Button-type battery and electronic device

Abstract

To provide a button-type battery and an electronic device that improve the non-uniformity of dimensions at various locations of an electrode assembly in a button-type battery and improve the service life. 【Solution means】The button-type battery includes an electrode assembly, a first tab, and a second tab. The first current collector of the first electrode piece includes a first starting side and a first ending side, and the second electrode piece includes a second current collector. The line passing through the first starting side and the central axis of the electrode assembly is the first virtual line, the line passing through the central axis and perpendicular to the first virtual line is the second virtual line, the first connection segment of the first tab has a first center line, the second connection segment of the second tab has a second center line, the line connecting the first center line and the central axis is the third virtual line, the line connecting the second center line and the central axis is the fourth virtual line, and the relatively smaller of the angles formed by the third and fourth virtual lines is α1, and 90° ≤ α1 ≤ 180°.

Description

Technical Field

[0001] This application relates to the field of energy storage technologies, and in particular, to button-type batteries and electronic devices.

Background Art

[0002] A button-type battery is a device that converts external energy into electrical energy, stores it internally, and supplies power to external devices (such as portable electronic devices) when needed. Generally, a button-type battery includes a case, an electrode assembly housed in the case, and a tab. The electrode assembly includes a first pole piece, a second pole piece, and a separator. The first pole piece has the opposite polarity to the second pole piece, and a separator for isolation is arranged between them. The electrode assembly is wound in a spiral shape and housed in a columnar case.

Summary of the Invention

Problems to be Solved by the Invention

[0003] When the inventor of this application realized this application, when looking along the central axis around which the electrode assembly in the button-type battery is wound, the dimensions from the central axis to various places on the edge of the electrode assembly are non-uniform. As a result, during the manufacture and use of the electrode assembly, the pressures received at different places are also non-uniform. This causes the interface between the first pole piece and the second pole piece to deteriorate, resulting in a low capacity retention rate after repeating the preset number of charge and discharge cycles of the button-type battery, which affects the service life of the button-type battery.

[0004] The purpose of this application is to provide a button-type battery and an electronic device to improve the non-uniformity of the dimensions of each part of the electrode assembly in the button-type battery and improve the service life.

[0005] To solve its technical problems, this application adopts the following technical solutions.

[0006] The button-type battery includes an electrode assembly, a first tab, and a second tab. The electrode assembly includes a first electrode plate and a second electrode plate. The first electrode plate and the second electrode plate are laminated and spirally wound around a central axis. The extending direction of the central axis is the first direction, and the first direction is perpendicular to the winding direction. The first electrode plate includes a first current collector, and the first current collector includes a first starting side and a first ending side that are oppositely arranged in the winding direction. The second electrode plate includes a second current collector. When viewed from the first direction, a line passing through the first starting side and the central axis is defined as a first virtual line, and a line passing through the central axis and perpendicular to the first virtual line is defined as a second virtual line. The electrode assembly is divided into a first region, a second region, a third region, and a fourth region that are connected in order along the winding direction from the first starting side by the first virtual line and the second virtual line. The first tab includes a first connection segment that extends along the first direction and is connected to the first current collector, and the first connection segment includes a first center line that extends along the first direction. The second tab includes a second connection segment that extends along the first direction and is connected to the second current collector, and the second connection segment includes a second center line that extends along the first direction. When viewed from the first direction, a line connecting the first center line and the central axis is defined as a third virtual line, and a line connecting the second center line and the central axis is defined as a fourth virtual line. The third virtual line and the fourth virtual line are not simultaneously located in any one of the first region, the second region, the third region, and the fourth region. The smaller of the angles formed by the third virtual line and the fourth virtual line is α1, and 90° ≤ α1 ≤ 180°.

[0007] When 90° ≤ α1 ≤ 180°, the third virtual line and the fourth virtual line are not simultaneously located in any one of the first region, the second region, the third region, and the fourth region. There is an appropriate distance between the first tab and the second tab, which can improve the non-uniformity of the dimensions of the electrode assembly to which the first tab and the second tab are connected to a certain extent, greatly improve the cycle capacity retention rate of the button-type battery, and improve the service life.

[0008] In some embodiments, when viewed from the first direction, a semi-line passing through the first starting side with the central axis as an endpoint is defined as a first virtual semi-line, and at least one of the first connection segment and the second connection segment is arranged away from the first virtual semi-line.

[0009] When both the first connection segment and the second connection segment intersect the first virtual half-line, the arrangement of the first tab and the second tab causes the electrode assembly to generate an extrusion stress at this location, and the biasing force at this portion is transmitted to the tip of the first pole piece along the radial direction of the electrode assembly, which may cause the first active material layer to peel off near the first starting side. When neither the first connection segment nor the second connection segment intersects the first virtual half-line, the above risk can be effectively reduced. In addition, in other embodiments of the present application, only one of the first connection segment or the second connection segment may be separated from the first virtual half-line, whereby the above risk can also be reduced to a certain extent, and it is understood that it is only necessary to ensure that at least one of the first connection segment and the second connection segment is separated from the first virtual line.

[0010] In some embodiments, the third virtual line is located in the fourth region, and the fourth virtual line is located in the second region. By arranging in this way, the third virtual line and the fourth virtual line are located in the opposing regions and not in the same region as the first virtual half-line, the distance between them is far, which is advantageous for improving the flatness of the entire button-type battery.

[0011] In some embodiments, the first pole piece is a cathode piece, and the second pole piece is an anode piece.

[0012] In some embodiments, the second current collector includes a second starting side and a second ending side that are arranged to face each other in the winding direction. When viewed from the first direction, a half-line passing through the second starting side with the central axis as an endpoint is defined as the fifth virtual line, and a half-line passing through the first starting side with the central axis as an endpoint is defined as the first virtual half-line. The angle formed from the fifth virtual line along the winding direction to the first virtual half-line is α2, and 90° ≤ α2 ≤ 180°.

[0013] When α2 < 90°, it is relatively difficult to wind the electrode assembly around the winding core. Lithium precipitation exists at the tip of the second pole piece, and the cycle capacity retention rate of the button-type battery is low. When 90° ≤ α2 ≤ 180°, it is relatively easy to wind the electrode assembly around the winding core. The risk of lithium precipitation at the tip of the second pole piece is small, and the cycle capacity retention rate of the button-type battery is high.

[0014] In some embodiments, one of the first tab and the second tab is disposed in the fifth region. The fifth region is the region between the fifth virtual line and the first virtual half-line. Along the winding direction, the fifth virtual line, the fifth region, and the first virtual half-line are arranged in sequence.

[0015] Since the first arc portion is not disposed between the two innermost second arc portions, the first tab or the second tab is disposed in the fifth region, which is advantageous for achieving the balance of the dimensions of the entire electrode assembly.

[0016] In some embodiments, the second current collector includes a second starting side and a second ending side that are disposed opposite to each other in the winding direction. When viewed from the first direction, a half-line passing through the first ending side with the central axis as an endpoint is defined as the sixth virtual line, and a half-line passing through the second ending side with the central axis as an endpoint is defined as the seventh virtual line. The angle formed from the sixth virtual line to the seventh virtual line along the winding direction is α3, and 90° ≤ α3 ≤ 180°.

