200 can be an aluminum-plastic film shell for the battery cell.

[0029] The aforementioned core 100 can be formed by flattening the stacked positive electrode sheet 110, separator 120 and negative electrode sheet 130, and then winding the core 100 from one end in the length direction to the other end in the length direction. That is, one end of the core 100 in the length direction is located at the innermost end of the core 100, and the other end of the core 100 in the length direction is located at the outermost end of the core 100.

[0030] Please see Figure 2 The aforementioned winding layer 140 is the winding core 100 along the... Figure 2 The portion extending along the x-axis, i.e., the thickness direction. Figure 2 The z-axis direction is shown in the diagram. Since the core 100 is formed by winding a stack of positive electrode 110, separator 120, and negative electrode 130 arranged in sequence, the core 100 includes three sub-layers: positive electrode 110, separator 120, and negative electrode 130. Correspondingly, the winding layer 140 is part of the length direction of the core 100; therefore, the winding layer 140 also includes three sub-layers. It is understood that each winding layer 140 includes a separator layer in the middle and positive electrode layers and negative electrode layers on both sides of the separator layer. The separator layer is a portion of the separator 120, the positive electrode layer is the region of the positive electrode 110 covering one side of the separator layer, and the negative electrode layer is the region of the negative electrode 130 covering the other side of the separator layer.

[0031] Since the purpose of providing two positive tabs in this embodiment is to reduce the internal resistance of the positive electrode 110, if the two positive tabs are too close together, some areas of the positive electrode 110 will be far from both tabs, resulting in a still relatively high internal resistance. Therefore, in this embodiment, when the second tab group 400 includes the second positive tab 410, by placing the first positive tab 310 and the second positive tab 410 in different winding layers 140 of the plurality of winding layers 140, the distance between the first positive tab 310 and the second positive tab 410 can be avoided from being too close, thereby helping to reduce the internal resistance of the positive electrode 110.

[0032] Accordingly, since the purpose of providing two negative tabs in this embodiment is to reduce the internal resistance of the negative electrode 130, if the two negative tabs are too close together, some areas of the negative electrode 130 will be far from both tabs, resulting in a still relatively high internal resistance in the negative electrode 130. Therefore, in this embodiment, when the second tab group 400 includes the second negative tab 420, by placing the first negative tab 320 and the second negative tab 420 in different winding layers 140 of the plurality of winding layers 140, the distance between the first negative tab 320 and the second negative tab 420 can be avoided from being too close, thereby helping to reduce the internal resistance in the negative electrode 130.

[0033] The first positive electrode tab 310 and the second positive electrode tab 410 being located in different winding layers 140 of the plurality of winding layers 140 can refer to the connection positions of the first positive electrode tab 310 and the positive electrode plate 110 and the second positive electrode tab 410 and the positive electrode plate 110 being located in different winding layers 140 of the plurality of winding layers 140. Correspondingly, the first negative electrode tab 320 and the second negative electrode tab 420 being located in different winding layers 140 of the plurality of winding layers 140 can refer to the connection positions of the first negative electrode tab 320 and the negative electrode plate 130 and the second negative electrode tab 420 and the negative electrode plate 130 being located in different winding layers 140 of the plurality of winding layers 140.

[0034] One end of the first positive tab 310 can be welded to the positive electrode plate 110, and the other end of the first positive tab 310 can extend out of the housing 200. The first positive tab 310 is encapsulated with the housing 200, that is, the housing 200 surrounds the side wall of the first positive tab 310 and is attached to the side wall of the first positive tab 310. The housing 200 can be fixedly connected to the side wall of the first positive tab 310 by tab adhesive 160 to achieve the encapsulation of the first positive tab 310 and the housing 200.

[0035] Accordingly, one end of the first negative electrode tab 320 can be welded to the negative electrode sheet 130, and the other end of the first negative electrode tab 320 can extend out of the housing 200. The first negative electrode tab 320 is encapsulated with the housing 200, that is, the housing 200 surrounds the side wall of the first negative electrode tab 320 and is attached to the side wall of the first negative electrode tab 320. The housing 200 can be fixedly connected to the side wall of the first negative electrode tab 320 by the tab adhesive 160 to achieve the encapsulation of the first negative electrode tab 320 and the housing 200.

[0036] In the case where the second tab assembly 400 includes a second positive tab 410, one end of the second positive tab 410 can be welded to the positive electrode plate 110, and the other end of the second positive tab 410 can extend beyond the housing 200. The second positive tab 410 is encapsulated with the housing 200, that is, the housing 200 surrounds the side wall of the second positive tab 410 and is attached to the side wall of the second positive tab 410. The housing 200 can be fixedly connected to the side wall of the second positive tab 410 by tab adhesive 160 to achieve the encapsulation of the second positive tab 410 and the housing 200.

[0037] In the case where the second tab assembly 400 includes a second negative tab 420, one end of the second negative tab 420 can be welded to the negative electrode sheet 130, and the other end of the second negative tab 420 can extend beyond the housing 200. The second negative tab 420 is encapsulated with the housing 200, that is, the housing 200 surrounds the side wall of the second negative tab 420 and is attached to the side wall of the second negative tab 420. The housing 200 can be fixedly connected to the side wall of the second negative tab 420 by tab adhesive 160 to achieve the encapsulation of the second negative tab 420 with the housing 200.

