A sealed bottom cover and a snap-on energy storage device
By setting a deformation space on the sealing ring of the sealed bottom cover, the problem of limited sealing and stability of button-type energy storage devices is solved, enabling stable and long-term use in extreme environments.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- EVE ENERGY CO LTD
- Filing Date
- 2025-07-11
- Publication Date
- 2026-07-07
Smart Images
Figure CN224472554U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of energy storage device technology, and in particular to a sealed bottom cover and a button-type energy storage device. Background Technology
[0002] Coin cell energy storage devices include coin cells, coin cells, and coin supercapacitors. Their button-shaped structure is one of their unique designs, often used in applications requiring compact space and concentrated energy. Conventional coin cell energy storage devices have a wound electrode structure, which is relatively large in size, has low internal space utilization, and requires the use of solvents to reduce the viscosity of the slurry during electrode fabrication, making it impossible to fabricate thick electrodes.
[0003] To address the shortcomings of the aforementioned core structure, current button cell energy storage devices employ lamination or pressing processes to fabricate their electrodes. The lamination process requires a binder capable of effective fiberization, forming a mesh structure through multiple roll passes to firmly bond the electrode powder, creating a self-supporting electrode film. This facilitates uniform electrode material distribution, avoids electrode delamination caused by excessive solvent evaporation, and allows for the fabrication of thick electrodes. The pressing process, as described in patent CN118629791A, involves pre-treating the powder and adding a binder, then using a die to press and form a rigid electrode sheet. The electrode strength depends on the die, pressing pressure, and powder quantity. The pressing process can produce thick electrodes without concerns about continuous production, and offers advantages such as simple operation, high efficiency, and high powder utilization. From a production perspective, the pressing process is more feasible than the lamination process.
[0004] While the hard electrodes prepared by the pressing process can reduce assembly gaps and improve the internal space utilization of coin cell energy storage devices, and facilitate the fabrication of thicker electrodes to accommodate more active materials and thus increase the energy density of coin cell energy storage devices, the hard electrodes also limit the compression of the sealing rings. This affects the sealing performance and stability of the coin cell energy storage devices, especially in extreme environments such as high temperatures, which can easily lead to leakage and increased internal resistance, significantly reducing the lifespan of the coin cell energy storage devices. Utility Model Content
[0005] To address the aforementioned deficiencies in the prior art, the present application aims to provide a sealed bottom cover and a button-type energy storage device. By improving the deformation and compression degree and uniformity of the sealing ring, the sealing performance between the sealing ring and the outer shell is improved, and the bending deformation caused to the bottom cover is reduced, thereby improving the sealing performance and stability of the button-type energy storage device and ensuring its lifespan.
[0006] The first aspect of this application provides a sealing bottom cover, comprising:
[0007] The bottom cover includes the cover body and the sidewalls formed by bending the outer periphery on the same side;
[0008] A sealing ring is circumferentially injection molded onto the sidewall, and the sealing ring wraps around the end of the sidewall away from the cover.
[0009] The deformation space is located on the circumferential outer side and / or circumferential inner side of the end of the sealing ring near the cover, so that the sealing ring can deform toward the deformation space when it is compressed.
[0010] In a preferred embodiment, in the first aspect of this application, the circumferential outer surface of the sealing ring near the end of the cover is an outwardly inclined outer slope to form a deformation space on the circumferential outer side of the outer slope.
[0011] And / or, the circumferential inner surface of the sealing ring near the end of the cover is an inwardly inclined inner slope to form a deformation space between the inner slope and the sidewall;
[0012] And / or, the inner and / or outer circumferential surfaces of the sealing ring near the end of the cover are rounded to create a deformation space between the rounded outer surface and / or the rounded surface and the sidewall.
[0013] In a preferred embodiment, in the first aspect of this application, the angle α between the outer inclined plane and the vertical direction is 25°-50°.
[0014] In a preferred embodiment, in the first aspect of this application, the angle β between the inner inclined surface and its adjacent horizontal end face is 130°-170°.
[0015] In a preferred embodiment, in the first aspect of this application, the radius (R) of the fillet is 0.1mm-0.8mm.
[0016] In a preferred embodiment, in the first aspect of this application, the sealing ring has a first end face near the end of the cover, and the first end face extends radially away from the side wall by a dimension L of 0.1mm-0.27mm.
[0017] In a preferred embodiment, in the first aspect of this application, the circumferential outer surface of the sealing ring at the end away from the cover is a slope, and the end of the slope near the cover is positioned further away from the sidewall than the opposite end.
