Button cell and electronic device

Abstract

The application provides a button cell and an electronic device. The button cell comprises a first shell, a second shell, an electrode assembly and a first layer. The electrode assembly comprises a winding body and a first metal plate. The winding body comprises a first pole piece, and the first pole piece comprises a first current collector. The first metal plate is connected with the first current collector and extends out of the first current collector along a first direction. The part where the first metal plate is connected with the first current collector is a first part. The first layer is connected with the first metal plate and covers the first part. Along a winding direction, the first layer comprises a first side edge and a second side edge. The first side edge intersects with the first current collector at a first end point, and the second side edge intersects with the first current collector at a second end point. When viewed from the first direction, a line connecting the first end point and a winding central axis of the winding body is defined as a first virtual line, a line connecting the second end point and the winding central axis is defined as a second virtual line, and the included angle between the first virtual line and the second virtual line is 54°-66°.

Description

Technical Field

[0001] This application relates to the field of electrochemical device technology, and in particular to a button cell and electronic device. Background Technology

[0002] Due to their advantages such as being rechargeable and reusable, button batteries are widely used in various electronic devices, such as portable electronic devices. A typical button battery consists of two interconnected housings and an electrode assembly housed inside the housings. The electrode assembly includes a wound body and tabs electrically connected to the wound body.

[0003] In related technologies, the tabs can be connected to the winding body by welding or other methods. In order to reduce the impact of burrs on the edge of the tabs and burrs at the welding position on the electrode assembly, it is often necessary to attach an adhesive layer, such as adhesive tape, to the tabs. However, the adhesive layer may affect the casing of the button cell and thus affect the packaging reliability of the button cell. Summary of the Invention

[0004] The purpose of this application is to provide a coin cell battery and electronic device to reduce the impact of the first layer on the casing of the coin cell battery, thereby improving the yield and packaging reliability of the coin cell battery.

[0005] An embodiment of the first aspect of this application provides a coin cell battery. The coin cell battery includes a first housing, a second housing, an electrode assembly, and a first layer. The first housing has a recess facing a first direction, and the second housing covers the recess and is connected to and cooperates with the first housing to form a receiving space. The electrode assembly is placed within the receiving space and includes a wound body and a first metal plate. The wound body includes a first electrode sheet, and the first electrode sheet includes a first current collector. The first metal plate is connected to the first current collector and extends the first current collector along the first direction, and the portion of the first metal plate connected to the first current collector is a first portion. The first direction is perpendicular to the winding direction of the wound body. The first layer is in contact with the first metal plate and covers the first portion. Along the winding direction, the first layer includes a first side and a second side, the first side and the second side extending along the first direction to form the first current collector, and the first side intersects the first current collector at a first end point, and the second side intersects the first current collector at a second end point. Viewed from the first direction, the line connecting the first endpoint and the winding center axis of the winding body is defined as the first virtual line, and the line connecting the second endpoint and the winding center axis is defined as the second virtual line. The included angle between the first virtual line and the second virtual line is 54° to 66°.

[0006] This application limits the width of the first layer in the winding direction. Setting the angle between the first and second virtual lines to be greater than or equal to 54° ensures sufficient width for both the first layer and the first metal plate, thereby improving the conductivity of the first metal plate and reducing the risk of burrs on the first metal plate damaging the first current collector or causing a short circuit. Setting the angle between the first and second virtual lines to be less than or equal to 66° provides an appropriate width for the first layer, thereby reducing the risk of interference between the first layer and the coin cell casing and improving the manufacturing efficiency and packaging reliability of the coin cell.

[0007] In some embodiments, the width of the first metal plate along the winding direction is W1 mm, the width of the first layer along the winding direction is W2 mm, and the distance from the winding center axis to the outer edge of the wound body, viewed from the first direction, is R mm, where 0.4R≤W1≤0.7R and 0.95R≤W2≤1.15R. This configuration helps to further reduce the risk of burrs on the first metal plate damaging the first current collector or causing a short circuit, and also helps to further reduce the risk of interference between the first layer and the coin cell casing, thereby improving the production efficiency and packaging reliability of the coin cell.

[0008] In some embodiments, the coin cell further includes a second layer, which is in contact with and covers the first current collector. The second layer is located on the side of the first current collector opposite to the first layer, and extends out of the first current collector along a first direction and is in contact with the first metal plate. This arrangement allows the first metal plate to be double-wrapped by the first and second layers, which helps to further reduce the risk of burrs on the first metal plate damaging the first current collector or causing a short circuit.

[0009] In some embodiments, the winding body further includes a second electrode and a separator disposed between the first electrode and the second electrode; the second electrode includes a second current collector, and the electrode assembly further includes a second metal plate connected to the second current collector.

[0010] In some embodiments, the second housing is electrically connected to the first metal plate, and the first housing is electrically connected to the second metal plate. This allows the current generated by the electrode assembly to be released through the coin cell's housing, which improves the contact area for charging and discharging the coin cell, thereby enhancing the charging and discharging reliability and performance of the coin cell.

[0011] In some embodiments, the second housing is welded to the first metal plate, and the first housing is welded to the second metal plate. This welding method helps to improve the reliability of the connections between the first metal plate and the second housing, and between the first housing and the second metal plate.

[0012] In some embodiments, the first current collector includes a first region where the first active material layer is disposed and a second region that is adjacent to one side of the first region in the winding direction. The first part is connected to the second region, and the first layer includes a third region covering the first active material layer. The first layer has a third region overlapping with the first region where the first active material layer is disposed. That is to say, a part of the first layer covers the edge of the first active material layer, which helps to reduce the risk of the active material detaching from the first current collector, improve the reliability of the button cell, and save the material cost of the first active material layer.

[0013] In some embodiments, along the winding direction, there is a first distance b1 mm between the first side edge and the first metal plate, and a second distance b2 mm between the second side edge and the first metal plate. The width of the third region is b0 mm, where 0 < b0 < b1 and b2 < W2 - W1. The first layer has a third region with a width of b0 in the winding direction covering the edge of the first active material layer, which helps to reduce the risk of the active material detaching from the first current collector, improve the reliability of the button cell, and save the material cost of the first active material layer. It can also balance the distance between the first metal plate and the first active material layer, improve the uniformity of the current near the first metal plate, and reduce the risk of lithium plating.

[0014] In some embodiments, the first electrode sheet is a cathode electrode sheet, the second electrode sheet is an anode electrode sheet, and the material of the first metal plate is aluminum or aluminum alloy. Such a setting helps to improve the flexibility of the first metal plate, making it easy to bend, reducing the impact of the first layer on the encapsulation of the second housing, and improving the manufacturing efficiency and encapsulation reliability.

[0015] In some embodiments, the first housing includes a first column section and a second column section connected to the first column section in the first direction. The first column section is placed inside the second housing; the button cell further includes a first insulating layer, which includes a first section and a second section connected to the first section in the first direction. The first section is located between the first column section and the second housing, and the second section extends out of the second housing. The first housing and the second housing are hermetically connected through the first insulating layer, which helps to improve the convenience and reliability of the button cell housing seal.