[0017] By arranging in this way, the first ending side and the second ending side are not located in the same region, which is advantageous for achieving the balance of the influence on the flatness of the entire button-type battery by the termination portions of the first current collector and the second current collector. It is also advantageous for reducing the influence of the cycle expansion of one of the pole pieces due to the too-close proximity of the first ending side and the second ending side on the reliability of the termination portion of the button-type battery.

[0018] In some embodiments, one of the first tab and the second tab is disposed in the sixth region. Here, the sixth region is the region between the sixth virtual line and the seventh virtual line, and along the winding direction, the sixth virtual line, the sixth region, and the seventh virtual line are arranged in sequence.

[0019] Since the third arc portion is not disposed between the two outermost fourth arc portions, the first tab or the second tab is disposed in the sixth region, which is advantageous for balancing the thickness of the entire electrode assembly.

[0020] In some embodiments, the sixth virtual line is located in the first region, and the seventh virtual line is located in the third region.

[0021] In some embodiments, the second current collector includes a second starting side and a second ending side that are disposed opposite to each other in the winding direction. When viewed from the first direction, a half-line passing through the second starting side with the central axis as an endpoint is defined as the fifth virtual line, and at least one of the first connection segment and the second connection segment is disposed away from the fifth virtual line. By arranging in this way, the risk of interface failure at the position corresponding to the fifth virtual line due to the first connection segment or the second connection segment overlapping the fifth virtual line can be reduced.

[0022] In some embodiments, when viewed from the first direction, a half-line passing through the first starting side with the central axis as an endpoint is defined as the first virtual half-line, and a half-line passing through the first ending side with the central axis as an endpoint is defined as the sixth virtual line. The relatively smaller one of the angles formed by the sixth virtual line and the first virtual half-line is α4, and 0° ≤ α4 ≤ 30°.

[0023] By arranging in this way, the positions of the first starting side and the first ending side can be aligned to balance the flatness of the button-type battery, and the amount of the first current collector can be prevented from being excessive, thereby reducing the cost.

[0024] In some embodiments, the first ending side is located in the first region. This is advantageous for forming an extrusion from the first ending side to the first starting side, and is advantageous for improving the flatness of the button-type battery.

[0025] In some embodiments, the second current collector includes a second starting side and a second ending side that are disposed opposite to each other in the winding direction. When viewed from the first direction, a line connecting the second starting side and the central axis is defined as a fifth virtual line, a line connecting the second ending side and the central axis is defined as a seventh virtual line, and the relatively smaller one of the angles formed by the fifth virtual line and the seventh virtual line is α5, where 0° ≤ α5 ≤ 30°.

[0026] By arranging in this way, the positions of the second starting side and the second ending side can be aligned to balance the flatness of the button-type battery, and the second current collector can be prevented from being excessive, thereby reducing the cost.

[0027] In some embodiments, the first current collector includes a first non-coated segment and a second non-coated segment. The first starting side is disposed as a side of the first non-coated segment, the first ending side is disposed as a side of the second non-coated segment, and the first connecting segment is connected to the second non-coated segment. The arrangement of the first non-coated segment is advantageous for clamping the first current collector and for manufacturing the inner circumference of the winding of the button-type battery. The arrangement of the second non-coated segment is advantageous for connecting the first connecting segment and for reducing the influence of the first connection on the flatness of the button-type battery.

[0028] In some embodiments, the second current collector includes a second starting side and a second ending side that are disposed opposite to each other in the winding direction. The second current collector includes a third non-coated segment and a fourth non-coated segment. The second starting side is disposed as a side of the third non-coated segment, the second ending side is disposed as a side of the fourth non-coated segment, and the second connecting segment is connected to the fourth non-coated segment. The arrangement of the third non-coated segment is advantageous for clamping the second current collector and for manufacturing the inner circumference of the winding of the button-type battery. The arrangement of the fourth non-coated segment is advantageous for connecting the second connecting segment and for reducing the influence of the second connection on the flatness of the button-type battery.

[0029] In some embodiments, the electrode assembly includes a separator that separates the first and second electrode plates.

[0030] In some embodiments, the thickness of the first tab is 20 μm to 100 μm, and the thickness of the second tab is 20 μm to 100 μm. This is advantageous for balancing the overcurrent requirements of the first and second tabs and the impact on the flatness of the button cell.

[0031] To solve its technical problems, the present application also adopts the following technical solutions.

[0032] An electronic device including the above-described button cell. Since it includes the above-described button cell, the electronic device can improve the cycle capacity retention rate of the button cell and extend its service life.

Brief Description of the Drawings

[0033] To more clearly illustrate the technical solutions of the embodiments of the present application, the necessary drawings described in the following embodiments will be briefly described. The drawings described below are merely a part of the embodiments of the present application, and it is obvious that other drawings can be obtained based on the structures shown in these drawings.

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Embodiments for Carrying Out the Invention

[0034] For the convenience of understanding the present application, the following will refer to the drawings and specific embodiments to describe the present application in more detail. In addition, when it is described that an element is "fixed" / "adhered" to another element, the certain element may be directly present on the other element, or there may be elements arranged between one or more of them. When it is described that an element is "connected" to another element, the certain element may be directly connected to the other element, or there may be one or more elements arranged between them. The terms "vertical", "horizontal", "left", "right", "inside", "outside" and similar notations used in this specification are for illustrative purposes only.

[0035] Unless otherwise stated, all technical and scientific terms used in this specification have the same meaning as commonly understood by those skilled in the art belonging to the present application. The terms used in the specification of the present application are for the purpose of merely explaining specific embodiments and are not intended to limit the present application. Terms such as "and / or" used in this specification refer to any and all combinations of one or more of the related listed items.

[0036] In addition, the technical features according to different embodiments of the present application described below may be combined with each other as long as they do not conflict with each other.

[0037] In this specification, the above-mentioned "mounting" includes fixing or restricting a certain element or device to a specific position or location by means such as welding, screwing, engaging, sticking, etc. The element or device may remain immovable at the specific position or location, or may move within a limited range. After the element or device is fixed or restricted to a specific position or location, it may or may not be detached. It is not limited to the embodiments of the present application.

[0038] Referring to FIGS. 1 to 3, FIG. 1(A) shows a schematic diagram of a button-type battery 1 provided in an embodiment of the present application, FIG. 1(B) shows a schematic cross-sectional view along the illustrated M-M of the button-type battery, FIG. 2 shows a schematic view when looking along the illustrated first direction Z of the electrode assembly 200, and FIG. 3 shows a schematic view with the separator in FIG. 2 hidden. The button-type battery 1 includes an electrode assembly 200, a first tab 300, and a second tab 400. Here, the electrode assembly 200 is a core component for realizing the charge and discharge of the button-type battery 1. The first tab 300 is connected to the electrode assembly 200 and constitutes one pole of the button-type battery 1, and the second tab 40 is connected to the electrode assembly 200 and constitutes the other pole of the button-type battery 1. Further, the button-type battery 1 further includes a case 100 for accommodating the above-described electrode assembly 200, the first tab 300, the second tab 400, and the electrolyte. To better understand the button-type battery 1, subsequently, the specific structures of the case 100, the electrode assembly 200, the first tab 300, and the second tab 400 will be described in order.