[0018] In a preferred embodiment, in the first aspect of this application, the ratio of the radial dimension L1 to the vertical dimension L2 of the inclined plane is 0.3-1.7.
[0019] A second aspect of this application provides a button-type energy storage device, comprising: a housing and the aforementioned sealing bottom cover, wherein the housing and the sealing bottom cover are insulated and sealed together to form an accommodating space for accommodating an electrode assembly, and the housing covers the outer periphery of a sealing ring.
[0020] In a preferred embodiment, in the second aspect of this application, the electrode assembly includes a positive electrode hard sheet, a negative electrode hard sheet, and a separator disposed between the two, and the ratio of the thickness of the electrode assembly to the thickness H0 of the coin cell energy storage device is 0.7-0.8.
[0021] In a preferred embodiment, in the second aspect of this application, the ratio of the initial thickness H1 of the sealing ring to the thickness H0 of the button-type energy storage device is 100%-106%.
[0022] In a preferred embodiment, in the second aspect of this application, the sidewall includes a vertical wall connected to the cover, the end of the vertical wall away from the cover being U-shaped outwardly bent to form a bent wall and an outer straight wall connected in sequence, and a sealing ring covering the end of the vertical wall away from the cover, the bent wall and the outer straight wall.
[0023] In a preferred embodiment, in the second aspect of this application, the outer shell includes a main body and a side portion. The main body abuts against the end of the sealing ring away from the cover, and the side portion abuts against the outer periphery of the sealing ring. The main body and the side portion are connected by an arc-shaped transition portion. The end of the side portion away from the transition portion is bent toward the rounded corner of the side wall to form a rounded end and extends to cover the sealing ring.
[0024] In a preferred embodiment, in the second aspect of this application, the shortest distance G1 between the rounded corner inflection point and the outer straight wall is 0.1mm-0.45mm, the shortest distance G2 between the outer straight wall and the side is 0.1mm-0.5mm, the shortest distance G3 between the bent wall and the main body is 0.2mm-0.75mm, and the radius of curvature R1 of the rounded corner is 0.7mm-1.3mm.
[0025] In a preferred embodiment, in the second aspect of this application, the average thickness of the outer shell is T, the ratio of G1 to T is 50%-150%, the ratio of G2 to T is 60%-200%, and the ratio of G3 to T is 70%-300%.
[0026] The sealed bottom cover and button-type energy storage device provided in this application have the following technical advantages:
[0027] The design of the deformation space helps to improve the balanced deformation and compression of the sealing ring during the packaging of coin cell energy storage devices, thereby improving the sealing performance between the sealing ring and the shell, and reducing or even avoiding bending deformation of the bottom cover. This not only ensures good contact between the electrode assembly and the bottom cover and shell, but also effectively inhibits the evaporation of electrolyte and the intrusion of external liquids, thereby improving the sealing performance and stability of the coin cell energy storage device, ensuring its lifespan, and laying a good foundation for the stable and long-term use of the coin cell energy storage device in extreme environments. Attached Figure Description
[0028] Figure 1This is a schematic diagram of the button-type energy storage device of this application;
[0029] Figure 2 This is a cross-sectional view of the button-type energy storage device of this application;
[0030] Figure 3 This is a cross-sectional view with dimensions marked for the button-type energy storage device of this application;
[0031] Figure 4 This is a cross-sectional view of the first embodiment of the sealing bottom cover of this application;
[0032] Figure 5 This is a cross-sectional view of a second embodiment of the sealing bottom cover of this application;
[0033] Figure 6 This is a cross-sectional view of a third embodiment of the sealing bottom cover of this application;
[0034] Figure 7 This is a cross-sectional view of other embodiments or comparative embodiments of the sealing bottom cover of this application;
[0035] Figure 8 This is a schematic diagram of the structure of the sealing ring according to the first embodiment of this application;
[0036] Figure 9 This is a cross-sectional view of the first embodiment of the sealing ring of this application.
[0037] Figure label:
[0038] 100. Sealed bottom cover; 10. Bottom cover; 11. Cover body; 12. Side wall; 121. Vertical wall; 122. Bent wall; 123. Outer straight wall; 20. Outer shell; 21. Main body; 22. Side; 23. Transition part; 24. Rounded end; 30. Sealing ring; 31. Outer bevel; 32. Inner bevel; 33. Rounded corner; 34. First end face; 35. Bevel; 40. Accommodation space; 50. Deformation space. Detailed Implementation
[0039] To better understand and implement this application, the technical solutions in this application will be clearly and completely described below with reference to the accompanying drawings.
