Button cell and electronic device
Patent Information
- Application Number
- CN202280006999.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-06-21
- Publication Date
- 2026-10-27
- Estimated Expiration
- 2042-06-21
Smart Images
Figure CN116438706B_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of battery technology, and more particularly to a button cell battery and an electronic device. Background Technology
[0002] Button cells are typically regular cylindrical batteries packaged in a metal casing. The interior of a conventional button cell needs to operate in a relatively isolated space from the external environment, and this internal space is limited. During use, button cells may produce some gas. If this gas accumulates over time and is not properly channeled, it can increase the internal pressure of the button cell, potentially weakening its performance and safety. Summary of the Invention
[0003] This application aims to provide a button battery and electronic device with improved performance and safety.
[0004] This application provides the following technical solution to address its technical problem: a button cell battery, comprising a casing, an electrode assembly, and a first tab. The casing has a receiving cavity, in which the electrode assembly and the first tab are both received. The casing includes a first wall, and the first tab includes a first end and a second end disposed opposite to each other. The first end is connected to the electrode assembly, and the second end is connected to the first wall. The casing has a groove, which, when viewed along a first direction, includes at least two continuously connected curves. The orthographic projection of the first tab onto the first wall is a first projection. At least a portion of the two continuously connected curves lies outside the first projection. The number of intersection points between the outline of the first projection and the at least two continuously connected curves is less than or equal to two. The first direction is perpendicular to the first wall.
[0005] A groove is formed on the first wall of the casing, making the thickness of the first wall thinner at the groove location. When the internal pressure inside the casing increases, the groove will be ruptured by the gas inside the casing first. The ruptured groove can guide the gas out of the casing, which helps to reduce the risk of excessive internal pressure in the coin cell battery and improves the performance and safety of the coin cell battery. In addition, the groove includes at least two continuously connected curves, which can increase the stress concentration points of the groove, which helps to reduce the gas pressure required for the gas inside the casing to rupture the groove, further reducing the risk of excessive internal pressure in the coin cell battery. Moreover, coin cells are generally small in size, but in order to meet the design requirements of rate and electrical performance, as well as to improve the reliability of the connection between the first electrode and the casing and facilitate the connection between the first electrode and the casing during manufacturing, the first electrode needs to have a certain area and the first projection is relatively large relative to the first wall. The two continuously connected curves are designed so that at least a part of them are outside the first projection, and the number of intersection points between the outline of the first projection and the at least two continuously connected curves is less than or equal to two, which helps to improve the reliability of the groove's operation.
[0006] In some embodiments, the orthographic projection of the groove onto the first wall is the second projection, the area where the first and second projections overlap is P, the area of the first projection is Q, and P ≤ Q / 2. Satisfying this relationship reduces the risk of gas generated within the containment cavity being blocked by the first tab, facilitates timely gas compression of the groove, and ensures that the gas within the containment cavity can promptly break through the groove after reaching the required pressure, thus improving the safety of the button cell battery.
[0007] In some embodiments, when viewed along a first direction, the connection point between two adjacent curves of at least two continuously connected curves is a connection point, and at least one connection point is located outside the first projection. This reduces the risk of the connection point being completely covered by the first tab, and facilitates direct pressure relief of the gas inside the coin cell by compressing the connection point, thereby improving the safety of the coin cell.
[0008] In some embodiments, the groove is composed of two continuously connected curves, with the opposite ends of the groove being the third end and the fourth end. The first projection intersects the two continuously connected curves at a first intersection point and a second intersection point, with the first intersection point being closer to the third end than the second intersection point. The shortest distance from the third end to the edge of the first wall is S1, the shortest distance from the fourth end to the edge of the first wall is S2, the shortest distance from the first intersection point to the edge of the first wall is S3, and the shortest distance from the second intersection point to the edge of the first wall is S4, where S1 < S3, S2 < S3, S1 < S4, and S2 < S4. Thus, the two continuously connected curves pass through the two contour edges of the first projection, and the second projection is not completely covered by the first projection, meaning the groove is not completely covered by the first tab. This facilitates the gas in the containment cavity to break through the groove from the part not covered by the first tab, which helps the coin cell battery to release pressure in a timely manner. Furthermore, it saves on the installation of the groove, reduces the impact of the groove on the first wall, and results in a coin cell battery with a better lifespan.
[0009] In some embodiments, along the first direction, the thickness of the first wall is T1 μm, the depth of the groove is h μm, 0.2T1 < h < 0.7T1, and 30 ≤ T1 ≤ 300. Thus, the thickness of the first wall in the region where the groove is located will be thinner than the thickness of other regions of the first wall. The region where the groove is located is more easily deformed by the pressure of the gas inside the containment cavity, which facilitates the gas inside the containment cavity to break through the shell in the region where the groove is located, reducing the risk of excessive gas accumulation and excessive internal pressure in the coin cell. It can also reduce the impact of excessive groove thickness on the shell strength and improve the lifespan of the coin cell.