[0038] Understandably, when the aforementioned second electrode assembly 400 includes a second positive electrode 410, the first positive electrode 310 and the second positive electrode 410 are respectively connected to different positions along the length of the positive electrode 110. This allows current at different positions within the positive electrode 110 to flow out through the closer positive electrode, or external current to simultaneously flow to different positions within the positive electrode 110 through the first positive electrode 310 and the second positive electrode 410, thereby improving the uniformity of current distribution within the positive electrode 110. Correspondingly, when the aforementioned second electrode assembly 400 includes a second negative electrode 420, the first negative electrode 320 and the second negative electrode 420 are respectively connected to different positions along the length of the negative electrode 130, thereby improving the uniformity of current distribution within the negative electrode 130.

[0039] The aforementioned battery cell may further include a protection board, which may include solder pads. The protection board may be fixedly connected to the open end of the housing 200. The tabs in the first tab group 300 and the tabs in the second tab group 400 extend out of the housing 200 from one end of the open end. The tabs in the first tab group 300 and the tabs in the second tab group 400 are electrically connected to the solder pads in the protection board.

[0040] In some embodiments of this application, the battery cell may be a three-tab battery cell, and the second tab group 400 includes a second positive tab 410, that is, the three tabs of the battery cell are a first positive tab 310, a second positive tab 410 and a first negative tab 320, wherein the second positive tab 410 is a separate positive tab design, while the first positive tab 310 and the first negative tab 320 are stacked together as a whole.

[0041] In some embodiments of this application, the battery cell may be a three-tab battery cell, and the second tab group 400 includes a second negative tab 420. That is, the three tabs of the battery cell are a first positive tab 310, a second negative tab 420 and a first negative tab 320, wherein the second negative tab 420 is a separate positive tab design, while the first positive tab 310 and the first negative tab 320 are stacked together as a whole.

[0042] In some embodiments of this application, the battery cell may be a four-tab battery cell, and the second tab group 400 includes a second positive tab 410 and a second negative tab 420. That is, the four tabs of the battery cell are a first positive tab 310, a first negative tab 320, a second negative tab 420 and a second positive tab 410, wherein the second negative tab 420 and the second positive tab 410 are stacked together as a whole, and the first positive tab 310 and the first negative tab 320 are stacked together as a whole.

[0043] In this embodiment, by including a first tab group 300 and a second tab group 400 in the battery cell, the battery cell can be charged and discharged simultaneously through both the first tab group 300 and the second tab group 400, thus improving the uniformity of current distribution within the battery cell. Furthermore, by positioning the first positive tab 310 and the second positive tab 410 at different winding layers 140 of the plurality of winding layers 140 when the second tab group 400 includes the second negative tab 420, and by positioning the first negative tab 320 and the second negative tab 420 at different winding layers 140 of the plurality of winding layers 140, the distance between two tabs of the same polarity can be avoided. This helps reduce the overall internal resistance of the winding core, thereby reducing the charging time and the temperature rise during charging.

[0044] Optionally, the second electrode group 400 includes a second positive electrode 410 and a second negative electrode 420, wherein the first positive electrode 310 and the first negative electrode 320 are arranged along the thickness direction of the core 100, and the second positive electrode 410 and the second negative electrode 420 are arranged along the thickness direction.

[0045] The first tab group 300 and the second tab group 400 are staggered in the width direction of the core 100.

[0046] The aforementioned width direction can be a direction perpendicular to both the thickness direction and the length direction of the core 100. Please refer to [link / reference]. Figure 2 In some embodiments of this application, the thickness direction is... Figure 2 The z-axis direction, the width direction is... Figure 2 The x-axis direction in the figure, the length direction is... Figure 2 The y-axis direction in the diagram.

[0047] In this embodiment, since the second tab group 400 includes the second positive tab 410 and the second negative tab 420, that is, the battery cell includes two positive tabs and two negative tabs, the current distribution on the positive electrode plate 110 and the negative electrode plate 130 can be more uniform, thereby reducing the resistance of the battery cell and thus reducing the charging temperature rise and charging time. In addition, by staggering the first tab group 300 and the second tab group 400 in the width direction of the core 100, the first tab group 300 and the second tab group 400 can be staggered in the width direction of the battery cell, which facilitates the electrical connection of the two tab groups to different pads in the protection board. At the same time, it can also avoid the problem of short circuits between the tabs inside the first tab group 300 and the second tab group 400 due to the first tab group 300 and the second tab group 400 being too close.

[0048] Optionally, please see Figures 1 to 5 The core 100 includes a plurality of winding layers 140 stacked along the thickness direction, wherein the first positive electrode tab 310 and the first negative electrode tab 320 are located in the same winding layer 140 of the core 100; and the second positive electrode tab 410 and the second negative electrode tab 420 are located in the same winding layer 140 of the core 100.

[0049] The first positive electrode tab 310 and the first negative electrode tab 320 being located in the same winding layer 140 of the core 100 means that the first positive electrode tab 310 and the first negative electrode tab 320 are respectively electrically connected to the sub-layer where the positive electrode 110 is located and the sub-layer where the negative electrode 130 is located in the same winding layer 140. That is, the first positive electrode tab 310 is electrically connected to the positive electrode 110 in the winding layer 140, and the first negative electrode tab 320 is electrically connected to the negative electrode 130 in the winding layer 140.

