Cylindrical lithium battery cover and cylindrical lithium battery

Abstract

The utility model discloses a cylindrical lithium cell cap and cylindrical lithium cell, this cylindrical lithium cell cap includes insulating seal, metal pressing piece, top cover and explosion -proof subassembly, second through cavity has the first through groove and second through groove of upper and lower settings, and the inner diameter of first through groove is greater than the inner diameter of second through groove to form the load wall at the junction of both, and explosion -proof subassembly includes film and metal sheet, and film and metal sheet are spaced apart parallelly arranged, and the space between film and metal sheet forms the flame -retardant chamber, and the periphery of film is sealedly combined on the load wall, and the periphery of the lower surface of metal sheet is sealedly combined in the first through groove, and the middle part of the lower surface of metal sheet is equipped with the lancet for pricking the film, and the lower surface of metal sheet still is equipped with the flame -retardant layer. This cylindrical lithium cell cap can realize pressure -relief and flame -retardant, can reduce cylindrical lithium cell fire explosion probability, effectively improve security, and this cylindrical lithium cell cap structure is relatively simple, can effectively reduce production cost, can improve product competitiveness.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, and in particular to a cylindrical lithium battery cap and a cylindrical lithium battery. Background Technology

[0002] Lithium-ion batteries are widely used in new energy vehicles, energy storage systems, and other fields, making their safety a core concern in the industry. Cylindrical lithium batteries are widely used due to their compact structure and high energy density. However, under abnormal operating conditions such as overcharging, short circuits, or thermal runaway, violent reactions inside cylindrical lithium batteries can produce gases (such as carbon monoxide, hydrogen, and / or alkanes), easily leading to a rapid increase in internal pressure. If this pressure is not released in time, it may cause the cylindrical lithium battery to explode or even catch fire, posing a safety hazard. Utility Model Content

[0003] The technical problem to be solved by this utility model is to provide a cylindrical lithium battery cap and a cylindrical lithium battery.

[0004] The technical solution adopted by this utility model to solve its technical problem is as follows: a cylindrical lithium battery cap is constructed, including an insulating seal, a metal pressure plate, a top cover, and an explosion-proof component; the insulating seal includes a bearing portion, the bearing portion having a first through cavity, the metal pressure plate being coupled to the upper surface of the bearing portion, and the metal pressure plate having a second through cavity communicating with the first through cavity; the top cover being coupled to the upper surface of the metal pressure plate, and the top cover having a plurality of vent holes; The second passage cavity has a first passage groove and a second passage groove arranged vertically. The inner diameter of the first passage groove is larger than the inner diameter of the second passage groove, so as to form a bearing wall at the connection between the first passage groove and the second passage groove. The explosion-proof component is sealed and installed in the second passage cavity. The explosion-proof component includes a film and a metal sheet. The film and the metal sheet are arranged parallel to each other at intervals. The space between the film and the metal sheet forms a flame-retardant chamber. The periphery of the film is sealed to the support wall, and the periphery of the lower surface of the metal sheet is sealed to the upper periphery of the first through groove; a needle for piercing the film is provided in the middle of the lower surface of the metal sheet; a flame-retardant layer is also provided on the lower surface of the metal sheet.

[0005] In some embodiments, the metal sheet is provided with a cracking groove and a flipping groove, both of which are disposed opposite to the film; the thickness of the cracking groove is less than the thickness of the flipping groove, and the thickness of the flipping groove is less than the thickness of the metal sheet excluding the portion containing the cracking groove and the flipping groove.

[0006] In some embodiments, the film comprises a PP film or a PET film.

[0007] In some embodiments, the metal sheet is sealed to the upper edge of the first through groove by laser welding.

[0008] In some embodiments, the metal sheet is sealed to the upper edge of the first through groove by an adhesive.

[0009] In some embodiments, the metal sheet is a disc.

[0010] In some embodiments, the needle has a conical structure.

[0011] In some embodiments, the metal sheet comprises an aluminum sheet.

[0012] In some embodiments, the top cover includes a bottom wall, a top wall, and a side wall. The bottom wall has an annular structure and is combined with the upper surface of the metal pressure plate. The bottom wall and the top wall are arranged parallel to each other and spaced apart. The side wall connects the bottom wall and the top wall and is provided with the vent hole.

[0013] This utility model also discloses a cylindrical lithium battery, including a battery casing and a winding core disposed within the battery casing, wherein the upper end of the battery casing is provided with a cylindrical lithium battery cap according to any of the above embodiments.