[0039] Referring to FIG. 1, the case 100 is a mounting base and a container for other parts in the button-type battery 1. In this embodiment, the case 100 is generally columnar in shape and includes a first wall portion 110, a second wall portion 120, and a connecting wall portion 130. Both the first wall portion 110 and the second wall portion 120 are flat and columnar in shape, and the two are arranged opposite to each other along the illustrated first direction Z. The connecting wall portion 130 extends from the first wall portion 110 to the second wall portion 120, and the first wall portion 110, the second wall portion 120, and the connecting wall portion 130 together are surrounded as an accommodation chamber for accommodating the above-described electrode assembly 200, the first tab 300, and the second tab 400.

[0040] Specifically, referring to FIG. 2, the electrode assembly 200 generally exhibits a columnar structure and includes a first pole piece 210, a second pole piece 220, and a separator 230. The first pole piece 210 and the second pole piece 220 are stacked and arranged on the separator 230 and spirally wound around the central axis O. A separator 230 for isolation is disposed between the first pole piece 210 and the second pole piece 220. It should be noted that the electrode assembly 200 generally exhibits a columnar structure. The meaning of the "central axis" described in the text of this application is the axis of the electrode assembly 200 in a wound state. The "first direction Z" described in the text of this application is the extending direction of the central axis O and is perpendicular to the winding direction W of the electrode assembly 200. FIG. 2 is a view seen from the first direction Z. Each related element of the button-type battery appears as a planar shape in this view. For example, the central axis O appears as a point. The method for determining the central axis O may be as follows. An image of the electrode assembly 200 is acquired from the first direction Z, the image is processed, a circumcircle of the electrode assembly 200 is drawn, and the line along which the center of this circumcircle extends in the first direction Z is the central axis O. Next, an example in which the first pole piece 210 is a cathode piece and the second pole piece 220 is an anode piece will be used to describe the electrode assembly 200. However, in other embodiments of this application, it is understood that the first pole piece 210 may be an anode piece, and correspondingly, the second pole piece 220 may be a cathode piece.

[0041] Regarding the above-mentioned first electrode tab 210, specifically referring to FIGS. 4 and 5, a schematic diagram and a plan view of the first electrode tab 210 in an unfolded state are shown respectively. At the same time, with reference to FIGS. 1 and 2, the first electrode tab 210 includes a first current collector 211 and a first active material layer 212 coated on the surface of the first current collector 211. The first current collector 211 includes a first starting side 2101 and a first ending side 2102 arranged oppositely along the illustrated second direction X, and two first long sides 2103 arranged oppositely along the illustrated third direction Y. The first electrode tab 210 is wound around the first starting side 2101, that is, the first electrode tab includes a first starting side 2101 and a first ending side 2102 arranged oppositely along the winding direction W of the electrode assembly 200 shown in FIG. 3. When the first electrode tab 210 is in a wound state, the above-mentioned first long side 2103 extends along the winding direction W. The first starting side 2101 is the side located at the central position of the first electrode tab 210 of the first current collector 211, and the first ending side 2102 is the side located outside the outer periphery of the first electrode tab 210 in the first current collector 211. When the first electrode tab 210 is in an unfolded state, the first long side 2103 extends along the second direction X. More specifically, the first current collector 211 includes a first coated segment 2111, a first uncoated segment 2112, and a second uncoated segment 2113. Along the winding direction W of the electrode assembly 200 from the first starting side 2101 to the first ending side 2102, the first uncoated segment 2112, the first coated segment 2111, and the second uncoated segment 2113 are arranged in sequence. The first coated segment 2111 is an area where the first active material layer 212 is arranged on both sides, and the first uncoated segment 2112 and the second uncoated segment 2113 are areas where the first active material layer 212 is not arranged on at least one side. The above-mentioned first starting side 2101 is arranged as the side of the first uncoated segment 2112, that is, the first uncoated segment 2112 is located in the area approaching the inner circumference of the electrode assembly 200 in a wound state. The above-mentioned first ending side 2102 is arranged as the side of the second uncoated segment 2113, that is, the second uncoated segment 2113 is located in the area approaching the outer circumference of the electrode assembly 200 in a wound state.Note that the meaning of the "winding direction W" described in the text of this application is the extending direction from the inside to the outside in the wound state of the electrode assembly 200. For example, when viewed along the first direction Z, the first pole piece 210 extends from the first starting side 2101 to the first ending side 2102 along the winding direction W.

[0042] Regarding the second electrode tab 220, specifically referring to FIGS. 6 and 7, a schematic diagram and a plan view of the second electrode tab 220 in an unfolded state are shown respectively. At the same time, with reference to FIGS. 1 and 2, the second electrode tab 220 includes a second current collector 221 and a second active material layer 222 coated on the surface of the second current collector 221. Here, the second current collector 221 includes a second starting side 2201 and a second ending side 2202 that are oppositely arranged along the illustrated second direction X, and two second long sides 2203 that are oppositely arranged along the illustrated third direction Y. The second electrode tab 220 is wound around the second starting side 2201, that is, the second electrode tab includes the second starting side 2201 and the second ending side 2202 that are oppositely arranged along the winding direction W of the electrode assembly 200 shown in FIG. 3. When the second electrode tab 220 is in a wound state, the second long side 2203 extends along the winding direction W. The second starting side 2201 is the side located at the central position of the second electrode tab 220 of the second current collector 221, and the second ending side 2202 is the side located outside the outer periphery of the second electrode tab 220 in the second current collector 221. When the second electrode tab 220 is in an unfolded state, the second long side 2203 extends along the second direction X. More specifically, the second current collector 221 includes a second coating segment 2211, a third non - coating segment 2212, and a fourth non - coating segment 2213. Along the winding direction W from the second starting side 2201 to the second ending side 2202, the third non - coating segment 2212, the second coating segment 2211, and the fourth non - coating segment 2213 are arranged in sequence. Here, the second coating segment 2211 is the area where the second active material layer 222 is arranged on both sides, and the third non - coating segment 2212 and the fourth non - coating segment 2213 are the areas where the second active material layer 222 is not arranged on at least one side. The second starting side 2201 is arranged as the side of the third non - coating segment 2212, that is, the third non - coating segment 2212 is located in the area approaching the inner circumference of the electrode assembly 200 in a wound state. The second ending side 2202 is arranged as the side of the fourth non - coating segment 2213, that is, the fourth non - coating segment 2213 is located in the area approaching the outer circumference of the electrode assembly 200 in a wound state.

[0043] Also, with reference to FIGS. 2 and 3, the innermost circumference of the wound electrode assembly 200 is a portion of the second pole piece 220. That is, when viewed from the first direction Z, one end of the second pole piece 220 located in the central area of the electrode assembly 200 exceeds one end of the first pole piece 210 located in the central area of the electrode assembly 200. The outermost circumference of the wound electrode assembly 200 is a portion of the second pole piece 220. That is, when viewed from the first direction Z, one end of the second pole piece 220 away from the central area of the electrode assembly 200 exceeds one end of the first pole piece 210 away from the central area of the electrode assembly 200.