[0050] Accordingly, the second positive electrode tab 410 and the second negative electrode tab 420 being located in the same winding layer 140 of the core 100 means that the second positive electrode tab 410 and the second negative electrode tab 420 are respectively electrically connected to the sub-layer where the positive electrode 110 is located and the sub-layer where the negative electrode 130 is located in the same winding layer 140, that is, the second positive electrode tab 410 is electrically connected to the positive electrode 110 in the winding layer 140, and the second negative electrode tab 420 is electrically connected to the negative electrode 130 in the winding layer 140.

[0051] In this embodiment, by making the core 100 include a plurality of winding layers 140 stacked along the thickness direction, the first positive electrode tab 310 and the first negative electrode tab 320 are located in the same winding layer 140 of the core 100; the second positive electrode tab 410 and the second negative electrode tab 420 are located in the same winding layer 140 of the core 100, so that during the process of connecting the first positive electrode tab 310 and the first negative electrode tab 320 to the core 100, part of the adhesive layer 150 can be reused, thereby helping to reduce the overall thickness of the core 100.

[0052] Optionally, please see Figure 2 The diaphragm 120 includes a first region 121, a second region 122, a third region 123, a fourth region 124, a fifth region 125, and a sixth region 126. The first region 121, the second region 122, and the third region 123 are respectively located in three adjacent layers of a plurality of layers arranged along the thickness direction of the diaphragm 120. The first positive electrode tab 310 is located between the first region 121 and the second region 122, and the first negative electrode tab 320 is located between the second region 122 and the third region 123.

[0053] The fourth region 124, the fifth region 125 and the sixth region 126 are respectively located in three adjacent layers of the multiple layers arranged along the thickness direction of the diaphragm 120, and the second positive electrode tab 410 is located between the fourth region 124 and the fifth region 125, and the second negative electrode tab 420 is located between the fifth region 125 and the sixth region 126.

[0054] The first region 121 has adhesive layers 150 on both sides, the second region 122 has adhesive layers 150 on both sides, the third region 123 has adhesive layers 150 on both sides, the fourth region 124 has adhesive layers 150 on both sides, the fifth region 125 has adhesive layers 150 on both sides, and the sixth region 126 has adhesive layers 150 on both sides.

[0055] It is understood that the aforementioned adhesive layer 150 can be a green adhesive layer or an adhesive layer 150 formed from various film adhesive sheets, and the adhesive layer 150 can bond the two layers on both sides. For example, the adhesive layer 150 located between the positive electrode 110 and the separator 120 can bond and fix the positive electrode 110 and the separator 120. As another example, the adhesive layer 150 located between the first positive electrode tab 310 and the separator 120 can bond and fix the separator 120 and the first positive electrode tab 310. In this way, by setting the above six adhesive layers 150, the stability of the connection between the first electrode tab group 300, the second electrode tab group 400 and the core 100 can be improved.

[0056] In this embodiment, since two adhesive layers 150 are required to connect both sides of each tab, and each tab group includes two tabs, if the two tabs in the same tab group are not located on the same winding layer 140, eight adhesive layers 150 will be required for the same tab group. However, in this embodiment, by placing the two tabs in the same tab group on the same winding layer 140, the two tabs in the same tab group can share the two adhesive layers 150 located between them, thereby reducing the number of adhesive layers 150. Since the tab is located at the thickest point of the core 100, the cell thickness will be reduced by 10µm to 26µm at the tab location, and the height difference at the welding position will also be reduced, which is expected to improve the problem of purple spot lithium plating at the welding position.

[0057] Optionally, please see Figures 6 to 10 The core 100 includes a plurality of winding layers 140 stacked along the thickness direction. The first positive electrode tab 310 and the first negative electrode tab 320 are located in different winding layers 140 of the core 100, and the second positive electrode tab 410 and the second negative electrode tab 420 are located in different winding layers 140 of the core 100.

[0058] Please see Figure 7Since the first positive tab 310 and the first negative tab 320 are located on different winding layers 140 of the core 100, and the second positive tab 410 and the second negative tab 420 are also located on different winding layers 140 of the core 100, a certain gap exists between the first positive tab 310 and the second negative tab 420. This prevents a short circuit between the first positive tab 310 and the first negative tab 320 due to excessive proximity. Correspondingly, a certain gap exists between the second positive tab 410 and the second negative tab 420. This also prevents a short circuit between the second positive tab 410 and the second negative tab 420 due to excessive proximity.

[0059] The spacing between the first positive electrode tab 310 and the first negative electrode tab 320 can be configured as needed. For example, the first positive electrode tab 310 and the first negative electrode tab 320 can be connected to two adjacent winding layers 140, respectively. Alternatively, the first positive electrode tab 310 and the first negative electrode tab 320 can be spaced apart by one winding layer 140, or by two winding layers 140, etc. Correspondingly, the spacing between the second positive electrode tab 410 and the second negative electrode tab 420 can be configured as needed. For example, the second positive electrode tab 410 and the second negative electrode tab 420 can be connected to two adjacent winding layers 140, respectively. Alternatively, the second positive electrode tab 410 and the second negative electrode tab 420 can be spaced apart by one winding layer 140, or by two winding layers 140, etc.

