End cover assembly and cylindrical battery

Abstract

The utility model discloses an end cover assembly and relates to the technical field of cylindrical batteries. The end cover assembly comprises a top cover piece, an anti-explosion piece, an inner rubber ring, a lower end plate and an outer insulating ring, the top cover piece downwards abuts against the anti-explosion piece, the inner rubber ring is arranged at the bottom of the anti-explosion piece, the lower end plate is arranged at the bottom of the inner rubber ring, the outer insulating ring is provided with a limiting part, and the anti-explosion piece downwards abuts against the limiting part; the abutting end face of the limiting part is provided with a glue containing groove, the bottom end of the side part of the limiting part is provided with an anti-overflow part, and the anti-overflow part extends towards the center direction of the outer insulating ring. The utility model further discloses a cylindrical battery comprising the end cover assembly, the glue containing groove is formed in the end face, abutting against the anti-explosion piece, of the outer insulating ring, and the anti-overflow part is further arranged on the side portion of the glue containing groove, so that the effect of gluing and fixing the outer insulating ring is enhanced, and glue liquid is effectively prevented from overflowing and dripping into the battery.

Description

TECHNICAL FIELD

[0001] The utility model relates to cylindrical battery technical field especially relates to a end cover subassembly and cylindrical battery. BACKGROUND

[0002] The utility model discloses a cylindrical lithium ion battery discloses the utility model relates to a cylindrical lithium ion battery, including the casing, the top of casing fixed mounting has the explosion -proof cap subassembly, the bottom of casing fixed mounting has the explosion -proof bottom cover subassembly, the explosion -proof cap subassembly includes the top, the explosion -proof sheet, the insulating ring and the hole plate, the explosion -proof sheet is located the lower side of top and is conducted with top, the insulating ring is located between the bottom surface of explosion -proof sheet and the top surface of hole plate, to make the explosion -proof sheet and hole plate separate, the middle part of explosion -proof sheet is protruding and forms the folding part towards hole plate, and the folding part passes through the inner ring of insulating ring and hole plate and abuts, the bottom surface of explosion -proof sheet is equipped with the first nick in the peripheral of folding part, the explosion -proof bottom cover subassembly includes the bottom cover plate, and the bottom surface of bottom cover plate is equipped with the second nick.

[0003] In the cylindrical lithium ion battery, under the limiting effect of the upper end portion of the casing, the end cover can be clamped and fixed at the upper end opening of the casing through the insulating ring, and the insulating ring can also be clamped and arranged between the casing and the explosion -proof sheet to further form a seal between the periphery of the battery end cover and the upper end opening of the casing.

[0004] However, based on the above-mentioned cylindrical lithium ion battery, when the upper end portion of the casing is bent and sealed to correspondingly clamp and fix the end cover assembly and the insulating ring, the following problems often occur:

[0005] 1. Since the insulating ring is made of plastic and has elasticity, when the upper end portion of the casing is bent, the insulating ring will be deformed by being pressed by the casing body, which will cause the insulating ring to be unable to support the hole plate, affecting the normal use of the battery.

[0006] 2. When the insulating ring is deformed by being pressed, wrinkles may appear on its surface, which will cause the sealing effect of the insulating ring to deteriorate. Moreover, after the battery has been used for a period of time, the clamping force of the casing will decrease, which will also cause a gap to appear between the insulating ring and the explosion -proof valve sheet, resulting in deterioration of the sealing effect of the insulating ring.

[0007] In this regard, when the insulating ring is installed at the explosion -proof valve sheet, the technician will also apply glue to the end surface where the insulating ring and the explosion -proof valve sheet contact each other, so that the insulating ring is tightly attached to the surface of the explosion -proof valve sheet, and the glue can also fill the gap between the insulating ring and the explosion -proof valve sheet, thereby enhancing the sealing performance of the insulating ring.