[0010] In some embodiments, the groove has a first cross-section in a direction perpendicular to its extension direction, and the first cross-section is trapezoidal in shape. In the first direction, the first cross-section has a first side and a second side disposed opposite to each other, the first side being closer to the receiving cavity than the second side, and the size of the first side being larger than the size of the second side. Thus, the inner wall of the groove forms an inclined surface relative to the surface of the first wall, which facilitates the convergence of gas within the receiving cavity towards the bottom of the groove and further facilitates the gas within the receiving cavity to push open the groove, thereby reducing the risk of excessive internal pressure in the coin cell battery.
[0011] In some embodiments, the coin cell further includes terminals, an insulator, and a second tab, with a first wall disposed opposite to the terminals in a first direction. The housing has an opening, with the terminals and insulator located at the opening and engaging to close it; the insulator insulates the terminals and housing. The second tab includes a fifth end and a sixth end disposed opposite to each other; the fifth end connects to an electrode assembly, and the sixth end connects to the terminals. Thus, the housing can serve as the electrodes of the coin cell to meet the needs of different assembly environments, facilitating direct electrical connection between the coin cell and electronic devices.
[0012] In some embodiments, the coin cell battery further includes an insulating member and a second tab. The housing includes a first housing and a second housing, which are connected and together form a receiving cavity. The insulating member insulates the first and second housings. The fifth end of the second tab is connected to an electrode assembly, and the sixth end of the second tab is connected to the second housing. A first wall is disposed on the first housing, and the first wall and the second housing are disposed opposite each other in a first direction. Thus, the first housing and the second housing respectively serve as the positive and negative terminals of the coin cell battery, which simplifies the assembly process and facilitates direct electrical connection between the coin cell battery and an electronic device.
[0013] In some embodiments, the adjacent curves of at least two continuously connected curves have the same orientation. This facilitates the creation of larger stress concentration points, improving the operational reliability of the groove; furthermore, it allows for the reduction and concentration of the groove within a certain range while meeting pressure relief reliability requirements, reducing the possibility of the groove occupying a large area of the first wall and facilitating other treatments of the first wall.
[0014] In some embodiments, the first electrode tab is welded to the first wall. This improves the reliability of the connection between the first electrode tab and the first wall.
[0015] In some embodiments, the first wall is flat. This facilitates better consistency of the grooves provided on the first wall along their extension direction, and also helps to improve the consistency of the grooves provided on different first walls in mass production.
[0016] In some embodiments, the electrode assembly is a wound structure or a stacked structure.
[0017] This application also provides an electronic device including the aforementioned button battery.
[0018] The beneficial effects of this application's embodiments are as follows: The button battery provided in this application's embodiments has a groove on the first wall of its casing, which is equivalent to thinning the area where the groove is located on the first wall. The groove is located in an area where the thickness of the first wall is small. When the internal pressure inside the casing increases, the groove will be ruptured by the gas inside the casing first. The ruptured groove can guide the gas inside the casing to flow out, which helps to reduce the risk of the button battery exploding and improves the performance and safety of the button battery. In addition, the groove includes at least two continuously connected curves, increasing the stress concentration points of the groove, which helps to reduce the gas pressure required for the gas inside the casing to rupture the groove, further helping to reduce the risk of excessive internal pressure in the button battery. Attached Figure Description
[0019] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly described below. Obviously, the drawings described below are only some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings.
[0020] Figure 1 This is a top view of a button cell according to one embodiment of this application;
[0021] Figure 2 yes Figure 1 A schematic diagram of one possible outcome after cutting along line AA;
[0022] Figure 3 yes Figure 1 A schematic diagram of another scenario after cutting along line AA;
[0023] Figure 4 yes Figure 2 A schematic diagram of the electrode assembly after being cut along line BB;
[0024] Figure 5 This is a schematic diagram of the orthographic projection of the groove of a current button cell onto the first wall.