[0014] The present invention has the following advantages: the cylindrical lithium battery has a cylindrical lithium battery cap, which can realize pressure relief and flame retardancy, reduce the probability of cylindrical lithium battery fire and explosion, effectively improve safety, and the cylindrical lithium battery cap has a relatively simple structure, which can effectively reduce production costs and improve product competitiveness. Attached Figure Description

[0015] To more clearly illustrate the technical solution of this utility model, the present utility model will be further described below in conjunction with the accompanying drawings and embodiments. It should be understood that the following drawings only show some embodiments of this utility model and should not be considered as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort. In the drawings: Figure 1 This is a schematic diagram of the structure of the cylindrical lithium battery cap in some embodiments of this utility model; Figure 2 This is one of the detailed views of the cylindrical lithium battery cap in some embodiments of this utility model; Figure 3 This is the second detailed view of the cylindrical lithium battery cap in some embodiments of this utility model; Figure 4 This is a schematic diagram of the structure of the metal pressure plate in some embodiments of this utility model; Figure 5This is a schematic diagram of the structure of the metal sheet in some embodiments of this utility model; Figure 6 This is a schematic diagram of the structure of a cylindrical lithium battery in some embodiments of this utility model. Detailed Implementation

[0016] To provide a clearer understanding of the technical features, objectives, and effects of this utility model, the specific embodiments of this utility model are now described in detail with reference to the accompanying drawings. In the following description, it should be understood that the orientations or positional relationships indicated by terms such as "front," "rear," "upper," "lower," "left," "right," "longitudinal," "horizontal," "vertical," "horizontal," "top," "bottom," "inner," "outer," "head," and "tail" are based on the orientations or positional relationships shown in the accompanying drawings, and are constructed and operated in a specific orientation. They are only for the convenience of describing this technical solution and do not indicate that the device or component referred to must have a specific orientation; therefore, they should not be construed as limitations on this utility model.

[0017] It should also be noted that, unless otherwise explicitly specified and limited, terms such as "installation," "connection," "joining," "fixing," and "setting" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. When an component is referred to as being "on" or "below" another component, the component can be located "directly" or "indirectly" on the other component, or there may be one or more intermediary components. The terms "first," "second," "third," etc., are only for the convenience of describing this technical solution and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, features defined with "first," "second," "third," etc., may explicitly or implicitly include one or more of that feature. For those skilled in the art, the specific meaning of the above terms in this utility model can be understood according to the specific circumstances.

[0018] In the following description, specific details such as particular system structures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of the present invention. However, those skilled in the art will understand that the present invention can be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods are omitted so as not to obscure the description of the present invention with unnecessary detail.

[0019] Please see Figures 1 to 5This utility model discloses a cylindrical lithium battery cap, which includes an insulating seal 10, a metal pressure plate 20, a top cover 30, and an explosion-proof component 40. The insulating seal 10 includes an annular support portion 11, with an annular side portion 12 extending around the periphery of the support portion 11. The support portion 11 has a first through cavity 111. The metal pressure plate 20 has an annular structure and is attached to the upper surface of the support portion 11. The metal pressure plate 20 has a second through cavity 21 that communicates with the first through cavity 111. The inner diameter of the second through cavity 21 may be smaller than the inner diameter of the first through cavity 111. The top cover 30 is attached to the upper surface of the metal pressure plate 20 and has a plurality of vent holes 331. Specifically, the top cover 30 includes a bottom wall 31, a top wall 32, and a side wall 33. The bottom wall 31 has an annular structure and is combined with the upper surface of the metal pressure plate 20. The bottom wall 31 and the top wall 32 are arranged in parallel and spaced apart. The inner diameter and outer diameter of the bottom wall 31 can both be larger than the diameter of the top wall 32. The side wall 33 connects the bottom wall 31 and the top wall 32 and is provided with a plurality of ventilation holes 331.

[0020] like Figures 2 to 4 As shown, the second through cavity 21 has a first through groove 211 and a second through groove 212 arranged vertically. The inner diameter of the first through groove 211 is larger than the inner diameter of the second through groove 212, so as to form a bearing wall 213 at the connection between the first through groove 211 and the second through groove 212. The bearing wall 213 can be a planar structure.

[0021] The explosion-proof component 40 is sealed and installed in the second cavity 21. The explosion-proof component 40 includes a membrane 41 and a metal sheet 42. The membrane 41 and the metal sheet 42 are arranged parallel to each other at intervals. The space between the membrane 41 and the metal sheet 42 forms a flame-retardant chamber.