[0008] However, since the end faces of the insulation ring and the explosion-proof valve plate in contact with each other are flat, when the upper end portion of the bent shell body is clamped with the end cover assembly to close the shell body, the insulation ring is extruded by the shell body, so even if the technician applies glue on the end faces of the insulation ring and the explosion-proof valve plate in contact with each other, the glue will overflow due to external pressure, affecting the sealing effect of the insulation ring; even if the glue overflows to the battery cell inside the shell, it will also directly affect the electrical performance of the battery. Utility model content

[0009] To solve the above technical defects existing in the prior art, the utility model provides a kind of end cover assembly and cylindrical battery, by being set with glue containing groove on the end face of outer insulation ring and explosion-proof piece, and still being provided with anti-overflow part in the side of glue containing groove, to enhance the effect of gluing and fixing outer insulation ring, and effectively prevent glue overflow and drip to the inside of battery.

[0010] The technical scheme for solving the above problems of the utility model is: provide an end cover assembly, the end cover assembly includes top cover sheet, explosion-proof sheet, inner rubber ring, lower end plate, outer insulation ring, the top cover sheet is down and is in contact with the explosion-proof sheet, the inner rubber ring is arranged at the bottom of the explosion-proof sheet, the lower end plate is arranged at the bottom of the inner rubber ring, the outer insulation ring is equipped with limiting portion, the explosion-proof sheet is down and is in contact with the limiting portion, the limiting portion is equipped with glue containing groove on the end face of contact, the side of the limiting portion is equipped with anti-overflow part at the bottom end, and the anti-overflow part is arranged in the direction of the center of the outer insulation ring.

[0011] Further, the overall radial width W0 of the outer insulation ring at the anti-overflow part is 2-4mm, the radial distance from the center of the glue containing groove to the outer side wall of the outer insulation ring is W1, and W1 is 34-48% of W0.

[0012] Further, the end face of the limiting portion is divided into a first end face and a second end face by the glue containing groove, the first end face is located outside the second end face with respect to the center of the outer insulation ring, the overall radial width W0 of the outer insulation ring at the anti-overflow part is 2-4mm, the radial distance from the center of the second end face to the end of the anti-overflow part in the direction of the center of the outer insulation ring is W2, and W2 is 36-46% of W0.

[0013] Further, the slot width W3 of the glue containing groove is 0.5-0.7mm, the width of the second end face is W4, and W4 is 75-95% of W3.

[0014] Further, the overall radial width W0 of the outer insulation ring at the anti-overflow part is 2-4mm, the radial width of the anti-overflow part is W5, and W5 is 26-38% of W0.

[0015] Further, the thickness H1 of the limiting portion is 0.8-1mm, the thickness of the anti-overflow portion is H2, and H2 is 28-46% of H1.

[0016] Further, the thickness H1 of the limiting portion is 0.8-1mm, the groove depth of the glue containing groove is H3, and H3 is 12-22% of H1.

[0017] Further, the area S of the cross section of the glue containing groove is 0.04-0.1㎡.

[0018] Further, the cross section of the glue containing groove is trapezoidal, the slot width W3 of the glue containing groove is 0.5-0.7mm, and the slot bottom width W41 of the glue containing groove is 40-60% of W3.

[0019] The utility model also provides a cylindrical battery, the cylindrical battery includes electric core, cylindrical casing, and the end cover subassembly of any one of above.

[0020] The utility model discloses beneficial effect:

[0021] 1, the bottom of outer insulation ring is equipped with limiting portion, and the upper end surface of limiting portion is equipped with glue containing groove, and technical personnel can first inject glue solution into glue containing groove, and then in the bending shell opening place body with clamping fixed end cover subassembly, and then seal the battery, through extruding outer insulation ring, so that glue solution can be extruded from glue containing groove and evenly overflow to the both sides end surface of glue containing groove, thereby bonding and fixing outer insulation ring and explosion -proof sheet, and the sealing effect of outer insulation ring is enhanced, too many glue solution can be effectively extruded from the upper end surface of limiting portion.