[0025] Figure 6 This is a schematic diagram of the structure of the first electrode tab and the groove projected onto the first wall in one embodiment of this application;
[0026] Figure 7 This is a schematic diagram of the structure of the first electrode lug and the groove projected onto the first wall in another embodiment;
[0027] Figure 8This is a schematic diagram of the structure of the first electrode lug and the groove projected onto the first wall in another embodiment;
[0028] Figure 9 This is a schematic diagram of the structure of the first electrode lug and the groove projected onto the first wall in another embodiment;
[0029] Figure 10 yes Figure 8 A schematic diagram showing the overlap of the first electrode lug and the groove's orthographic projection onto the first wall;
[0030] Figure 11 This is a schematic diagram of the structure of the first electrode tab and the groove projected onto the first wall in one embodiment of this application;
[0031] Figure 12 This is a schematic diagram of the orthographic projection of the first electrode lug and the groove on the first wall in another embodiment;
[0032] Figure 13 This is a schematic diagram of the structure of the first electrode lug and the groove projected onto the first wall in another embodiment;
[0033] Figure 14 This is a schematic diagram of the structure of the first electrode lug and the groove projected onto the first wall in another embodiment;
[0034] Figure 15 This is a schematic diagram of the structure of the first electrode lug and the groove projected onto the first wall in another embodiment;
[0035] Figure 16 This is a schematic diagram of the structure of the first electrode lug and the groove projected onto the first wall in another embodiment;
[0036] Figure 17 This is a schematic diagram of the structure of the first electrode lug and the groove projected onto the first wall in another embodiment;
[0037] Figure 18 This is a schematic diagram of the structure of the first electrode lug and the groove projected onto the first wall in another embodiment;
[0038] Figure 19 This is a partial schematic diagram of the cross-sectional view of the first wall;
[0039] Figure 20 This is a cross-sectional view of a button battery according to yet another embodiment of this application;
[0040] Figure 21 This is a structural block diagram of an electronic device according to another embodiment of this application;
[0041] In the diagram: 100, button cell; 10, casing; 20, electrode assembly; 30, first tab; 40, second tab; 50, insulator; 60, terminal post; 31, first end; 32, second end; 41, fifth end; 42, sixth end; 101, receiving cavity; 102, opening; 201, first electrode; 202, second electrode; 203, separator; 110, first casing; 120, second casing; 112, first wall; 114, groove; 30a, first projection; 114a. Second projection; 1140, continuous curve; 1143, connection point; 1141, first curve; 1142, second curve; 311, first projection edge; 312, second projection edge; 313, third projection edge; 1140a, first part; 1140b, second part; 1144, third end; 1145, fourth end; 301, first intersection point; 302, second intersection point; 114b, first cross section; 114b1, first side; 114b2, second side; 200, electronic device. Detailed Implementation
[0042] To facilitate understanding of this application, a more detailed description is provided below with reference to the accompanying drawings and specific embodiments. It should be noted that when an element is described as "fixed to" / "connected to" another element, it can be directly on the other element, or one or more intermediate elements may exist between them. When an element is described as "connected to" another element, it can be directly connected to the other element, or one or more intermediate elements may exist between them. The terms "end," "lower," "rearward," etc., used in this specification indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.
[0043] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the scope of this application.
[0044] Furthermore, the technical features involved in the different embodiments of this application described below can be combined with each other as long as they do not conflict with each other.
[0045] like Figure 1-2 As shown, Figure 1 This is a top view of a button cell 100 according to one embodiment of this application. Figure 2 yes Figure 1A schematic diagram cut along line AA shows that one embodiment of the coin cell 100 provided in this application includes a housing 10, an electrode assembly 20, and a first tab 30. The housing 10 has a receiving cavity 101, in which the electrode assembly 20 and the first tab 30 are both housed. The receiving cavity 101 can hold an electrolyte (not shown in the figure). The first tab 30 has a first end 31 and a second end 32, which are oppositely disposed. The first end 31 is connected to the electrode assembly 20, and the second end 32 is connected to the inner wall of the housing 10. Thus, the housing 10 can directly serve as the electrode of the coin cell 100. It should be understood that although... Figure 1-2 The housing 10 shown is cylindrical, but the shape of the housing 10 is not limited to the cylindrical shape shown in the figure. It can also be other shapes, as long as it can accommodate the electrode assembly 20 and the electrolyte.
[0046] The housing 10 is made of a metallic or alloy material. In some embodiments, when the housing 10 is connected to the positive electrode, the housing 10 may be made of aluminum or an aluminum alloy. The aluminum alloy housing includes the element Al and one or more of Mn, Cr, Ni, Co, Cu, Fe, Mg, Si, Ti, V, and Zn, which can reduce the risk of the housing 10 being corroded by the electrolyte. In some embodiments, when the housing 10 is connected to the negative electrode, the housing 10 may be made of steel. The steel housing includes the elements Fe and C, and may also include one or more of Ni, Co, Al, Mn, Cr, Cu, Mg, Mo, S, Si, Ti, V, Pb, Sb, N, and P, which can reduce the risk of the housing 10 being corroded by the electrolyte. In some embodiments, when the housing 10 is a steel housing, a nickel (Ni) layer may be provided on the surface of the housing 10 facing the electrode assembly 20, which helps to further reduce the risk of the housing being corroded by the electrolyte. In some embodiments, a nickel (Ni) layer may be provided on the surface of the housing 10 away from the electrode assembly 20, which helps to reduce the risk of the housing 10 being corroded by the external environment.
[0047] like Figure 2 and Figure 3 As shown, the electrode assembly 20 includes a first electrode 201, a second electrode 202, and a separating membrane 203. The separating membrane 203 is disposed between the first electrode 201 and the second electrode 202. The first electrode 201 and the second electrode 202 have different polarities, and the separating membrane 203 is used to reduce the risk of short circuit between the first electrode 201 and the second electrode 202. In one embodiment, such as... Figure 2 and Figure 4 As shown, Figure 4 yes Figure 2A schematic diagram of the middle electrode assembly after being cut along straight line BB. The first electrode 201, the second electrode 202, and the separator 203 are stacked and wound to form a wound structure. In another embodiment, such as... Figure 2 or Figure 3 The number of first electrode 201, second electrode 202 and separator 203 shown are multiple. Multiple first electrode 201, multiple second electrode 202 and multiple separator 203 are stacked along the thickness direction of separator 203. At this time, the thickness direction of electrode assembly 20 is the same as the thickness direction of separator 203.
[0048] It should be understood that in the second case, the thickness direction of the electrode assembly 20 may be the same as or different from the thickness direction of the housing 10. For example, as Figure 2 As shown, with Figure 2 In the first direction X, the thickness direction of the housing 10 is different from that of the housing 10. At this time, the thickness direction of the isolation membrane 203 is perpendicular to the first direction X.