[0044] Regarding the first tab 300, referring to FIG. 3, FIG. 3 shows a schematic diagram after hiding the separator 230 in FIG. 2, and the first tab 300 is connected to the first pole piece 210. Specifically, the first tab 300 includes a first connection segment 310 and a first extending segment 320 that are sequentially arranged along the first direction Z. Here, the first connection segment 310 extends along the first direction Z and is connected to the first current collector 211. In this embodiment, the first connection segment 310 is connected to the second non-coated segment 2113. The first extending segment 320 is connected to the first connection segment 310 and is located outside the first current collector 211. The first connection segment 310 has a first center line P that extends along the first direction Z. When viewed along the first direction Z, the first center line P passes through the center point of the first tab 300. Preferably, the thickness of the first tab 300 is 20 μm to 100 μm. By arranging it in this way, while the overcurrent requirement of the button-type battery 1 can be satisfied, it can be ensured that the electrode assembly 200 has appropriate flatness, that is, the balance between the overcurrent requirement and the flatness of the electrode assembly 200 can be achieved.

[0045] Next, referring to FIG. 3, the second tab 400 is connected to the second current collector 220. Specifically, the second tab 400 includes a second connection segment 410 and a second extending segment 420 that are sequentially arranged along the first direction Z. The second connection segment 410 extends along the first direction Z and is connected to the second current collector 221. In this embodiment, the second connection segment 410 is connected to the fourth non-coated segment 2213. The second extending segment 420 is connected to the second connection segment 410 and is located outside the second current collector 221. The second connection segment 410 has a second center line Q that extends along the first direction Z. When viewed along the first direction Z, the second center line Q passes through the center point of the second tab 400. Preferably, the thickness of the second tab 400 is 20 μm to 100 μm. By arranging it in this way, while the overcurrent requirement of the button-type battery 1 can be satisfied, it can be ensured that the electrode assembly 200 has appropriate flatness, that is, the balance between the overcurrent requirement and the flatness of the electrode assembly can be achieved.

[0046] To better understand the electrode assembly 200, it is defined as follows. Referring to FIG. 3, when viewed from the first direction Z, a straight line passing through the central axis O and the first starting side 2101 is defined as the first virtual line a, a straight line passing through the central axis O and perpendicular to the first virtual line a is defined as the second virtual line b. When viewed along the first direction Z, the electrode assembly 200 is divided by the first virtual line a and the second virtual line b into a first region A, a second region B, a third region C, and a fourth region D that are sequentially connected along the winding direction W from the first starting side 2101. There are no overlapping regions among the first region A, the second region B, the third region C, and the fourth region D. The four coordinate axes formed by the first virtual line a and the second virtual line b respectively belong to the first region A, the second region B, the third region C, and the fourth region D. The first starting side 2101 belongs to the first region A. It is understood that the next coordinate axis along the winding direction W from the first starting side 2101 belongs to the second region B, and the next coordinate axis along the reverse direction of the winding direction W from the first starting side 2101 belongs to the fourth region D. When viewed along the first direction Z, a half-line passing through the first starting side 2101 with the central axis O as an endpoint is defined as the first virtual half-line a'. When viewed along the first direction Z, a half-line passing through the first center line P with the central axis O as an endpoint is defined as the third virtual line c. When viewed along the first direction Z, a half-line passing through the second center line Q with the central axis O as an endpoint is defined as the fourth virtual line d. When viewed along the first direction Z, a half-line passing through the second starting side 2201 with the central axis O as an endpoint is defined as the fifth virtual line e. When viewed along the first direction Z, a half-line passing through the first ending side 2102 with the central axis O as an endpoint is defined as the sixth virtual line f. When viewed along the first direction Z, a half-line passing through the second ending side 2202 with the central axis O as an endpoint is defined as the seventh virtual line g.

[0047] Furthermore, when viewed along the first direction Z, if the smaller of the angles formed by the third virtual line c and the fourth virtual line d is α1, and one of the two angles formed by the third virtual line c and the fourth virtual line d is less than or equal to a straight angle, then α1 is the angle of that one angle. The angle formed by rotating from the fifth virtual line e along the winding direction W to the first virtual half-line a' is α2, the angle formed by rotating from the sixth virtual line f along the winding direction W to the seventh virtual line g is α3. The smaller of the angles formed by the first virtual half-line a' and the sixth virtual line f is α4, and if one of the two angles formed by the first virtual half-line a' and the sixth virtual line f is less than or equal to a straight angle, then α4 is the angle of that one angle. The smaller of the angles formed by the fifth virtual line e and the seventh virtual line g is α5, and if one of the two angles formed by the fifth virtual line e and the seventh virtual line g is less than or equal to a straight angle, then α5 is the angle of that one angle.

[0048] After winding the electrode assembly 200, due to the arrangement of the first tab 300 and the second tab 400, the dimensions at various locations of the electrode assembly 200 are likely to be non-uniform. Furthermore, since the surfaces of the first electrode tab 210 and the second electrode tab 220 receive inconsistent pressures at different locations, there may be an interface defect between the first electrode tab 210 and the second electrode tab 220, which may affect the cycle life of the button-type battery 1. Therefore, there should be an appropriate distance between the first tab 300 and the second tab 400 to reduce the risk that excessive deformation of the local area of the electrode assembly 200 caused by their over-approaching. The third virtual line c and the fourth virtual line d are not simultaneously located in one of the first region, the second region, the third region, and the fourth region so as to have a large interval between the first tab 300 and the second tab 400. Next, with experimental data, the influence of the relative positional relationship between the first tab 300 and the second tab 400 on the capacity retention rate of the button-type battery 1 after 500 cycles will be explained. To better understand the experiment, the following first explains the technical terms related to the experiment. The meaning of the "angle formed by the cathode tab and the anode tab" described in the text of this application is the angle formed by the first tab 300 and the second tab 400 when viewed along the first direction, that is, the relatively small angle formed by the above-mentioned third virtual line c and the fourth virtual line d, and the angle is α1.

[0049] The meaning of the "angle formed by the starting positions of the cathode tab and the anode tab" described in the text of this application is the angle formed by the portion where the leading edges of the first electrode tab 210 and the second electrode tab 220 are shifted with respect to the central axis O when viewed along the first direction, that is, the angle formed by the above-mentioned fifth virtual line e rotating along the winding direction W to the first virtual half-line a´, and the angle is α2.

[0050] The meaning of the "angle formed by the head and the tail of the cathode" described in the text of this application is the angle formed by the first starting side 2101, the central axis O, and the first ending side 2102 of the first electrode tab 210 when viewed along the first direction Z, that is, the relatively small one of the angles formed by the above-mentioned first virtual half-line a´ and the above-mentioned sixth virtual line f, and the angle is α4.