[0022] 2, the side of limiting portion still extends the anti-overflow portion of outer insulation ring's center direction horizontally, and the anti-overflow portion can form glue containing platform in the inboard of glue containing groove, so that even if there is glue overflow between the end surface of outer insulation ring and explosion -proof sheet mutual abutment, it also can only overflow to the anti-overflow portion, and cannot fall into the battery interior.

[0023] And, the cavity left between anti-overflow portion and explosion -proof sheet can also be used as material running cavity, for extruded deformation material running of outer insulation ring, to avoid that outer insulation ring is forcedly extruded and also can not correspond to deformation, thereby causing stress concentration, leading to cracking. DRAWINGS

[0024] The accompanying drawings, which are incorporated into and form a part of the specification, illustrate embodiments of the present application and, together with the description, serve to explain the principles of the present application. In the drawings: Like reference numerals are used to designate like elements throughout the various figures. The accompanying drawings are of some embodiments of the present application and not all embodiments. Other drawings can be derived from these drawings by a person of ordinary skill in the art without paying creative efforts.

[0025] Figure 1 is a structural view of an end cover assembly of the embodiment;

[0026] Figure 2 is a structural view of a cross section of an outer insulation ring of the embodiment;

[0027] Figure 3 is a dimension identification view of the outer insulation ring of the embodiment;

[0028] 1 - top cover sheet, 2 - explosion-proof sheet, 3 - inner rubber ring, 4 - lower end plate, 5 - outer insulation ring, 51 - limiting portion, 52 - glue containing groove, 53 - anti-overflow portion, 54 - first end face, 55 - second end face. DETAILED DESCRIPTION

[0029] In the present specification, the orientation terms such as up, down, left, right, front, back, front face, back face, top, bottom, etc. mentioned or possibly mentioned are defined with respect to the configuration shown in the drawings, and the words "inner" and "outer" respectively refer to the direction towards or away from the geometric center of a particular component, which are relative concepts, so it is possible to change accordingly according to different positions, different use states. Therefore, these or other orientation terms should not be interpreted as restrictive terms.

[0030] Referring to Figure 1 , the end cover assembly of the embodiment is used for a 21 series cylindrical battery, and the end cover assembly comprises a top cover sheet 1, an explosion-proof sheet 2, an inner rubber ring 3, a lower end plate 4 and an outer insulation ring 5. The top cover sheet 1, the explosion-proof sheet 2 and the lower end plate 4 are all conductive metal structures. The top cover sheet 1 downwardly abuts against the explosion-proof sheet 2 and is in conductive connection with the explosion-proof sheet 2. The middle part of the explosion-proof sheet 2 downwardly abuts against the lower end plate 4 and is in conductive connection with the lower end plate 4. The lower surface of the lower end plate 4 is in conductive connection with the tab of the cell inside the cylindrical battery to form a positive electrode end of the battery.

[0031] In addition, the lower end of the explosion-proof sheet 2 is provided with a snap-fit ​​ring inclined towards its center. The inner rubber ring 3 is snapped into the snap-fit ​​ring to be fixedly installed on the lower surface of the explosion-proof sheet 2. The lower end of the inner rubber ring 3 also forms an annular snap-fit ​​groove. The edge of the lower end plate 4 is inserted into the annular snap-fit ​​groove to be snapped into the bottom of the inner rubber ring 3. When the lower end plate 4 is inserted into the annular snap-fit ​​groove, it also cooperates with the snap-fit ​​ring to further clamp and fix the inner rubber ring 3 to prevent the inner rubber ring 3 from falling downward. The lower end plate 4 and the explosion-proof sheet 2 are also in contact at the middle position to ensure that when the explosion-proof sheet 2 bulges from the middle to play its explosion-proof role, the explosion-proof sheet 2 can still separate from the lower end plate 4 at the first time to disconnect the internal circuit of the battery and further ensure battery safety. The outer insulating ring 5 is arranged on the outside of the top cover plate 1 and the explosion-proof plate 2 that abut against each other, and is spaced between the inner wall of the cylindrical battery casing and the explosion-proof plate 2, so as to further form a sealing structure between the cylindrical battery casing and the explosion-proof plate 2 and ensure the sealing performance of the cylindrical battery.