[0049] The first end 31 of the first electrode tab 30 can be connected to either the first electrode plate 201 or the second electrode plate 202, depending on actual needs. For ease of description, the following detailed explanation will take the connection of the first end 31 of the first electrode tab 30 to the first electrode plate 201 as an example.
[0050] The button cell battery 100 needs to operate in a relatively isolated space from the external environment, and its internal space is limited. During use, some gas may be generated. If this gas accumulates over time and is not properly released, the internal pressure of the button cell battery 100 will increase, potentially weakening its performance and safety, thus posing a safety hazard. Therefore, it is necessary to design a structure to promptly release the excess gas pressure inside the button cell battery 100, reducing the risk of explosion.
[0051] The button cell battery 100 can have different explosion-proof methods. One method is to install an explosion-proof valve directly on the casing, which is connected to the receiving cavity inside the casing. However, this explosion-proof method requires the installation of an additional explosion-proof valve, which is relatively expensive.
[0052] Another approach involves creating a weak point on a portion of the casing surface, where the casing has a thinner section. When the gas pressure reaches a certain level, this thin point can be breached to release pressure. The inventors of this application discovered that the location and structural design of the weak point in this explosion-proof method are too arbitrary. This can lead to the weak point being covered by the tab, preventing the button cell from releasing pressure properly and posing a safety hazard. Therefore, the inventors of this application have designed the shape of the weak point and its position relative to the first tab to improve the safety performance of the button cell. The specific solution is as follows.
[0053] In some embodiments, such as Figure 2 As shown, the housing 10 includes a first housing 110 and a second housing 120, which are connected to form a receiving cavity 101. The first housing 110 includes a first wall 112 and a groove 114 disposed on the first wall 112. The groove 114 may be located on the side of the first wall 112 facing the electrode assembly 20, or it may be located on the side of the first wall 112 away from the electrode assembly 20, depending on actual needs. In the accompanying drawings of this embodiment, the structure of the button cell battery of this application is illustrated with an example of the groove 114 being located on the side of the first wall 112 facing the electrode assembly 20.
[0054] The first tab 30 is connected to the first wall 112. The connection can be achieved by welding, by using an adhesive with conductive properties, or by other means.
[0055] Taking the direction perpendicular to the surface of the first wall 112 near the electrode assembly 20 as the first direction X, when viewed along the first direction X, the orthographic projection of the first electrode tab 30 on the first wall 112 is the first projection 30a, and the orthographic projection of the groove 114 on the first wall 112 is the second projection 114a. The outline of the first projection 30a refers to the edge outline of the projected shape of the first electrode tab 30 projected onto the surface of the first wall 112 in the first direction X. The outline of the second projection 114a refers to the edge outline of the projected shape of the groove 114 projected onto the surface of the first wall 112 in the first direction X.
[0056] The inventors of this application discovered that, Figure 5As shown, when the groove 114 is designed as a circular arc groove, its outline projected onto the surface of the first wall 112 forms a circular arc curve. The position of the groove 114 is arbitrarily set, which poses a risk that the groove 114 may be completely covered by the first tab 30, increasing the difficulty for gas in the receiving cavity 101 to break through the groove 114, which is not conducive to improving the safety performance of the button battery 100. In addition, the stress concentration points of the groove 114 are insufficient, and the reliability of pressure relief needs to be improved. To this end, the inventors of this application have improved the shape and position of the groove 114, designing the groove 114 to include at least two continuously connected curves, and at least a portion of the two continuously connected curves is located outside the outline of the first projection 30a, and the number of intersection points between the outline of the first projection 30a and the at least two continuously connected curves is less than or equal to 2.
[0057] A groove 114 is provided on the first wall 112 of the housing 10, making the thickness of the groove 114 on the first wall 112 thinner. When the internal pressure inside the housing 10 increases, the groove 114 will be ruptured by the gas inside the housing first. The ruptured groove 114 can guide the gas inside the housing to flow out, which helps to reduce the risk of excessive internal pressure in the coin cell battery 100 and improves the performance and safety of the coin cell battery 100. In addition, the groove 114 includes at least two continuously connected curves, increasing the stress concentration points of the groove 114, which helps to reduce the gas pressure required for the gas inside the housing 10 to rupture the groove 114, further helping to reduce the risk of excessive internal pressure in the coin cell battery 100. Furthermore, while the button cell 100 is generally small in size, in order to meet the design requirements of high rate and equal electrical performance, as well as to improve the reliability of the connection between the first tab 30 and the housing 10 and facilitate the connection between the first tab 30 and the housing 10 during manufacturing, the first tab 30 needs to have a certain area, and the first projection 30a has a relatively large proportion relative to the first wall 112. At least a portion of at least two continuously connected curves are located outside the first projection 30a, and the number of intersection points between the outline of the first projection 30a and the at least two continuously connected curves is less than or equal to 2, which is beneficial to improving the working reliability of the groove 114.
