Single battery and battery pack

Abstract

The utility model provides a single battery and a battery pack, the single battery comprises a battery shell, the battery shell comprises a sealing part, and the top end of the sealing part is provided with an opening; the cap assembly is installed in the sealing part to seal the opening, the cap assembly comprises a sealing ring, a part of the outer surface of the sealing ring is arranged to abut against the inner surface of the sealing part, a dispensing groove is formed in the outer surface, the dispensing groove is arranged to contain first sealant, and the sealing part is arranged to seal the first sealant. The first sealant is arranged to seal the joint of the end, close to the opening, of the sealing part and the sealing ring.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a single cell and a battery pack. Background Art

[0002] In related art, cylindrical batteries include a battery housing, a sealing ring, and a top cover. The battery housing, sealing ring, and top cover form a semi-sealed seal. This seal can easily form a gap between the sealing ring and the battery housing when the battery is squeezed or collided, leading to leakage. A Chinese patent (application number 201020277866.4) discloses a sealing structure for cylindrical batteries that eliminates the groove structure of the battery housing and instead uses an adhesive to connect the sealing ring and battery housing. The adhesive in batteries with this sealing structure can enter the battery through the gap between the sealing ring and the battery housing, thereby affecting battery performance. Utility Model Content

[0003] The embodiments of the present utility model provide a single cell and a battery pack, which can improve the technical problem of adhesive glue entering the interior of the battery through the gap between the sealing ring and the battery shell.

[0004] In a first aspect, an embodiment of the present invention provides a single battery, comprising: a battery housing including a sealing portion, wherein a top end of the sealing portion is provided with an opening;

[0005] A cap assembly is installed in the sealing part to seal the opening. The cap assembly includes a sealing ring. A portion of the outer surface of the sealing ring is configured to abut against the inner surface of the sealing part. The outer surface is provided with a glue dispensing groove. The glue dispensing groove is configured to accommodate a first sealant. The first sealant is configured to seal the connection between the end of the sealing part close to the opening and the sealing ring.

[0006] In one embodiment, the sealing ring includes a sealing bending portion, the sealing bending portion includes a first sealing bending section and a second sealing bending section that are bent and connected, the second sealing bending section is bent relative to the first sealing bending section toward the direction close to the central axis of the battery shell, the second sealing bending section includes a first part and a second part, the first part is connected between the first sealing bending section and the second part, the outer surface of the first sealing bending section and the outer surface of the first part abut the inner surface of the sealing portion; wherein, the glue dispensing groove is provided on the outer surface of the connection between the first part and the second part.

[0007] In one embodiment, the distance between the end of the glue dispensing groove and the end of the second sealing bending section is 0.8 mm to 1.2 mm.

[0008] In one embodiment, the dispensing groove is set as an arc groove, the inner diameter of the dispensing groove is set to r, the thickness of the sealing ring is set to d, the ratio between r and d is not greater than 0.45, and the ratio between r and d is not less than 0.36.

[0009] In one embodiment, the second portion of the second sealing bend segment is warped relative to the first portion of the second sealing bend segment.

[0010] In one embodiment, the sealing portion includes a first connecting section and a second connecting section that are bent and connected, and the second connecting section is bent relative to the first connecting section toward the direction close to the central axis of the single battery housing; wherein, the outer surface of the first part of the second sealing bent section of the sealing ring abuts against the inner surface of the second connecting section, the first sealant is configured to seal the connection between the second connecting section and the first part, and the second part of the second sealing bent section of the sealing ring extends beyond the second connecting section.

[0011] In one embodiment, the battery shell also includes a rolling groove portion, the outer surface of the rolling groove portion is provided with a rolling groove, and the first connecting section is connected to the top of the rolling groove portion; wherein, the sealing bending portion of the sealing ring also includes a third sealing bending section, the third sealing bending section is connected to the end of the first sealing bending section away from the second sealing bending section, and the third sealing bending section abuts the inner surface of the rolling groove portion.

[0012] In one embodiment, the cap assembly further includes a burst-proof disk, and the inner surface of the third sealing bend section of the sealing ring is provided with a protrusion, and the protrusion abuts against the burst-proof disk.