[0032] Please see Figure 1 and Figure 2 ,by Figure 2 Taking the orientation shown as an example, in this embodiment, it should be specifically noted that: the bottom end of the through hole in the middle of the outer insulating ring 5 is also integrally provided with a limiting part 51. The explosion-proof sheet 2 is limited in the through hole of the outer insulating ring 5 by pressing it downward against the limiting part 51, thereby forming an assembly effect in which the outer insulating ring 5 is sleeved on the outer periphery of the explosion-proof sheet 2.

[0033] Furthermore, an annular adhesive groove 52 is provided at the upper end of the limiting part 51. The cross-section of the adhesive groove 52 is an inverted trapezoidal cross-section. An overflow prevention part 53 is integrally provided at the bottom of the side of the limiting part 51 facing the center direction of the outer insulating ring 5. The overflow prevention part 53 is an annular plastic plate that extends horizontally from the bottom end of the limiting part 51. The bottom end of the overflow prevention part 53 is flush with the bottom end of the limiting part 51.

[0034] To address this, technicians can first inject adhesive into the adhesive reservoir 52, and then insert the explosion-proof sheet 2 and the top cover sheet 1 into the outer insulating ring 5. By further pressing the explosion-proof sheet 2 and the top cover sheet 1 downwards, or by bending the end of the battery casing for sealing, the adhesive reservoir 52 can be further squeezed, causing the adhesive in the adhesive reservoir 52 to overflow to the upper end face of the limiting part 51. This allows the explosion-proof sheet 2 to adhere downwards to the upper end face of the limiting part 51, effectively preventing gaps between the explosion-proof sheet 2 and the outer insulating ring 5, reducing the amount of adhesive overflowing from the upper end face of the limiting part 51, or even preventing the adhesive from overflowing from the upper end face of the limiting part 51 to the side of the limiting part 51.

[0035] Moreover, even if the adhesive overflows from the upper edge of the limiting part 51 due to excessive compression of the outer insulating ring 5, the overflowing adhesive can only flow to the upper surface of the anti-overflow part 53, and cannot flow over the anti-overflow part 53 onto the battery cell.

[0036] In addition, in the present embodiment, the thickness H1 of the limiting portion 51 is 0.8-1mm, and the thickness H2 of the anti-overflow portion 53 is 28-46% of the thickness H1 of the limiting portion 51; in this way, after the end cover assembly of the present embodiment is installed in place, the anti-overflow portion 53 will form a material running cavity directly above; in this way, when the outer insulation ring 5 is deformed due to extrusion, the outer insulation ring 5 can also be deformed into the material running cavity, so as to prevent the outer insulation ring 5 from being unable to deform due to extrusion, and further prevent the problem of excessive stress concentration of the outer insulation ring 5 leading to cracking of the outer insulation ring 5, or excessive rebound force leading to deformation of the end cover assembly or the battery shell in the reverse direction.

[0037] In the present embodiment, the thickness H1 of the limiting portion 51 is 0.8mm, and the thickness H2 of the anti-overflow portion 53 is 0.224mm; but in other embodiments, when the thickness H1 of the limiting portion 51 is 0.8mm, the thickness H2 of the anti-overflow portion 53 can also be set to 0.368mm.