[0058] In some embodiments, such as Figure 6-17 Viewed from the first direction X, the first pole ear 30 has a first projection edge 311, a second projection edge 312 and a third projection edge 313 on the outline of the first projection 30a of the first wall 112. The first projection edge 311 and the second projection edge 312 are two projection edges that are arranged opposite to the first projection 30a. The third projection edge 313 connects the first projection edge 311 and the second projection edge 312.
[0059] The curve of the groove 114 described in this application refers to a line that extends continuously on one side of the direction perpendicular to the extension direction of the groove 114, as viewed from the first direction X. The connection point is defined as the junction between two adjacent curves in at least two continuously connected curves. It is understood that the abrupt change in shape at the connection point between at least two continuously connected curves is conducive to the formation of a stress concentration point, i.e., the stress is more concentrated at the connection point, which is the weakest point. This allows the gas pressure inside the coin cell 100 to first break through the connection point and then spread outwards to create a tear, thereby breaking through the groove 114. This facilitates the timely release of gas inside the coin cell 100 and enhances the safety of the coin cell 100.
[0060] A continuous curve 1140 is defined as a curve with at least two consecutive connected segments. A continuous curve 1140 is a single, continuous curve, which is composed of multiple consecutive connected segments. Adjacent segments may have the same or different orientations. A continuous curve 1140 can consist of only two consecutive connected segments, or it can consist of three or more segments, depending on the specific requirements. Based on the orientation of the multiple consecutive connected segments of a continuous curve 1140, the following cases exist:
[0061] (1) If two adjacent curves in several consecutively connected curves have different curvature orientations, this can be determined based on the number of orientation changes of the consecutively connected curves. If the number of orientation changes of the consecutively connected curves of continuous curve 1140 is one, then continuous curve 1140 has two consecutively connected curves; if the number of orientation changes of the consecutively connected curves of continuous curve 1140 is two, then continuous curve 1140 has three consecutively connected curves, and so on. This will not be elaborated further here. In this case, the connection point 1143 between two adjacent curves is the inflection point. For example, as shown... Figure 9 As shown, the orientation of the multiple connected curve segments in continuous curve 1140 changes once, meaning that continuous curve 1140 is now composed of two continuously connected curve segments, as shown below. Figure 9 The first curve 1141 and the second curve 1142 are shown in the figure. The connection point between the first curve 1141 and the second curve 1142 is the connection point 1143.
[0062] (2) If several consecutive curve segments all have the same orientation, and the continuous curve 1140 is observed from the same angle and with the same reference object, if the continuous curve 1140 has n concave parts relative to the reference object, then the continuous curve 1140 corresponds to a continuous curve segment of n segments. In this case, the connection point between two adjacent curve segments is located at the point where the shape of two adjacent concave parts changes abruptly. Figure 11Taking the example, the continuous curve 1140 has two concave parts relative to the third projection edge 313 (with the third projection edge 313 as a reference). At this time, the continuous curve 1140 is composed of two continuously connected curves, and the shape of the continuous curve 1140 changes abruptly at the connection point 1143. It can be determined that the connection point of the two curves is located at the connection point 1143.
[0063] (3) If the continuous curve 1140 includes parts with the same orientation and parts with different orientations, then the continuous parts of the continuous curve 1140 with different orientations can be divided into the first part, and the curves of the continuous curve 1140 with the same orientation connected to the first part are the second part. The specific number of curve segments and the number of inflection points in the first part are determined according to the method in case (1) above, and the second part is determined according to the method in case (2) above. This will not be repeated here. For example, to facilitate understanding case (3), Figure 8 Taking the shape of the continuous curve 1140 shown as an example, the continuous curve 1140 includes a first part 1140a with opposite orientations and a second part 1140b connected to the first part 1140a. The multiple curve segments connected in the first part 1140a have different orientations. In this case, it can be determined from the situation in (1) that the first part 1140a is composed of two curve segments connected together, and the orientation of the second part 1140b is the same as the orientation of the curves it is connected to. Figure 8 The second part 1140b shown in the figure consists of only one segment, therefore it can be directly determined that the second part 1140b has only one curve segment, that is... Figure 8 The continuous curve 1140 consists of three consecutive connected curve segments. Understandably, if the second part 1140b can be extended to form multiple curves facing the same direction, then the number of curves and the number of connection points are determined according to situation (2).
[0064] For example, the outline of the first projection 30a intersects the continuous curve 1140 at two points, that is, at this time, the projections of the groove 114 and the first tab 30 onto the first wall 112 in the first direction X have an overlapping portion. The overlap between the first projection 30a and the continuous curve 1140 includes, but is not limited to, the following situations: (1) such as Figure 6-11 As shown, the continuous curve 1140 passes through the first projection edge 311 and the second projection edge 312; (2) as Figure 12 As shown, the continuous curve 1140 passes through the first projection edge 311 and the third projection edge 313; (3) as Figure 13 As shown, the continuous curve 1140 passes through the second projection edge 312 and the third projection edge 313; (4) as Figure 14As shown, the continuous curve 1140 intersects only the first projection edge 311, that is, the continuous curve 1140 enters from the first projection edge 311 and extends out of the first projection edge 311 from the first projection edge 311 into the first projection 30a; (5) as Figure 15 As shown, the continuous curve 1140 intersects only the second projection edge 312, that is, along the direction of extension of the second projection 114a, the continuous curve 1140 enters from the second projection edge 312 and extends out of the second projection edge 312 into the first projection 30a.