[0060] In this embodiment, by making the core 100 include a plurality of winding layers 140 stacked along the thickness direction, the first positive tab 310 and the first negative tab 320 are located in different winding layers 140 of the core 100, and the second positive tab 410 and the second negative tab 420 are located in different winding layers 140 of the core 100, the problem of short circuit between the first positive tab 310 and the first negative tab 320 due to being too close can be avoided. At the same time, the problem of short circuit between the second positive tab 410 and the second negative tab 420 due to being too close can be avoided, thereby improving the safety of the battery cell.

[0061] Optionally, the diaphragm 120 includes a seventh region 127, an eighth region 128, a ninth region 129, a tenth region 1210, an eleventh region 1211, a twelfth region 1212, a thirteenth region 1213, and a fourteenth region 1214. The seventh region 127 and the eighth region 128 are located in two adjacent layers of the multiple layers of the diaphragm 120 arranged along the thickness direction. The ninth region 129 and the tenth region 1210 are located in two adjacent layers of the multiple layers of the diaphragm 120 arranged along the thickness direction. The eleventh region 1211 and the twelfth region 1212 are located in two adjacent layers of the multiple layers of the diaphragm 120 arranged along the thickness direction. The thirteenth region 1213 and the fourteenth region 1214 are located in two adjacent layers of the multiple layers of the diaphragm 120 arranged along the thickness direction.

[0062] The first positive electrode 310 is located between the seventh region 127 and the eighth region 128, the first negative electrode 320 is located between the ninth region 129 and the tenth region 1210, the second positive electrode 410 is located between the eleventh region 1211 and the twelfth region 1212, and the second negative electrode 420 is located between the thirteenth region 1213 and the fourteenth region 1214.

[0063] The seventh region 127 has adhesive layers 150 on both sides, the eighth region 128 has adhesive layers 150 on both sides, the ninth region 129 has adhesive layers 150 on both sides, the tenth region 1210 has adhesive layers 150 on both sides, the eleventh region 1211 has adhesive layers 150 on both sides, the twelfth region 1212 has adhesive layers 150 on both sides, the thirteenth region 1213 has adhesive layers 150 on both sides, and the fourteenth region 1214 has adhesive layers 150 on both sides.

[0064] It is understood that the aforementioned adhesive layer 150 can be a green adhesive layer or an adhesive layer 150 formed from various film adhesive sheets, and the adhesive layer 150 can bond the two layers on both sides. For example, the adhesive layer 150 located between the positive electrode 110 and the separator 120 can bond and fix the positive electrode 110 and the separator 120. As another example, the adhesive layer 150 located between the first positive electrode tab 310 and the separator 120 can bond and fix the separator 120 and the first positive electrode tab 310. In this way, by setting the above six adhesive layers 150, the stability of the connection between the first electrode tab group 300, the second electrode tab group 400 and the core 100 can be improved.

[0065] In this embodiment, by providing adhesive layers 150 on both sides of the seventh region 127, the eighth region 128, the ninth region 129, the tenth region 1210, the eleventh region 1211, the twelfth region 1212, the thirteenth region 1213, and the fourteenth region 1214, the stability of the connection between the first tab group 300, the second tab group 400, and the winding core 100 can be improved.

[0066] It should be noted that the number of electrodes and the stacking method in the first electrode group 300 and the second electrode group 400 can be, in addition to adopting, the following methods can be used. Figure 2 and Figure 7 Besides the quantity and stacking method shown, other quantities and stacking methods are also possible. For example, the battery cell can be a three-tab battery cell, and the tabs in the first tab group 300 can also be stacked with the tabs in the second tab group 400 in the thickness direction of the core 100. For ease of understanding, this application further explains the quantity and stacking method of the tabs with some embodiments:

[0067] Optionally, the second electrode group 400 includes a second positive electrode 410 and a second negative electrode 420, wherein the first positive electrode 310 and the second positive electrode 410 are arranged along the thickness direction of the core 100, and the first negative electrode 320 and the second negative electrode 420 are arranged along the thickness direction of the core 100; the first positive electrode 310 and the first negative electrode 320 are staggered in the width direction of the core 100; or,

[0068] The second electrode lug group 400 includes a second positive electrode lug 410, the first positive electrode lug 310 and the first negative electrode lug 320 are arranged along the thickness direction of the core 100, and the first positive electrode lug 310 and the second positive electrode lug 410 are staggered in the width direction of the core 100; or,

[0069] The second electrode assembly 400 includes a second positive electrode 410, the first positive electrode 310 and the second positive electrode 410 are arranged along the thickness direction of the core 100, and the first positive electrode 310 and the first negative electrode 320 are staggered in the width direction of the core 100; or,

[0070] The second electrode assembly 400 includes a second negative electrode 420. The first positive electrode 310 and the first negative electrode 320 are arranged along the thickness direction of the core 100, and the first positive electrode 310 and the second negative electrode 420 are staggered in the width direction of the core 100; or,

[0071] The second electrode group 400 includes a second negative electrode 420. The first negative electrode 320 and the second negative electrode 420 are arranged along the thickness direction of the core 100, and the first positive electrode 310 and the first negative electrode 320 are staggered in the width direction of the core 100.