[0022] The periphery of the film 41 is sealed to the support wall 213, and the periphery of the lower surface of the metal sheet 42 is sealed to the upper periphery of the first through groove 211; a needle 43 for piercing the film 41 is provided in the middle of the lower surface of the metal sheet 42; a flame retardant layer 44 is also provided on the lower surface of the metal sheet 42.

[0023] like Figure 2 and Figure 3 As shown, when the internal pressure of the cylindrical lithium battery exceeds a threshold (e.g., 2 MPa), the gas inside the cylindrical lithium battery drives the thin film 41 to deform toward the metal sheet 42. When the needle 43 punctures the thin film 41, the gas enters the flame-retardant chamber to contact the flame-retardant layer 44. The gas then continues to impact the metal sheet 42, which can cause the metal sheet 42 to rupture or at least part of the structure of the metal sheet 42 to separate from the metal pressure plate 20. The gas rushes out of the flame-retardant chamber and is then discharged from the vent 331 to achieve pressure relief and flame retardancy.

[0024] like Figure 5 As shown, in some embodiments, the metal sheet 42 is provided with a cracking groove 421 and a flipping groove 422, both of which are disposed opposite to the film 41. The thickness of the cracking groove 421 is less than the thickness of the flipping groove 422, and the thickness of the flipping groove 422 is less than the thickness of the metal sheet 42 excluding the portion containing the cracking groove 421 and the flipping groove 422. Both the cracking groove 421 and the flipping groove 422 can be arc-shaped grooves, and they can be connected together to form a circular structure. The width and thickness of the cracking groove 421 and the flipping groove 422 can be selected and set according to actual needs, and are not specifically limited here.

[0025] like Figure 2 and Figure 3 As shown, when the internal pressure of the cylindrical lithium battery exceeds a threshold (e.g., 2 MPa), the gas-driven thin film 41 inside the cylindrical lithium battery deforms towards the metal sheet 42. When the needle 43 punctures the thin film 41 (e.g., ...), the gas-driven thin film 41 inside the cylindrical lithium battery deforms towards the metal sheet 42. Figure 3 As shown, gas enters the flame-retardant chamber and comes into contact with the flame-retardant layer 44. The gas then continues to impact the metal sheet 42. Due to the small thickness of the rupture groove 421, it ruptures first, allowing the gas to escape from the flame-retardant chamber through the gap. The metal sheet 42 is also flipped along the flipping groove 422 under the impact of the gas, allowing the gas to escape from the flame-retardant chamber and then exit through the vent 331, thus achieving pressure relief and flame retardancy. Furthermore, at least some of the gas remains in contact with the flame-retardant layer 44 during the exhaust process, ensuring that the flame-retardant layer 44 maintains its flame-retardant effect.

[0026] In some embodiments, the film 41 comprises a PP film or a PET film. The thickness of the film 41 can be from 0.01 mm to 0.1 mm, for example, the thickness of the film 41 can be 0.01 mm, 0.02 mm, 0.03 mm, 0.04 mm, 0.05 mm, 0.06 mm, 0.07 mm, 0.08 mm, 0.09 mm, or 0.1 mm. Of course, the material and size of the film 41 can be selected and set according to actual needs, and are not specifically limited here.

[0027] In some embodiments, the metal sheet 42 is sealed to the upper edge of the first through groove 211 by laser welding, that is, the metal sheet 42 is sealed to the upper surface of the metal pressure plate 20 by laser welding.

[0028] In some embodiments, the metal sheet 42 is sealed to the upper circumferential edge of the first through groove 211 by an adhesive. The adhesive includes, but is not limited to, PP adhesive. The metal sheet 42 is sealed to the upper circumferential edge of the first through groove 211 by PP adhesive. When gas impacts the metal sheet 42, at least a portion of the structure of the metal sheet 42 can detach from the metal pressure plate 20, ensuring effective pressure relief.

[0029] like Figure 2 and Figure 5 As shown, in some embodiments, the metal sheet 42 is a circular sheet. The metal sheet 42 can be, but is not limited to, an aluminum sheet, and its thickness can be from 0.1mm to 0.3mm. For example, the thickness of the metal sheet 42 can be 0.1mm, 0.11mm, 0.12mm, 0.13mm, 0.14mm, 0.15mm, 0.16mm, 0.17mm, 0.18mm, 0.19mm, 2mm, 0.21mm, 0.22mm, 0.23mm, 0.24mm, 0.25mm, 0.26mm, 0.27mm, 0.28mm, 0.29mm, or 0.3mm. Of course, the diameter and thickness of the metal sheet 42 can be selected and set according to actual needs, and are not specifically limited here. Furthermore, the metal sheet 42 can also be made of other metal materials, and are also not specifically limited here.