[0013] In one embodiment, the explosion-proof piece includes a main body and an explosion-proof bending portion connected to the outside of the main body, the explosion-proof bending portion includes a first explosion-proof bending section and a second explosion-proof bending section that are bent and connected, the second explosion-proof bending section is bent relative to the first explosion-proof bending section toward the direction close to the central axis of the battery shell, the outer surface of the main body abuts the inner surface of the third sealing bending section, the first explosion-proof bending section abuts the inner surface of the first sealing bending section of the sealing ring, a part of the second explosion-proof bending section of the explosion-proof piece abuts the inner surface of the second sealing bending section of the sealing ring, and another part of the second explosion-proof bending section of the explosion-proof piece exceeds the second sealing bending section of the sealing ring.

[0014] In one embodiment, a first portion of the second sealant, a second portion of the second sealant and a third portion of the second sealant are provided between the explosion-proof plate and the sealing ring, the first portion of the second sealant is provided between the first explosion-proof bending section of the explosion-proof plate and the first sealing bending section of the sealing ring, the second portion of the second sealant is provided between the second explosion-proof bending section and the second sealing bending section of the sealing ring, the third portion of the second sealant is provided between the main body of the explosion-proof plate and the second sealing bending section of the sealing ring, and the third portion of the second sealant is provided on the side of the protrusion close to the battery shell.

[0015] In a second aspect, an embodiment of the present invention provides a battery pack, which includes the aforementioned multiple batteries and a box for accommodating the multiple batteries.

[0016] Beneficial effects of the embodiments of the present utility model:

[0017] In an embodiment of the present invention, a dispensing groove is provided on the outer surface of the sealing ring where it contacts the battery housing. The dispensing groove contains a first sealant, which seals the end of the connection between the battery housing and the sealing ring with the first sealant, thereby forming a fully sealed structure for the battery, effectively preventing electrolyte leakage to the outside of the battery through the connection gap between the battery housing and the sealing ring. Furthermore, the first sealant is contained within the dispensing groove and does not enter the interior of the battery housing through the connection gap between the sealing ring and the battery housing, thereby preventing the first sealant from affecting battery performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0019] Figure 1 This is a three-dimensional diagram of a single battery provided by an embodiment of the present utility model;

[0020] Figure 2 is a cross-sectional structural diagram of a cap assembly provided in an embodiment of the present utility model;

[0021] Figure 3 This is a cross-sectional structural diagram of a portion of the structure of a single cell provided by an embodiment of the present utility model;

[0022] Figure 4 yes Figure 3 A partial enlarged view of

[0023] Figure 5yes Figure 4 A partial enlarged view of

[0024] Figure 6 This is a top view of a sealing ring provided in an embodiment of the present utility model;

[0025] Figure 7 is a cross-sectional view of a sealing ring provided in an embodiment of the present utility model;

[0026] Figure Number:

[0027] 100. Battery; 10. Cap assembly;

[0028] 1. Battery housing; 11. Opening; 12. Sealing portion; 121. First connecting section; 122. Second connecting section; 13. Grooving portion; 131. Grooving;

[0029] 2. Sealing ring; 21. Outer surface; 22. Inner surface; 23. Glue dispensing groove; 24. Sealing bend; 241. First sealing bend section; 242. Second sealing bend section; 2421. First portion; 2422. Second portion; 243. Third sealing bend section; 25. Protrusion; 26. Extension;

[0030] 3. Top cover;

[0031] 4. Explosion-proof disk; 41. Main body; 42. Explosion-proof bending portion; 421. First explosion-proof bending section; 422. Second explosion-proof bending section; 43. Welding boss;

[0032] 5. Orifice plate;

[0033] 6. Orifice plate gasket;

[0034] 7. Second sealant; 71. First portion of second sealant; 72. Second portion of second sealant; 73. Third portion of second sealant; 8. First sealant; DETAILED DESCRIPTION

[0035] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention. In addition, it should be understood that the specific implementation methods described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention. In the present invention, unless otherwise specified, the directional words used, such as "upper" and "lower", generally refer to the upper and lower parts of the device in actual use or working state, specifically the drawing direction in the accompanying drawings; while "inside" and "outside" refer to the outline of the device.