[0072] In some embodiments of this application, the battery cell can be a four-tab battery cell. The second tab group 400 includes a second positive tab 410 and a second negative tab 420, that is, the four tabs of the battery cell are a first positive tab 310, a first negative tab 320, a second negative tab 420, and a second positive tab 410, respectively. The main difference between this embodiment and the above embodiment is that the first positive tab 310 and the second positive tab 410 are arranged along the thickness direction of the core 100, that is, the first positive tab 310 and the second positive tab 410 are stacked to form a whole. The first negative tab 320 and the second negative tab 420 are arranged along the thickness direction of the core 100, that is, the first negative tab 320 and the second negative tab 420 are stacked to form a whole. The first positive tab 310 and the first negative tab 320 are staggered in the width direction of the core 100. It should be noted that in the embodiments of this application, the connection and positional relationship between the stacked tabs and other parts of the core can be the same as in the above embodiments. To avoid repetition, it will not be described again here.

[0073] In some embodiments of this application, the battery cell can be a three-tab battery cell, and the second tab group 400 includes a second positive tab 410. That is, the three tabs of the battery cell are a first positive tab 310, a second positive tab 410, and a first negative tab 320, respectively. The second positive tab 410 is a separate positive tab design, while the first positive tab 310 and the first negative tab 320 are stacked as a whole. Specifically, the first positive tab 310 and the first negative tab 320 are arranged along the thickness direction of the core 100, and the first positive tab 310 and the second positive tab 410 are staggered along the width direction of the core 100. It should be noted that in the embodiments of this application, the connection and positional relationships between the stacked tabs and other parts of the core can be the same as in the above embodiments. To avoid repetition, these will not be described again here.

[0074] In some embodiments of this application, the battery cell may be a three-tab battery cell, and the second tab group 400 includes a second positive tab 410. That is, the three tabs of the battery cell are a first positive tab 310, a second positive tab 410, and a first negative tab 320, wherein the first negative tab 320 is a separate positive tab design, while the first positive tab 310 and the second positive tab 410 are stacked as a whole. That is, the first positive tab 310 and the second positive tab 410 are arranged along the thickness direction of the core 100, and the first positive tab 310 and the first negative tab 320 are staggered in the width direction of the core 100. It should be noted that in the embodiments of this application, the connection relationship and positional relationship between the stacked tabs and other parts of the core can be the same as those in the above embodiments. To avoid repetition, they will not be described again here.

[0075] In some embodiments of this application, the battery cell can be a three-tab battery cell, and the second tab group 400 includes a second negative tab 420. That is, the three tabs of the battery cell are a first positive tab 310, a second negative tab 420, and a first negative tab 320, respectively. The second negative tab 420 is a separate positive tab design, while the first positive tab 310 and the first negative tab 320 are stacked together as a whole. Specifically, the first positive tab 310 and the first negative tab 320 are arranged along the thickness direction of the core 100, and the first positive tab 310 and the second negative tab 420 are staggered along the width direction of the core 100. It should be noted that in the embodiments of this application, the connection and positional relationships between the stacked tabs and other parts of the core can be the same as in the above embodiments; to avoid repetition, they will not be described again here.

[0076] In some embodiments of this application, the battery cell can be a three-tab battery cell, and the second tab group 400 includes a second negative tab 420. That is, the three tabs of the battery cell are a first positive tab 310, a second negative tab 420, and a first negative tab 320, respectively. The first positive tab 310 is a separate positive tab design, while the second negative tab 420 and the first negative tab 320 are stacked together as a whole. Specifically, the first negative tab 320 and the second negative tab 420 are arranged along the thickness direction of the core 100, and the first positive tab 310 and the first negative tab 320 are staggered along the width direction of the core 100. It should be noted that in the embodiments of this application, the connection and positional relationships between the stacked tabs and other parts of the core can be the same as in the above embodiments; to avoid repetition, they will not be described again here.

[0077] In this embodiment, by designing the number and stacking method of the electrodes in the first electrode group 300 and the second electrode group 400, various forms of battery cells can be obtained, which is beneficial to adapting to various application scenarios.

[0078] Optionally, an insulating film layer 170 is provided on the end face of the first positive electrode 310 facing the first negative electrode 320, and / or, an insulating film layer 170 is provided on the end face of the first negative electrode 320 facing the first positive electrode 310.

[0079] An insulating film layer 170 is provided on the end face of the second positive electrode tab 410 facing the second negative electrode tab 420, and / or, an insulating film layer 170 is provided on the end face of the second negative electrode tab 420 facing the second positive electrode tab 410.

[0080] The insulating film layer 170 described above can be any flexible film layer capable of providing insulation. For example, in some embodiments of this application, the insulating film layer 170 can be a coating layer formed of polyethylene terephthalate (PET) film.

[0081] Specifically, at least one of the first end face of the first positive electrode 310 and the second end face of the first negative electrode 320 is provided with an insulating film layer 170. The first end face is the end face of the first positive electrode 310 facing the end of the first negative electrode 320, and the second end face is the end face of the first negative electrode 320 facing the end of the first positive electrode 310.

[0082] In the case where the second tab group 400 includes the second positive tab 410 and the second negative tab 420, at least one of the third end face of the second positive tab 410 and the fourth end face of the second negative tab 420 is provided with a second insulating film layer 170. The third end face is the end face of the second positive tab 410 facing the end of the second negative tab 420, and the fourth end face is the end face of the second negative tab 420 facing the end of the second positive tab 410.

