Cover plate assembly and button cell

Abstract

The utility model provides a cover plate assembly and a button cell, the cover plate assembly comprises a cover plate main body, a first insulating part and a conductive part, the cover plate main body comprises a first part and a second part, the second part comprises a bottom wall and a side wall, the bottom wall and the side wall define a containing groove, the first part is connected to the side wall in a surrounding manner, and the conductive part is arranged in the first direction; height difference exists between the first part and the bottom wall, and a through hole is formed in the bottom wall; the first insulating part is provided with a first through hole, the first through hole is communicated with the through hole, and at least one part of the first insulating part is located in the containing groove and connected with the bottom wall; the conductive part is connected to one side, deviating from the bottom wall, of the first insulating part and covers the first through hole; the side wall and the first part are used for being matched with the cavity wall of the containing cavity to define a first containing space. The button battery comprises a roll core, a shell and the cover plate assembly, the roll core is located in the containing cavity of the shell, and the cover plate assembly is connected with the shell. According to the cover plate assembly and the button cell, the overflow of the electrolyte can be effectively relieved, and the electrolyte retention capacity of the button cell is improved.

Description

Technical Field

[0001] This application relates to the field of battery technology, specifically to a cover plate assembly and a button battery. Background Technology

[0002] In the field of battery technology, button batteries typically consist of three parts: a cover, a core, and a casing. The casing has a receiving cavity, and the core is located within the receiving cavity. The cover is welded to the casing to seal the receiving cavity. However, during the welding of the cover, it comes into contact with the electrolyte inside the receiving cavity, causing the electrolyte level to rise and making it prone to overflow. This affects the welding quality of the cover and the performance of the battery. Utility Model Content

[0003] This application aims to address at least one of the technical problems existing in the prior art. To this end, this application proposes a cover plate assembly that can effectively mitigate electrolyte leakage and ensure the welding quality and battery performance of the button cell.

[0004] This application also proposes a button battery including the aforementioned cover assembly.

[0005] A cover plate assembly according to an embodiment of this application is used to connect a housing having a receiving cavity. The cover plate assembly includes a cover plate body, a first insulating member, and a conductive member.

[0006] The cover plate body includes a first part and a second part. The outer periphery of the first part is used to connect the shell. The second part includes a bottom wall and a side wall. The bottom wall and the side wall enclose a receiving groove. The first part is connected to the side wall around it. Along the first direction, the first part and the bottom wall have a height difference. The bottom wall is provided with a through hole for connecting the receiving cavity.

[0007] The first insulating element has a first through hole that communicates with the through hole, and at least a portion of the first insulating element is located in the receiving groove and connected to the bottom wall.

[0008] A conductive element is connected to the side of the first insulating element away from the bottom wall and covers the first through hole;

[0009] The sidewall and the first part of the cavity wall, which are used to accommodate the cavity, together form the first accommodating space.

[0010] The button battery according to the embodiments of this application has at least the following beneficial effects: the bottom wall is used to make initial contact with the electrolyte during welding operations, causing the electrolyte level to rise. The first accommodating space is used to contain the electrolyte, effectively mitigating the electrolyte rising to the welding position or even overflowing, avoiding interference with the welding between the first part and the casing, and helping to ensure the welding quality of the button battery. In addition, the first insulating member is used to block electrical conduction between the conductive member and the bottom wall, and provides a seal between the conductive member and the bottom wall. The first insulating member can deform when heated, thereby losing its sealing performance when the button battery experiences high-temperature thermal runaway. Subsequently, gas is discharged through the through hole, the first through hole, and the gap between the conductive member and the bottom wall to achieve pressure relief, ensuring the safety of the button battery.

[0011] Therefore, the cover plate assembly in this application can effectively mitigate electrolyte leakage while ensuring battery safety, which is beneficial to ensuring the welding quality and performance of the button cell battery.