[0040] In the description of this application, it should be noted that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", 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] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the specification of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application.
[0042] This application provides a button-type energy storage device, see reference. Figure 1 and Figure 2 The device includes a housing 20 and a sealed bottom cover 100, which are insulated and sealed together to form an accommodating space 40 for accommodating electrode components. The coin-type energy storage device can be a coin primary battery, a coin secondary battery, a coin supercapacitor, or other energy storage devices with similar structures. Its dimensions include, but are not limited to, 1016 (diameter 10mm, thickness 1.6mm), 1216 (diameter 12mm, thickness 1.6mm), 2016 (diameter 20mm, thickness 1.6mm), 2032 (diameter 20mm, thickness 3.2mm), and 2450 (diameter 24mm, thickness 5mm). As long as the energy storage device has the components of this application and the connection structure between the components is the same as or similar to that of this application, the technical solution of this application can be used for design.
[0043] To overcome the drawbacks of large size, low space utilization, and inability to fabricate thick electrodes in wound-core structure electrode assemblies, this application's coin-type energy storage device employs a pressing process to fabricate rigid electrodes, namely, a positive electrode rigid sheet and a negative electrode rigid sheet. The negative electrode rigid sheet is then placed abutting against a sealed bottom cover 100 for initial liquid injection. Subsequently, a separator and the positive electrode rigid sheet are sequentially added, followed by a second liquid injection. The outer shell 20 is then placed on top to encapsulate and form a semi-finished product. After static treatment at room temperature and high temperature, the device is then subjected to formulation and capacity testing to obtain the coin-type energy storage device. The number of positive and negative electrode rigid sheets can be one or more, with no limit, selected according to actual needs. It is important to ensure that the positive and negative electrode rigid sheets are separated by a separator. The rigid electrode configuration reduces assembly gaps, improves the internal space utilization of the coin-type energy storage device, and facilitates the fabrication of thick electrodes, allowing the coin-type energy storage device to accommodate more active material, thus contributing to increased energy density. Meanwhile, the use of hard electrodes helps ensure good contact between components during packaging and reduces the risk of excessive increase in internal resistance due to deformation or movement.
[0044] While coin cell energy storage devices with rigid electrode structures have the aforementioned advantages, the rigid electrodes limit the compression of the sealing structure, thus affecting the sealing performance and stability of the devices. In particular, under extreme environments such as high temperatures, leakage and increased internal resistance are likely to occur, significantly reducing the lifespan of the coin cell energy storage devices.
[0045] Based on this, this application also provides a sealed bottom cover 100 suitable for button-type energy storage devices, see reference. Figure 4-6 The sealing bottom cover 100 includes a bottom cover 10, a sealing ring 30, and a deformation space 50. The bottom cover 10 includes a cover body 11 and a side wall 12 formed by bending its outer periphery on the same side. The sealing ring 30 is circumferentially injection molded onto the side wall 12, and the sealing ring 30 covers the end of the side wall 12 away from the cover body 11. The deformation space 50 is located on the circumferentially outer side and / or circumferentially inner side of the sealing ring 30 near the end of the cover body 11, so that the sealing ring 30 deforms toward the deformation space 50 when compressed. When the sealing bottom cover 100 is insulated and sealed with the outer shell 20 to form a button-type energy storage device, the outer shell 20 covers the outer periphery of the sealing ring 30.
[0046] Both the bottom cover 10 and the outer shell 20 can be made of stainless steel. The bottom cover 10 and the sealing ring 30 are integrally formed by injection molding, which not only reduces the assembly process between the bottom cover 10 and the sealing ring 30 to improve production efficiency, but also helps to improve the sealing performance between the bottom cover 10 and the sealing ring 30, preventing leakage or intrusion of external liquids.
[0047] The deformation space 50 can be the gap between the end of the sealing ring 30 near the cover 11 and the side wall 12, and / or, before the sealing bottom cover 100 and the outer shell 20 are fastened together and sealed, the gap between the end of the sealing ring 30 near the cover 11 and the outer shell 20. The deformation space 50 is a chamber structure that allows the sealing ring 30 to deform towards the deformation space 50 under force during sealing, thereby dispersing the assembly pressure. Thus, the setting of the deformation space 50 is beneficial to improve the balanced deformation and compression of the sealing ring 30 during the sealing of the coin cell energy storage device, thereby improving the sealing performance between the sealing ring 30 and the outer shell 20, and reducing or even avoiding bending deformation of the bottom cover 10. This not only ensures good contact between the electrode assembly and the bottom cover 10 and the outer shell 20, but also effectively inhibits the evaporation of the electrolyte and the intrusion of external liquids, thereby improving the sealing performance and stability of the coin cell energy storage device, ensuring the lifespan of the coin cell energy storage device, and laying a good foundation for the stable and long-term use of the coin cell energy storage device in extreme environments.