[0083] It is understood that, in some embodiments of this application, the insulating film layer 170 may be provided only on the surface of one of the second end faces of the first negative electrode 320, or one insulating film layer 170 may be provided on both the first end face of the first positive electrode 310 and the second end face of the first negative electrode 320. Correspondingly, the insulating film layer 170 may be provided only on the surface of one of the third end face of the second positive electrode 410 and the fourth end face of the second negative electrode 420, or one insulating film layer 170 may be provided on both the third end face of the second positive electrode 410 and the fourth end face of the second negative electrode 420.

[0084] For ease of understanding, in this embodiment of the application, an insulating film layer 170 is provided on the first end face of the first positive electrode 310 and the second end face of the first negative electrode 320, and an insulating film layer 170 is provided on the third end face of the second positive electrode 410 and the fourth end face of the second negative electrode 420, respectively, to further explain the structure of the above-mentioned battery cell. The specific structure includes:

[0085] The aforementioned coated tabs are coated on one side only, with the other side being a metal surface, and the metal surface is in contact with and welded to the corresponding electrode sheet. Specifically, the first end face of the first positive tab 310 can be covered with a PET film, while the side of the first positive tab 310 facing away from the first end face can be a metal surface, and the first positive tab 310 can be in contact with and welded to the positive electrode sheet 110 through the side facing away from the first end face. Correspondingly, the second end face of the first negative tab 320 can also be covered with a PET film, while the side of the first negative tab 320 facing away from the second end face can be a metal surface, and the first negative tab 320 can be in contact with and welded to the negative electrode sheet 130 through the side facing away from the second end face. The third end face of the second positive tab 410 can be covered with a PET film, while the side of the second positive tab 410 facing away from the third end face can be a metal surface, and the second positive tab 410 can be in contact with and welded to the positive electrode sheet 110 through the side facing away from the third end face. The fourth end face of the second negative electrode tab 420 can also be covered with a PET film, and the side of the second negative electrode tab 420 facing away from the fourth end face can be a metal surface, and the second negative electrode tab 420 can be welded to the negative electrode sheet 130 through the side facing away from the fourth end face.

[0086] The PET film can be bonded to the first, second, third, and fourth end faces by hot pressing or adhesive bonding.

[0087] The thickness of the aforementioned insulating film layer 170 can range from 4µm to 10µm.

[0088] In this embodiment, by providing an insulating film layer 170 on the end face of the first positive electrode 310 facing the first negative electrode 320, and / or providing an insulating film layer 170 on the end face of the first negative electrode 320 facing the first positive electrode 310; and providing an insulating film layer 170 on the end face of the second positive electrode 410 facing the second negative electrode 420, and / or providing an insulating film layer 170 on the end face of the second negative electrode 420 facing the second positive electrode 410, the insulating film layer 170 located between the first positive electrode 310 and the first negative electrode 320 can separate the first positive electrode 310 and the first negative electrode 320, thereby avoiding the problem of short circuit due to the first positive electrode 310 and the first negative electrode 320 being too close. Meanwhile, since the insulating film layer 170 located between the second positive tab 410 and the second negative tab 420 can relatively separate the second positive tab 410 and the second negative tab 420, the problem of short circuit caused by the second positive tab 410 and the second negative tab 420 being too close can be avoided, which is conducive to improving the safety of the battery cell.

[0089] Optionally, when the second electrode group 400 includes the second positive electrode 410, the distance between the first positive electrode 310 and the second positive electrode 410 along the length direction of the core 100 ranges from L / 4 to 3L / 4.

[0090] When the second electrode group 400 includes the second negative electrode 420, the distance between the first negative electrode 320 and the second negative electrode 420 along the length direction of the core 100 ranges from L / 4 to 3L / 4.

[0091] Wherein, L is the length of the core 100.

[0092] Specifically, since the purpose of providing two positive tabs in this embodiment is to reduce the internal resistance of the battery cell, if the two positive tabs are too close together, some areas in the positive electrode 110 will be far from both positive tabs, resulting in a still relatively high internal resistance in the positive electrode 110. Therefore, in this embodiment, the distance between the first positive tab 310 and the second positive tab 410 along the length of the core 100 is set to a range of L / 4 to 3L / 4. This avoids the first positive tab 310 and the second positive tab 410 being too close, thereby helping to reduce the internal resistance in the positive electrode 110.

[0093] Accordingly, by making the distance between the first negative electrode tab 320 and the second negative electrode tab 420 along the length direction of the core 100 range from L / 4 to 3L / 4, it is possible to avoid the distance between the first negative electrode tab 320 and the second negative electrode tab 420 being too close, thereby helping to reduce the internal resistance in the negative electrode sheet 130.