[0051] The meaning of the "angle formed by the head and the tail of the anode" described in the text of this application is the angle formed by the second starting side 2201 of the second pole piece 220, the central axis O, and the second ending side 2202 when viewed along the first direction Z, that is, the relatively smaller one of the angles formed by the above-mentioned fifth virtual line e and the above-mentioned seventh virtual line g, and the angle is α5.

[0052] The meaning of the "capacity retention rate after 500 cycles" described in the text of this application is the ratio of the fully discharged battery capacity C2 after such charge and discharge cycles are carried out 500 times to the battery capacity C1 at the time of the first full discharge after manufacturing completion, after the button-type battery is manufactured, charged to 4.45V at a constant current of 0.5C at 25°C, left standing for 30 min, and then discharged to 3.0V at 0.5C. For example, if the capacity of the first full discharge of button-type battery 1 is 5000 milliampere-hours (mAh), and the capacity of the full discharge after the 500th cycle of charge and discharge of button-type battery 1 is 4000 mAh, the "capacity retention rate after 500 cycles" of button-type battery 1 is 80%.

[0053] Specifically, the preparation of the button-type batteries provided in the comparative example and each example will be described below.

[0054] Comparative Example 1 (1) Preparation of the positive electrode sheet Lithium cobaltate, polyvinylidene fluoride, and conductive carbon black (SP) were put into N-methylpyrrolidone (NMP) at a weight ratio of 97:1.5:1.5 and stirred well to form a uniform positive electrode slurry. Then, the positive electrode slurry was applied to both surfaces of the front and back of the positive electrode current collector (aluminum foil, with a thickness of 12 μm and a width of 4.0 mm) to form a uniform coating layer. After drying and cold pressing treatments, the thickness of the single-sided coating layer was 50 μm. Then, a conductive plate was welded to the positive electrode sheet to obtain the positive electrode sheet.

[0055] (2) Preparation of the negative electrode sheet A graphite material, styrene-butadiene rubber (SBR), and sodium carboxymethyl cellulose (CMC) were put into deionized water at a weight ratio of 97.4:1.2:1.4 and stirred well to form a uniform negative electrode slurry. The negative electrode slurry was applied to a negative electrode current collector (copper foil with a thickness of 10 μm and a width of 4.5 mm) pre-coated with an undercoat layer, dried, and cold-pressed. After that, the thickness of the single-sided coating layer was 60 μm, and a negative electrode sheet was obtained. The undercoat layer was formed by mixing SP, CMC, and SBR at a mass ratio of 60:5:35 and then applying it to both surfaces of the current collector by the gravure coating method. Then, a conductive plate was welded to the negative electrode sheet to obtain a negative electrode sheet.

[0056] (3) Preparation of separator A single-layer film base layer made of polyethylene (PE) material was used as the separator, and the thickness of the separator was 16 μm.

[0057] (4) Preparation of button-type battery The prepared positive electrode sheet, separator, and negative electrode sheet were stacked in order and wound so that the separator was interposed between the positive electrode sheet and the negative electrode sheet to play a role of isolation, and an electrode assembly was obtained. The electrode assembly was placed in a first case, and a second case was engaged with the top of the first case. Moisture was removed at 80 °C, and the prepared electrolytic solution (the composition of the electrolytic solution was ethylene carbonate (EC):propylene carbonate (PC):diethyl carbonate (DEC) = 1:1:1, and the concentration of LiPF6 was 1.15 mol / L) was injected. After processes such as sealing, standing, and forming, a button-type battery was obtained. The angle α1 formed by the cathode tab and the anode tab was 80 °, the angle α2 formed by the leading positions of the cathode sheet and the anode sheet was 120 °, the angle α4 formed by the leading and trailing ends of the cathode was 20 °, and the angle α5 formed by the leading and trailing ends of the anode was 20 °.

[0058] Example 1 The button-type battery provided in Example 1 was almost the same as that in Comparative Example 1. The main difference from the button-type battery provided in Comparative Example 1 was that in the button-type battery of Example 1, the angle α1 formed by the cathode tab and the anode tab was 90 °.

[0059] Example 2 The button-type battery provided in Example 2 is substantially the same as Comparative Ratio 1. The main difference from the button-type battery provided in Comparative Ratio 1 is that in the button-type battery of Example 2, the angle α1 formed by the cathode tab and the anode tab is 100°.

[0060] Example 3 The button-type battery provided in Example 3 is substantially the same as Comparative Ratio 1. The main difference from the button-type battery provided in Comparative Ratio 1 is that in the button-type battery of Example 3, the angle α1 formed by the cathode tab and the anode tab is 110°.

[0061] Example 4 The button-type battery provided in Example 4 is substantially the same as Comparative Ratio 1. The main difference from the button-type battery provided in Comparative Ratio 1 is that in the button-type battery of Example 4, the angle α1 formed by the cathode tab and the anode tab is 120°.

[0062] Example 5 The button-type battery provided in Example 5 is substantially the same as Comparative Ratio 1. The main difference from the button-type battery provided in Comparative Ratio 1 is that in the button-type battery of Example 5, the angle α1 formed by the cathode tab and the anode tab is 130°.

[0063] Example 6 The button-type battery provided in Example 6 is substantially the same as Comparative Ratio 1. The main difference from the button-type battery provided in Comparative Ratio 1 is that in the button-type battery of Example 6, the angle α1 formed by the cathode tab and the anode tab is 150°.

[0064] Example 7 The button-type battery provided in Example 7 is substantially the same as Comparative Ratio 1. The main difference from the button-type battery provided in Comparative Ratio 1 is that in the button-type battery of Example 7, the angle α1 formed by the cathode tab and the anode tab is 180°.

[0065] Referring to Table 1, the relationship between the relative positional relationship between the first tab 300 and the second tab 400 and the capacity retention rate of the button-type battery 1 after 500 cycles is shown. As can be seen from Table 1, when the angle α1 formed by the first tab 300 and the second tab 400 is less than 90°, the capacity retention rate of the button-type battery 1 after 500 cycles is clearly lower than 90%. However, when 90 ≤ α1 ≤ 180°, the capacity retention rate of the button-type battery 1 after 500 cycles is close to or higher than 90%, and its service life is longer. In addition, by arranging them as 90 ≤ α1 ≤ 180°, a large interval is provided between the first tab 300 and the second tab 400, and the phenomenon of current noise caused by the first tab 300 getting too close to the second tab 400 can be reduced.