[0065] For example, such as Figure 16 or Figure 17 As shown, the outline of the first projection 30a intersects the continuous curve 1140 at one point. The area occupied by the first projection 30a on the surface of the first wall 112 is defined as the first region, and the area on the surface of the first wall 112 excluding the first region is defined as the second region. That is, one end of the continuous curve 1140 is located in the second region, and the other end of the continuous curve 1140 extends into the first region from the first projection edge 311, the second projection edge 312, or the third projection edge 313.
[0066] For example, such as Figure 18 As shown, the outline of the first projection 30a has no intersection with the continuous curve 1140. At this time, the first projection 30a and the second projection 114a do not overlap on the first wall 112. At this time, the first tab 30 does not cover the groove 114.
[0067] In some embodiments, please refer again Figure 10 Let Q be the area of the first projection 30a, and P be the area where the first projection 30a and the second projection 114a coincide in the first direction X, satisfying P≤Q / 2. When this relationship is satisfied, the risk of gas generated in the receiving cavity 101 being blocked by the first tab 30 can be reduced, which is beneficial for the gas to squeeze the groove 114 in time, and for the gas in the receiving cavity 101 to break through the groove 114 in time after reaching the gas pressure required to break through the groove 114, thereby improving the safety of the button battery 100.
[0068] In some embodiments, please refer again Figure 9The continuous curve 1140 comprises two continuously connected curves, namely the first curve 1141 and the second curve 1142, with the connection point 1143 being the junction of the first curve 1141 and the second curve 1142. The two ends of the groove 114 are the third end 1144 and the fourth end 1145. Since the continuous curve 1140 is an edge line of the groove 114, the two ends of the groove 114 are also the two ends of the continuous curve 1140. The first projection 30a intersects the continuous curve 1140 at the first intersection point 301 and the second intersection point 302, with the first intersection point 301 being closer to the third end 1144 than the second intersection point 302. At this point, the shortest distance from the third end 1144 to the edge of the first wall 112 is S1, the shortest distance from the fourth end 1145 to the edge of the first wall 112 is S2, the shortest distance from the first intersection point 301 to the edge of the first wall 112 is S3, and the shortest distance from the second intersection point 302 to the edge of the first wall 112 is S4, satisfying: S1 < S3, S2 < S3, S1 < S4, S2 < S4. When this relationship is satisfied, the continuous curve 1140 passes through at least two projection edges of the first projection 30a, which can be the first projection edge 311 and the second projection edge 312, or the first projection edge 311 (or the second projection edge 312) and the third projection edge 313. Thus, in the first direction X, the second projection 114a has a portion not covered by the first projection 30a, indicating that the groove 114 is not completely covered by the first tab 30. This is beneficial for the gas in the receiving cavity 101 to break through the groove 114 from the portion of the groove 114 not covered by the first tab 30, which is beneficial for the button battery 100 to release pressure in a timely manner.
[0069] It is understandable that the first curve 1141 and the second curve 1142 have the same orientation and their shapes change at the connection point 1143. This increases the stress concentration at the inflection point of the first curve 1141 and the second curve 1142, which is beneficial to improving the safety of the button cell 100.
[0070] It should be noted that the measurements of S1, S2, S3, and S4 can be obtained by first scanning the button cell 100 with a CT (Computed Tomography) instrument to obtain a metallographic image of the first tab 30 and the groove 114 superimposed. Based on the obtained metallographic image, the edge contour of the first wall 112 is divided into several equal points at a preset interval. The distances from the several equal points to the same measurement point are measured. Then, the smallest of the multiple distances measured at the same measurement point is taken as the minimum distance of that measurement point. For example, if the minimum distance from the first intersection point 301 to the first wall 112 is to be measured, the edge contour of the first wall 112 is divided into n equal points at 3mm intervals. The distances from these n equal points to the first intersection point 301 are measured respectively, and the smallest of the measured distances is taken as the minimum distance from the first intersection point 301 to the edge of the first wall 112.
[0071] In some embodiments, when viewed along the first direction X, at least one connection point 1143 is located outside the first projection 30a. This reduces the risk that the connection point 1143 is completely covered by the first tab 30, which is beneficial for the gas inside the button cell 100 to directly compress the connection point 1143, thereby releasing the gas pressure inside the button cell 100 in a timely manner and improving the safety of the button cell 100.
[0072] In some embodiments, along the first direction X, the thickness of the first wall 112 is T1 μm, the depth of the groove 114 is h μm, 0.2T1 < h < 0.7T1, and 30 ≤ T1 ≤ 300. Thus, the thickness of the first wall 112 in the region where the groove 114 is located is thinner than the thickness of other regions of the first wall 112. The region where the groove 114 is located is more easily deformed by the pressure of the gas inside the containment cavity, which facilitates the gas inside the containment cavity breaking through the shell in the region where the groove 114 is located. This reduces the risk of excessive gas accumulation and excessive internal pressure inside the coin cell 100, and also reduces the impact of excessive groove 114 thickness on the strength of the shell 10, thus improving the service life of the coin cell 100. On the other hand, the relatively thin first wall 112 in the region where the groove 114 is located reduces the risk of the coin cell 100 failing due to the groove 114 being punctured by external force after the first wall 112 is subjected to vibration or slight impact during transportation. The depth of groove 114 refers to the maximum depth of groove 114. It can be measured by acquiring a cross-sectional image of the first wall 112 and measuring the depth in the image; or it can be measured by an instrument in the first direction X.
