Battery sealing structure and battery

Abstract

The invention relates to the technical field of batteries, and discloses a battery sealing structure and a battery, the battery sealing structure comprises a cover plate, a sealing member, a pole and a pressing ring, the cover plate is used for sealing an opening of a battery shell, a through hole is formed in the center of the cover plate, the cover plate is provided with a first side surface and a second side surface opposite to each other, and the first side surface faces the interior of the battery shell; the sealing piece is annularly arranged in the through hole and extends to the first side surface and the second side surface; the first connecting section, the second connecting section and the third connecting section are sequentially connected in the axial direction, the diameters of the first connecting section, the second connecting section and the third connecting section are sequentially increased, the diameter of the through hole is larger than that of the second connecting section and smaller than that of the third connecting section, and the second connecting section penetrates through the inner hole of the sealing piece and right faces the hole wall of the inner hole; the pressing ring sleeves the periphery of the first connecting section and is riveted with the first connecting section; one side surface, facing the cover plate, of the pressing ring is attached to one end surface of the second connecting section; and the sealing piece is tightly matched with the pressing ring and the third connecting section. According to the invention, the battery has a good sealing effect, and the internal resistance of the battery can be reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of batteries, in particular to a battery sealing structure and a battery comprising the same. BACKGROUND

[0002] With the development of lithium ion battery applications, the market requirements for lithium ion batteries have gradually increased, especially in some outdoor and automotive application scenarios, higher wide temperature resistance and high reliability requirements are put forward for lithium ion batteries. However, the current cylindrical lithium ion battery generally uses a narrow temperature range, especially poor high temperature performance, and generally cannot be used in an environment above 60℃. On the one hand, the mechanical seal has insufficient airtightness, and the sealing rubber ring is easily aged under long-term use at high temperature, resulting in a decrease in sealing performance, easy leakage, and serious performance degradation. Especially for some areas with high humidity for a long time, humidity will further affect the reliability of the battery. On the other hand, the current cylindrical lithium ion battery is designed with a current interrupt device (CID) in the cap. The structure has a pressure threshold of 1~1.5MPa. For long-term use in subtropical or hot regions, the lithium ion battery is used at a high temperature for a long time, and the gas generated by the internal side reaction accumulates to a certain extent, and the CID will flip, causing the battery to suddenly drop in performance. Therefore, this structure is difficult to make the lithium ion battery long-term use at high temperature, and the application range is limited.

[0003] In addition, although the CID structure will flip through the CID when overcharged or externally short-circuited, the internal circuit of the entire battery will be disconnected to a certain extent, preventing the internal reaction from continuing to ferment. However, for mechanical abuse such as heavy impact, extrusion, and needle puncture, it directly leads to internal short circuit of the battery, and the protection of the CID is very limited. Even if the CID flips to disconnect the internal circuit of the battery, the internal reaction will continue to occur, and there is still a safety risk. Therefore, it is urgent to develop a new high-reliability battery structure that can ensure safety while being suitable for long-term use at high temperature. SUMMARY

[0004] The purpose of the embodiment of the present application is to provide a battery sealing structure and a battery. The battery sealing structure is applied to the battery, which can make the battery have good sealing effect and environmental adaptability, improve the reliability of the battery, and reduce the internal resistance of the battery.

[0005] To achieve the above purpose, the technical scheme adopted by the present application is as follows:

[0006] On the one hand, a battery sealing structure is provided, comprising:

[0007] A cover plate for sealing an opening of a battery case, the cover plate having a through hole in a center thereof, the cover plate having a first side and a second side opposite to each other in a thickness direction thereof, the first side facing an inside of the battery case;

[0008] A seal member annularly disposed in the through hole and extending to the first side and the second side;

[0009] A pole having a first connecting section, a second connecting section and a third connecting section connected in sequence and having diameters gradually increasing in an axial direction thereof, the second connecting section having a diameter smaller than that of the through hole, the third connecting section having a diameter larger than that of the through hole, the pole being disposed in an inner hole of the seal member, a hole wall of the inner hole facing the second connecting section, the first connecting section being located outside the battery case, the third connecting section being located inside the battery case;

[0010] A compression ring sleeved on an outer periphery of the first connecting section and being riveted to the first connecting section, a side of the compression ring facing the cover plate being attached to an end face of the second connecting section axially away from the third connecting section, the seal member being tightly fitted with the compression ring and the third connecting section.