[0016] In some embodiments, in the first direction, the thickness of the electrode assembly is T mm, the length of the second section is L1 mm, and the length of the first section is L2 mm, where 1 / 2T ≤ L2 ≤ T and L1 < L2. The first section is filled between the first column section and the second housing. Using a first section with a larger length helps to improve the encapsulation reliability between the first housing and the second housing, and thus helps to improve the performance of the button cell. And setting the relationship between the thickness of the first section and the electrode assembly to satisfy the above formula helps to improve the encapsulation reliability and further reduce the impact of the first layer on the encapsulation of the second housing.

[0017] In some embodiments, along the first direction, the thickness of the electrode assembly is T mm, and there is a third distance S mm between the winding body and the second housing, where 0.03T < S ≤ 0.1T. Such a setting is beneficial to increasing the energy density of the button cell while reducing the risk of the second housing squeezing the electrode assembly, and further reducing the influence of the first layer on the encapsulation of the second housing.

[0018] In some embodiments, the material of the first insulating layer includes at least one of polyethylene oxide, polyvinylidene fluoride, styrene-butadiene rubber, copolymer of vinylidene fluoride and hexafluoropropylene, polyvinylidene fluoride, modified polyvinylidene fluoride, polyacrylate, modified polyacrylate, modified polyethylene or modified polyvinylidene fluoride. Sealing the first housing and the second housing with the first insulating layer made of the above materials is beneficial to improving the housing sealing reliability and performance of the button cell.

[0019] In some embodiments, the first part is connected to the outermost circle of the first current collector. Since the first part is connected to the outermost circle of the first current collector, and the outermost circle has a large radius of curvature, a first metal plate with a larger size can be selected, which is beneficial to improving the electrical performance of the battery. Correspondingly, it is also possible to reduce the influence on the thickness of the electrode assembly when arranged on the inner circle, which is beneficial to improving the energy density and interface performance of the battery.

[0020] In some embodiments, the first metal plate is farther from the winding central axis than the second metal plate. At this time, the first metal plate is located outside the second metal plate. When the first metal plate is connected to the second housing, by limiting the angle between the first virtual line and the second virtual line to be more than 54°, it is beneficial to ensure the electrical conductivity of the first metal plate and also beneficial to reducing the risk that the burrs on the first metal plate damage the first current collector or cause a short circuit; by limiting the angle between the first virtual line and the second virtual line to be within 66°, the width of the first layer is appropriate, which is beneficial to reducing the risk of interference between the first layer on the outer first metal plate and the second housing of the button cell, and improving the manufacturing efficiency and encapsulation reliability of the button cell.

[0021] In some embodiments, the first virtual line or the extension line of the first virtual line at the first end point passes through the second metal plate. In this way, when observing from the outer circle to the inner circle of the winding body, there is an overlapping part between the first metal plate and the second metal plate, and the positions of the first metal plate and the second metal plate are relatively concentrated, which is beneficial to facilitating the connection of the first metal plate and the second metal plate to the battery housing.

[0022] In some embodiments, the second virtual line or the extension line of the second virtual line at the second end point passes through the second metal plate. In this way, when observing from the outer circle to the inner circle of the winding body, there is an overlapping part between the first metal plate and the second metal plate, and the positions of the first metal plate and the second metal plate are relatively concentrated, which is beneficial to facilitating the connection of the first metal plate and the second metal plate to the housing.

[0023] In some embodiments, the portion of the second metal plate connected to the second current collector is a third portion, and the first portion and the third portion overlap in a direction perpendicular to the first direction. This arrangement is advantageous for increasing the connection size between the first portion and the first current collector and / or the connection size between the third portion and the second current collector, thereby improving connection stability, reducing connection impedance, and enhancing safety performance.

[0024] The second aspect of this application provides an electronic device comprising the button battery of the first aspect. Attached Figure Description

[0025] To more clearly illustrate the technical solutions of this application and the prior art, the drawings used in this application and the prior art are briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other embodiments can be obtained based on these drawings.

[0026] Figure 1 This is a cross-sectional view of a button battery along the XY plane according to an embodiment of this application;

[0027] Figure 2 This is a schematic diagram of one structure of the first current collector in this application where it is not wound.

[0028] Figure 3 for Figure 2 A schematic diagram of the structure in the Z direction;

[0029] Figure 4 This is a schematic diagram of the Z-direction structure of another embodiment of the present application where the first current collector is not wound.

[0030] Figure 5 This is a schematic diagram of another structure of the first current collector in this application, where it is not wound.

[0031] Figure 6 for Figure 5 A schematic diagram of the structure in the Z direction;

[0032] Figure 7 This is a cross-sectional view of a button battery along the YZ plane according to an embodiment of this application;

[0033] Figure 8 This is a schematic diagram of the structure of an electronic device according to an embodiment of this application;

[0034] Figure 9 This is a schematic diagram of the outer circle of the wound body according to an embodiment of this application;

[0035] Figure 10 This is a schematic cross-sectional view of a button cell along the XY plane according to an embodiment of this application.

[0036] Figure 11 This is a schematic diagram of the unwound structure of the second current collector according to an embodiment of this application;

[0037] Figure 12 This is another cross-sectional view of the button battery along the XY plane according to an embodiment of this application;

[0038] Figure 13 This is another cross-sectional view of the button battery along the XY plane according to an embodiment of this application;

[0039] Figure 14 This is another cross-sectional view of the button battery along the YZ plane according to an embodiment of this application.

[0040] Figure label:

[0041] 10 - Electronic device; 100 - Button cell battery; 110 - First housing; 120 - Second housing; 130 - Electrode assembly; 140 - First layer; 131 - Wound body; 132 - First metal plate; 1311 - First current collector; 1311a - First end edge; 1311b - Second end edge; 134 - First side; 135 - Second side; 1318 - First electrode; 1319 - Second electrode; 300 - Recess; 310 - Bottom wall; 320 - Side wall; 330 - Opening; 400 - Circumscribed circle; 410 - Center; 500 - First surface; 600 - Second surface; 1321 - First portion; 1322 - Second portion; 141 - First side edge; 142 - Second side edge; 143 - Third side edge; 144 - Fourth side edge; A - First end point; B - Second end point; M - Wound Around the central axis; 150 - First virtual line; 160 - Second virtual line; 170 - Second layer; 1312 - Second current collector; 1313 - Separating membrane; 133 - Second metal plate; 1314 - First region; 1315 - Second region; 1316 - Third region; 111 - First column segment; 112 - Second column segment; 180 - First insulating layer; 181 - First section; 182 - Second section; α - Included angle; 1317 - First active material layer; 1320 - Second active material layer; 190 - Third layer; 1901 - Fifth side; 1902 - Sixth side; 1903 - Third part; 1904 - Fourth part; 136 - Third side; 137 - Fourth side; 200 - Third virtual line; 210 - Fourth virtual line; E - Third endpoint; F - Fourth endpoint; β - Included angle. Detailed Implementation

[0042] The technical solutions in the embodiments of this application are described clearly and in detail below. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the specification of this application is for the purpose of describing particular embodiments only and is not intended to limit this application.