[0048] It should be noted that the purpose of the deformation space 50 is to provide a reasonable space for the deformation of the sealing ring 30 under stress, so as to ensure that the sealing ring 30 has sufficient compression and uniform deformation, and to distribute the assembly pressure, thereby enabling a stable seal between the sealing ring 30 and the outer shell 20 and the bottom cover 10. However, it is important to note that the position, size, and structure of the deformation space 50 must be reasonably set to avoid the sealing ring 30 pressing against the side wall 12, causing the bottom cover 10 to bend and affecting the reasonable distribution of assembly force, and to avoid gaps between the sealing ring 30 and the side wall of the outer shell 20 and the end of the outer shell 20 away from the bottom cover 10 after assembly, which would affect the sealing performance. Furthermore, if the deformation of the sealing ring 30 presses against the side wall 12, causing the bottom cover 10 to bend, it will inevitably affect the sealing effect between the sealing ring 30 and the outer shell 20. This makes the requirements for setting the deformation space 50 on the inner circumferential side of the end of the sealing ring 30 near the cover 11 more stringent, and more difficult to process, resulting in a lower yield. Therefore, it is preferable to set the deformation space 50 on the outer circumferential side of the end of the sealing ring 30 near the cover 11.
[0049] Generally, the sides of the outer casing 20 are vertically oriented, and the sidewall 12 is vertically oriented at the end near the cover 11. Based on this, the outer circumferential surface of the sealing ring 30 near the end near the cover 11 is an outwardly inclined outer slope 31, forming a deformation space 50 on the outer circumferentially outer side of the outer slope 31. And / or, the inner circumferential surface of the sealing ring 30 near the end near the cover 11 is an inwardly inclined inner slope 32, forming a deformation space 50 between the inner slope 32 and the sidewall 12. And / or, the inner circumferential surface and / or the outer circumferential surface of the sealing ring 30 near the end near the cover 11 are rounded corners 33, forming a deformation space 50 on the outer circumferential surface of the rounded corners 33 and / or between the rounded corners 33 and the sidewall 12.
[0050] See Figure 4 and Figure 8 In the first embodiment, the outer inclined surface 31 is provided so that a deformation space 50 can be formed between the outer inclined surface 31 and the outer shell 20. The angle α between the outer inclined surface 31 and the vertical direction is 25°-50°. Within this angle range, the assembly force can be effectively distributed during the packaging of the coin-type energy storage device, so that the sealing ring 30 is mainly deformed in the deformation space 50 between the outer inclined surface 31 and the outer shell 20, avoiding bending deformation of the bottom cover 10 under pressure, and also helping to improve the compression and balanced deformation of the sealing ring 30 between the bottom cover 10 and the outer shell 20, avoiding the situation of misalignment of the sealing ring 30 and insufficient compression in the packaged coin-type energy storage device. Furthermore, the electrode assembly inside the coin cell energy storage device can maintain good contact with the bottom cover 10 and the outer shell 20 through the compression of the sealing ring 30. This ensures electrical performance while effectively inhibiting the evaporation of the electrolyte and the intrusion of external liquids, thereby improving the sealing and stability of the coin cell energy storage device and ensuring its lifespan. This lays a good foundation for the stable and long-term use of the coin cell energy storage device in extreme environments.
[0051] If the angle α between the outer bevel 31 and the vertical direction is less than 25°, the compression of the sealing ring 30 will be insufficient, and the sealed ring 30 may be misaligned after encapsulation. If the angle α between the outer bevel 31 and the vertical direction is greater than 50°, the sealing ring 30 of the bottom cover 10 will bend to some extent when pressing the side wall 12 during encapsulation, making it impossible to better distribute the assembly force during assembly, resulting in lower uniformity of compression of the sealed ring 30 after encapsulation. Therefore, when the angle α between the outer bevel 31 and the vertical direction is not within the range of 25°-50°, it will affect the sealing effect of the coin-type energy storage device, thereby accelerating the evaporation of the electrolyte and facilitating the intrusion of external liquids, affecting the stability and service life of the coin-type energy storage device, making it difficult for the coin-type energy storage device to be used stably and for a long time in extreme environments.