[0073] In some embodiments, such as Figure 19 As shown, in a direction perpendicular to the extending direction of the groove 114, the groove 114 has a first cross-section 114b. The first cross-section 114b has a first side 114b1 and a second side 114b2 disposed opposite to each other, with the first side 114b1 being closer to the receiving cavity 101 than the second side 114b2. The dimension of the first side 114b1 is a μm, and the dimension of the second side 114b2 is b μm.
[0074] It is understandable that the shape of the first section 114b can be varied, such as a trapezoid, a pentagon, or other irregular polygon, as long as the above-mentioned size relationship is met.
[0075] Furthermore, b < a, the shape of the first cross-section 114b is trapezoidal, and the groove 114 is disposed on the side of the first wall 112 near the receiving cavity 101. In this way, the inner wall of the groove 114 will form an inclined surface relative to the surface of the first wall 112, which is conducive to the gas in the receiving cavity 101 converging from the first side 114b1 towards the second side 114b2, that is, conducive to the gas in the receiving cavity 101 converging towards the groove 114, and even more conducive to the gas in the receiving cavity 101 rushing open the groove 114, thereby reducing the risk of the button battery 100 exploding.
[0076] The direction perpendicular to the first direction X is defined as the second direction Y. The shape of the housing 10 can be cylindrical. In this case, the first direction X is the height direction of the housing 10, and the second direction Y is the radial direction of the cylindrical housing 10. By cutting the first housing 110 along the second direction Y passing through the groove 114, the first cross-section 114b can be obtained. In some embodiments, the shape of the housing 10 can also be non-cylindrical. For example, it can be a columnar body with a D-shaped cross-section profile when transversely cut along the second direction Y. Of course, it can also be other shapes. The shape of the housing 10 can be designed according to actual needs.
[0077] In some embodiments, the housing 10 is cylindrical, and the first housing 110 and the second housing 120 can be directly or indirectly connected to form the aforementioned receiving cavity 101. In one case, such as... Figure 20 As shown, when the first housing 110 is indirectly connected to the second housing 120, the button cell 100 also includes a second tab 40 and an insulating member 50. The second tab 40 includes a fifth end 41 and a sixth end 42, which are the two ends of the second tab 40 that are disposed opposite to each other. The insulating member 50 is disposed between the first housing 110 and the second housing 120, and is used to insulate the first housing 110 from the second housing 120. The insulating member 50 can be installed on the first housing 110 or the second housing 120 by means of bonding or the like. The second tab 40 can be directly connected to the inner wall of the second housing 120, that is, the fifth end 41 is connected to the second electrode 202, and the sixth end 42 is connected to the second housing 120. The first wall 112 is disposed on the first housing 110, and the first wall 112 and the second housing 120 are disposed opposite to each other in the first direction X. Thus, under the insulating effect of the insulating member 50, the first housing 110 and the second housing 120 have different polarities. Insulator 50 may include, but is not limited to, gaskets made of insulating materials.
[0078] In another case, please refer to [the relevant documentation]. Figure 2The first housing 110 and the second housing 120 can be directly connected by welding or threaded connection. The button cell 100 includes a second tab 40, an insulating member 50, and a terminal 60. The insulating member 50 is used to insulate the terminal 60 from the housing 10. The housing 10 has an opening 102. The insulating member 50 is installed in the opening 102 and sleeves the terminal 60 so that the terminal 60 is snapped into the housing 10. The terminal 60 and the insulating member 50 cooperate to close the opening 102. The fifth end 41 of the second tab 40 is connected to the second electrode 202, and the sixth end 42 of the second tab 40 is connected to the terminal 60. The housing 10 and the terminal 60 have different polarities. The first wall 112 is disposed in the first housing 110, and the first wall 112 and the terminal 60 are disposed opposite each other in a first direction.
[0079] It is understood that the second housing 120 is a rotating body with a receiving space, for example, the second housing 120 is in the shape of a regular cylinder or other shapes; the first housing 110 is in the shape of a flat plate, and the first housing 110 is connected to the second housing 120 to form the aforementioned housing 10. The first wall 112 may be provided in the first housing 110 or in the second housing 120, depending on the specific needs.