[0043] The embodiments of this application will be described in detail below. However, this application may be embodied in many different forms and should not be construed as limited to the exemplary embodiments set forth herein. Rather, these exemplary embodiments are provided to provide a thorough and detailed understanding of this application to those skilled in the art.

[0044] Additionally, for brevity and clarity, the dimensions or thicknesses of various components and layers may be enlarged in the accompanying drawings. Throughout the text, the same numerical values ​​refer to the same elements. As used herein, the terms "and / or" and "and / or" include any and all combinations of one or more of the associated enumerated items. Furthermore, it should be understood that when element A is referred to as "connecting" element B, element A may be directly connected to element B, or there may be an intermediate element C and element A and element B may be indirectly connected to each other.

[0045] Furthermore, when describing the implementation of this application, the word "may" refers to "one or more implementations of this application".

[0046] The technical terms used herein are for the purpose of describing particular embodiments and are not intended to limit this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. It should be further understood that the term "comprising," as used in this specification, means the presence of the described features, values, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, values, steps, operations, elements, components, and / or combinations thereof.

[0047] Spatial terms, such as "above," may be used herein for convenience in describing the relationship between one element or feature and another element (or feature) or feature (or feature) illustrated in the figures. It should be understood that, in addition to the directions depicted in the figures, spatial terms are intended to include different orientations of the device or apparatus during use or operation. For example, if the device in the figure is flipped, an element described as "above" or "on" other elements or features would be oriented "below" or "under" other elements or features. Therefore, the exemplary term "above" can include both above and below orientations. It should be understood that although the terms first, second, third, etc., may be used herein to describe various elements, components, regions, layers, and / or portions, these elements, components, regions, layers, and / or portions should not be limited by these terms. These terms are used to distinguish one element, component, region, layer, or portion from another element, component, region, layer, or portion. Therefore, a first element, component, region, layer, or portion discussed below may be referred to as a second element, component, region, layer, or portion without departing from the teachings of the exemplary embodiments.

[0048] The various embodiments in this specification are described in a related manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0049] The following describes some embodiments of this application in detail. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0050] like Figure 1 , Figure 2 , Figure 3 and Figure 7 As shown, an embodiment of the first aspect of this application provides a coin cell battery 100, including a first housing 110, a second housing 120, an electrode assembly 130, and a first layer 140. In some embodiments, the first housing 110 and the second housing 120 may be made of metal. Figure 7As shown, the first housing 110 has a recess 300 facing a first direction, and the second housing 120 covers the recess 300 and is connected to and cooperates with the first housing 110 to form a receiving space. The electrode assembly 130 is placed in the receiving space. The first housing 110 has a bottom wall 310 and a side wall 320 connecting the bottom wall 310, and the bottom wall 310 and the side wall 320 surround the recess 300. The direction perpendicular to one surface of the bottom wall 310 is the first direction Z. The side wall 320 extends from the edge of the bottom wall 310 along the first direction Z, and the end of the side wall 320 away from the bottom wall 310 surrounds an opening 330. The recess 300 is disposed facing the first direction Z, and the bottom wall 310 to the opening 330 is disposed along the first direction. The electrode assembly 130 includes a wound body 131 and a first metal plate 132. The wound body 131 includes a first current collector 1311. The wound body 131 indicates that the electrode assembly 130 is a wound structure. Define a fourth direction X and a fifth direction Y that are perpendicular to each other. The plane formed by the fourth direction X and the fifth direction Y is perpendicular to the first direction Z.

[0051] like Figure 2 and Figure 3 As shown, Figure 2 This is a schematic diagram of the structure where the first current collector 1311 is connected to the first metal plate 132 without being wound. Figure 3 for Figure 2 A schematic diagram of the structure in the first direction. The first current collector 1311 has a first end edge 1311a and a second end edge 1311b disposed opposite to each other along the second direction X'. The first end edge 1311a and / or the second end edge 1311b extend along the first direction Z. The third direction Y', the first direction Z, and the second direction X' are perpendicular to each other.

[0052] like Figure 2 As shown, a first metal plate 132 is connected to a first current collector 1311 and extends outward from the first current collector 1311 along a first direction Z. The first metal plate 132 includes a first portion 1321 connected to the first current collector 1311 and a second portion 1322 extending outward from the first current collector 1311. The first direction Z is perpendicular to the winding direction W of the winding body 131. Figure 1 and Figure 2 As shown, the winding direction W of the winding body 131 refers to the direction in which the first end edge 1311a of the first current collector 1311 is wound towards the second end edge 1311b. That is, the winding direction W of the winding body 131 is equivalent to the second direction X' when the first current collector 1311 is not wound. Figure 2As shown, the first layer 140 is connected to the first metal plate 132 and covers the first portion 1321. Along the winding direction W of the winding body 131, i.e., along the second direction X' from the first end edge 1311a to the second end edge 1311b of the first current collector 1311, the first layer 140 includes a first side edge 141 and a second side edge 142 disposed opposite to each other, and the first metal plate 132 includes a first side edge 134 and a second side edge 135 disposed opposite to each other. Viewed from a third direction Y', the first side edge 141 is one edge of the first layer 140 extending along the first direction Z, and the second side edge 142 is another edge of the first layer 140 extending along the first direction Z. The first layer 140 covers the first portion 1321, and the first layer 140 covers at least a portion of the first side edge 134 and at least a portion of the second side edge 135 of the first metal plate 132. First side 141 and second side 142 extend along the first direction Z to form a first current collector 1311. Viewed from the third direction Y', the first side 141 intersects the first current collector 1311 at the first end point A, and the second side 142 intersects the first current collector 1311 at the second end point B. Figure 1 As shown, viewed from the first direction Z, the line connecting the first endpoint A and the winding center axis M of the winding body 131 is defined as the first virtual line 150, and the line connecting the second endpoint B and the winding center axis M is defined as the second virtual line 160. The included angle α between the first virtual line 150 and the second virtual line 160 is 54° to 66°.

[0053] The first layer 140 may be attached to the first metal plate 132 and the first current collector 1311 by adhesive or other means. In some embodiments, the first layer 140 includes a substrate layer and an adhesive layer disposed on the substrate layer. The adhesive layer bonds the first metal plate 132 and the first current collector 1311. The substrate layer is made of at least one of polyfluoroolefin, polyethylene terephthalate, polyimide, polyamide-imide, polyvinyl chloride, or polyolefin. The adhesive layer includes an adhesive material, which includes at least one of carboxymethyl cellulose, styrene-butadiene rubber, polyvinylidene fluoride, polytetrafluoroethylene, fluorinated rubber, polyurethane, polyacrylamide, sodium polyacrylate, polyetheramide, or acrylate.