[0052] See Figure 5 In the second embodiment, the inner inclined surface 32 allows a deformation space 50 to be formed between the inner inclined surface 32 and the side wall 12. The angle β between the inner inclined surface 32 and its adjacent horizontal end face is 130°-170°. Within this angle range, when the coin-type energy storage device is packaged, the sealing ring 30 is mainly deformed towards the deformation space 50 between the inner inclined surface 32 and the side wall 12. This helps to increase the compression and balanced deformation of the sealing ring 30 between the bottom cover 10 and the outer shell 20, ensuring good contact between the electrode assembly inside the coin-type energy storage device and the bottom cover 10 and the outer shell 20 through the compression of the sealing ring 30. To a certain extent, this can suppress the evaporation of the electrolyte and the intrusion of external liquids, thereby improving the sealing performance and stability of the coin-type energy storage device.
[0053] However, because the inner bevel 32 causes the deformation space 50 to be close to the sidewall 12, during the packaging of the coin-type energy storage device, the deformation of the sealing ring 30 towards the deformation space 50 may compress the sidewall 12, causing a slight bend in the bottom cover 10, and / or, insufficient improvement in the uniformity of the compression of the sealing ring 30 may result in a small gap between the sealing ring 30 and the outer casing 20. Therefore, the improvement in sealing performance and stability of the coin-type energy storage device by the inner bevel 32 may be slightly lower than that by the outer bevel 31.
[0054] See Figure 5In the third embodiment, the rounded corner 33 on the outer circumferential side allows a deformation space 50 to be formed between the rounded corner 33 and the outer casing 20. The R value of the rounded corner 33 is 0.1mm-0.8mm. Within this range, when the coin cell energy storage device is packaged, the sealing ring 30 is mainly deformed towards the deformation space 50 between the rounded corner 33 and the outer casing 20. This helps to increase the compression and balanced deformation of the sealing ring 30 between the bottom cover 10 and the outer casing 20, ensuring good contact between the electrode assembly inside the coin cell energy storage device and the bottom cover 10 and the outer casing 20 through the compression of the sealing ring 30. To a certain extent, this can suppress the evaporation of the electrolyte and the intrusion of external liquids, thereby improving the sealing performance and stability of the coin cell energy storage device. If the radius (R) of the fillet 33 is less than 0.1 mm, it is close to a right angle structure, and the deformation space 50 is small. During assembly, the deformation of the sealing ring 30 will squeeze the side wall 12, causing the bottom cover 10 to be severely bent. This will prevent the proper distribution of assembly force, resulting in gaps between the sealing ring 30 and the side wall of the outer shell 20, as well as the end of the outer shell 20 away from the bottom cover 10, affecting the sealing performance. If the radius (R) of the fillet 33 is greater than 0.8 mm, gaps will exist between the sealing ring 30 and the side wall of the outer shell 20, as well as the end of the outer shell 20 away from the bottom cover 10 after assembly, affecting the sealing performance.
[0055] However, due to the small radius of the outer circumferential fillet 33, the deformation space 50 is relatively small. During the packaging of the coin-type energy storage device, the deformation space 50 may not provide sufficient space for the deformation of the sealing ring 30. This could lead to compression of the sidewall 12 causing slight bending of the bottom cover 10, and / or insufficient improvement in the uniformity of sealing ring 30 compression, resulting in a small gap between the sealing ring 30 and the outer shell 20, and / or insufficient improvement in the compression amount of the sealing ring 30. Therefore, the improvement in sealing performance and stability of the coin-type energy storage device by the outer circumferential fillet 33 may be slightly lower than that of the outer bevel 31, or even the inner bevel 32.
[0056] In the fourth embodiment, the rounded corner 33 on the inner circumferential side creates a deformation space 50 between the rounded corner 33 and the sidewall 12. In this structure, because the deformation space 50 is close to the sidewall 12, the pressure deformation of the sealing ring 30 may further compress the sidewall 12, resulting in a slightly larger bend in the bottom cover 10 compared to the rounded corner 33 on the outer circumferential side. However, overall, it still improves the sealing performance and stability of the button-type energy storage device.
[0057] Of course, this application only points out the possible defects of the inner bevel 32 and the fillet 33. Such defects may not exist. Even if they do exist, the setting of the inner bevel 32 and the fillet 33 can greatly improve the sealing and stability of the button energy storage device, only slightly lower than the performance of the outer bevel 31.