[0011] As a further scheme of the battery sealing structure, a ratio of the diameter of the second connecting section to that of the first connecting section is 1.1-1.4.

[0012] As a further scheme of the battery sealing structure, the first connecting section after riveting has a connecting body and a limiting portion coaxially connected, the limiting portion and the second connecting section being respectively located at two ends of the connecting body in the axial direction thereof, the limiting portion having a diameter larger than that of the connecting body, a clamping groove clamping the seal member being formed between the limiting portion and an end face of the second connecting section.

[0013] As a further scheme of the battery sealing structure, the compression ring includes a compression ring body and a boss coaxially arranged, the boss being protruded at an end of the compression ring body axially facing the seal member, the inner hole penetrating through the compression ring body and the boss, the boss being attached to an end face of the second connecting section.

[0014] As a further scheme of the battery sealing structure, an outer peripheral surface of the boss protrudes from an outer peripheral surface of the second connecting section, the boss being capable of shielding a position where the seal member abuts against the second connecting section.

[0015] As a further scheme of the battery sealing structure, a ratio of an outer diameter of the compression ring to an outer diameter of the seal member is 0.7-0.9.

[0016] As a further scheme of the battery sealing structure, a ratio of an outer diameter of the compression ring to an outer diameter of the sealing member is 0.7-0.9; and / or,

[0017] A ratio of an outer diameter of the first connecting section to an outer diameter of the compression ring is 0.3-0.7; and / or,

[0018] A compression ratio of the third connecting section and the compression ring to the sealing member is 10%-50%; and / or,

[0019] A second side of the cover plate is provided with a flange, the flange is located at an outer periphery of the cover plate, and a height of the flange is 20%-60% of a thickness of the cover plate.

[0020] As a further scheme of the battery sealing structure, a sealing nail is further included, the cover plate is provided with a liquid injection hole penetrating in a thickness direction of the cover plate, the sealing nail includes a nail body and a nail tip coaxially connected, the nail tip is a conical structure, a length of the nail body is greater than the thickness of the cover plate, a hole diameter of the liquid injection hole is less than a diameter of the nail body and greater than a tip diameter of the nail tip, and the nail body is in interference fit with the liquid injection hole.

[0021] As a further scheme of the battery sealing structure, a ratio of the diameter of the nail body to the hole diameter of the liquid injection hole is 1.02-1.10, and a ratio of the tip diameter of the nail tip to the hole diameter of the liquid injection hole is 0.5-0.8.

[0022] In another aspect, a battery is provided, including a battery shell, a pole piece, a tab, and the battery sealing structure, the cover plate of the battery sealing structure is connected with an opening of the battery shell to seal the opening, the pole piece is located in the battery shell and connected with the pole post of the battery sealing structure through the tab.

[0023] Beneficial effects: the pole post is designed as the first connecting section, the second connecting section and the third connecting section which are connected in sequence and have diameters increasing in sequence, so that an end face of the second connecting section connected with the first connecting section forms a step face, the step face is attached to an end face of the compression ring facing the step face, the step face can provide support for the compression ring when the first connecting section is riveted and connected with the compression ring, the compression ring is pressed on the step face, the second connecting section expands outward with its center as the center, so that better contact effect is achieved between the pole post, the compression ring and the sealing member, thereby the sealing property can be improved and the internal resistance of the battery can be reduced. BRIEF DESCRIPTION OF DRAWINGS

[0024] The application will be further described in detail below according to the drawings and examples.

[0025] Figure 1 is a sectional view of the battery sealing structure (not including the sealing nail) of the application;

[0026] Figure 2 A cross-sectional view of the assembled cover plate and seal according to the present application;

[0027] Figure 3 A cross-sectional view of the compression ring according to the present application;

[0028] Figure 4 A cross-sectional view of the pole according to the present application;

[0029] Figure 5 A cross-sectional view of the sealing spike according to the present application;

[0030] Figure 6 A box plot of internal resistance for various embodiments and comparative examples of the present application.