[0054] In this application, the button cell 100 includes a first housing 110, a second housing 120, an electrode assembly 130, and a first layer 140. The first housing 110 and the second housing 120 are connected to form a receiving space, within which the electrode assembly 130 is placed. The first housing 110 and the second housing 120 protect the electrode assembly 130, reducing the impact of external objects on it. The first housing 110 and the second housing 120 can be welded using various methods such as ultrasonic welding and laser welding to form a sealed space; or, as... Figure 1 and Figure 7As shown, a first insulating layer 180 may also be provided between the first housing 110 and the second housing 120, and the first housing 110 and the second housing 120 are connected by the first insulating layer 180 to form a sealed space. In some embodiments, the material of the first insulating layer 180 includes at least one of polyethylene oxide, polyvinylidene fluoride, styrene-butadiene rubber, copolymer of polyvinylidene fluoride and hexafluoropropylene, polyvinylidene fluoride, modified polyvinylidene fluoride, polyacrylate, modified polyacrylate, modified polyethylene, or modified polyvinylidene fluoride.

[0055] Electrode assembly 130 is a component in the coin cell 100 where an electrochemical reaction occurs to generate electrical energy. Electrode assembly 130 includes a wound body 131 and a first metal plate 132. (The text abruptly ends here.) Figure 1 and Figure 2 As shown, the wound body 131 includes a first electrode 1318, a second electrode 1319, and a separating membrane 1313 disposed between the first electrode 1318 and the second electrode 1319. The first electrode 1318 includes a first current collector 1311. The first electrode 1318 can be a cathode electrode or an anode electrode, and correspondingly, the second electrode 1319 can be an anode electrode or a cathode electrode. The first electrode 1318, the second electrode 1319, and the separating membrane 1313 are wound around a central axis M to form the wound body 131. Figure 1 As shown, the first electrode 1318 further includes a first active material layer 1317 disposed on the surface of the first current collector 1311, the first active material layer 1317 comprising a first active material; the second electrode 1319 further includes a second active material layer 1320 disposed on the surface of the second current collector 1312, the second active material layer 1320 comprising a second active material. In some embodiments, the first electrode 1318 is a cathode electrode, the first current collector 1311 may be made of aluminum, the first active material includes compounds capable of deionizing, such as lithium transition metal oxide or sodium transition metal oxide, the second electrode 1319 is an anode electrode, the second current collector 1312 may be made of copper, and the second active material includes substances capable of intercalating ions, such as carbon materials, silicon materials, etc.

[0056] In addition, such as Figure 2 and Figure 3As shown, the first portion 1321 of the first metal plate 132 is connected to the first current collector 1311. That is, viewed from a third party towards Y', the first portion 1321 of the first metal plate 132 is the area where the first metal plate 132 and the first current collector 1311 overlap. The first metal plate 132 also has a second portion 1322, which, viewed from a third party towards Y', extends away from the first current collector 1311 and in the first direction Z, and is the area where the first metal plate 132 does not overlap with the first current collector 1311. In other words, in the button cell 100, the second portion 1322 of the first metal plate 132 is closer to the second housing 120 relative to the first housing 110, which facilitates the connection between the second portion 1322 and the second housing 120. The first portion 1321 of the first metal plate 132 can be connected to the first current collector 1311 by welding. Furthermore, when the first electrode 1318 is a cathode electrode, the first metal plate 132 can be a cathode tab connected to the cathode electrode; when the first electrode 1318 is an anode electrode, the first metal plate 132 can be an anode tab connected to the anode electrode. Furthermore, when the first metal plate 132 is a cathode tab, the material can include at least one of aluminum (Al) or aluminum alloys; when the first metal plate 132 is an anode tab, the material can include at least one of nickel (Ni), copper (Cu), or nickel-plated copper (Ni-Cu).

[0057] By setting the first layer 140, it is beneficial to reduce the risk of burrs on the first metal plate 132 causing damage to the first current collector and causing short circuits.

[0058] like Figure 2 As shown, the first layer 140 also extends the first current collector 1311 along the first direction Z. The dimension D4 of the first layer 140 extending the first current collector 1311 in the first direction Z is smaller than the dimension D5 of the second part 1322 of the first metal plate 132 in the first direction Z. This makes the end of the first metal plate 132 extending out of the first current collector 1311 have an area exposed by the first layer 140, which is beneficial for connecting the second part 1322 of the first metal plate 132 to the casing of the button cell 100.

[0059] This application improves the design of the first layer 140. Specifically, in the second direction X', the width of the first layer 140 exceeds the width of the first metal plate 132. A first side 141 and a second side 142 of the first layer 140 extend from both sides of the first metal plate 132, respectively. The first side 141 intersects the first current collector 1311 at a first endpoint A, and the second side 142 intersects the first current collector 1311 at a second endpoint B. For example... Figure 1As shown, connecting the first endpoint A to the winding center axis M of the winding body 131 forms a first virtual line 150, and connecting the second endpoint B to the winding center axis M forms a second virtual line 160. That is, viewed from the first direction Z, the winding center axis M has a projection point M1 in the first direction Z. Connecting the first endpoint A to the winding center axis M of the winding body 131 and connecting the second endpoint B to the winding center axis M means: connecting the projection point M1 and the first endpoint A to form the first virtual line 150, and connecting the projection point M1 and the second endpoint B to form the second virtual line 160. The angle α between the first virtual line 150 and the second virtual line 160 is between 54° and 66°.

[0060] In this application, such as Figure 1 , Figure 7 and Figure 9 As shown, the winding center axis M is the axis on which the winding body 131 is wound. By acquiring an image of the electrode assembly 130 viewed in the first direction Z, the circumcircle 400 of the winding body 131 can be drawn, and the center 410 of this circumcircle 400 can be determined. The line extending from the center 410 in the first direction Z is then the winding center axis M. This can be understood as... Figure 9 The middle part is for clear illustration of the outer circle 400 and the winding body 131. In reality, the outer circle 400 and the outer contour of the winding body 131 are connected.

[0061] This application improves the production yield and performance of the coin cell 100 by designing the size and structural relationship between the first layer 140 and the first metal plate 132. Specifically, the first layer 140 is connected to the first portion 1321 of the first metal plate 132, and when viewed from the first direction Z, the angle α between the first virtual line 150 and the second virtual line 160 is specifically 54° to 66°. In other words, this application limits the width of the first layer 140 in the winding direction W of the winding body 131. When the angle α between the first virtual line 150 and the second virtual line 160 is ≥54°, both the first layer 140 and the first metal plate 132 have sufficient width, which helps to ensure the conductivity of the first metal plate 132 and also helps to reduce the risk of burrs on the first metal plate 132 damaging the first current collector 1311 or causing a short circuit. When the angle α between the first virtual line 150 and the second virtual line 160 is ≤66°, the width of the first layer 140 is appropriate, which helps to reduce the risk of interference between the first layer 140 and the second casing 120 of the button cell 100 and improves the manufacturing efficiency and packaging reliability of the button cell 100.