[0094] In some embodiments of this application, the first positive electrode tab 310 is located at 1 / 4 of the length of the positive electrode sheet 110, and the second positive electrode tab 410 is located at 3 / 4 of the length of the positive electrode sheet 110. For example, the distance between the first positive electrode tab 310 and the beginning of the positive electrode sheet 110 is L / 4, and the distance between the second positive electrode tab 410 and the beginning of the positive electrode sheet 110 is 3L / 4. The beginning of the positive electrode sheet 110 is the end of the positive electrode sheet 110 located at the innermost side of the core 100. Accordingly, the first negative electrode tab 320 is located at 1 / 4 of the length of the negative electrode sheet 130, and the second negative electrode tab 420 is located at 3 / 4 of the length of the negative electrode sheet 130. For example, the distance from the first negative electrode tab 320 to the beginning of the negative electrode sheet 130 is L / 4, and the distance from the second negative electrode tab 420 to the beginning of the negative electrode sheet 130 is 3L / 4, wherein the beginning of the negative electrode sheet 130 is the end of the negative electrode sheet 130 located at the innermost side of the core 100. In this way, it can also be ensured that the first positive electrode tab 310 and the first negative electrode tab 320 are located in the same winding layer 140 of the core 100; the second positive electrode tab 410 and the second negative electrode tab 420 are located in the same winding layer 140 of the core 100.

[0095] In some embodiments of this application, the first tab group 300 and the second tab group 400 can be staggered relative to each other along the length of the winding layer 140. This allows the first tab group 300 and the second tab group 400 to extend from different positions within the housing 200. It should be noted that the distance from the first positive tab 310 to the beginning of the positive electrode 110 can also fluctuate around L / 4, and the distance from the second positive tab 410 to the beginning of the positive electrode 110 can also fluctuate around 3L / 4, so that the first tab group 300 and the second tab group 400 can be staggered relative to each other along the length of the winding layer 140. Alternatively, the length of each winding layer 140 can be adjusted to achieve the same staggered arrangement.

[0096] The length of the core 100 mentioned above refers to the distance between the two ends of the core 100 in the length direction after the core 100 is flattened.

[0097] In this embodiment, when the second tab group 400 includes the second positive tab 410, the distance between the first positive tab 310 and the second positive tab 410 along the length direction of the core 100 is in the range of L / 4 to 3L / 4; when the second tab group 400 includes the second negative tab 420, the distance between the first negative tab 320 and the second negative tab 420 along the length direction of the core 100 is in the range of L / 4 to 3L / 4. In this way, the distance between two tabs of the same polarity is avoided from being too close, which helps to reduce the overall internal resistance of the core 100, thereby reducing the charging time during the battery charging process and reducing the temperature rise during the charging process.

[0098] Optionally, the thickness range of the first positive electrode tab 310, the thickness range of the first negative electrode tab 320, the thickness range of the second positive electrode tab 410, and the thickness range of the second negative electrode tab 420 are all 50um to 100um.

[0099] In this embodiment, by making the thickness range of the first positive tab 310, the thickness range of the first negative tab 320, the thickness range of the second positive tab 410, and the thickness range of the second negative tab 420 all 50um to 100um, the problem of increasing the overall thickness of the battery cell due to excessive tab thickness can be avoided, while ensuring that the tabs have sufficient structural strength.

[0100] It should be noted that in this embodiment, by making the first tab group 300 and the second tab group 400 each consist of one positive tab and one negative tab, the positive tab and the negative tab can be arranged adjacently when the core 100 is welded inside the battery cell, that is, they can be arranged in the same winding layer 140. Thus, since the two tabs in the same tab group can share the adhesive layer 150 between them, it is beneficial to reduce the number of adhesive layers 150.

[0101] Please refer to Table 1 below, which describes some embodiments of this application. Figure 2 The illustrated embodiment Figure 7 The illustrated embodiment and two comparative examples from related technologies were tested, and the test results were compared. Comparative Example 1 shows a mid-mid-tab (MMT) structure in the related technology, where the MMT structure includes only one positive tab and one negative tab. Comparative Example 2 shows a multi-tab cell (SFC) structure in the related technology, where the SFC structure includes one positive tab and multiple small negative tabs formed by die-cutting the negative tab.

[0102] Table 1:

[0103]

[0104]

[0105] As shown in Table 1, considering fast charging, cost, and energy dissipation (ED), this application... Figure 2 and Figure 7 The performance of the two embodiments is superior to that of the two comparative examples.

[0106] This application also provides a battery, including the battery cell described in the above embodiments.

[0107] In this embodiment, since the battery includes the battery cell described in the above embodiments, the battery can realize all the processes of the battery cell in the above embodiments and has the same beneficial effects. To avoid repetition, it will not be described again here.

[0108] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.

Claims

1. A battery cell, characterized in that, include: A housing, wherein a receiving cavity is provided within the housing; A core, wherein the core is disposed within the accommodating cavity, the core comprising a positive electrode sheet, a separator and a negative electrode sheet stacked sequentially, and the core is in a wound shape; The first electrode group includes a first positive electrode and a first negative electrode. One end of the first positive electrode is electrically connected to the positive electrode sheet, and the other end of the first positive electrode is located outside the housing. One end of the first negative electrode is electrically connected to the negative electrode sheet, and the other end of the first negative electrode is located outside the housing. The winding core includes a plurality of winding layers stacked along the thickness direction. The second tab group includes at least one of a second positive tab and a second negative tab. When the second tab group includes a second positive tab, one end of the second positive tab is electrically connected to the positive electrode plate, and the other end of the second positive tab is located outside the housing. The first positive tab and the second positive tab are located in different winding layers of the plurality of winding layers. When the second tab group includes a second negative tab, one end of the second negative tab is electrically connected to the negative electrode plate, and the other end of the second negative tab is located outside the housing. The first negative tab and the second negative tab are located in different winding layers of the plurality of winding layers.