[0031] In the figures:

[0032] 100, cover plate; 1001, through hole; 1002, first side; 1003, second side; 1004, liquid injection hole; 110, flange; 120, second protrusion; 200, seal; 2001, inner hole; 300, pole; 310, first connecting section; 311, connecting body; 312, limiting portion; 320, second connecting section; 330, third connecting section; 3301, notch; 340, fourth connecting section; 350, first protrusion; 400, compression ring; 4001, groove; 4002, central hole; 410, compression ring body; 420, boss; 500, sealing spike; 510, spike body; 520, spike tip. DETAILED DESCRIPTION

[0033] In order to make the technical problems solved by the present application, the technical solutions adopted and the technical effects achieved more clear, the technical solutions of the embodiments of the present application will be further described in detail below with reference to the drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0034] In the description of the present application, unless otherwise explicitly specified and limited, the terms "connected", "connected", "fixed" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0035] In the present application, unless otherwise explicitly specified and limited, the first feature is "on" or "under" the second feature can include that the first feature and the second feature are in direct contact, or that the first feature and the second feature are not in direct contact but are in contact through another feature between them. Moreover, the first feature is "on", "above" and "over" the second feature includes that the first feature is directly above and obliquely above the second feature, or only indicates that the first feature is higher in horizontal height than the second feature. The first feature is "under", "below" and "underneath" the second feature includes that the first feature is directly below and obliquely below the second feature, or only indicates that the first feature is lower in horizontal height than the second feature.

[0036] In the description of the present embodiment, if the terms "upper", "lower", "left", "right" and the like orientation or position relationship appear, they are based on the orientation or position relationship shown in the drawings, and are only for the convenience of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, if the terms "first", "second" and the like appear, they are only used to distinguish in description and have no special meaning.

[0037] As shown in Figure 1 and Figure 2 , the present embodiment provides a battery sealing structure, comprising a cover plate 100, a sealing member 200, a pole 300 and a compression ring 400.

[0038] The cover plate 100 is used to seal the opening of the battery shell, the center of the cover plate 100 is provided with a through hole 1001, the cover plate 100 has opposite first and second side surfaces 1002 and 1003 along its thickness direction, the first side surface 1002 faces the inside of the battery shell; the sealing member 200 is annularly arranged in the through hole 1001 and extends to the first and second side surfaces 1002 and 1003; the pole 300 has a first connecting section 310, a second connecting section 320 and a third connecting section 330 connected in sequence along its axial direction and with diameters increasing in sequence, the diameter of the second connecting section 320 is smaller than that of the through hole 1001, the diameter of the third connecting section 330 is larger than that of the through hole 1001, the pole 300 is arranged in the inner hole 2001 of the sealing member 200, and the hole wall of the inner hole 2001 is opposite to the second connecting section 320, the first connecting section 310 is located outside the battery shell, and the third connecting section 330 is located inside the battery shell; the compression ring 400 is sleeved on the outer periphery of the first connecting section 310 and is riveted and connected with the first connecting section 310, one side of the compression ring 400 facing the cover plate 100 is attached to the end surface of the second connecting section 320 axially away from the third connecting section 330; the sealing member 200 is tightly matched with the compression ring 400 and the third connecting section 330.

[0039] In this embodiment, the electrode post 300 is designed as a first connecting segment 310, a second connecting segment 320, and a third connecting segment 330 connected in sequence with increasing diameters. This creates a stepped surface at the end face of the second connecting segment 320 that connects to the first connecting segment 310. This stepped surface fits against the end face of the pressure ring 400 facing the stepped surface. When the first connecting segment 310 and the pressure ring 400 are riveted together, the stepped surface provides support for the pressure ring 400. The pressure ring 400 presses against the stepped surface, causing the second connecting segment 320 to expand outward from its center. This results in better contact between the electrode post 300, the pressure ring 400, and the seal 200, thereby improving sealing and reducing the battery's internal resistance.

[0040] The cover plate 100 has a second side surface 1003, and the flange 110 is located on the outer periphery of the cover plate 100. The flange 110 increases the contact area with the inner wall of the opening of the battery casing, ensuring a tight seal. For example, the height of the flange 110 is 20% to 60% of the thickness of the cover plate 100, such as 20%, 22%, 25%, 28%, 30%, 35%, 40%, 45%, 50%, 55%, or 60%.

[0041] In a specific example, the seal 200 is made of sealant, which is integrally injection molded with the cover plate 100. This can improve the sealing performance between the cover plate 100 and the pole post 300 and the pressure ring 400, and reduce the assembly difficulty and improve the assembly efficiency.