[0062] In some embodiments, such as Figure 2 As shown, the width of the first metal plate 132 along the winding direction W, which is also the second direction X', is W1mm, and the width of the first layer 140 along the winding direction W, which is also the second direction X', is W2mm. Figure 1As shown, when viewed along the first direction Z, the distance from the winding center axis M to the outer edge of the winding body 131 is R mm, where 0.4R ≤ W1 ≤ 0.7R, and 0.95R ≤ W2 ≤ 1.15R. In this application, as... Figure 9 As shown, the distance R from the winding center axis M to the outer edge of the winding body 131 is the radius of the circumcircle 400 of the winding body 131.

[0063] When the width W1 of the first metal plate 132 and the width W2 of the first layer 140 are within the above range, that is, by limiting the first layer 140 from exceeding the width range of the first metal plate 132, it is beneficial to further reduce the risk of burrs on the first metal plate 132 damaging the first current collector 1311 or causing a short circuit. It is also beneficial to further reduce the risk of interference between the first layer 140 and the coin cell 100 casing, thereby improving the production efficiency and performance of the coin cell 100.

[0064] like Figure 1 and Figure 4 As shown, in some embodiments, the button cell 100 further includes a second layer 170, which is connected to the first current collector 1311 and covers the first portion 1321 when viewed from the three directions Y'. The second layer 170 is located on the side of the first current collector 1311 away from the first layer 140. The second layer 170 extends out of the first current collector 1311 along the first direction Z and is connected to the first metal plate 132.

[0065] like Figure 2 and Figure 4 As shown, the first current collector 1311 has a first surface 500 and a second surface 600 disposed opposite to each other in the third direction Y', that is, the third direction Y' can be the thickness direction of the first current collector 1311. A first metal plate 132 is welded to the first surface 500, and a first active material layer 1317 is provided on both the first surface 500 and the second surface 600 of the first current collector 1311. A first layer 140 covers a first portion 1321 of the first metal plate 132, and a second layer 170 is located on the side of the first current collector 1311 opposite to the first layer 140, that is, the second layer 170 is located on the second surface 600 of the first current collector 1311. The second layer 170 covering the first portion 1321 means that the projection of the second layer 170 in the third direction Y' covers the first portion 1321. In other words, after the first metal plate 132 is welded to the first surface 500 of the first current collector 1311, the second layer 170 and the first layer 140 can be located on both sides of the first metal plate 132 along the thickness direction. The second layer 170 extends out of the first current collector 1311 along the first direction Z and is also connected to the first metal plate 132. The areas of the first layer 140 and the second layer 170 are both larger than the area of ​​the first part 1321.

[0066] In some embodiments, the second layer 170 may also be configured to correspond with the size specifications of the first layer 140. Specifically, as shown below... Figure 4 As shown, the width of the second layer 170 in the second direction X' can be W3mm, and 0.95R≤W3≤1.15R. In the second direction X', the second layer 170 also has a third side 143 and a fourth side 144. Optionally, the third side 143 and the first side 141 can be flush in the second direction X' (e.g., ...). Figure 4 and Figure 6 As shown), they can also be non-aligned; the fourth side 144 and the second side 142 can be aligned in the second direction X'. Figure 4 and Figure 6 As shown, the metal plate 132 may not be flush with the first metal plate 132. In this embodiment, the first metal plate 132 is double-wrapped by the first layer 140 and the second layer 170, which helps to further reduce the risk of burrs on the first metal plate 132 damaging the first current collector 1311 or causing a short circuit.

[0067] like Figure 1 and Figure 7 As shown, in some embodiments, the wound body 131 further includes a second electrode 1319 and a separating membrane 1313 disposed between the first electrode 1318 and the second electrode 1319. The second electrode 1319 includes a second current collector 1312, and the electrode assembly 130 includes a second metal plate 133, which is connected to the second current collector 1312.

[0068] The separator 1313 is a component used to separate the first current collector 1311 and the second current collector 1312 to prevent short circuits within the first electrode 1318 and the second electrode 1319, and to allow electrolytic ions to pass freely to form a conductive path. The separator 1313 is a porous plastic film, commonly made of materials including polypropylene (PP), polyethylene (PE), copolymers of propylene and ethylene, and polyethylene homopolymers. The second metal plate 133 is connected to the second current collector 1312, and the second metal plate 133 can be a cathode tab or an anode tab.

[0069] Furthermore, such as Figure 7 As shown, the second housing 120 is electrically connected to the first metal plate 132, and the first housing 110 is electrically connected to the second metal plate 133.

[0070] Electrical connection refers to the direct connection between the second housing 120 and the first metal plate 132, or the indirect connection between the first housing 110 and the second metal plate 133, or through conductive components. For example, in a specific embodiment, the second housing 120 and the first metal plate 132 can be connected and fixed by welding or other methods. The second metal plate 133 can first be connected to conductive components such as copper or nickel sheets, and then connected to the first housing 110 through the conductive components. In this application, the current generated by the electrode assembly 130 can be released through the housing of the coin cell 100, which helps to increase the contact area for charging and discharging the coin cell 100, thereby improving the charging and discharging reliability and performance of the coin cell 100.

[0071] Furthermore, such as Figure 7 As shown, the second housing 120 is welded to the first metal plate 132, and the first housing 110 is welded to the second metal plate 133. This welding method helps to improve the reliability of the connection between the first metal plate 132 and the second housing 120, and between the first housing 110 and the second metal plate 133.

[0072] In some embodiments, the first electrode 1318 is a cathode electrode, the second electrode 1319 is an anode electrode, the second housing 120 can be made of steel, aluminum, or an aluminum alloy, and the first housing 110 can be made of steel, which helps reduce the risk of corrosion of the second housing 120 and the first housing 110 due to differences in electrolyte or anode / cathode potentials. In some embodiments, the steel housing includes the elements Fe and C, and may also include one or more of the elements Ni, Co, Al, Mn, Cr, Cu, Mg, Mo, S, Si, Ti, V, Pb, Sb, N, and P. In some embodiments, the aluminum alloy housing includes the element Al, and may also include one or more of the elements Mn, Cr, Ni, Co, Cu, Fe, Mg, Si, Ti, V, and Zn. In some embodiments, a nickel (Ni) layer can be provided on the surface of the steel housing facing the winding body 131, which helps reduce the risk of corrosion of the steel housing by the electrolyte. In some embodiments, a nickel (Ni) layer can be provided on the surface of the steel housing away from the winding body 131, which helps reduce the risk of corrosion of the steel housing due to external environmental influences.

[0073] In some embodiments, the first electrode 1318 is an anode electrode, the second electrode 1319 is a cathode electrode, the second housing 120 can be made of steel, and the first housing 110 can be made of steel, aluminum, or aluminum alloy.