[0066] Table 1. Relationship table between the relative positional relationship between the first tab and the second tab and the capacity retention rate of the button-type battery after 500 cycles

[0067]

Table 1

[0068] In some embodiments, when viewed from the first direction Z, both the first connection segment 310 and the second connection segment 410 are separated from the first virtual half-line a'. If both the first connection segment 310 and the second connection segment 410 intersect the first virtual half-line a', the arrangement of the first tab 300 and the second tab 400 will cause the electrode assembly 200 to generate extrusion stress at this location, and the biasing force at this part will be transmitted to the tip of the first pole piece 210 along the radial direction of the electrode assembly 200, which will cause the first active material layer 212 to peel off near the first starting side 2101. If neither the first connection segment 310 nor the second connection segment 410 intersects the first virtual half-line a', the above risk can be effectively reduced. In this embodiment, the third virtual line c is located in the fourth region D, and the fourth virtual line d is located in the second region B. By arranging in this way, the first tab 300 is approximately located in the fourth region D, the second tab 400 is approximately located in the second region B, and the distance between the two is far. Of course, in other embodiments of the present application, the specific positions of the third virtual line c and the fourth virtual line d can be appropriately deformed based on the above, and the present application does not specifically limit this. Also, in other embodiments of the present application, only one of the first connection segment 310 or the second connection segment 410 may be separated from the first virtual half-line a', and it can also reduce the above risk to a certain extent. It is understood that it is only necessary to ensure that at least one of the first connection segment 310 and the second connection segment 410 is separated from the first virtual half-line a'.

[0069] In some embodiments, 90° ≤ α2 ≤ 180°. Specifically, when manufacturing the electrode assembly 200, the first electrode tab 210, the second electrode tab 220, and the separator 230 are stacked and arranged by the above stacking method. One end of the stacked electrode assembly 200 is wound around a bobbin, and then the bobbin is rotated to wind the electrode assembly 200 spirally around the bobbin. When the leading ends of the first electrode tab 210 and the second electrode tab 220 are flush, or the distance by which they are offset is small, it is difficult to wind the electrode assembly 200. Further, due to the presence of the third non-coated segment 2212, when the leading ends of the first electrode tab 210 and the second electrode tab 220 are flush, or the distance by which they are offset is small, one end of the second coated segment 2211 approaching the third non-coated segment 2212 may not be able to exceed one end of the first coated segment 2111 approaching the first non-coated segment 2112, which may result in a lithium deposition phenomenon. Furthermore, this may cause the capacity retention rate of the button-type battery 1 after 500 cycles to be low.

[0070] Specifically, the preparation of the button-type batteries provided in Examples 8 to 13 will be described below.

[0071] Example 8 The button-type battery provided in Example 8 is substantially the same as Comparative Example 1. The main difference from the button-type battery provided in Comparative Example 1 is that in the button-type battery of Example 8, the angle α1 formed by the cathode tab and the anode tab is 130°, and the angle α2 formed by the starting positions of the leading ends of the cathode tab and the anode tab is 80°.

[0072] Example 9 The button-type battery provided in Example 9 is substantially the same as Example 8. The main difference from the button-type battery provided in Example 8 is that in the button-type battery of Example 9, the angle α2 formed by the starting positions of the leading ends of the cathode tab and the anode tab is 90°.

[0073] Example 10 The button-type battery provided in Example 10 is substantially the same as that in Example 8. The main difference from the button-type battery provided in Example 8 is that, in the button-type battery of Example 10, the angle α2 formed by the leading start positions of the cathode plate and the anode plate is 100°.

[0074] Example 11 The button-type battery provided in Example 11 is substantially the same as that in Example 8. The main difference from the button-type battery provided in Example 8 is that, in the button-type battery of Example 11, the angle α2 formed by the leading start positions of the cathode plate and the anode plate is 140°.

[0075] Example 12 The button-type battery provided in Example 12 is substantially the same as that in Example 8. The main difference from the button-type battery provided in Example 8 is that, in the button-type battery of Example 12, the angle α2 formed by the leading start positions of the cathode plate and the anode plate is 160°.

[0076] Example 13 The button-type battery provided in Example 13 is substantially the same as that in Example 8. The main difference from the button-type battery provided in Example 8 is that, in the button-type battery of Example 13, the angle α2 formed by the leading start positions of the cathode plate and the anode plate is 180°.

[0077] Referring to Table 2, the relationship between the above angle α2 and the capacity retention rate of the button-type battery 1 after 500 cycles is shown. As can be seen from Table 2, when α2 < 90°, it is relatively difficult to wind the electrode assembly 200 around the winding core, and there is a slight lithium precipitation at the leading end of the second pole piece 220, and the capacity retention rate of the button-type battery 1 after 500 cycles is lower than 90%. However, when 90° ≤ α2 ≤ 180°, it is relatively easy to wind the electrode assembly 200 around the winding core, there is no lithium precipitation at the leading end of the second pole piece 220, and the capacity retention rate of the button-type battery 1 after 500 cycles is close to or higher than 90%.

[0078] Table 2, Relationship between the angle α2 and the capacity retention rate of the button-type battery after 500 cycles

[0079]

Table 2

[0080] In some embodiments, both the first connection segment 310 and the second connection segment 410 are away from the fifth virtual line e. If both the first connection segment 310 and the second connection segment 410 intersect the fifth virtual line e, due to the arrangement of the first tab 300 and the second tab 400, the electrode assembly 200 generates extrusion stress at this location, and the biasing force at this portion is transmitted along the radial direction of the electrode assembly 200 to the tip of the second pole piece 220, which causes the second active material layer 222 to peel off near the second starting side 2201. If neither the first connection segment 310 nor the second connection segment 410 intersects the fifth virtual line e, the above risk can be effectively reduced. In other embodiments of the present application, only one of the first connection segment 310 or the second connection segment 410 may be away from the fifth virtual line e, and thus the above risk can also be reduced to a certain extent. It is understood that at least one of the first connection segment 310 and the second connection segment 410 should be ensured to be away from the fifth virtual line e.

[0081] Note that one end of the second pole piece 220 having the second terminal side 2202 is arranged beyond the first terminal side 2102 along the winding direction W so that the first terminal side 2102 is covered by the second pole piece 220 and indirectly compression-fixed. The button-type battery 1 includes a fixing adhesive 240, and the fixing adhesive 240 is fixed to the outer surface of the electrode assembly 200, is located at the second terminal side 2202, and fixes the second terminal side 2202.

[0082] In some embodiments, 90°≦α3≦180°. This is an arrangement for providing an appropriate gap between the second end edge 2202 and the first end edge 2102. When the distance between the two is short, that is, when the ends of the first pole piece 210 and the second pole piece 220 are stacked, the thickness of this portion is large, so that the fixing adhesive 240 has difficulty fixing the second end edge 2202. Meanwhile, since the ends of the first pole piece 210 and the second pole piece 220 tend to expand due to heat during operation of the electrode assembly 200, both of them expand at the same time, and the fixing effect of the fixing adhesive 240 tends to weaken or lose. On the other hand, by arranging 90°≦α3≦180°, an appropriate gap is ensured between the ends of the first pole piece 210 and the second pole piece 220, thus overcoming the above-mentioned deficiency. For example, in this embodiment, the first end edge 2102 is located in the first area A, and the second end edge 2202 is located in the third area, that is, the sixth virtual line f is located in the first area A, and the seventh virtual line g is located in the third area C.

[0083] In some embodiments, 0°≦α4≦30°. This arrangement ensures that the first pole piece 210 is wound approximately an integral number of times, thereby improving the thickness uniformity of the electrode assembly at various points. In particular, the preparation of the button batteries provided in Examples 14 to 17 is described below.