[0042] Optionally, the seal 200 is made of a high-temperature resistant polymer material, specifically selected from any one of the following polymer materials: PFA (Polyfluoroalkoxy), PPS (Polyphenylene Sulfide), and PEEK (Polyether Ether Ketone). It is resistant to high temperatures, has good plasticity, and is easy to injection mold.

[0043] Furthermore, the ratio of the diameter of the second connecting segment 320 to the diameter of the first connecting segment 310 is 1.1 to 1.4, such as 1.1, 1.15, 1.2, 1.25, 1.3, 1.35, or 1.4. By controlling the ratio of the diameter of the second connecting segment 320 to the diameter of the first connecting segment 310 within the range of 1.1 to 1.4, the stepped surface of the second connecting segment 320 can provide sufficient support to the pressure ring 400 during the riveting process. The force during the riveting process gives the second connecting segment 320 sufficient expansion, while not affecting the compression ratio of the pressure ring 400 on the seal 200, ensuring that the battery sealing structure has good sealing performance, thereby reducing the internal resistance of the battery and improving the consistency of the internal resistance of the battery.

[0044] Further, the first connecting section 310 after riveting has a coaxially connected connecting body 311 and a limiting portion 312, the limiting portion 312 and the second connecting section 320 are respectively located at both ends of the connecting body 311 along the axial direction, the diameter of the limiting portion 312 is greater than that of the connecting body 311, and the limiting portion 312 and the end face of the second connecting section 320 form a clamping groove of the clamping seal 200.

[0045] When the first connecting section 310 is riveted with the compression ring 400, the end of the first connecting section 310 away from the second connecting section 320 expands outward with the axial center as the center, so that the first connecting section 310 forms a T-shaped structure, that is, the first connecting section 310 after riveting is composed of the connecting body 311 and the limiting portion 312, the limiting portion 312 tightly presses the compression ring 400 on the end face of the second connecting section 320, and forms a clamping groove structure to improve the riveting connection sealing performance of the compression ring 400 and the pole 300.

[0046] Further, as shown in Figure 3 the compression ring 400 includes a coaxially arranged compression ring body 410 and a boss 420, the boss 420 is protruded on the end of the compression ring body 410 along the axial direction towards the seal 200, the inner hole 2001 penetrates through the compression ring body 410 and the boss 420, and the boss 420 is attached to the end face of the second connecting section 320. The boss 420 can increase the sealing strength of the seal 200 when the pole 300 is riveted with the compression ring 400, and facilitate the judgment of the front and back of the compression ring 400 in the production process, thereby improving the production efficiency.

[0047] Further, the outer peripheral surface of the boss 420 protrudes from the outer peripheral surface of the second connecting section 320, and the boss 420 can shield the position where the seal 200 abuts against the second connecting section 320.

[0048] In this embodiment, the width of the boss 420 along the radial direction is designed to shield the position where the seal 200 abuts against the second connecting section 320, which can further improve the sealing performance.

[0049] In this embodiment, the compression ring 400 is provided with a groove 4001 and a center hole 4002 communicating with the groove 4001 along the axial direction, and the first connecting section 310 of the pole 300 penetrates through the center hole 4002 and the groove 4001, and the upper end of the first connecting section 310 tightly abuts against the groove 4001 of the compression ring 400 due to the riveting pressure.

[0050] After riveting and combination, the extrusion compression ratio of the third connecting section 330 and the compression ring 400 to the seal 200 is 10%~50%, and by controlling the extrusion compression ratio of the seal 200 to be 10%~50%, the cover plate 100, the pole 300 and the compression ring 400 have good sealing effect.

[0051] Specifically, the compression ratio of the third connecting section 330 and the pressure ring 400 to the seal 200 is 10%, 11%, 12%, 13%, 14%, 15%, 18%, 20%, 22%, 25%, 28%, 30%, 35%, 40%, 42%, 45%, 48%, or 50%, etc.

[0052] Optionally, the material of the pressure ring 400 can be selected from any one of nickel alloy, iron-nickel alloy, nickel-plated iron, stainless iron, or stainless steel.