[0074] In some embodiments, such as Figure 12As shown, the first metal plate 132 is further away from the winding center axis M than the second metal plate 133. At this time, the first metal plate 132 is located outside the second metal plate 133. When the first metal plate 132 is connected to the second housing 120, limiting the angle between the first virtual line 150 and the second virtual line 160 to above 54° helps ensure the conductivity of the first metal plate 132 and reduces the risk of burrs on the first metal plate 132 damaging the first current collector 1311 or causing a short circuit. Limiting the angle between the first virtual line 150 and the second virtual line 160 to within 66° ensures a suitable width for the first layer 140, thereby reducing the risk of interference between the first layer 140 on the outer first metal plate 132 and the second housing 120 of the coin cell 100, and improving the manufacturing efficiency and packaging reliability of the coin cell 100.

[0075] In some embodiments, such as Figure 5 As shown, the first current collector 1311 includes a first region 1314 on which a first active material layer 1317 is disposed and a second region 1315 connected to the first region 1314 along the winding direction W of the winding body 131, that is, the second direction X'. A first part 1321 is connected to the second region 1315. The first layer 140 includes a third region 1316 covering the first active material layer 1317.

[0076] like Figure 5 and Figure 6 As shown, typically, the first current collector 1311 has a first active material layer 1317 on both sides of the third-direction Y', i.e., on the first surface 500 and the second surface 600, which is beneficial to improving the energy density of the battery. The first layer 140 has a third region 1316 that overlaps with the first region 1314 where the first active material layer 1317 is disposed, that is, as Figure 5 As shown, viewed from a third direction Y', the third region 1316 of the first layer 140 completely covers the tail region of the first active material layer 1317 near the first metal plate 132. In the second direction X', the third region 1316 overlaps with the first active material layer 1317; in the first direction Z, the overlap between the first layer 140 and the first current collector 1311 is equal to the width of the first current collector 1311. This arrangement helps reduce the risk of active material detaching from the first current collector 1311, improves the reliability of the coin cell, and saves on the material cost of the first active material layer 1317. Furthermore, when the first current collector 1311 is a cathode current collector, the third region 1316 covers the tail of the first active material layer 1317 of the cathode current collector, which helps to make the width of the active material layer of the cathode current collector smaller than the width of the active material layer of the anode current collector, thereby helping to reduce the risk of lithium plating in the cathode current collector.

[0077] In some embodiments, such as Figure 5 and Figure 6 As shown, along the winding direction W of the winding body 131, that is, the second direction X', there is a first distance b1 mm between the first side 141 and the first metal plate 132, a second distance b2 mm between the second side 142 and the first metal plate 132, and the width of the third region 1316 is b0 mm, where 0 < b0 < b1, and b2 < W2 - W1. As Figure 5 shown, the first distance between the first side 141 and the first metal plate 132 refers to the distance between the first side 141 and the first edge 134 of the first metal plate 132 in the second direction X'; the second distance between the second side 142 and the first metal plate 132 refers to the distance between the second side 142 and the second edge 135 of the first metal plate 132 in the second direction X'. The width of the third region 1316 refers to the width of the overlap between the third region 1316 and the first active material layer 1317 in the second direction X'. As Figure 5 shown, it is easy to understand that b1 + b2 = W2 - W1, that is, in the embodiments of the present application, when b2 < W2 - W1, the first distance b1 will not be 0.

[0078] When b0 > 0, it is beneficial to reduce the risk of the active material detaching from the first current collector 1311, improve the reliability of the button cell and save the material cost of the first active material layer 1317. It can also balance the distance between the first metal plate 132 and the first active material layer 1317, improve the uniformity of the current near the first metal plate 132, and reduce the risk of lithium plating.

[0079] When b0 < b1, the area of the first active material layer 1317 covered by the third region 1316 will not be too large, which is beneficial to improving the energy density of the battery.

[0080] Furthermore, as Figure 6 shown, the second layer 170 can also have a region with a width of b3 mm in the second direction X' and cover the tail of the first active material layer 1317 on the side of the first current collector 1311 facing away from the first metal plate 132, which is beneficial to further reducing the risk of the active material detaching from the first current collector 1311, improving the reliability of the button cell and saving the material cost of the first active material layer 1317; and when the first current collector 1311 is a cathode current collector, it is also beneficial to reduce the risk of lithium plating on the cathode current collector.

[0081] As can be seen from the above-mentioned multiple embodiments, the overlapping sizes of the first layer 140 and the second layer 170 with the first current collector 1311 in the first direction Z can be various. Specifically, define the size of the overlap of the first layer 140 or the second layer 170 with the first current collector 1311 in the first direction Z as D1 mm, define the size of the first part 1321 of the first metal plate 132 in the first direction Z as D2 mm, and define the width of the first current collector 1311 in the first direction Z as D3 mm. It is easy to understand that, as Figure 2 shown, when there is no area where the first layer 140 or the second layer 170 overlaps with the first active material layer 1317, D2 < D1 ≤ D3; or, as Figure 5 shown, when there is an area where the first layer 140 or the second layer 170 overlaps with the first active material layer 1317, D2 < D1 = D3.

[0082] In some embodiments, as Figure 7 shown, the first housing 110 includes a first column section 111 and a second column section 112. The first column section 111 is placed inside the second housing 120; the button cell 100 further includes a first insulating layer 180. The first insulating layer 180 is located between the first housing 110 and the second housing 120. The first insulating layer 180 includes a first section 181 and a second section 182. The first section 181 is located between the first column section 111 and the second housing 120, and the second section 182 extends out of the second housing 120. The first housing 110 and the second housing 120 are hermetically connected through the first insulating layer 180, which is beneficial to improving the convenience and reliability of the housing seal of the button cell 100.

[0083] In some embodiments, the material of the first insulating layer 180 includes at least one of polyethylene oxide, polyvinylidene fluoride, styrene-butadiene rubber, copolymer of vinylidene fluoride and hexafluoropropylene, polyvinylidene fluoride, modified polyvinylidene fluoride, polyacrylate, modified polyacrylate, modified polyethylene or modified polyvinylidene fluoride. By using the first insulating layer 180 made of the above materials to seal the first housing 110 and the second housing 120, it is beneficial to improve the housing seal reliability and performance of the button cell 100.

[0084] In some embodiments, as Figure 7As shown, along the first direction Z, the thickness of the electrode assembly 130 is T, the length of the second segment 182 is L1, and the length of the first segment 181 is L2, where 1 / 2T≤L2≤T, and L1<L2. The first segment 181 fills the space between the first pillar segment 111 and the second housing 120. Using a longer first segment 181 helps improve the sealing reliability between the first housing 110 and the second housing 120, thereby improving the performance of the coin cell 100. Furthermore, setting the thickness relationship between the first segment 181 and the electrode assembly 130 to satisfy the above formula helps improve the encapsulation reliability and further reduces the impact of the first layer 140 on the encapsulation of the second housing 120.