[0084] Example 14 The button battery provided in Example 14 is almost the same as that provided in Comparative Example 1. The main difference between the button battery provided in Comparative Example 1 and the button battery provided in Example 14 is that in the button battery of Example 14, the angle α1 between the cathode tab and the anode tab is 130°, and the angle α4 between the head and tail of the cathode is 40°.

[0085] Example 15 The button battery provided in Example 15 is almost the same as that in Example 14, and the main difference from the button battery 1 provided in Example 14 is that in the button battery of Example 15, the angle α4 between the head and tail of the cathode is 0°.

[0086] Example 16 The button-type battery provided in Example 16 is substantially the same as that in Example 14. The main difference from the button-type battery provided in Example 14 is that in the button-type battery of Example 16, the angle α4 formed by the head and the tail of the cathode is 10°.

[0087] Example 17 The button-type battery provided in Example 17 is substantially the same as that in Example 14. The main difference from the button-type battery provided in Example 14 is that in the button-type battery 1 of Example 17, the angle α4 formed by the head and the tail of the cathode is 30°.

[0088] Table 3 shows the relationship between the angle formed by the head and the tail of the first electrode tab 210 and the capacity retention rate of the button-type battery 1 after 500 cycles. As can be seen from Table 3, when α4 > 30°, the capacity retention rate of the button-type battery 1 after 500 cycles is lower than 85%. However, when 0° ≤ α4 ≤ 30°, the capacity retention rate of the button-type battery 1 after 500 cycles is close to or higher than 90%, showing a significant improvement.

[0089] Table 3. Relationship table between the angle formed by the head and the tail of the first electrode tab and the capacity retention rate of the button-type battery after 500 cycles

[0090]

Table 3

[0091] In some embodiments, 0° ≤ α5 ≤ 30°. By arranging in this way, by ensuring that the second electrode tab 2200 is wound around approximately an integer number of turns, the uniformity of the thickness at various locations of the electrode assembly is improved to a certain extent. Specifically, the preparation of the button-type batteries provided in Examples 18 to 21 will be described below.

[0092] Example 18 The button-type battery provided in Example 18 is substantially the same as Comparative Ratio 1. The main difference from the button-type battery provided in Comparative Ratio 1 is that in the button-type battery 1 of Example 18, the angle α1 formed by the cathode tab and the anode tab is 130°, and the angle α5 formed by the head and the tail of the anode is 40°.

[0093] Example 19 The button-type battery provided in Example 19 is substantially the same as Example 18. The main difference from the button-type battery provided in Example 18 is that in the button-type battery of Example 19, the angle α5 formed by the head and the tail of the anode is 0°.

[0094] Example 20 The button-type battery provided in Example 20 is substantially the same as Example 18. The main difference from the button-type battery provided in Example 18 is that in the button-type battery of Example 20, the angle α5 formed by the head and the tail of the anode is 10°.

[0095] Example 21 The button-type battery provided in Example 21 is substantially the same as Example 18. The main difference from the button-type battery provided in Example 18 is that in the button-type battery of Example 21, the angle α5 formed by the head and the tail of the anode is 30°.

[0096] Table 4 shows the relationship between the angle formed by the head and the tail of the second pole piece 220 and the capacity retention rate of the button-type battery 1 after 500 cycles. As can be seen from Table 4, when α5 > 30°, the capacity retention rate of the button-type battery 1 after 500 cycles is lower than 85%, but when 0° ≤ α5 ≤ 30°, the capacity retention rate of the button-type battery 1 after 500 cycles is close to or higher than 90%, showing a significant improvement.

[0097] Table 4, Relationship table between the angle formed by the head and the tail of the second pole piece and the capacity retention rate of the button-type battery after 500 cycles

[0098]

Table 4

[0099] In some embodiments, one of the first tab 300 and the second tab 400 is disposed in the fifth region, which is the region between the fifth virtual line and the first virtual half-line. Along the winding direction W, the fifth virtual line, the fifth region, and the first virtual half-line are arranged in sequence. The first pole piece 210 includes a plurality of first arc portions 213 located in the fifth region, and each of the first arc portions 213 is arranged in sequence from the inside to the outside. The second pole piece 220 includes a plurality of second arc portions 223 located in the fifth region, and each of the second arc portions 223 is arranged in sequence from the inside to the outside. Since the first arc portion 213 is not arranged between the two innermost second arc portions 223, arranging the first tab 300 or the second tab 400 in the fifth region is advantageous for balancing the thickness of the entire electrode assembly 200.

[0100] In some embodiments, one of the first tab 300 and the second tab 400 is disposed in the sixth region, which is the region between the sixth virtual line f and the seventh virtual line g. Along the winding direction W, the sixth virtual line f, the sixth region, and the seventh virtual line g are arranged in sequence. The first pole piece 210 includes a plurality of third arc portions 214 located in the sixth region, and each of the third arc portions 214 is arranged in sequence from the inside to the outside. The second pole piece 220 includes a plurality of fourth arc portions 224 located in the sixth region, and each of the fourth arc portions 224 is arranged in sequence from the inside to the outside. Since the third arc portion 214 is not arranged between the two outermost fourth arc portions 224, arranging the first tab 300 or the second tab 400 in the sixth region is advantageous for balancing the thickness of the entire electrode assembly 200.

[0101] As described above, the button-type battery 1 provided in the embodiment of the present application includes an electrode assembly 200, a first tab 300, and a second tab 400. The electrode assembly 200 includes a first electrode plate 210 and a second electrode plate 220. The first electrode plate 210 and the second electrode plate 220 are laminated and spirally wound around a central axis. The first electrode plate 210 includes a first current collector 211, and the first current collector 211 includes a first starting side 2101 and a first ending side 2102 that are arranged opposite to the winding direction W. The second electrode plate 220 includes a second current collector. When viewed from the first direction Z, the electrode assembly 200 is divided into a first region A, a second region B, a third region C, and a fourth region D that are sequentially connected along the winding direction W from the first starting side by the first virtual line a and the second virtual line b.

[0102] The first tab 300 includes a first connection segment 310 that extends along the first direction Z and is connected to the first current collector 211. The first connection segment 310 includes a first center line P that extends along the first direction Z. The second tab 400 includes a second connection segment 410 that extends along the first direction Z and is connected to the second current collector 221. The second connection segment 410 includes a second center line Q that extends along the first direction Z. When viewed along the first direction Z, the third virtual line c passes through the first center line P from the central axis O, and the fourth virtual line d passes through the second center line Q from the central axis O. The third virtual line c and the fourth virtual line d are not simultaneously located in one of the first region A, the second region B, the third region C, and the fourth region D. The smaller one of the angles formed by the third virtual line c and the fourth virtual line d is α1, and 90° ≤ α1 ≤ 180°.

[0103] When 90° ≤ α1 ≤ 180°, in order to provide an appropriate distance between the first tab 300 and the second tab 400, the current situation where the thickness of the electrode assembly to which the first tab and the second tab are connected is non-uniform is improved to a certain extent. The capacity retention rate of the button-type battery 1 after 500 cycles is close to or higher than 90%, and its service life is high. That is, the button-type battery 1 provided in the embodiment of the present application can improve the current situation where the capacity retention rate after 500 cycles is low.