[0036] The embodiment of the present utility model provides a single battery 100, such as Figures 1 to 4 As shown, taking a cylindrical lithium-ion secondary battery as an example, a single battery 100 includes a battery housing 1 , a cap assembly 10 and a winding core assembly.

[0037] The battery housing 1 is made of nickel-plated steel sheet material and has a hollow cylindrical structure. The top of the battery housing 1 is provided with an opening 11. The top of the battery housing 1 is provided with a sealing portion 12 and a groove portion 13 connected to the bottom end of the sealing portion 12. The sealing portion 12 includes a first connecting section 121 and a second connecting section 122. The first connecting section 121 is connected to the top of the groove portion 13, and the second connecting section 122 is connected to the end of the first connecting section 121. The second connecting section 122 is bent relative to the first connecting section 121 toward the central axis of the battery housing 1. The outer surface of the groove portion 13 is provided with a groove 131. By providing the groove 131 on the top of the battery housing 1, the core assembly inside the battery housing 1 and the cap assembly 10 at the opening 11 of the battery housing 1 can both abut against the inner surface of the groove 131, thereby preventing the core assembly and the cap assembly 10 from shaking inside the battery housing 1.

[0038] The core assembly includes a positive electrode sheet, a negative electrode sheet and a separator. The separator is preferably made of polyethylene film material. The separator is used to separate the positive electrode sheet and the negative electrode sheet. The positive electrode sheet, the separator and the negative electrode sheet are stacked and wound layer by layer to form a core assembly.

[0039] The cap assembly 10 is crimped to the opening 11 of the battery housing 1 and seals the opening 11 of the battery housing 1. The single cell 100 can be a battery pack formed by multiple single cells to provide power to electronic devices. Alternatively, the single cell 100 can be a battery pack formed by multiple single cells placed inside a housing to provide power to new energy vehicles or energy storage devices.

[0040] Continue to refer Figures 1 to 4 , taking the structure of the cap assembly 10 of a cylindrical lithium-ion battery as an example for explanation, the cap assembly 10 includes a top cover 3, an explosion-proof disk 4, an orifice plate 5, an orifice plate gasket 6 and a sealing ring 2.

[0041] The orifice plate 5 is disposed on the core assembly, and at least one of the positive electrode sheet and the negative electrode sheet of the core assembly is electrically connected to the orifice plate 5 .

[0042] The explosion-proof disc 4 is mounted on the orifice plate 5 and welded to the orifice plate 5. The disc 4 comprises a main body 41, an explosion-proof folded portion 42, and a welding boss 43. The welding boss 43 is located inside the main body 41, while the explosion-proof folded portion 42 is located outside the main body 41. The welding boss 43 of the disc 4 is welded to the orifice plate 5. The explosion-proof folded portion 42 includes a first explosion-proof folded section 421 and a second explosion-proof folded section 422. The first explosion-proof folded section 421 is positioned adjacent to the battery housing 1, while the second explosion-proof folded section 422 bends relative to the first explosion-proof folded section 421 toward the central axis of the battery housing 1.

[0043] The orifice plate 5 includes a welding portion provided at the center thereof, and the welding portion of the orifice plate 5 is welded to the bottom end surface of the explosion-proof disk 4 where the welding boss 43 is located.

[0044] The orifice plate gasket 6 is provided in the non-welding area between the orifice plate 5 and the explosion-proof disc 4 to prevent the orifice plate 5 and the explosion-proof disc 4 from being connected in the non-welding area and thus causing a short circuit in the battery.

[0045] The top cover 3 is arranged on the explosion-proof plate 4, and the top cover 3 includes a boss portion. The boss portion of the top cover 3 is arranged to protrude in the opposite direction to the welding boss 43 of the explosion-proof plate 4, so that the main body 41 of the explosion-proof plate 4 can be flipped in the space between the boss portion of the top cover 3 and the explosion-proof plate 4.