[0085] In some embodiments, such as Figure 7 As shown, along the first direction Z, there is a third distance S mm between the wound body 131 and the second housing 120, where 0.03T≤S≤0.1T. This arrangement helps to increase the energy density of the coin cell 100 while reducing the risk of the first housing 110 and / or the second housing 120 squeezing the electrode assembly 130, and further reduces the impact of the first layer 140 on the encapsulation of the second housing 120.

[0086] In some embodiments, the first portion 1321 is connected to the outermost ring of the first current collector 1311. Since the first portion 1321 is connected to the outermost ring of the first current collector 1311, and the outermost ring has a large radius of curvature, a larger first metal plate 132 can be selected to improve electrical performance. It can also reduce the impact on the thickness of the electrode assembly 130 when it is placed near the inner ring, thereby improving energy density and interface performance.

[0087] In this application, parameters such as the width W2 of the first layer 140 in the third direction Y', the width W1 of the first metal part 132 in the third direction Y', the distance R from the winding center axis M to the outer edge of the winding body 131, the first distance b1, the second distance b2, the width b0 of the third region, the thickness T of the electrode assembly 130, the length L1 of the second segment, the length L2 of the first segment, and the third distance S can be obtained by averaging multiple measurements of relevant parts of the button cell 100. For example, when measuring the width W2 of the first layer 140 using a measuring tool, 20 measurements can be performed, and then the average of the 20 measurements can be calculated to improve measurement error. This helps to improve the reliability of the data. The measuring tool can be, but is not limited to, a micrometer, a vernier caliper, a coordinate measuring machine, etc.

[0088] In some embodiments, the second metal plate 133 may be connected to the second housing 120. For example... Figure 10 and Figure 11As shown, the second metal plate 133 has a third layer 190. The second metal plate 133 is located outside the first metal plate 132, that is, when viewed from the first direction Z, the second metal plate 133 is farther away from the winding center axis M relative to the first metal plate 132. The width W6 of the third layer 190 in the second direction X' is greater than the width W7 of the second metal plate 133, and the third layer 190 has a fifth side 1901 and a sixth side 1902 in the second direction X'.

[0089] Specifically, such as Figure 11 The diagram shows the unwound structure of the second current collector 1312 and the second metal plate 133. A second active material layer 1320 is disposed on the surface of the second current collector 1312. Viewed from a third direction Y', the second metal plate 133 and the second current collector 1312 have an overlapping third portion 1903, and the second metal plate 133 also has a fourth portion 1904 extending in the first direction Z without overlapping with the second current collector 1312. The second metal plate 133 has a third side 136 and a fourth side 137 disposed opposite to each other, and a third layer 190 covers the third portion 1903, that is, the third layer 190 covers the third side 136 and the fourth side 137 of the second metal plate 133. A fifth side 1901 and a sixth side 1902 extend from the second current collector 1312 along the first direction Z. The fifth side 1901 intersects the second current collector 1312 at the third endpoint E, and the sixth side 1902 intersects the second current collector 1312 at the fourth endpoint F. like Figure 10 As shown, viewed from the first direction Z, the line connecting the third endpoint E and the winding center axis M of the winding body 131 is defined as the third virtual line 200, and the line connecting the fourth endpoint F and the winding center axis M is defined as the fourth virtual line 210. The included angle β between the third virtual line 200 and the fourth virtual line 210 is 54° to 66°.

[0090] When the angle β between the third virtual line 200 and the fourth virtual line 210 is ≥54°, both the third layer 190 and the second metal plate 133 have sufficient width, which helps to ensure the conductivity of the second metal plate 133 and also helps to reduce the risk of burrs on the second metal plate 133 damaging the second current collector 1312 or causing a short circuit. When the angle β between the third virtual line 200 and the fourth virtual line 210 is ≤66°, the width of the third layer 190 is appropriate, which helps to reduce the risk of interference between the third layer 190 on the outer second metal plate 133 and the second casing 120 of the button cell 100, thereby improving the manufacturing efficiency and packaging reliability of the button cell 100.

[0091] In some embodiments, such as Figure 1As shown, the first virtual line 150 or the extension of the first virtual line 150 at the first endpoint A passes through the second metal plate 133. Thus, when viewed from the outer circle to the inner circle of the winding body 131, there is an overlapping portion between the first metal plate 132 and the second metal plate 133, and the positions of the first metal plate 132 and the second metal plate 133 are relatively concentrated, which facilitates the simultaneous extension of the first metal plate 132 and the second metal plate 133 out of the current collector, thereby facilitating the connection with the battery casing.

[0092] In some embodiments, such as Figure 12 As shown, the second virtual line 160 or the extension of the second virtual line 160 at the second end point B passes through the second metal plate 133. Thus, when viewed from the outer circle to the inner circle of the winding body 131, there is an overlapping portion between the first metal plate 132 and the second metal plate 133, and the positions of the first metal plate 132 and the second metal plate 133 are relatively concentrated, which facilitates the simultaneous extension of the first metal plate 132 and the second metal plate 133 out of the current collector, thereby facilitating the connection with the battery casing.

[0093] In some embodiments, such as Figure 13 As shown, when viewed from the outer circle to the inner circle of the winding body 131, the first metal plate 132 and the second metal plate 133 do not overlap. That is, the first virtual line 150 or its extension at the first endpoint A does not pass through the second metal plate 133, and the second virtual line 160 or its extension at the second endpoint B also does not pass through the second metal plate 133. Thus, the first metal plate 132 and the second metal plate 133 are relatively dispersed. It is easy to understand that the design of the first layer 140 of the first metal plate 132 helps reduce the risk of burrs on the first metal plate 132 damaging the first current collector 1311 or causing a short circuit, and the design of the third layer 190 of the second metal plate 133 helps reduce the risk of burrs on the second metal plate 133 damaging the second current collector 1312 or causing a short circuit. By arranging the first metal plate 132 and the second metal plate 133 in a relatively dispersed manner, the protection range of the first layer 140 and the third layer 190 for the circumferential direction of the battery winding body 131 is improved, thereby improving battery performance.

[0094] In some embodiments, such as Figure 14As shown, in a direction perpendicular to the first direction Z, the first part 1321 overlaps with the third part 1903. The direction perpendicular to the first direction Z encompasses all possible directions on the plane perpendicular to the first direction Z. This facilitates increasing the connection size between the first part 1321 and the first current collector 1311 and / or the connection size between the third part 1903 and the second current collector 1312, improving connection stability and reducing connection impedance. It also helps reduce the difference in stress applied to the winding body 131 by the first part 1321 and the third part 1903 under external force, improving the uniformity of stress on the winding body 131 and enhancing safety performance.

[0095] Specifically, several embodiments and comparative examples are provided to illustrate the above implementation methods in more detail. Table 1 shows the experimental results of short-circuit and sealing tests using coin cells in various different states:

[0096] Table 1. Influence of first layer width and included angle on button cell performance.