[0030] like Figure 2 As shown, in some embodiments, the needle 43 has a conical structure, ensuring that after the needle 43 pierces the film 41, the resulting through-hole allows gas to enter the flame-retardant chamber. The needle 43 may be located in the middle of the lower surface of the metal sheet 42. There may be one or more needles 43, and the needles 43 may be made of aluminum and may be an integral structure with the metal sheet 42. Of course, the location, number, structure, material, and size of the needles 43 can be selected according to actual needs, and are not specifically limited here.

[0031] like Figure 2As shown, in some embodiments, the flame-retardant layer 44 is made of red phosphorus-based flame retardant, aluminum hydroxide, and silicone rubber in a mass ratio of 3:5:2. Specifically, the flame-retardant component 16 can be molded by mixing red phosphorus-based flame retardant (30% by mass), aluminum hydroxide (50%), and silicone rubber (20%). When the cylindrical lithium battery depressurizes and combustible gas enters the flame-retardant chamber 40a, the red phosphorus-based flame retardant in the flame-retardant layer 44 decomposes and absorbs heat, the aluminum hydroxide releases water of crystallization upon heating, and the silicone rubber carbonizes to form a heat-insulating layer. The gas temperature drops from 250°C to below 150°C, effectively preventing the cylindrical lithium battery from exploding. Compared to a cylindrical lithium battery without a flame-retardant layer 44, it improves the explosion-proof effect. Of course, the composition and proportion of the flame-retardant layer 44 can be selected and set according to actual needs, and are not specifically limited here.

[0032] like Figure 1 As shown, in some embodiments, the insulating seal 10 can be made of fluororubber resistant to electrolyte corrosion. The insulating seal 10 is mainly used for mounting components such as the metal pressure plate 20, top cover 30, and explosion-proof assembly 40, and ensures that the metal pressure plate 20, top cover 30, etc., do not directly contact the battery casing 50 of the cylindrical lithium battery, effectively preventing short circuits. The thickness of the insulating seal 10 is 0.5mm to 0.65mm. The thickness of the insulating seal 10 can be selected according to actual needs and is not specifically limited here. The material of the insulating seal 10 can also be selected according to actual needs, and is also not specifically limited here.

[0033] In some embodiments, the metal sheet 20 may be, but is not limited to, an aluminum sheet, and the thickness of the metal sheet 20 may be 0.4 mm to 0.6 mm. For example, the thickness of the metal sheet 20 may be 0.4 mm, 0.5 mm or 0.6 mm, and no specific limitation is made here.

[0034] like Figure 1 As shown, in some embodiments, the outer edge of the metal pressure plate 20 is bent to wrap around the outer edge of the bottom wall 31 of the top cover 30, and the upper end of the side portion 12 of the insulating seal 10 is bent to extend to form a wrapping portion that wraps around the edge of the metal pressure plate 20, so as to improve the insulation performance of the insulating seal 10, effectively prevent the metal pressure plate 20 or the top cover 30 from contacting the battery case 50, and effectively avoid the risk of failure caused by the stacking of multiple components.

[0035] like Figure 1As shown, in some embodiments, the top cover 30 can be made of 304 stainless steel, and the overall height of the top cover 30 can be 3.5mm to 4mm, while the height of the side wall 33 can be 0.5mm to 0.6mm. The number of vent holes 331 can be 3 to 6, distributed at equal angles along the circumference, primarily serving as pressure relief holes. Of course, the structural shape, material, and size of the top cover 30 can be selected and set according to actual needs, and are not specifically limited here.

[0036] like Figure 1 As shown, in some embodiments, the metal pressure plate 20 and the insulating seal 10 can be fixed by laser welding, and the metal pressure plate 20 and the top cover 30 can be fixed by laser welding to improve the tightness of the connection between the components. Of course, other fixing methods can also be used, which are not specifically limited here.

[0037] The cylindrical lithium battery cap has the following beneficial effects: it can relieve pressure and retard flame, reduce the probability of cylindrical lithium battery fire and explosion, effectively improve safety, and its structure is relatively simple, which can effectively reduce production costs and improve product competitiveness.

[0038] like Figure 6 As shown, this utility model also discloses a cylindrical lithium battery, which includes, but is not limited to, a high-energy-density cylindrical lithium battery, and can be applied to power batteries for new energy electric vehicles or battery modules for energy storage systems.