[0046] In the related art, a semi-sealed sealing structure is formed between the battery shell, the sealing ring and the top cover. This sealing structure makes it easy to form gaps between the top cover and the sealing ring, and between the sealing ring and the battery shell when the battery is squeezed and collided, thereby causing leakage. There are mainly two paths for leakage of cylindrical batteries, namely path A and path B. Path A is formed between the top cover and the sealing ring, and path B is formed between the sealing ring and the battery shell. A Chinese patent (application number 201020277866.4) discloses a sealing structure for a cylindrical battery, which eliminates the rolling groove structure of the battery shell and adopts a bonding method to connect the sealing ring and the battery shell. Since the battery with this sealing structure does not have a dispensing path between the sealing ring and the battery shell, the bonding glue will enter the interior of the battery cell through the gap between the sealing ring and the battery shell, thereby affecting the performance of the battery cell.

[0047] Continue to refer Figures 3 to 6 In some embodiments provided herein, the portion of the outer surface 21 of the sealing ring 2 that contacts the battery housing 1 is provided with a dispensing groove 23. The dispensing groove 23 is configured to accommodate a first sealant, which is configured to seal the end portion of the connection between the battery housing 1 and the sealing ring 2. The first sealant 8 may be a UV (Ultraviolet) first sealant 8.

[0048] A dispensing groove 23 is provided on the portion of the outer surface 21 where the sealing ring 2 contacts the battery housing 1. The dispensing groove 23 accommodates a first sealant 8, which seals the end portion of the connection between the battery housing 1 and the sealing ring 2. This creates a fully sealed structure for the single battery 100, effectively preventing electrolyte leakage to the exterior of the battery through the connection gap between the battery housing 1 and the sealing ring 2. Furthermore, the first sealant 8 is contained within the dispensing groove 23 and does not enter the interior of the battery housing 1 through the connection gap between the sealing ring 2 and the battery housing 1, thereby preventing the first sealant 8 from affecting battery performance.

[0049] Continue to refer Figure 3 、 Figure 4 and Figure 7 The sealing portion 12 of the battery casing 1 is provided with a first connecting section 121 and a second connecting section 122 that are bent and connected. The sealing ring 2 includes a sealing bending portion 24, which includes a first sealing bending section 241 and a second sealing bending section 242. The second sealing bending section 242 is connected to the end of the first sealing bending section 241, and the second sealing bending section 242 is bent relative to the first sealing bending section 241 toward the direction close to the central axis of the battery casing 1. The first sealing bend section 241 of the sealing ring 2 abuts against the inner side of the first connecting section 121 of the battery housing 1. The second sealing bend section 242 of the sealing ring 2 includes a first portion 2421 and a second portion 2421. The glue dispensing groove 23 is located between the first portion 2421 and the second portion 2422 of the second sealing bend section 242. The first portion 2421 of the second sealing bend section 242 of the sealing ring 2 abuts against the inner surface of the second connecting section 122 of the battery housing 1, and the second portion 2422 of the second sealing bend section 242 of the sealing ring 2 extends beyond the second connecting section 122 of the battery housing 1. The second portion 2422 is warped relative to the first portion 2421, so that the glue dispensing groove 23 between the first portion 2421 and the second portion 2422 can accommodate more first sealant 8.

[0050] By setting a two-section bent abutment structure between the sealing ring 2 and the sealing portion 12 of the battery shell 1, and the glue dispensing groove 23 is located on the second sealing bent section 242 of the sealing ring 2, during the glue dispensing process, it is difficult for excess first sealant 8 to enter the gap between the first sealing bent section 241 of the sealing ring 2 and the first connecting section 121 of the battery shell 1, and it is even more difficult to enter the interior of the battery shell 1.

[0051] Continue to refer Figures 1 to 4The battery housing 1 includes a groove portion 13, the first connecting section 121 is connected to the top of the groove portion 13, and the sealing bending portion 24 of the sealing ring 2 also includes a third sealing bending section 243, the third sealing bending section 243 is connected to the end of the first sealing bending section 241 away from the second sealing bending section 242, and the third sealing bending section 243 abuts against the inner surface of the groove portion 13.