[0012] According to some embodiments of this application, along a first direction, the conductive element is provided with a conductive post, and the conductive post passes through the first through hole and the through hole;

[0013] Along the second direction, the conductive posts are spaced apart from the wall of the through hole, and the first direction is perpendicular to the second direction;

[0014] The outer peripheral wall of the conductive post, the wall of the through hole, and the first insulating element together enclose the second accommodating space.

[0015] According to some embodiments of this application, the wall of the first through hole is spaced apart from the outer peripheral wall of the conductive post, and the wall of the first through hole, the wall of the through hole, and the outer peripheral wall of the conductive post together enclose the second accommodating space.

[0016] According to some embodiments of this application, the bottom wall and the side wall have an included angle α, where 30°≤α≤85°.

[0017] According to some embodiments of this application, the cover plate assembly further includes a second insulating member connected to the side of the bottom wall opposite to the receiving groove. The second insulating member is provided with a second through hole that communicates with a through hole and is used to communicate with the receiving cavity.

[0018] According to some embodiments of this application, along the first direction, the second through hole is located on the side of the through hole opposite to the first through hole, and the second insulating member covers the hole wall of the through hole;

[0019] Along the second direction, the wall of the second through hole is spaced apart from the wall of the through hole, and the first direction is perpendicular to the second direction.

[0020] According to some embodiments of this application, along the second direction, the distance from the connection between the first part and the sidewall to the outer periphery of the first part is b, the extension dimension of the second part is c, 0.3mm≤b≤8mm, 4mm≤c≤20mm, and the second direction is perpendicular to the first direction.

[0021] According to some embodiments of this application, a marking portion is also provided on the side of the conductive element facing away from the bottom wall.

[0022] A button battery according to an embodiment of this application includes a winding core, a casing, and a cover assembly in any of the above embodiments;

[0023] The housing has a receiving cavity, the winding core is located in the receiving cavity, and the winding core is electrically connected to the housing;

[0024] The cover plate assembly is connected to the housing, and the core is electrically connected to the conductive parts.

[0025] The button battery according to the embodiments of this application has at least the following beneficial effects: the cover assembly can seal the receiving cavity and together with the shell define a first receiving space, which is used to contain electrolyte, effectively avoiding interference of electrolyte with the welding of the cover assembly and electrolyte overflow, and is beneficial to improving the electrolyte retention of the button battery.

[0026] According to some embodiments of this application, the housing is provided with a mounting groove, which is located at the opening of the receiving cavity, and the outer periphery of the first part is located in the mounting groove.

[0027] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0028] The present application will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0029] Figure 1 This is a schematic diagram of the structure of a button battery according to an embodiment of this application;

[0030] Figure 2 This is a schematic diagram of the explosion of a button battery according to an embodiment of this application;

[0031] Figure 3 This is a side view of the housing and cover assembly according to an embodiment of this application;

[0032] Figure 4 for Figure 3 Sectional view at point AA;

[0033] Figure 5 for Figure 4 A magnified view of a portion of point B in the middle;

[0034] Figure 6for Figure 4 A magnified view of a portion of point C in the middle;

[0035] Figure 7 for Figure 4 A magnified view of a portion of point D.

[0036] Reference numerals: housing 100, receiving cavity 110, first receiving space 111, second receiving space 112, mounting groove 120;

[0037] Core 200;

[0038] Cover plate assembly 300, cover plate body 310, first part 311, second part 312, receiving groove 3121, bottom wall 3122, side wall 3123, through hole 3124, first insulating member 320, first through hole 321, conductive member 330, conductive post 331, marking part 332, second insulating member 340, and second through hole 341. Detailed Implementation

[0039] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0040] In the description of this application, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They 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. Therefore, they should not be construed as limitations on this application.

[0041] In the description of this application, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0042] In the description of this application, unless otherwise expressly defined, terms such as "setup," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this application in conjunction with the specific content of the technical solution.