[0039] The cylindrical lithium battery includes a battery casing 50 and a core 60 disposed within the battery casing 50. The upper end of the battery casing 50 is provided with a cylindrical lithium battery cap according to any of the above embodiments.

[0040] The battery casing 50 may be generally cylindrical and conductive. For example, the battery casing 50 may be, but is not limited to, a steel casing. The cylindrical lithium battery cap may be welded and fixed to the inner cavity at the upper end of the battery casing 50 (either by laser welding or ultrasonic welding). The core 60 may include a positive electrode assembly and a negative electrode assembly that cooperate with each other. The positive electrode assembly and the negative electrode assembly may be wound into a cylindrical structure by a separator assembly. The positive electrode tab of the positive electrode assembly may be connected to the metal pressure plate 20 (e.g., by laser welding), and the negative electrode tab of the negative electrode assembly may be connected to the battery casing 50 (e.g., by laser welding).

[0041] It is understood that the above embodiments only illustrate preferred embodiments of the present utility model, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present utility model patent. It should be noted that for those skilled in the art, the above technical features can be freely combined, and several modifications and improvements can be made without departing from the concept of the present utility model, all of which fall within the protection scope of the present utility model. Therefore, all equivalent transformations and modifications made within the scope of the claims of the present utility model should fall within the coverage of the claims of the present utility model.

Claims

1. A cylindrical lithium battery cap, characterized by, The device includes an insulating seal (10), a metal pressure plate (20), a top cover (30), and an explosion-proof assembly (40). The insulating seal (10) includes a support portion (11) having a first through cavity (111). The metal pressure plate (20) is attached to the upper surface of the support portion (11) and has a second through cavity (21) communicating with the first through cavity (111). The top cover (30) is attached to the upper surface of the metal pressure plate (20) and has a plurality of vent holes (331). The second through cavity (21) has a first through groove (211) and a second through groove (212) arranged vertically. The inner diameter of the first through groove (211) is larger than the inner diameter of the second through groove (212) so as to form a bearing wall (213) at the connection between the first through groove (211) and the second through groove (212). The explosion-proof component (40) is sealed and installed in the second through cavity (21). The explosion-proof component (40) includes a membrane (41) and a metal sheet (42). The membrane (41) and the metal sheet (42) are arranged parallel to each other at intervals. The space between the membrane (41) and the metal sheet (42) forms a flame-retardant chamber. The periphery of the film (41) is sealed to the bearing wall (213), and the periphery of the lower surface of the metal sheet (42) is sealed to the upper periphery of the first through groove (211); a needle (43) for piercing the film (41) is provided in the middle of the lower surface of the metal sheet (42); a flame retardant layer (44) is also provided on the lower surface of the metal sheet (42).

2. The cylindrical lithium battery cap of claim 1, wherein, The metal sheet (42) is provided with a crack groove (421) and a flip groove (422), both of which are disposed opposite to the film (41); the thickness of the crack groove (421) is less than the thickness of the flip groove (422), and the thickness of the flip groove (422) is less than the thickness of the metal sheet (42) excluding the portion of the crack groove (421) and the flip groove (422).

3. The cylindrical lithium battery cap according to claim 1, characterized in that, The film (41) includes PP film or PET film.

4. The cylindrical lithium battery cap according to claim 1, characterized in that, The metal sheet (42) is sealed to the upper edge of the first through groove (211) by laser welding.

5. The cylindrical lithium battery cap according to claim 1, characterized in that, The metal sheet (42) is sealed to the upper edge of the first through groove (211) by an adhesive.

6. The cylindrical lithium battery cap according to claim 1, characterized in that, The metal sheet (42) is a circular sheet.

7. The cylindrical lithium battery cap according to claim 1, characterized in that, The needle (43) has a conical structure.

8. The cylindrical lithium battery cap according to claim 1, characterized in that, The metal sheet (20) includes an aluminum sheet.

9. The cylindrical lithium battery cap according to claim 1, characterized in that, The top cover (30) includes a bottom wall (31), a top wall (32) and a side wall (33). The bottom wall (31) has an annular structure and is combined with the upper surface of the metal pressure plate (20). The bottom wall (31) and the top wall (32) are arranged in parallel and spaced apart. The side wall (33) connects the bottom wall (31) and the top wall (32) and is provided with the vent hole (331).

10. A cylindrical lithium battery, characterized in that, It includes a battery casing (50) and a core (60) disposed within the battery casing (50), wherein the upper end of the battery casing (50) is provided with a cylindrical lithium battery cap as described in any one of claims 1 to 9.

Images