[0058] The above embodiments are for conventional vertical structures of the outer shell 20 and side wall 12. In practical applications, the end of the outer shell 20 near the cover 11 may be radially outward, or the end of the side wall 12 near the cover 11 may be inward. In this case, the outer circumferential outer surface of the sealing ring 30 near the cover 11 may be a right-angle structure. Figure 7 Alternatively, a slightly convex structure can also create a deformation space 50 between the sealing ring 30 and the outer shell 20 or side wall 12, thereby improving the uniform deformation and compression of the sealing ring 30 and thus enhancing the sealing performance and stability of the coin-type energy storage device. This structure is unconventional and rarely used, so it will not be described in detail here.
[0059] Based on the above implementation methods, please refer to Figure 9 The sealing ring 30 has a first end face 34 at the end near the cover 11. The radial extension dimension L of the first end face 34 away from the side wall 12 is 0.1mm-0.27mm. The radial dimension of the first end face 34, in conjunction with the outer bevel 31, inner bevel 32, and rounded corner 33, is more conducive to improving the uniform distribution of pressure on the sealing bottom cover 100 during the packaging process of the button-type energy storage device, further reducing the pressure on the side wall 12 to weaken or even eliminate bending, increasing the compression of the outer shell 20 and the sealing ring 30, thereby improving the sealing performance.
[0060] Meanwhile, the circumferential outer surface of the sealing ring 30 at the end furthest from the cover 11 is a bevel 35, with the end of the bevel 35 closer to the cover 11 being further away from the sidewall 12 than the opposite end. The bevel 35 improves the smoothness and accuracy of the assembly between the sealing bottom cover 100 and the outer casing 20 during the packaging process of the coin-type energy storage device. The ratio of the radial dimension L1 to the vertical dimension L2 of the bevel 35 is 0.3-1.7. This range helps to further reduce assembly difficulty, achieve smooth assembly, and improve production feasibility and efficiency.
[0061] Based on the above structure, see [link / reference] Figure 3 The electrode assembly includes a positive electrode hard sheet, a negative electrode hard sheet, and a separator disposed between them. The thickness ratio of the electrode assembly to the thickness H0 of the coin cell energy storage device is 0.7-0.8. This thickness ratio range is beneficial for improving the good contact between the electrode assembly and the housing 20 and the bottom cover 10, so as to ensure good electrical performance of the coin cell energy storage device. This thickness ratio is determined for the packaged coin cell energy storage device.
[0062] The ratio of the initial thickness H1 of the sealing ring 30 to the thickness H0 of the coin-type energy storage device is 100%-106%. The initial thickness H1 refers to the thickness of the uncompressed sealing ring 30 within the sealing base 100, while the thickness H0 of the coin-type energy storage device refers to the thickness of the encapsulated coin-type energy storage device. Within this thickness ratio range, the compression of the sealing ring 30 is sufficient and the deformation is uniform, which is beneficial for improving the sealing performance of the coin-type energy storage device.
[0063] For the specific structure of the bottom cover 10, please refer to Figure 2 , Figure 4-6 The side wall 12 includes a vertical wall 121 connected to the cover 11. The end of the vertical wall 121 away from the cover 11 is U-shaped and bent outward to form a bent wall 122 and an outer straight wall 123 connected in sequence. The sealing ring 30 covers the end of the vertical wall 121 away from the cover 11, the bent wall 122, and the outer straight wall 123. The U-shaped bend at the end of the side wall 12 away from the cover 11 is more conducive to improving its bonding force with the sealing ring 30 and preventing the side wall 12 from detaching from the sealing ring 30, so as to ensure the sealing effect of the sealing bottom cover 100.
[0064] See Figure 2 The outer casing 20 includes a main body 21 and a side portion 22. The main body 21 abuts against the end of the sealing ring 30 away from the cover 11, and the side portion 22 abuts against the outer periphery of the sealing ring 30. The main body 21 and the side portion 22 are connected by an arc-shaped transition portion 23. The end of the side portion 22 away from the transition portion 23 is bent towards the rounded corner of the side wall 12 to form a rounded end 24 and extends to cover the sealing ring 30. The transition portion 23 helps to improve the structural strength of the outer casing 20 and can cooperate with the inclined surface 35 to achieve smooth and precise assembly of the sealing bottom cover 100 and the outer casing 20.