[0043] In the description of this application, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0044] The embodiments of this application are described below with reference to the accompanying drawings:

[0045] refer to Figures 1 to 4 According to an embodiment of this application, the cover plate assembly 300 is used to connect a housing 100 having a receiving cavity 110. The receiving cavity 110 is used to accommodate a winding core 200. The housing 100, the winding core 200, and the cover plate assembly 300 are assembled to form a button battery. The cover plate body 310 includes a first part 311 and a second part 312. The outer periphery of the first part 311 is used to connect to the housing 100. The second part 312 includes a bottom wall 3122 and a side wall 3123. The bottom wall 3122 and the side wall 3123 enclose a receiving groove 3121. The first part 311 is connected to the side wall 3123. Along a first direction, the first part 311 and the bottom wall 3122 have a height difference. During assembly, the bottom wall 3122 first contacts the electrolyte in the receiving cavity 110. The bottom wall 3122 is provided with a through hole 3124 for communicating with the receiving cavity 110.

[0046] The first insulating member 320 is provided with a first through hole 321, which communicates with the through hole 3124. At least a portion of the first insulating member 320 is located in the receiving groove 3121 and connected to the bottom wall 3122. The opening orientation of the receiving groove 3121 is configured to be consistent with the opening orientation of the receiving cavity 110. The conductive member 330 is connected to the side of the first insulating member 320 away from the first bottom wall 3122 and covers the first through hole 321, thereby sealing the receiving cavity 110. Thus, the conductive member 330 can be electrically connected to the winding core 200 through the through hole 3124 and the first through hole 321.

[0047] The sidewall 3123 of the receiving groove 3121 and the first part 311 are used to cooperate with the cavity wall of the receiving cavity 110 to enclose the first receiving space 111. The first receiving space 111 is used to contain electrolyte to alleviate electrolyte overflow and prevent the electrolyte level from rising and affecting the welding quality between the cover plate assembly 300 and the housing 100. In turn, it helps to ensure the performance of the button battery.

[0048] Specifically, the core 200 includes a positive electrode and a negative electrode. The conductive element 330 is electrically connected to the positive electrode of the core 200 through the through hole 3124 and the first through hole 321, and the negative electrode of the core 200 is electrically connected to the housing 100. The cover plate body 310 is connected to the housing 100, therefore, the cover plate body 310 is electrically connected to the negative electrode of the core 200. The first insulating element 320 is located between the bottom wall 3122 and the conductive element 330. On one hand, it seals the gap between the bottom wall 3122 and the conductive element 330 to ensure the sealing of the cavity; on the other hand, it prevents conduction between the conductive element 330 and the bottom wall 3122, avoiding a short circuit between the positive and negative electrodes.

[0049] The receiving cavity 110 has an opening, and the housing 100 is connected to the outer periphery of the first part 311 at one end where the opening is located. At least a part of the cover plate body 310 is placed in the receiving cavity 110. When the cover plate body 310 and the housing 100 are welded together, the bottom wall 3122 first contacts the electrolyte in the receiving cavity 110, causing the electrolyte level in the receiving cavity 110 to rise. The first receiving space 111 can accommodate the electrolyte, increasing the electrolyte capacity of the button battery, avoiding electrolyte interference with the welding of the first part 311 and the housing 100, which is beneficial to ensuring the welding quality between the first part 311 and the housing 100. At the same time, it can also effectively prevent electrolyte overflow, thereby ensuring the performance of the button battery.

[0050] In addition, the conductive component 330, the first insulating component 320, and the cover plate body 310 are assembled by heating and pressurizing.

[0051] When heated, the first insulating component 320 bonds the conductive component 330 to the cover body 310. As a result, the first insulating component 320 will undergo thermal melting failure when the button battery experiences thermal runaway. Consequently, the gas generated by the button battery can be discharged through the through hole 3124, the first through hole 321, and the first insulating component 320 (through the first insulating component 320, i.e., through the conductive component 330 and the bottom wall 3122), thereby depressurizing the button battery, preventing the button battery from over-expanding and exploding, and improving the safety of the button battery.