[0053] Furthermore, the outer diameter of the seal 200 should be larger than the outer diameter of the pressure ring 400. When the pole post 300 and the pressure ring 400 are riveted together, the seal 200 can wrap around part of the outer circumferential surface of the pressure ring 400 by compression, thereby improving the sealing effect.

[0054] In this embodiment, the ratio of the outer diameter of the pressure ring 400 to the outer diameter of the seal 200 is 0.7 to 0.9, such as 0.7, 0.72, 0.75, 0.78, 0.8, 0.82, 0.85, 0.88, or 0.9. If this ratio is too small, the contact surface between the axial end face of the pressure ring 400 and the seal 200 will be insufficient, affecting the sealing effect. If the ratio is too large, the contact surface between the outer circumferential surface of the pressure ring 400 and the seal 200 will be too small, which will also affect the sealing effect.

[0055] The thickness of the seal 200 shall not exceed the height of the flange 110 of the cover plate 100.

[0056] Furthermore, the ratio of the outer diameter of the first connecting section 310 to the outer diameter of the pressure ring 400 is 0.3 to 0.7. If the ratio is less than 0.3, it will increase the internal resistance of the battery and affect its performance. If the ratio is greater than 0.7, it will affect the contact area between the seal 200 and the cover plate 100, resulting in reduced sealing performance. It will also affect the battery's assemblability. Optionally, the ratio of the outer diameter of the first connecting section 310 to the outer diameter of the pressure ring 400 is 0.30, 0.32, 0.35, 0.38, 0.4, 0.42, 0.45, 0.5, 0.55, 0.6, 0.65, or 0.7, etc.

[0057] In this embodiment, such as Figure 1 and Figure 4 As shown, the terminal post 300 also has a fourth connecting section 340, which is connected to the end face of the third connecting section 330 away from the second connecting section 320. The fourth connecting section 340 is used to connect the battery tabs, and the diameter of the fourth connecting section 340 is smaller than the diameter of the first connecting section 310.

[0058] Further, the fourth connecting section 340 is coaxial with the third connecting section 330, by arranging the fourth connecting section 340 with a smaller diameter than the first connecting section 310 at the center of the end face of the third connecting section 330 away from the second connecting section 320, the connection operation between the fourth connecting section 340 and the tab of the battery can be facilitated.

[0059] Further, the third connecting section 330 is annularly arranged with a first protrusion 350 at the end face away from the fourth connecting section 340, and the cover plate 100 is annularly arranged with a second protrusion 120 at the first side face 1002, the second protrusion 120 is located at the end of the through hole 1001 of the cover plate 100, and the distance between the second protrusion 120 and the center of the cover plate 100 is smaller than the distance between the first protrusion 350 and the center of the cover plate 100, so that the first protrusion 350 and the second protrusion 120 form an “anti-buckling” structure, increasing the extrusion degree and sealing path of the sealing member 200, and further improving the sealing performance.

[0060] Further, the third connecting section 330 is annularly arranged with a notch 3301 at the corner of the outer edge, the outer diameter of the notch 3301 is consistent with the outer diameter of the compression ring 400, and during the riveting of the first connecting section 310 and the compression ring 400, the sealing member 200 is extruded to wrap part of the outer circumferential surface of the notch 3301, so that the extrusion degree of the sealing member 200 extending to the outer edge of the region of the first side face 1002 and the second side face 1003 is consistent.

[0061] In the prior art, an insulating gasket is generally arranged on the outer circumferential surface of the notch of the pole column to improve the sealing performance. The present scheme eliminates the insulating gasket, and at the same time, the sealing member 200 wraps part of the outer circumferential surface of the notch 3301 by extrusion, which also achieves good sealing performance, and the structure is simpler and the cost is lower.

[0062] In the present embodiment, in order to facilitate liquid injection, the cover plate 100 is provided with a liquid injection hole 1004 along the axial direction thereof, and the battery sealing structure further comprises a sealing pin 500, the sealing pin 500 is in interference fit with the liquid injection hole 1004, electrolyte can be injected into the battery shell through the liquid injection hole 1004, and after the injection is completed, the sealing of the liquid injection hole 1004 is realized through the interference fit between the sealing pin 500 and the liquid injection hole 1004. The material of the sealing pin 500 is consistent with the material of the cover plate 100.