[0065] Before encapsulation, the side portion 22 has a vertical structure to facilitate the fastening of the sealing bottom cover 100 and the outer casing 20. During encapsulation, the end of the side portion 22 away from the transition portion 23 is bent towards the rounded corner of the side wall 12 to form a rounded end 24 and extends to cover the sealing ring 30. This not only improves the bonding strength between the outer casing 20 and the sealing bottom cover 100, but also the rounded end 24 helps to increase the compression and uniform deformation of the sealing ring 30, thereby improving the sealing performance of the button-type energy storage device.
[0066] Based on this, see Figure 3 The shortest distance G1 between the rounded corner inflection point of the rounded end 24 and the outer straight wall 123 is 0.1mm-0.45mm; the shortest distance G2 between the outer straight wall 123 and the side portion 22 is 0.1mm-0.5mm; the shortest distance G3 between the bent wall 122 and the main body 21 is 0.2mm-0.75mm; and the radius of curvature R1 of the rounded end 24 is 0.7mm-1.3mm. These dimensions improve the tightness of the seal between the sealed bottom cover 100 and the outer casing 20 after encapsulation, thereby preventing electrolyte evaporation and external liquid intrusion, ensuring the sealing and stability of the coin-type energy storage device.
[0067] In addition, the average thickness of the outer casing 20 is T, the ratio of G1 to T is 50%-150%, the ratio of G2 to T is 60%-200%, and the ratio of G3 to T is 70%-300%, in order to further improve the sealing performance of the assembled button-type energy storage device.
[0068] The present application will be further described in detail below through specific embodiments and comparative examples. The following embodiments are merely simplified examples of the present application and do not represent or limit the scope of protection of the present application. The scope of protection of the present application shall be determined by the claims.
[0069] The following embodiments and comparative examples are all illustrated using a button-type supercapacitor as an example. The preparation methods of the positive electrode hard sheet, negative electrode hard sheet, and separator, as well as the assembly method of the button-type supercapacitor, all adopt the scheme of Embodiment 1 in the specification of the patent disclosed in CN118629791A. The side of the outer shell 20 and the vertical wall 121 of the bottom cover 10 are both vertical structures. The structure and parameters adopt the technical solution of this application. The differences are limited to the following embodiments and comparative examples.
[0070] Example 1
[0071] See Figure 4 This embodiment provides a button-type energy storage device. The sealing ring 30 is made of polypropylene PP8830. The circumferential outer surface of the sealing ring 30 near the end of the cover 11 is an outwardly inclined outer slope 31. The angle α between the outer slope 31 and the vertical direction is 40°. The ratio of the radial dimension L1 to the vertical dimension L2 of the slope 35 is 1. The ratio of the thickness of the electrode assembly to the thickness H0 of the button-type energy storage device is 0.7. The shortest distance G1 between the rounded corner inflection point of the rounded end 24 and the outer straight wall 123 is 0.24 mm. The shortest distance G2 between the outer straight wall 123 and the side part 22 is 0.31 mm. The shortest distance G3 between the bent wall 122 and the main body 21 is 0.2 mm. The radius of curvature R1 of the rounded end 24 is 1.1 mm.
[0072] Example 2
[0073] See Figure 6 This embodiment also provides a button-type energy storage device, which differs from Embodiment 1 in that: the outer circumferential side of the sealing ring 30 near the end of the cover 11 is rounded 33, and the R value of the rounded corner 33 is 0.5mm.
[0074] Comparative Example 1
[0075] See Figure 7 This comparative example also provides a button-type energy storage device, which differs from Example 1 in that the circumferential side of the sealing ring 30 near the end of the cover 11 is a right-angle structure.
[0076] Test methods
[0077] A 60°C high-temperature storage experiment was conducted on the coin-type energy storage devices obtained in Examples 1-2 and Comparative Example 1 to test the changes in internal resistance and weight loss rate of the coin-type energy storage devices under high-temperature conditions.
[0078] First, the initial internal resistance and initial weight of the coin energy storage devices obtained in Examples 1-2 and Comparative Example 12 were tested using the same method. Then, the coin energy storage devices were stored at 60°C for 21 days in a high-temperature chamber. After storage, the internal resistance and weight were tested using the same method, and the weight loss rate was calculated. The specific results are shown in Table 1.
[0079] Table 1
[0080]
[0081] As shown in Table 1, the sealing ring 30 structure of this application can reduce the evaporation of electrolyte inside the coin-type energy storage device, thereby improving the sealing performance. At the same time, it can also effectively prevent poor internal contact of the coin-type energy storage device caused by the expansion of the outer shell 20 under high temperature conditions, which is beneficial to improving the electrical performance, stability, sealing performance and lifespan of the coin-type energy storage device.