[0052] It should be noted that, compared to preventing electrolyte overflow by lowering the electrolyte level, the button battery in this application, while keeping the electrolyte level constant, uses the first accommodating space 111 to accommodate the rising electrolyte, which is equivalent to increasing the space for accommodating the electrolyte and is beneficial to improving the electrolyte retention capacity of the button battery.

[0053] refer to Figures 1 to 4In other embodiments, the cover plate body 310 is formed by stamping. The stamped cover plate body 310 has stronger structural stability compared with the planar structure. While ensuring the structural stability of the cover plate body 310, it is beneficial to reduce the thickness of the cover plate body 310. For example, the thickness of the base material used for stamping is not more than 0.15 mm, and the depth of the receiving groove 3121 is not less than 0.15 mm. For example, the depth of the receiving groove 3121 can be 0.15 mm, 0.2 mm, 0.3 mm, 0.4 mm, etc. It can be understood that along the first direction, the thickness of the first part 311 is not more than 0.15 mm, and the thickness of the bottom wall 3122 is not more than 0.15 mm.

[0054] refer to Figures 1 to 4 In other embodiments, the first insulating element 320 and the conductive element 330 are located in the receiving groove 3121. By receiving the first insulating element 320 and the conductive element 330 in the receiving groove 3121, the thickness of the cover assembly 300 is thinner, which in turn helps to reduce the volume occupied by the button battery, avoids the partial protrusion of the button battery, facilitates the assembly of multiple button batteries into a more compact power supply device, and helps to improve the energy density of the power supply device.

[0055] refer to Figures 1 to 4 In other embodiments, the core 200 includes a positive electrode and a negative electrode. The negative electrode of the core 200 is electrically connected to the housing 100, and the cover plate body 310 is connected to the housing 100. Therefore, the cover plate body 310 is electrically connected to the negative electrode of the core 200. The positive electrode of the core 200 passes through the through hole 3124 and the first through hole 321 and is electrically connected to the conductive member 330. There is a gap between the positive electrode of the core 200 and the hole wall of the through hole 3124 to prevent the positive electrode of the core 200 from contacting the bottom wall 3122 and conducting electricity. In addition, the first insulating member 320 is located between the bottom wall 3122 and the conductive member 330. The first insulating member 320 is used to block the electrical conduction between the conductive member 330 and the bottom wall 3122 to prevent the button battery from short-circuiting.

[0056] refer to Figures 1 to 5 In some embodiments, along the first direction, the conductive member 330 is provided with a conductive post 331, which passes through the first through hole 321 and the through hole 3124. The conductive post 331 is used for electrical connection with the winding core 200. Along the second direction, the conductive post 331 and the hole wall of the through hole 3124 are spaced apart to avoid short circuit between the conductive post 331 and the through hole 3124. The first direction is perpendicular to the second direction. The outer peripheral wall of the conductive post 331, the hole wall of the through hole 3124, and the first insulating member 320 together enclose a second accommodating space 112. The second accommodating space 112 is used to accommodate electrolyte. Together with the first accommodating space 111, it helps to further increase the electrolyte capacity and effectively prevent electrolyte overflow.

[0057] Specifically, when the bottom wall 3122 contacts the electrolyte, the electrolyte level rises, allowing the electrolyte to enter the first accommodating space 111 and the second accommodating space 112. The first accommodating space 111 and the second accommodating space 112 increase the space for containing the electrolyte. While preventing electrolyte overflow, this helps to increase the initial electrolyte level in the accommodating cavity 110, further improving the electrolyte retention capacity of the button battery.

[0058] refer to Figures 1 to 5 In some embodiments, the wall of the first through hole 321 is spaced from the outer peripheral wall of the conductive post 331. The wall of the first through hole 321, the wall of the through hole 3124, and the wall of the conductive post 331 together enclose the second accommodating space 112. The gap between the wall of the first through hole 321 and the outer peripheral wall of the conductive post 331 further expands the volume of the second accommodating space 112, which is beneficial to accommodate more electrolyte and improve the electrolyte retention of the button battery.