[0063] Further, as shown in FIG. 6, the fourth connecting section 340 is annularly arranged with a second protrusion 3402 at the end face away from the third connecting section 330, and the cover plate 100 is annularly arranged with a third protrusion 1004 at the first side face 1002, the third protrusion 1004 is located at the end of the through hole 1001 of the cover plate 100, and the distance between the third protrusion 1004 and the center of the cover plate 100 is smaller than the distance between the second protrusion 3402 and the center of the cover plate 100, so that the second protrusion 3402 and the third protrusion 1004 form an “anti-buckling” structure, increasing the extrusion degree and sealing path of the sealing member 200, and further improving the sealing performance. Figure 5As shown, the sealing nail 500 includes a nail body 510 and a nail tip 520 coaxially connected, the nail body 510 is a cylindrical structure, the nail tip 520 is a conical structure, the length of the nail body 510 is greater than the thickness of the cover plate 100, the hole diameter of the liquid injection hole 1004 is smaller than the diameter of the nail body 510 and greater than the tip diameter of the nail tip 520. Through the structure design, the sealing nail 500 can be smoothly inserted into the liquid injection hole 1004, and the sealing connection is realized by the interference fit between the nail body 510 and the liquid injection hole 1004.

[0064] Further, the ratio of the diameter of the nail body 510 to the hole diameter of the liquid injection hole 1004 is 1.02-1.10, if the ratio is less than 1.02, it will cause poor sealing effect, and if the ratio is greater than 1.1, it will cause the liquid injection hole 1004 to be deformed; the ratio of the diameter of the tip of the nail tip 520 to the hole diameter of the liquid injection hole 1004 is 0.5-0.8, which is conducive to the smooth insertion of the sealing nail 500 into the liquid injection hole 1004 to realize sealing.

[0065] The present embodiment also provides a battery including a battery shell, a pole piece, a tab, and a battery sealing structure of any of the above embodiments, the cover plate 100 of the battery sealing structure is connected with the opening of the battery shell to block the opening, and the pole piece is located in the battery shell and connected with the pole post 300 of the battery sealing structure through the tab.

[0066] The cover plate 100 and the battery shell are integrally formed by laser welding to form a full-sealing structure.

[0067] In the prior art, a cylindrical battery usually has an explosion-proof valve, which allows the cylindrical battery to have a certain gas permeability to ensure its safety. If the sealing performance of the cover plate structure of the cylindrical battery is poor, it will lead to insufficient sealing and increase the risk of liquid leakage. In the present embodiment, after the battery sealing structure is sealingly connected with the battery shell, the battery has reliable sealing performance and small gas permeability, thereby reducing the risk of liquid leakage.

[0068] Further, the gas permeability of the battery of the present embodiment is less than 10 -8 Pa·m 3 / s (He), which means that the gas used to test the gas permeability of the battery is helium (He). The service life of the battery of the present embodiment can reach more than 10 years, and the battery can be charged and discharged in a temperature range of -40℃ to 100℃.

[0069] The battery sealing structure of the present embodiment applied to the cylindrical battery can make the battery product have no liquid leakage, no fire, and no explosion after 2000h under the condition of 85℃&85%RH, thereby significantly improving the reliability of the product. The battery sealing structure of the present embodiment solves the problem of high temperature and high humidity (85℃&85%RH) in the battery industry, and is safe and reliable.

[0070] Of course, the battery sealing structure of the present embodiment is not limited to be applied to a cylindrical battery, but is also applicable to other shaped batteries such as an oval battery or a square battery.

[0071] Next, specific embodiments and comparative examples for a cylindrical battery are provided to prepare a battery sealing structure with fixed parameters.

[0072] Embodiment 1

[0073] The battery sealing structure of the present embodiment includes a cover plate 100, a pole 300, a compression ring 400, a sealing member 200, and a sealing nail 500, which are assembled according to the structure and assembly method shown in Figure 1 The specific structure and assembly method are as described above, and are not described in detail.

[0074] The ratio of the diameter of the second connecting section 320 to the diameter of the first connecting section 310 is 1.4, the ratio of the outer diameter of the compression ring 400 to the outer diameter of the sealing glue (sealing member 200) is 0.9, the extrusion compression ratio of the third connecting section 330 and the compression ring 400 to the sealing glue is 50%, the ratio of the diameter of the first connecting section 310 to the outer diameter of the compression ring 400 is 0.5, and the ratio of the diameter of the nail body 510 of the sealing nail 500 to the hole diameter of the liquid injection hole 1004 is 1.06.