[0104] Based on the same inventive concept, the present application further provides an electronic device 2. Referring to FIG. 8, a schematic diagram of the electronic device 2 is shown. The electronic device 2 includes the button-type battery 1 in the above embodiment and a load driven by the button-type battery 1. In this embodiment, the electronic device 2 is a wristwatch. In other embodiments of the present application, it is understood that the electronic device 2 may be any other electronic device such as an anti-theft device, an access control device, a computer, and a bracelet.

[0105] Since it includes the above-described button-type battery 1, the electronic device 2 can improve the current situation where the capacity retention rate of the button-type battery after 500 cycles is low.

[0106] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present application and do not limit them. With the idea of the present application, the technical features in the above embodiments or different embodiments may be combined well, the steps may be realized in any order, and there are some other changes in the different points of the present application above. For the sake of brevity and clarity, their details are not described. Although the present application has been described in detail with reference to the above embodiments, for those skilled in the art, it is still possible to modify the technical solutions described in the above embodiments or equivalently replace some of the technical features therein, but it is understood that these modifications and replacements do not deviate from the spirit of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A button-type battery including an electrode assembly, a first tab, and a second tab, wherein the electrode assembly includes a first electrode plate and a second electrode plate, the first electrode plate and the second electrode plate are laminated and wound in a spiral around a central axis, a direction of extension of the central axis is a first direction, and the first direction is perpendicular to a winding direction, the first electrode plate includes a first current collector, and the first current collector includes a first starting side and a first ending side that are disposed opposite to each other in the winding direction, the second electrode plate includes a second current collector, when viewed from the first direction, a line passing through the first starting side and the central axis is defined as a first virtual line, a line passing through the central axis and perpendicular to the first virtual line is defined as a second virtual line, and the electrode assembly is divided by the first virtual line and the second virtual line into a first region, a second region, a third region, and a fourth region that are sequentially connected along the winding direction from the first starting side, the first tab includes a first connection segment that extends along the first direction and is connected to the first current collector, and the first connection segment has a first center line that extends along the first direction, the second tab includes a second connection segment that extends along the first direction and is connected to the second current collector, and the second connection segment has a second center line that extends along the first direction, When viewed from the first direction, a line connecting the first center line and the central axis is defined as a third virtual line, and a line connecting the second center line and the central axis is defined as a fourth virtual line. The third virtual line and the fourth virtual line are not simultaneously located in any one of the first region, the second region, the third region, and the fourth region, and the relatively smaller of the angles formed by the third virtual line and the fourth virtual line is α １ and 90° ≤ α １ ≤ 180°, which is characterized by A button-type battery.

2. When viewed from the first direction, a half-line passing through the first starting side with the central axis as an end point is defined as a first virtual half-line, and at least one of the first connection segment and the second connection segment is disposed away from the first virtual half-line. The button-type battery according to Claim 1.

3. The third virtual line is located in the fourth region, and the fourth virtual line is located in the second region. The button-type battery according to Claim 1.

4. The first electrode plate is a cathode plate, and the second electrode plate is an anode plate. The button-type battery according to Claim 1.

5. The second current collector includes a second starting side and a second ending side that are disposed opposite to each other in the winding direction. When viewed from the first direction, a half-line passing through the first initial side with the central axis as an endpoint is defined as the first virtual half-line, and a half-line passing through the second initial side with the central axis as an endpoint is defined as the fifth virtual line. The angle formed by the fifth virtual line and the first virtual half-line along the winding direction is α2, and 90° ≤ α2 ≤ 180°, which is characterized by The button-type battery according to claim 1.

6. One of the first tab and the second tab is arranged in the fifth area, The fifth area is the area between the fifth virtual line and the first virtual half-line. Along the winding direction, the fifth virtual line, the fifth area, and the first virtual half-line are arranged in sequence, which is characterized by The button-type battery according to claim 5.

7. The second current collector includes a second initial side and a second terminal side that are arranged opposite to each other in the winding direction, When viewed from the first direction, a half-line passing through the first terminal side with the central axis as an endpoint is defined as a sixth virtual line, and a half-line passing through the second terminal side with the central axis as an endpoint is defined as a seventh virtual line. The angle formed by the sixth virtual line and the seventh virtual line along the winding direction is α ３ where 90° ≤ α ３ ≤ 180°, which is characterized by The button-type battery according to claim 1.

8. One of the first tab and the second tab is arranged in the sixth area, The sixth area is the area between the sixth virtual line and the seventh virtual line. Along the winding direction, the sixth virtual line, the sixth area, and the seventh virtual line are arranged in sequence, which is characterized by The button-type battery according to claim 7.

9. The sixth virtual line is located in the first area, and the seventh virtual line is located in the third area, which is characterized by The button-type battery according to claim 7.

10. The second current collector includes a second initial side and a second terminal side that are arranged opposite to each other in the winding direction, When viewed from the first direction, a half-line passing through the second initial side with the central axis as an endpoint is defined as the fifth virtual line. At least one of the first connection segment and the second connection segment is arranged away from the fifth virtual line, which is characterized by The button-type battery according to claim 1.

11. When viewed from the first direction, a half-line passing through the first initial side with the central axis as an endpoint is defined as a first virtual half-line, and a half-line passing through the first terminal side with the central axis as an endpoint is defined as a sixth virtual line. Among the angles formed by the sixth virtual line and the first virtual half-line, the relatively smaller one is α ４ and 0° ≤ α ４ ≤ 30°, which is characterized by The button-type battery according to claim 1.

12. The first terminal side is located in the first area, which is characterized by The button-type battery according to claim 11.

13. The second current collector includes a second initial side and a second terminal side that are arranged opposite to each other in the winding direction, When viewed from the first direction, a line connecting the second initial side and the central axis is defined as a fifth virtual line, a line connecting the second terminal side and the central axis is defined as a seventh virtual line, and the relatively smaller one of the angles formed by the fifth virtual line and the seventh virtual line is α ５ where 0° ≤ α ５ ≤ 30°, which is characterized by The button-type battery according to claim 1.

14. The first current collector includes a first non-coated segment and a second non-coated segment. The first starting side is arranged as a side of the first non-coated segment, the first ending side is arranged as a side of the second non-coated segment, and the first connection segment is connected to the second non-coated segment. The button-type battery according to claim 1.

15. The second current collector includes a second starting side and a second ending side that are arranged opposite to each other in the winding direction. The second current collector includes a third non-coated segment and a fourth non-coated segment. The second starting side is arranged as a side of the third non-coated segment, the second ending side is arranged as a side of the fourth non-coated segment. The second connection segment is connected to the fourth non-coated segment. The button-type battery according to claim 1.

16. The thickness of the first tab is 20 μm to 100 μm, and the thickness of the second tab is 20 μm to 100 μm. The button-type battery according to claim 1.

17. The electrode assembly includes a separator that separates the first electrode tab and the second electrode tab. The button-type battery according to claim 1.

18. Characterized by including the button-type battery according to any one of claims 1 to 17. An electronic device.

Images