[0059] refer to Figures 1 to 5 In other embodiments, the inner peripheral wall of the through hole 3124 is covered with an insulating layer, which is used to block the electrical conduction between the conductive post 331 and the hole wall of the through hole 3124, so as to avoid short circuit.

[0060] refer to Figures 2 to 6 In some embodiments, there is an included angle α (which should be understood as an acute angle) between the bottom wall 3122 and the side wall 3123 of the receiving groove 3121, 30°≤α≤85°. The cover plate body 310 can be formed by stamping. The lower limit of α is used to ensure that the receiving groove 3121 is formed by stamping and to limit the space occupied by the receiving groove 3121. The upper limit of α is used to avoid local excessive bending and breakage of the cover plate body 310.

[0061] The included angle α can be any angle value among 30°, 35°, 40°, 45°, 50°, 55°, 60°, 65°, 70°, 75°, 80° or 85°, or it can be any two angle values ​​as the range of endpoints of the interval, which can be adaptively adjusted according to the size of the cover plate body 310.

[0062] Specifically, the first part 311 includes a plane parallel to the bottom wall 3122 of the receiving groove 3121. The included angle α between the bottom wall 3122 and the side wall 3123 of the receiving groove 3121 can also be understood as the included angle between the first part 311 and the side wall 3123 of the receiving groove 3121. The connection between the first part 311 and the side wall 3123 has an R angle R1, R1≥0.05mm, and the connection between the side wall 3123 and the bottom wall 3122 has an R angle R2, R2≥0.15mm. The lower limits of R1 and R2 are defined to prevent the connection from being excessively bent and breaking.

[0063] refer to Figures 1 to 5 In some embodiments, the cover assembly 300 further includes a second insulating member 340, which is connected to the side of the bottom wall 3122 opposite to the receiving groove 3121 (in a button cell battery, the second insulating member 340 can also be understood as being located between the second part 312 and the core 200). The second insulating member 340 also has a second through hole 341, which communicates with the through hole 3124. The second through hole 341 is used to connect the receiving cavity 110. Through the first through hole 321, the through hole 3124, and the second through hole 341, the conductive member 330 can be electrically connected to the positive electrode of the core 200. The second insulating member 340 is used to block the electrical conduction between the positive electrode of the core 200 and the conductive member 330, preventing the positive electrode of the core 200 from contacting the bottom wall 3122 and causing a short circuit between the positive and negative electrodes. Thus, the core 200 can be closer to the second part 312, which is beneficial for making full use of the space in the receiving cavity 110 and improving the energy density of the button cell battery.

[0064] refer to Figures 2 to 6 In some embodiments, along the first direction, the second through hole 341 is located on the side of the through hole 3124 opposite to the first through hole 321, that is, the through hole 3124 is located between the first through hole 321 and the second through hole 341. The through hole 3124 is used to connect the receiving cavity 110 through the second through hole 341. The second insulating member 340 covers the hole wall of the through hole 3124. Along the second direction, the hole wall of the second through hole 341 is spaced from the hole wall of the through hole 3124. The first direction is perpendicular to the second direction. Thus, when the positive electrode of the core 200 is electrically connected to the conductive member 330, the hole wall of the second through hole 341 can prevent the positive electrode of the core 200 from contacting the hole wall of the through hole 3124, or prevent the conductive member 330 from contacting the hole wall of the through hole 3124, so as to avoid short circuit.

[0065] For example, both the second through hole 341 and the through hole 3124 are circular holes, arranged concentrically. The diameter of the second through hole 341 is smaller than that of the through hole 3124. Therefore, the wall of the second through hole 341 can restrict the positive electrode or conductive element 330 of the winding core 200 from contacting the wall of the through hole 3124 along the second direction, preventing a short circuit in the button battery. It should be understood that the second through hole 341 and the through hole 3124 can also be square holes or other shapes, as long as the wall of the second through hole 341 can prevent the positive electrode or conductive element 330 of the winding core 200 from contacting the wall of the through hole 3124.