[0075] Embodiment 2

[0076] The present embodiment is basically the same as the above-mentioned embodiment 1, except that the ratio of the diameter of the second connecting section 320 to the diameter of the first connecting section 310 is 1.1.

[0077] Embodiment 3

[0078] The present embodiment is basically the same as the above-mentioned embodiment 1, except that the ratio of the outer diameter of the compression ring 400 to the outer diameter of the sealing glue is 0.7.

[0079] Embodiment 4

[0080] The present embodiment is basically the same as the above-mentioned embodiment 1, except that the extrusion compression ratio of the third connecting section 330 and the compression ring 400 to the sealing glue is 50%.

[0081] Embodiment 5

[0082] The present embodiment is basically the same as the above-mentioned embodiment 1, except that the ratio of the diameter of the first connecting section 310 to the outer diameter of the compression ring 400 is 0.7.

[0083] Embodiment 6

[0084] The present embodiment is basically the same as the above-mentioned embodiment 1, except that the ratio of the diameter of the first connecting section 310 to the outer diameter of the compression ring 400 is 0.3.

[0085] Example 7

[0086] This example is substantially the same as the above-described Example 1, except that the ratio of the diameter of the shank 510 of the sealing nail 500 to the hole diameter of the liquid injection hole 1004 is 1.02.

[0087] Example 8

[0088] This example is substantially the same as the above-described Example 1, except that the ratio of the diameter of the shank 510 of the sealing nail 500 to the hole diameter of the liquid injection hole 1004 is 1.10.

[0089] Comparative Example 1

[0090] This comparative example is substantially the same as the above-described Example 1, except that the ratio of the diameter of the second connecting section 320 to the diameter of the first connecting section 310 is 1.0.

[0091] Comparative Example 2

[0092] This comparative example is substantially the same as the above-described Example 1, except that the ratio of the outer diameter of the compression ring 400 to the outer diameter of the sealing gel is 0.6.

[0093] Comparative Example 3

[0094] This comparative example is substantially the same as the above-described Example 1, except that the ratio of the outer diameter of the compression ring 400 to the outer diameter of the sealing gel is 1.0.

[0095] Comparative Example 4

[0096] This comparative example is substantially the same as the above-described Example 1, except that the ratio of the diameter of the first connecting section 310 to the outer diameter of the compression ring 400 is 0.2.

[0097] Comparative Example 5

[0098] This comparative example is substantially the same as the above-described Example 1, except that the ratio of the diameter of the first connecting section 310 to the outer diameter of the compression ring 400 is 0.8.

[0099] Sealing tests were performed on Examples 1 to 8 and Comparative Examples 1 to 5, and internal resistance tests were performed using the same jelly-roll to assemble a battery.

[0100] The sealing test method is that the battery sealing structure of each example is laser welded with the battery shell (empty steel shell) to form a sealed empty shell structure (5 empty shell structures are prepared for each example for testing), and then a helium mass spectrometer leak detector is used to test the air tightness under a helium atmosphere for 4 hours or more with a pressure of 0.3 MPa; the internal resistance test method is that the cylindrical battery sealing structure of each example is assembled into a battery using the same winding core and steel shell (5 batteries are prepared for each example for testing), and an internal resistance tester is used to test the alternating current internal resistance at 1 kHz as the internal resistance value; the sealing test and internal resistance test results are shown in Table 1.

[0101] Table 1. Sealing test and internal resistance test results

[0102]

[0103] It can be known from the comparison of the results that the battery sealing structure of the application has a gas permeability of less than 10 -8 Pa·m 3 / s (He) when applied to a sealed empty shell structure assembled from a battery shell, effectively isolates the external environment, and has high environmental adaptability. The battery sealing structure of the application can effectively reduce the internal resistance of the battery.

[0104] The internal resistance consistency of the same batch of batteries of each example and each comparative example (the number of the same batch of batteries of each example is 30) is tested according to IEC61960, and the test results are shown in Figure 6 From the figure, it can be seen that the battery sealing structure of the application can effectively improve the internal resistance consistency of the battery, and the internal resistance consistency can be improved by more than 30%.