[0082] The technical means disclosed in this application are not limited to those disclosed in the above embodiments, but also include technical solutions composed of any combination of the above technical features. It should be noted that those skilled in the art can make several improvements and modifications without departing from the principles of this application, and these improvements and modifications are also considered to be within the scope of protection of this application.
Claims
1. A sealed bottom cover, characterized in that, include: The bottom cover includes a cover body and a side wall formed by bending the outer periphery on the same side; A sealing ring, which is circumferentially injection molded onto the sidewall and wraps around the end of the sidewall away from the cover; A deformation space is provided on the circumferential outer side and / or circumferential inner side of the end of the sealing ring near the cover body, so that the sealing ring deforms toward the deformation space when it is compressed.
2. The sealing bottom cover according to claim 1, characterized in that: The outer circumferential surface of the sealing ring near the end of the cover is an outwardly inclined surface, so as to form the deformation space on the outer circumferential side of the outwardly inclined surface; And / or, the circumferential inner surface of the sealing ring near the end of the cover is an inwardly inclined inner slope to form the deformation space between the inner slope and the sidewall; And / or, the inner and / or outer circumferential surfaces of the sealing ring near the end of the cover are rounded to form the deformation space between the outer circumferential surface of the rounded corner and / or between the rounded corner and the sidewall.
3. The sealing bottom cover according to claim 2, characterized in that: The angle α between the outer inclined plane and the vertical direction is 25°-50°.
4. The sealing bottom cover according to claim 2, characterized in that: The angle β between the inner inclined surface and its adjacent horizontal end face is 130°-170°.
5. The sealing bottom cover according to claim 2, characterized in that: The radius (R) of the fillet is 0.1mm-0.8mm.
6. The sealing bottom cover according to any one of claims 1-5, characterized in that: The sealing ring has a first end face near the end of the cover, and the first end face extends radially away from the side wall by a dimension L of 0.1mm-0.27mm.
7. The sealing bottom cover according to any one of claims 1-5, characterized in that: The outer circumferential surface of the sealing ring at the end away from the cover is a slope, and the end of the slope near the cover is further away from the side wall than the opposite end.
8. The sealing bottom cover according to claim 7, characterized in that: The ratio of the radial dimension L1 to the vertical dimension L2 of the inclined plane is 0.3-1.
7.
9. A button-type energy storage device, characterized in that, include: The housing and the sealing bottom cover according to any one of claims 1-8, wherein the housing and the sealing bottom cover are insulated and sealed together to form an accommodating space for receiving an electrode assembly therebetween, the housing covering the outer periphery of the sealing ring.
10. The button-type energy storage device according to claim 9, characterized in that: The electrode assembly includes a positive electrode hard sheet, a negative electrode hard sheet, and a separator disposed between the two. The ratio of the thickness of the electrode assembly to the thickness H0 of the coin cell energy storage device is 0.7-0.
8.
11. The button-type energy storage device according to claim 9, characterized in that: The ratio of the initial thickness H1 of the sealing ring to the thickness H0 of the button-type energy storage device is 100%-106%.
12. The button-type energy storage device according to any one of claims 9-11, characterized in that: The sidewall includes a vertical wall connected to the cover, and the end of the vertical wall away from the cover is U-shaped outwardly bent to form a bent wall and an outer straight wall connected in sequence. The sealing ring covers the end of the vertical wall away from the cover, the bent wall and the outer straight wall.
13. The button-type energy storage device according to claim 12, characterized in that: The outer shell includes a main body and a side portion. The main body abuts against the end of the sealing ring away from the cover. The side portion abuts against the outer periphery of the sealing ring. The main body and the side portion are connected by an arc-shaped transition portion. The end of the side portion away from the transition portion is bent toward the rounded corner of the side wall to form a rounded end and extends to cover the sealing ring.
14. The button-type energy storage device according to claim 13, characterized in that: The shortest distance G1 between the rounded corner inflection point and the outer straight wall is 0.1mm-0.45mm, the shortest distance G2 between the outer straight wall and the side is 0.1mm-0.5mm, the shortest distance G3 between the bent wall and the main body is 0.2mm-0.75mm, and the radius of curvature R1 of the rounded corner is 0.7mm-1.3mm.
15. The button-type energy storage device according to claim 14, characterized in that: The average thickness of the outer shell is T, the ratio of G1 to T is 50%-150%, the ratio of G2 to T is 60%-200%, and the ratio of G3 to T is 70%-300%.