[0066] refer to Figures 1 to 5In some embodiments, along the second direction, the distance between the wall of the second through hole 341 and the wall of the through hole 3124 is e, where e ≥ 0.05 mm. e can take values ​​such as 0.05 mm, 0.1 mm, 0.3 mm, 0.5 mm, 0.7 mm, or 0.9 mm. Depending on the size of the button battery, the value of e can be adjusted as needed to avoid short circuits in the button battery.

[0067] refer to Figures 2 to 5 In some other embodiments, along the first direction, the conductive element 330 has a conductive post 331 on the side facing the core 200. The conductive post 331 passes through the first through hole 321, the through hole 3124 and the second through hole 341. The conductive post 331 is connected to the positive electrode of the core 200, so that the conductive element 330 is the positive electrode of the button battery. The wall of the second through hole 341 can limit the contact between the conductive post 331 and the wall of the through hole 3124, so as to prevent the conductive post 331 from being electrically connected to the cover plate body 310 and causing a short circuit.

[0068] refer to Figures 1 to 7 In some embodiments, along the second direction, the distance from the junction of the first portion 311 and the sidewall 3123 to the outer periphery of the first portion 311 is b (refer to...). Figure 7 The extension dimension of the second part 312 is c, 0.3mm≤b≤8mm, 4mm≤c≤20mm. In this application, the button battery first heat-presses the cover assembly 300 and then welds the cover assembly 300 to the shell 100. Thus, limiting the range of values ​​for b and c is beneficial to better balance the sealing width of the first insulating member 320 while keeping the size of the cover body 310 unchanged, and effectively avoids the heat generated by welding the first part 311 to the shell 100 causing the first insulating member 320 to melt and affect the sealing width, which is beneficial to ensuring the sealing performance of the button battery.

[0069] For example, b can be any value among 0.3mm, 0.4mm, 0.5mm, 1mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm and 8mm, and c can be any value among 4mm, 6mm, 8mm, 10mm, 12mm, 14mm, 16mm, 18mm and 20mm.

[0070] It should be noted that b ≥ 0.3 mm, meaning the distance between the welding position and the sidewall is at least 0.3 mm. This ensures the volume of the first accommodating space 111 for containing the electrolyte, and also prevents the heat generated during welding of the first part 311 to the casing 100 from affecting the seal of the first insulating component 320, thus contributing to the sealing performance of the button battery. The accommodating groove 3121 can be a circular groove with a diameter c ≥ 4.0 mm, used to ensure the heat-sealing width of the first insulating component 320 and prevent the button battery from failing to seal. Therefore, based on 0.3 mm ≤ b ≤ 8 mm and 4 mm ≤ c ≤ 20 mm, the values ​​of b and c can be adaptively adjusted to better balance the sealing performance of the button battery and the amount of electrolyte contained.

[0071] refer to Figures 2 to 6 In some other embodiments, at least a portion of the conductive element 330 is located in the receiving groove 3121, which helps to reduce the overall space occupied by the button battery, thereby increasing the energy density of the button battery. There is a gap d between the outer periphery of the conductive element 330 and the side wall 3123, where d ≥ 0.2 mm. This gap is set to prevent the conductive element 330 from contacting the cover plate body 310 and short-circuiting. On the other hand, it also facilitates the observation of the hot-melt state of the outer periphery of the first insulating element 320 and accommodates the glue overflowing from the hot-melt of the first insulating element 320. This allows for the sealing of the outer periphery of the conductive element 330, making the fixing of the conductive element 330 more stable and improving the sealing performance of the button battery.

[0072] Where d can take values ​​such as 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm or 1mm.