2. The battery cell according to claim 1, characterized in that, The second electrode group includes a second positive electrode and a second negative electrode. The first positive electrode and the first negative electrode are arranged along the thickness direction of the core, and the second positive electrode and the second negative electrode are arranged along the thickness direction. The first electrode group and the second electrode group are staggered in the width direction of the core.

3. The battery cell according to claim 2, characterized in that, The core includes a plurality of winding layers stacked along the thickness direction, wherein the first positive tab and the first negative tab are located in the same winding layer of the core; the second positive tab and the second negative tab are located in the same winding layer of the core.

4. The battery cell according to claim 3, characterized in that, The diaphragm includes a first region, a second region, a third region, a fourth region, a fifth region, and a sixth region. The first region, the second region, and the third region are respectively located in three adjacent layers of a plurality of layers arranged along the thickness direction of the diaphragm. The first positive electrode tab is located between the first region and the second region, and the first negative electrode tab is located between the second region and the third region. The fourth region, the fifth region, and the sixth region are respectively located in three adjacent layers of the multiple layers of the diaphragm arranged along the thickness direction, and the second positive electrode tab is located between the fourth region and the fifth region, and the second negative electrode tab is located between the fifth region and the sixth region; The first region has adhesive layers on both sides, the second region has adhesive layers on both sides, the third region has adhesive layers on both sides, the fourth region has adhesive layers on both sides, the fifth region has adhesive layers on both sides, and the sixth region has adhesive layers on both sides.

5. The battery cell according to claim 2, characterized in that, The core includes multiple winding layers stacked along the thickness direction, the first positive tab and the first negative tab are located in different winding layers of the core, and the second positive tab and the second negative tab are located in different winding layers of the core.

6. The battery cell according to claim 5, characterized in that, The diaphragm includes a seventh region, an eighth region, a ninth region, a tenth region, an eleventh region, a twelfth region, a thirteenth region, and a fourteenth region. The seventh region and the eighth region are located in two adjacent layers of the diaphragm arranged along the thickness direction. The ninth region and the tenth region are located in two adjacent layers of the diaphragm arranged along the thickness direction. The eleventh region and the twelfth region are located in two adjacent layers of the diaphragm arranged along the thickness direction. The thirteenth region and the fourteenth region are located in two adjacent layers of the diaphragm arranged along the thickness direction. The first positive electrode is located between the seventh region and the eighth region, the first negative electrode is located between the ninth region and the tenth region, the second positive electrode is located between the eleventh region and the twelfth region, and the second negative electrode is located between the thirteenth region and the fourteenth region; Adhesive layers are provided on both sides of the seventh region, the eighth region, the ninth region, the tenth region, the eleventh region, the twelfth region, the thirteenth region, and the fourteenth region.

7. The battery cell according to claim 1, characterized in that, The second electrode assembly includes a second positive electrode and a second negative electrode. The first positive electrode and the second positive electrode are arranged along the thickness direction of the core, and the first negative electrode and the second negative electrode are also arranged along the thickness direction of the core. The first positive electrode and the first negative electrode are staggered in the width direction of the core. Alternatively, The second electrode lug group includes a second positive electrode lug, and the first positive electrode lug and the first negative electrode lug are arranged along the thickness direction of the winding core, and the first positive electrode lug and the second positive electrode lug are staggered in the width direction of the winding core; or, The second electrode lug group includes a second positive electrode lug, the first positive electrode lug and the second positive electrode lug are arranged along the thickness direction of the winding core, and the first positive electrode lug and the first negative electrode lug are staggered in the width direction of the winding core; or, The second electrode group includes a second negative electrode, and the first positive electrode and the first negative electrode are arranged along the thickness direction of the core, and the first positive electrode and the second negative electrode are staggered in the width direction of the core; or, The second electrode group includes a second negative electrode, the first negative electrode and the second negative electrode are arranged along the thickness direction of the core, and the first positive electrode and the first negative electrode are staggered in the width direction of the core.

8. The battery cell according to any one of claims 1 to 7, characterized in that, An insulating film layer is provided on the end face of the first positive electrode tab facing the first negative electrode tab, and / or, an insulating film layer is provided on the end face of the first negative electrode tab facing the first positive electrode tab. An insulating film layer is provided on the end face of the second positive electrode tab facing the second negative electrode tab, and / or, an insulating film layer is provided on the end face of the second negative electrode tab facing the second positive electrode tab.

9. The battery cell according to any one of claims 1 to 7, characterized in that, When the second electrode group includes the second positive electrode, the distance between the first positive electrode and the second positive electrode along the length direction of the core ranges from L / 4 to 3L / 4. When the second electrode group includes the second negative electrode, the distance between the first negative electrode and the second negative electrode along the length direction of the core ranges from L / 4 to 3L / 4. Wherein, L is the length of the core.

10. The battery cell according to any one of claims 1 to 7, characterized in that, The thickness range of the first positive electrode tab, the thickness range of the first negative electrode tab, the thickness range of the second positive electrode tab, and the thickness range of the second negative electrode tab are all 50um to 100um.

11. A battery, characterized in that, Includes the battery cell described in any one of claims 1 to 10.

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