[0052] By setting the sealing ring 2 as a three-section bending structure, the second sealing bending section 242 and the third sealing bending section 243 are respectively connected to the two ends of the first sealing bending section 241, and the second sealing bending section 242 and the third sealing bending section 243 are both constructed to bend toward the center axis of the battery shell 1, and the second sealing bending section 242 and the third sealing bending section 243 are both set to be perpendicular to the first sealing bending section 241. It can be understood that during the dispensing process, even if a part of the glue with strong fluidity enters the gap between the first sealing bending section 241 of the sealing ring 2 and the first connecting section 121 of the battery shell 1, this part of the glue is difficult to enter the gap between the third sealing bending section 243 of the sealing ring 2 and the top surface of the rolling groove 13, thereby further improving the sealing performance between the sealing ring 2 and the battery shell 1.

[0053] Continue to refer Figure 2 、 Figures 3 to 5 The distance h between the end of the dispensing groove 23 and the end of the second sealing bend section 242 is 0.8 mm to 1.2 mm. The end distance of the dispensing groove 23 is defined as the end of the dispensing groove 23 closest to the end of the second sealing bend section 242. In a specific embodiment, the distance between the end of the dispensing groove 23 and the end of the second sealing bend section 242 can be 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, 1.2 mm, or a value or range between any two of the above values.

[0054] Through research, the inventors discovered that when the height of the battery housing 1 remains unchanged, the corresponding bending length of the second connecting section 122 of the battery housing 1 remains unchanged. When the distance between the end of the glue dispensing groove 23 and the end of the second sealing bend section 242 is set to less than 0.8 mm, the end of the second sealing bend section 242 will be farther away from the end of the glue dispensing groove 23, thereby increasing the amount of glue used. When the distance between the end of the glue dispensing groove 23 and the end of the second sealing bend section 242 is set to greater than 1.2 mm, the glue dispensing groove 23 will be too close to the first connecting section 121 of the battery housing 1, thereby affecting the sealing effect between the second sealing bend section 242 of the sealing ring 2 and the second connecting section 122 of the battery housing 1.

[0055] Continue to refer Figure 5The glue dispensing groove 23 is configured as an arc-shaped groove, the inner diameter of the glue dispensing groove 23 is configured as r, the thickness of the sealing ring 2 is configured as d, the ratio between r and d is configured to be not less than 0.36, and the ratio between r and d is configured to be not greater than 0.45. In a specific implementation, the ratio between the inner diameter r of the glue dispensing groove 23 and the thickness d of the sealing ring 2 can be 0.36, 0.37, 0.38, 0.39, 0.40, 0.41, 0.42, 0.43, 0.44, 0.45, or a value between any two of the above values or a range between any two of the above values.

[0056] Through research, the inventors discovered that because the sealing ring 2 is made of a flexible material, if the radius of the glue dispensing groove 23 is set to exceed 45% of the wall thickness of the sealing ring 2, the structural strength of the sealing ring 2 will be insufficient, and the sealing ring 2 at the location of the glue dispensing groove 23 will be easily squeezed and broken, thereby affecting the sealing performance of the sealing ring 2. If the radius of the glue dispensing groove 23 is set to less than 36% of the wall thickness of the sealing ring 2, the depth of the glue dispensing groove 23 will be small, and glue will easily overflow during the glue dispensing process.

[0057] In a specific implementation provided in this application, Figure 7 As shown, the dispensing groove 23 is configured as a closed annular groove on the outer surface of the sealing ring 2. The diameter of the sealing ring 2 is set to 17.55mm, the thickness of the sealing ring 2 is set to 0.55mm, and the radius r of the dispensing groove 23 is set to 0.2mm to 0.25mm. During the dispensing process, a needle with a diameter of 0.26mm is used for dispensing. It is understood that if the radius of the dispensing groove 23 is set to less than 0.2mm, part of the needle will be located outside the dispensing groove 23, thereby affecting the stability of the dispensing process.

[0058] By providing a dispensing groove 23 at the end of the connection between the sealing ring 2 and the battery housing 1, and dispensing the first sealant 8 into the dispensing groove 23, the first sealant 8 can completely seal the end of the connection between the battery housing 1 and the sealing ring 2, thereby effectively preventing the electrolyte from leaking out of the battery housing 1 through the connection gap between the sealing ring 2 and the battery housing 1. In addition, during the dispensing process, the first sealant 8 is substantially contained in the dispensing groove 23, and thus will not leak into the battery through the gap between the sealing ring 2 and the battery housing 1.