[0073] refer to Figure 6 In other embodiments, the first insulating member 320 is located in the receiving groove 3121, and there is a gap between the first insulating member 320 and the side wall 3123 of the receiving groove 3121 along the second direction. The gap is greater than 0.1 mm. The gap between the first insulating member 320 and the side wall 3123 is used to disperse the stress generated by the heat-melting deformation of the first insulating member 320, thereby improving the heat-melting sealing effect of the first insulating member 320.

[0074] refer to Figures 1 to 7In other embodiments, the first insulating member 320 includes a first welded layer, a base layer, and a second welded layer stacked sequentially, with the base layer located between the first and second welded layers. The first welded layer is connected to the conductive member 330, and the second welded layer is connected to the bottom wall 3122 of the receiving groove 3121. The first and second welded layers have lower melting points than the base layer. The conductive member 330, the first insulating member 320, and the cover plate body 310 are composited by hot pressing. When the first and second welded layers are compressed due to hot melting, the base layer can maintain its original shape to support the first and second welded layers, making the thickness of the first insulating member 320 more uniform, which is beneficial to ensuring the consistency of the thickness of the cover plate assembly 300.

[0075] Specifically, the first and second fusion layers can be made of PP (Polypropylene) with a melting point range of 115°C to 140°C, and the base layer can be made of modified PP with a melting point range greater than 160°C. For example, when hot-pressing the cover assembly 300, the temperature is raised to 120°C, the first fusion layer is hot-melted to connect the conductive component 330 to the base layer, and the second fusion layer is hot-melted to connect the base layer to the cover body 310. Thus, when hot-pressing the cover assembly 300, only the thickness of the first and second fusion layers changes. The thickness of the first and second fusion layers after being compressed by heat can be 30% to 70% of the original thickness. Compared with the thickness change of the entire first insulating component 320, this is beneficial to alleviate the thickness uniformity of the first insulating component 320 after hot lamination, so that the thickness of the cover assembly 300 is more consistent.

[0076] In addition, the first welded layer, the base layer and the second welded layer together define the first through hole 321. The cover plate body 310 is provided with a through hole 3124, which connects to the receiving cavity 110. The first through hole 321 connects to the through hole 3124. The conductive component 330 is connected to the cover plate body 310 through the first insulating component 320 to seal the first through hole 321, thereby sealing the receiving cavity 110. The first welded layer and the second welded layer can be thermally melted when the button battery fails, realizing the pressure relief in the receiving cavity 110, which is beneficial to improving the safety of the button battery.

[0077] refer to Figure 1 and Figure 2 In some embodiments, the conductive element 330 is further provided with an identification part 332 on the side opposite to the bottom wall 3122. The identification part 332 is electrically connected to the core 200. The identification part 332 is used to provide identification for the button battery welding pins, so that the welding position of the pins on the conductive element 330 is consistent, which facilitates the connection and assembly between multiple button batteries.

[0078] refer to Figures 1 to 7According to an embodiment of this application, a button cell battery includes a housing 100, a winding core 200, and a cover assembly 300 as described in any of the above embodiments. The housing 100 has a receiving cavity 110, the winding core 200 is located in the receiving cavity 110, the negative terminal of the winding core 200 is electrically connected to the housing, the cover assembly 300 is connected to the housing 100 and is used to close the receiving cavity 110, and the positive terminal of the winding core 200 is electrically connected to a conductive element 330, thereby forming the button cell battery of this application, wherein the sidewall 3123 faces away from the receiving cavity. One side of the groove 3121, the side of the first part 311 facing the receiving cavity 110, and the cavity wall of the receiving cavity 110 together enclose the first receiving space 111. When the cover assembly 300 is welded to the housing 100, the bottom wall 3122 first contacts the electrolyte in the receiving cavity 110, the electrolyte level rises, and the first receiving space 111 can contain the electrolyte, increasing the electrolyte retention of the button battery, effectively avoiding interference from the rising electrolyte to the welding of the cover assembly 300, and preventing electrolyte overflow.