[0097]

[0098] In the table above, the short-circuit test specifically refers to: first, charging the coin cell to its upper voltage limit with a 0.2C current, then continuing to charge under constant voltage until the charging current drops to 0.05C. Next, short-circuiting the positive and negative terminals of the coin cell using a wire with a resistance of 80±20mΩ, discharging until the coin cell experiences thermal failure or a short circuit for 24 hours, or until the casing temperature drops by 20% from the maximum temperature rise. The pass rate refers to the percentage of coin cells that can withstand a 24-hour short circuit. C refers to the coin cell's capacity; 0.2C means charging at 0.2 times the coin cell's capacity, meaning it takes 5 hours to charge to the rated capacity.

[0099] The sealing performance of the top and bottom covers refers to visual inspection or microscopic examination to check whether there are any leaks or discontinuities in the sealing of the button cell. If there are none, the sealing is excellent.

[0100] By comparing Example 1 and Comparative Example 2, it can be seen that when there is an overlapping area between the first layer 140 and the first active material layer 1317 (b0 is not 0), the coin cell performance of Example 1 is better than that of Comparative Example 2. That is, the overlapping area between the first layer 140 and the active material layer helps to reduce the risk of the active material detaching from the first current collector 1311, thereby improving the reliability and performance of the coin cell.

[0101] By comparing Example 2 and Comparative Example 1, it can be seen that the coin cell of Example 2 performs better than the coin cell of Comparative Example 1. That is, when the angle α between the first virtual line 150 and the second virtual line 160 is between 54° and 66° and the width W2 of the first layer 140 is within the size range of 0.95R≤W2≤1.15R, it is beneficial to improve the reliability and performance of the coin cell.

[0102] like Figure 8 As shown, a second aspect of this application provides an electronic device 10, including the button cell battery 100 described in the first aspect. The electronic device 10 of this application uses the button cell battery 100 of the first aspect as a power source.

[0103] It should be noted that, in this document, relational terms such as “first” and “second” are used merely to distinguish one entity from another, and do not necessarily require or imply any such actual relationship or order between these entities. Furthermore, the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that an article or apparatus comprising a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such an article or apparatus.

[0104] The above description is only a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the principles of this application should be included within the scope of protection of this application.

Claims

1. A button cell battery, comprising: The first housing has a recess facing a first direction; The second housing covers the recess and is connected to the first housing to form a receiving space; An electrode assembly, placed within the receiving space, includes a wound body and a first metal plate. The wound body includes a first electrode sheet, the first electrode sheet including a first current collector. The first metal plate is connected to the first current collector and extends outward from the first current collector along a first direction. The portion of the first metal plate connected to the first current collector is a first portion. The first direction is perpendicular to the winding direction of the wound body. The first layer is connected to and covers the first portion of the first metal plate. Along the winding direction, the first layer includes a first side and a second side. The first side and the second side extend the first current collector along the first direction. The first side intersects the first current collector at a first end point, and the second side intersects the first current collector at a second end point. The first layer includes a substrate layer and an adhesive layer disposed on the substrate layer. The adhesive layer is used to bond the first metal plate and the first current collector. The substrate layer is made of at least one of polyfluoroolefin, polyethylene terephthalate, polyimide, polyamide-imide, polyvinyl chloride, or polyolefin. Viewed from the first direction, the line connecting the first endpoint and the winding center axis of the winding body is defined as the first virtual line, and the line connecting the second endpoint and the winding center axis is defined as the second virtual line. The included angle between the first virtual line and the second virtual line is 54° to 66°.

2. The button cell battery according to claim 1, wherein, The width of the first metal plate along the winding direction is W1 mm, the width of the first layer along the winding direction is W2 mm, and the distance from the winding center axis to the outer edge of the winding body when viewed from the first direction is R mm, where 0.4R≤W1≤0.7R and 0.95R≤W2≤1.15R.

3. The button cell battery according to claim 1, wherein, The button cell also includes a second layer, which is in contact with the first current collector and covers the first portion. The second layer is located on the side of the first current collector away from the first layer, and extends out of the first current collector along the first direction and is in contact with the first metal plate.

4. The button cell battery according to claim 1, wherein, The winding body further includes a second electrode and a separating membrane disposed between the first electrode and the second electrode; The second electrode includes a second current collector, and the electrode assembly further includes a second metal plate connected to the second current collector.

5. The button cell battery according to claim 4, wherein, The second housing is electrically connected to the first metal plate, and the first housing is electrically connected to the second metal plate.

6. The button cell battery according to claim 5, wherein, The second housing is welded to the first metal plate, and the first housing is welded to the second metal plate.

7. The button cell battery according to claim 4, wherein, The first current collector includes a first region having a first active material layer and a second region connected to one side of the first region along the winding direction, the first portion being connected to the second region, and the first layer including a third region covering the first active material layer.

8. The button cell battery according to claim 7, wherein, Along the winding direction, the first side has a first distance b1 mm between it and the first metal plate, the second side has a second distance b2 mm between it and the first metal plate, and the width of the third region is b0 mm. <b0<b1,b2<W2-W1。 9. The button cell battery according to claim 4, wherein, The first electrode is a cathode electrode, the second electrode is an anode electrode, and the first metal plate is made of aluminum or an aluminum alloy.

10. The button cell according to claim 1, wherein, The first housing includes a first column segment and a second column segment connected to the first column segment in the first direction, wherein the first column segment is placed inside the second housing; The button cell also includes a first insulating layer, the first insulating layer including a first segment and a second segment connecting the first segment in the first direction, the first segment being located between the first post segment and the second housing, and the second segment extending out of the second housing.

11. The button cell according to claim 10, wherein, In the first direction, the thickness of the electrode assembly is T mm, the length of the second segment is L1 mm, the length of the first segment is L2 mm, 1 / 2T≤L2≤T, L1 <L2。 12. The button cell according to claim 10, wherein, In the first direction, there is a third distance S mm between the winding body and the second housing, where 0.03T≤S≤0.1T.

13. The button cell according to any one of claims 10 to 12, wherein, The material of the first insulating layer includes at least one of polyethylene oxide, polyvinylidene fluoride, styrene-butadiene rubber, copolymer of vinylidene fluoride and hexafluoropropylene, polyvinylidene fluoride, modified polyvinylidene fluoride, polyacrylate, modified polyacrylate, modified polyethylene, or modified polyvinylidene fluoride.

14. The button cell according to claim 1, wherein, The first part is connected to the outermost ring of the first current collector.

15. The button cell according to claim 4, wherein, The first metal plate is further away from the winding center axis than the second metal plate.

16. The button cell according to claim 4, wherein, The first virtual line or the extension of the first virtual line at the first endpoint passes through the second metal plate.

17. The button cell according to claim 4, wherein, The second virtual line or the extension of the second virtual line at the second endpoint passes through the second metal plate.

18. The button cell according to claim 4, wherein, The portion where the second metal plate is connected to the second current collector is the third portion, and the first portion overlaps with the third portion in a direction perpendicular to the first direction.

19. An electronic device, characterized in that, The electronic device includes a button battery as described in any one of claims 1 to 18.

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