[0059] Continue to refer Figures 3 to 5A portion of the inner surface 22 of the sealing ring 2 abuts the outer surface of the burst-proof disc 4. A protrusion 25 is provided on the portion of the inner surface 22 of the sealing ring 2 that contacts the burst-proof disc 4. This protrusion 25 is located on the third sealing bend 243 of the sealing ring 2. The inner surface 22 of the sealing ring 2 and the outer surface of the burst-proof disc 4 are sealed together by the second sealant 7. By providing the protrusion 25 on the third sealing bend 243 of the sealing ring 2, that is, providing the protrusion 25 at the end where the sealing ring 2 and the burst-proof disc 4 are bonded, the protrusion 25 prevents the second sealant 7 from flowing further into the interior of the single cell 100.

[0060] Continue to refer Figures 3 to 5 The sealing ring 2 includes a sealing bending portion 24. Correspondingly, the outer side of the main body 41 of the explosion-proof plate 4 is connected to an explosion-proof bending portion 42. The explosion-proof bending portion 42 includes a first explosion-proof bending segment 421 and a second explosion-proof bending segment 422 that are bent and connected. The second explosion-proof bending segment 422 is bent relative to the first explosion-proof bending segment 421 toward the direction close to the central axis of the battery housing 1, wherein a portion of the outer surface of the main body 41 of the explosion-proof plate 4 abuts on the third sealing bending segment 243 of the sealing ring 2, the first explosion-proof bending segment 421 of the explosion-proof plate 4 abuts on the outer surface of the first sealing bending segment 241 of the sealing ring 2, a portion of the second explosion-proof bending segment 422 of the explosion-proof plate 4 abuts under the second sealing bending segment 242 of the sealing ring 2, and another portion of the second explosion-proof bending segment 422 of the explosion-proof plate 4 exceeds the second sealing bending segment 242 of the sealing ring 2.

[0061] Correspondingly, the second sealant 7 used to bond the explosion-proof disc 4 and the sealing ring 2 includes three parts, namely a first part of the second sealant 71, a second part of the second sealant 72, and a third part of the second sealant 73. The first part of the second sealant 71 is arranged between the first explosion-proof bend section 421 of the explosion-proof disc 4 and the first sealing bend section 241 of the sealing ring 2, the second part of the second sealant 72 is arranged between the second explosion-proof bend section 422 of the explosion-proof disc 4 and the second sealing bend section 242 of the sealing ring 2, and the third part of the second sealant 73 is arranged between the main body 41 of the explosion-proof disc 4 and the third sealing bend section 243 of the sealing ring 2, and the third part of the second sealant 73 terminates at the side of the protrusion 25 close to the battery housing 1. The first part of the second sealant 71, the second part of the second sealant 72, and the third part of the second sealant 73 are made of the same material, and suitable sealants include asphalt glue.

[0062] The sealing ring 2 and the explosion-proof disc 4 are sealed and bonded together by the second sealant 7, thereby effectively preventing the electrolyte inside the single cell 100 from leaking to the outside through the connection gap between the sealing ring 2 and the explosion-proof disc 4. At the same time, a protrusion 25 is provided at the end of the bonding point between the sealing ring 2 and the explosion-proof disc 4, thereby effectively preventing the second sealant 7 from flowing into the interior of the single cell 100 and affecting the battery performance.

[0063] The present application also provides a battery pack comprising a housing and a plurality of batteries disposed within the housing. The battery pack can be used to provide power for new energy electric vehicles, and multiple battery packs can also be combined into an energy storage container or energy storage battery cabinet.

[0064] The above is a detailed introduction to the embodiments of the present invention. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method and core idea of the present invention. At the same time, for those skilled in the art, based on the idea of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the contents of this specification should not be understood as limiting the present invention.