[0080] The button cell 100 provided in this application embodiment includes a housing 10, an electrode assembly 20, and a first tab 30. The housing 10 is provided with a receiving cavity 101 and includes a first wall 112. The electrode assembly 20 and the first tab 30 are both received in the receiving cavity 101. The first end 31 of the first tab 30 is connected to the electrode assembly 20, and the second end 32 of the first tab 30 is connected to the first wall 112. The housing 10 is provided with a groove 114. When viewed along the first direction X, the groove 114 includes at least two continuously connected curves. The projection of the first tab 30 onto the first wall 112 is a first projection 30a, and the projection of the groove 114 onto the first wall 112 is a second projection 114a. At least a portion of the at least two continuously connected curves is located outside the first projection 30a. The number of intersection points between the outline of the first projection 30a and the at least two continuously connected curves is less than or equal to two. The first direction X is perpendicular to the first wall 112. With the above structure, the first wall 112 is thin at the groove 114. When the gas pressure inside the receiving cavity 101 increases to a level sufficient to break through the groove 114, the groove 114 is squeezed and broken through by the gas inside the receiving cavity 101, allowing the gas inside the coin cell 100 to be released in time, reducing the risk of explosion caused by excessive internal gas pressure. At the same time, the groove 114 of this application includes at least two continuously connected curves. Multiple continuously connected curves can increase the stress concentration of the first wall 112 at the groove 114, and the stress concentration at the connection point between the multiple continuously connected curves is obvious, which is conducive to the gas inside the receiving cavity 101 breaking through the groove 114, thus improving the safety of the coin cell 100.
[0081] like Figure 21 As shown, another embodiment of this application provides an electronic device 200, which includes the aforementioned button cell battery 100, and the button cell battery 100 is used to provide power to the electronic device 200.
[0082] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them; under the concept of this application, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of this application as described above, which are not provided in detail for the sake of brevity; although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.
Claims
1. A button cell battery, comprising a casing, an electrode assembly, and a first tab, wherein the casing has a receiving cavity, and the electrode assembly and the first tab are both received within the receiving cavity; the casing includes a first wall, which is an end wall of the button cell battery, and the first tab includes a first end and a second end disposed opposite to each other, the first end being connected to the electrode assembly, and the second end being connected to the first wall; the casing is cylindrical; characterized in that, The housing is provided with a groove. When viewed along the first direction, the groove includes at least two continuously connected curves. The orthographic projection of the first tab onto the first wall is the first projection. At least a portion of the at least two continuously connected curves is located outside the first projection. The number of intersection points between the outline of the first projection and the at least two continuously connected curves is 2, and the 2 intersection points are located on different segments of the curves. The first direction is perpendicular to the first wall. Wherein, the orthographic projection of the groove on the first wall is the second projection, the area where the first projection and the second projection overlap is P, the area of the first projection is Q, and P≤Q / 2.
2. The button cell battery according to claim 1, characterized in that, When viewed along the first direction, the connection point between two adjacent curves of the at least two continuously connected curves is a connection point, and at least one of the connection points is located outside the first projection.
3. The button cell battery according to claim 1, characterized in that, The groove is composed of two continuously connected curves, and the two opposite ends of the groove are the third end and the fourth end. The first projection intersects the two continuously connected curves at a first intersection point and a second intersection point. The first intersection point is closer to the third end than the second intersection point. The shortest distance from the third end to the edge of the first wall is S1, the shortest distance from the fourth end to the edge of the first wall is S2, the shortest distance from the first intersection point to the edge of the first wall is S3, and the shortest distance from the second intersection point to the edge of the first wall is S4, where S1 < S3, S2 < S3, S1 < S4, and S2 < S4.
4. The button cell battery according to claim 1, characterized in that, Along the first direction, the thickness of the first wall is T1 μm, the depth of the groove is h μm, 0.2T1≤h≤0.7T1, 30≤T1≤300.
5. The button cell battery according to claim 1, characterized in that, In a direction perpendicular to the extension direction of the groove, the groove has a first cross section, the first cross section being trapezoidal in shape, and in the first direction, the first cross section having a first side and a second side disposed opposite to each other, the first side being closer to the receiving cavity than the second side, and the size of the first side being larger than the size of the second side.
6. The button cell battery according to claim 1, characterized in that, The button cell also includes a terminal post, an insulating component, and a second tab. The housing has an opening, and the terminal post and the insulating component are located at the opening. The terminal post and the insulating component cooperate to close the opening. The insulating component insulates the terminal post from the housing. The second tab includes a fifth end and a sixth end that are disposed opposite to each other. The fifth end is connected to the electrode assembly, and the sixth end is connected to the terminal post. The first wall and the pole are disposed opposite to each other in the first direction.
7. The button cell battery according to claim 1, characterized in that, The button cell also includes an insulating element and a second tab. The housing includes a first housing and a second housing, the first housing being connected to the second housing, and the first housing and the second housing together forming the receiving cavity. The insulating element is disposed between the first housing and the second housing, and the insulating element insulates the first housing and the second housing. The second tab includes a fifth end and a sixth end disposed opposite to each other. The fifth end is connected to the electrode assembly, and the sixth end is connected to the second housing. The first wall is disposed on the first housing, and the first wall and the second housing are disposed opposite to each other in the first direction.
8. The button cell battery according to claim 1, characterized in that, The two adjacent segments of the at least two continuously connected curves have the same orientation.
9. The button cell battery according to claim 1, characterized in that, The first electrode tab is welded to the first wall.
10. The button cell battery according to claim 1, characterized in that, The first wall is flat.
11. The button cell battery according to claim 1, characterized in that, The electrode assembly has a wound structure or a stacked structure.
12. An electronic device, characterized in that, Includes the button cell as described in any one of claims 1 to 11.
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