[0079] refer to Figures 1 to 7 In some embodiments, the housing 100 is further provided with a mounting groove 120, which is located at the opening of the receiving cavity 110. The outer periphery of the first portion 311 is located in the mounting groove 120. The mounting groove 120 is used to provide positioning for the installation of the cover body 310, so that the cover body 310 and the housing 100 have a defined installation position. For example, the mounting groove 120 is arranged around the cavity wall of the receiving cavity 110, and the outer periphery of the first portion 311 is located in the mounting groove 120, so that the cover assembly 300 is located in the receiving cavity 110, avoiding the cover assembly 300 from protruding outward, and the structure of the button battery is also more compact.

[0080] The embodiments of this application have been described in detail above with reference to the accompanying drawings. However, this application is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of this application. Furthermore, unless otherwise specified, the embodiments and features described in the embodiments of this application can be combined with each other.

Claims

1. A cover assembly for connecting a case provided with a receiving cavity, characterized by, The cover plate assembly comprises: a cover plate body comprising a first part and a second part, an outer periphery of the first part being used for connecting the shell, the second part comprising a bottom wall and a side wall, the bottom wall and the side wall enclosing a receiving groove, the first part being connected to the side wall in a first direction, the first part and the bottom wall having a height difference, the bottom wall being provided with a through hole used for communicating the receiving cavity; a first insulating piece provided with a first through hole in communication with the through hole, at least a part of the first insulating piece being located in the receiving groove and connected to the bottom wall; a conductive piece connected to a side of the first insulating piece away from the bottom wall and covering the first through hole; wherein the side wall and the first part are used for cooperating with the cavity wall of the receiving cavity to enclose a first accommodation space.

2. The cover plate assembly of claim 1, wherein, In the first direction, the conductive piece is provided with a conductive column penetrating into the first through hole and the through hole; in a second direction, the conductive column and the hole wall of the through hole are spaced apart, the first direction being perpendicular to the second direction; wherein the outer peripheral wall of the conductive column, the hole wall of the through hole and the first insulating piece jointly enclose a second accommodation space.

3. The cover plate assembly of claim 2, wherein, The hole wall of the first through hole and the outer peripheral wall of the conductive column have a spacing, and the hole wall of the first through hole, the hole wall of the through hole and the outer peripheral wall of the conductive column jointly enclose the second accommodation space.

4. The cover plate assembly of claim 1, wherein, The bottom wall and the side wall have an included angle a of 30°≤a≤85°.

5. The cover plate assembly of claim 1, wherein, The cover plate assembly further comprises a second insulating piece connected to a side of the bottom wall away from the receiving groove, the second insulating piece being provided with a second through hole in communication with the through hole, the second through hole being used for communicating the receiving cavity.

6. The cover plate assembly of claim 5, wherein, In the first direction, the second through hole is located on a side of the through hole away from the first through hole, and the second insulating piece covers the hole wall of the through hole; in a second direction, the hole wall of the second through hole and the hole wall of the through hole have a spacing, the first direction being perpendicular to the second direction.

7. The cover plate assembly of claim 1, wherein, In the second direction, the distance from the connection between the first part and the side wall to the outer periphery of the first part is b, the extension size of the second part is c, 0.3mm≤b≤8mm, 4mm≤c≤20mm, and the second direction is perpendicular to the first direction.

8. The cover plate assembly of claim 1, wherein, The side of the conductive piece away from the bottom wall is further provided with an identification part.

9. A coin cell battery characterized by, The cover plate assembly comprises: a winding core; a shell provided with a receiving cavity, the winding core being located in the receiving cavity and being electrically connected to the shell; the cover plate assembly of any one of claims 1 to 8, the cover plate assembly being connected to the shell, and the winding core being electrically connected to the conductive piece.

10. The button cell battery of claim 9, wherein, The shell is provided with a mounting groove located at an opening of the receiving cavity, and the outer periphery of the first part is located in the mounting groove.

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