[0105] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the application, but not to limit them; although the application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing examples, or make equivalent substitutions for part or all of the technical features; and these modifications or substitutions do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the application, and they should be covered in the scope of the claims and the specification of the application. In particular, as long as there is no structural conflict, each technical feature mentioned in each embodiment can be combined in any way. The application is not limited to the specific examples disclosed in the text, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery seal structure, characterized by, The application relates to a battery cover plate and a battery pole. The cover plate is used for sealing an opening of a battery shell, a through hole is arranged in the center of the cover plate, the cover plate has a first side face and a second side face opposite to each other along the thickness direction of the cover plate, and the first side face faces the inside of the battery shell. A sealing element is annularly arranged in the through hole and extends to the first side face and the second side face. A pole has a first connecting section, a second connecting section and a third connecting section connected in sequence along the axial direction of the pole, the diameters of the connecting sections are sequentially increased, the diameter of the second connecting section is smaller than the diameter of the through hole, the diameter of the third connecting section is larger than the diameter of the through hole, the pole is arranged in the inner hole of the sealing element, the hole wall of the inner hole is opposite to the second connecting section, the first connecting section is located outside the battery shell, and the third connecting section is located inside the battery shell. A compression ring is sleeved on the outer periphery of the first connecting section and is riveted and connected with the first connecting section, one side of the compression ring faces the second connecting section and is attached to the end face of the second connecting section which is axially away from the third connecting section, and the sealing element is tightly matched with the compression ring and the third connecting section.

2. The battery seal structure of claim 1, wherein, The ratio of the diameter of the second connecting section to the diameter of the first connecting section is 1.1-1.

4.

3. The battery seal structure of claim 1, wherein, The first connecting section after riveting has a connecting body and a limiting part which are coaxially connected, the limiting part and the second connecting section are respectively located at two ends of the connecting body along the axial direction of the connecting body, the diameter of the limiting part is larger than the diameter of the connecting body, and a clamping groove for clamping the sealing element is formed between the limiting part and the end face of the second connecting section.

4. The battery seal structure of claim 1, wherein, The compression ring comprises a compression ring body and a boss which are coaxially arranged, the boss is protruded from one end of the compression ring body which is axially towards the sealing element, the inner hole penetrates through the compression ring body and the boss, and the boss is attached to the end face of the second connecting section.

5. The battery seal structure of claim 4, wherein, The outer peripheral surface of the boss is protruded from the outer peripheral surface of the second connecting section, and the boss can shield the position where the sealing element is abutted against the second connecting section.

6. The battery seal structure of claim 1, wherein, The ratio of the outer diameter of the compression ring to the outer diameter of the sealing element is 0.7-0.9; and / or The ratio of the outer diameter of the first connecting section to the outer diameter of the compression ring is 0.3-0.7; and / or The extrusion compression ratio of the third connecting section and the compression ring to the sealing element is 10%-50%; and / or The second side face of the cover plate is provided with a flange, the flange is located on the outer periphery of the cover plate, and the height of the flange is 20%-60% of the thickness of the cover plate.

7. The battery seal structure of claim 1, wherein The pole further has a fourth connecting section which is connected with the end face of the third connecting section which is axially away from the second connecting section, and the fourth connecting section is used for connecting the tab of the battery.

8. The battery seal structure according to any one of claims 1 to 7, characterized by, The cover plate is provided with a liquid injection hole penetrating through the thickness direction of the cover plate, the sealing spike comprises a spike body and a spike tip which are coaxially connected, the spike tip is a conical structure, the length of the spike body is larger than the thickness of the cover plate, the hole diameter of the liquid injection hole is smaller than the diameter of the spike body and larger than the tip diameter of the spike tip, and the spike body is in interference fit with the liquid injection hole.

9. The battery seal structure of claim 8, wherein, The ratio of the diameter of the nail body to the hole diameter of the liquid injection hole is 1.02-1.10, and the ratio of the diameter of the tip of the nail tip to the hole diameter of the liquid injection hole is 0.5-0.

8.

10. A battery, characterized by The battery sealing structure of any one of claims 1 to 9, wherein a cover plate of the battery sealing structure is connected to an opening of the battery case to seal the opening, and the electrode tab is located in the battery case and connected to the pole post of the battery sealing structure through the electrode lug.

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