Claims

1. A single battery, characterized in that: include: The battery housing includes a sealing portion, wherein the top end of the sealing portion is provided with an opening; A cap assembly is installed in the sealing part to seal the opening. The cap assembly includes a sealing ring. A portion of the outer surface of the sealing ring is configured to abut against the inner surface of the sealing part. The outer surface is provided with a glue dispensing groove. The glue dispensing groove is configured to accommodate a first sealant. The first sealant is configured to seal the connection between the end of the sealing part close to the opening and the sealing ring.

2. The single cell according to claim 1, characterized in that: The sealing ring includes a sealing bending portion, which includes a first sealing bending section and a second sealing bending section that are bent and connected, the second sealing bending section is bent relative to the first sealing bending section toward the direction close to the central axis of the battery shell, the second sealing bending section includes a first part and a second part, the first part is connected between the first sealing bending section and the second part, the outer surface of the first sealing bending section and the outer surface of the first part abut the inner surface of the sealing portion; wherein, the glue dispensing groove is provided on the outer surface of the connection between the first part and the second part.

3. The single cell according to claim 2, characterized in that: The distance between the end of the glue dispensing groove and the end of the second sealing bending section is 0.8 mm to 1.2 mm.

4. The single cell according to claim 2, characterized in that: The dispensing groove is set as an arc groove, the inner diameter of the dispensing groove is set to r, the thickness of the sealing ring is set to d, the ratio between r and d is not greater than 0.45, and the ratio between r and d is not less than 0.

36.

5. The single cell according to claim 2, characterized in that: The second portion of the second sealing bend segment is warped relative to the first portion of the second sealing bend segment.

6. The single cell according to claim 2, characterized in that: The sealing portion includes a first connecting section and a second connecting section that are bent and connected, and the second connecting section is bent relative to the first connecting section toward the direction close to the central axis of the single battery housing; wherein, the outer surface of the first part of the second sealing bent section of the sealing ring abuts against the inner surface of the second connecting section, the first sealant is configured to seal the connection between the second connecting section and the first part, and the second part of the second sealing bent section of the sealing ring extends beyond the second connecting section.

7. The single cell according to claim 6, characterized in that: The battery case also includes a rolling groove portion, and the first connecting section is connected to the top end of the rolling groove portion; wherein, the sealing bending portion of the sealing ring also includes a third sealing bending section, and the third sealing bending section is connected to an end of the first sealing bending section away from the second sealing bending section, and the third sealing bending section abuts against the inner surface of the rolling groove portion.

8. The single cell according to claim 7, characterized in that: The cap assembly further includes an explosion-proof disk. The inner surface of the third sealing bend section of the sealing ring is provided with a protrusion, and the protrusion abuts against the explosion-proof disk.

9. The single cell according to claim 8, characterized in that: The explosion-proof sheet includes a main body and an explosion-proof bent portion connected to the outside of the main body, the explosion-proof bent portion includes a first explosion-proof bent section and a second explosion-proof bent section that are bent and connected, the second explosion-proof bent section is bent relative to the first explosion-proof bent section toward the direction close to the central axis of the battery shell, the outer surface of the main body abuts the inner surface of the third sealing bent section, the first explosion-proof bent section abuts the inner surface of the first sealing bent section of the sealing ring, a part of the second explosion-proof bent section of the explosion-proof sheet abuts the inner surface of the second sealing bent section of the sealing ring, and another part of the second explosion-proof bent section of the explosion-proof sheet extends beyond the second sealing bent section of the sealing ring.

10. The single cell according to claim 9, characterized in that: A first portion of the second sealant, a second portion of the second sealant and a third portion of the second sealant are provided between the explosion-proof disc and the sealing ring, the first portion of the second sealant is provided between the first explosion-proof bending section of the explosion-proof disc and the first sealing bending section of the sealing ring, the second portion of the second sealant is provided between the second explosion-proof bending section and the second sealing bending section of the sealing ring, the third portion of the second sealant is provided between the main body of the explosion-proof disc and the second sealing bending section of the sealing ring, and the third portion of the second sealant is provided on the side of the protrusion close to the battery housing.

11. A battery pack, characterized in that: The battery pack comprises a plurality of single cells according to any one of claims 1 to 10 and a box for accommodating the plurality of single cells.

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