[0038] In addition, in other embodiments, the thickness H1 of the limiting portion 51 can also be set to 1mm, and the thickness H2 of the anti-overflow portion 53 can also be set to 0.28mm or 0.35mm or 0.46mm; the thickness H1 of the limiting portion 51 can also be 0.9mm, and the thickness H2 of the anti-overflow portion 53 can also be set to 0.252mm or 0.3mm or 0.414mm.

[0039] Further, please refer to Figure 2 and Figure 3 Corresponding to the 21 series cylindrical battery, in the present embodiment, the bottom end of the anti-overflow portion 53, the bottom end of the limiting portion 51, and the bottom end of the outer insulation ring 5 are flush, and the overall radial width of the outer insulation ring 5 at the bottom end position is 2-4mm; at the same time, in the process of normally installing the explosion-proof sheet 2 or sealing the battery, in order to ensure that the glue solution in the glue tank 52 can just overflow the upper end surface of the entire limiting portion 51 when the outer insulation ring 5 is extruded by a corresponding external force, the radial distance W1 from the center of the glue tank 52 to the outer side wall of the outer insulation ring 5 is 34-48% of W0.

[0040] Furthermore, in the present embodiment, please refer to Figure 2 and Figure 3The abutting end face of the limiting part 51 is divided into a first end face 54 and a second end face 55 by the glue containing groove 52. The first end face 54 is located outside the second end face 55 relative to the center of the outer insulation ring 5. To ensure that the glue in the glue containing groove 52 can flow out uniformly to the first end face 54 and the second end face 55, the radial distance from the center of the second end face 55 to the end of the anti-overflow part 53 facing the center of the outer insulation ring 5 is W2, W2 is 36-46% of W0, and the radial width of the anti-overflow part 53 is W5, W5 is 26-38% of W0.

[0041] For example, in the present embodiment, the overall radial width W0 of the outer insulation ring 5 at its bottom end is 3 mm, and the radial distance W1 from the center of the glue containing groove 52 to the outer side wall of the outer insulation ring 5 can correspond to 1.088 mm or 2 mm or 1.536 mm, and the radial distance W2 from the center of the second end face 55 to the end of the anti-overflow part 53 facing the center of the outer insulation ring 5 can correspond to 1.152 mm or 1.3 mm or 1.472 mm; and in other embodiments, W0 can be 3.5 mm, W1 can correspond to 1.19 mm or 1.3 mm or 1.68 mm, and W2 can correspond to 1.26 mm or 1.4 mm or 1.61 mm; W0 can also be 4 mm, W1 can also correspond to 1.36 mm or 1.5 mm or 1.92 mm, and W2 can also correspond to 1.44 mm or 1.6 mm or 1.84 mm.

[0042] Further, in the present embodiment, to enable the glue containing groove 52 to be sized to match the upper end face of the limiting part 51, and to ensure that the glue in the glue containing groove 52 can flow out smoothly when the glue containing groove 52 is squeezed, the slot width W3 of the glue containing groove 52 is 0.5-0.7 mm, and the width of the second end face 55 is W4, W4 is 75-95% of W3.

[0043] That is, when W3 is 0.5 mm, W4 can be 0.375 mm or 0.45 mm or 0.475 mm; when W3 is 0.6 mm, W4 can be 0.45 mm or 0.5 mm or 0.57 mm; and when W3 is 0.7 mm, W4 can be 0.525 mm or 0.6 mm or 0.665 mm.

[0044] Further, please refer to Figure 2 and Figure 3In order to ensure that the glue tank 52 can store a proper amount of glue, avoid the problem that the glue cannot flow and spread on the upper end surface of the limiting part 51 due to too little glue in the glue tank 52, or too much glue overflowing from the upper end surface of the limiting part 51 due to too much glue in the glue tank 52, the thickness H1 of the limiting part 51 is 0.8-1mm, and the groove depth H3 of the glue tank 52 is 12-22% of H1; and the slot width W3 of the glue tank 52 is 0.5-0.7mm, and the groove bottom width W41 of the glue tank 52 is 40-60% of W3.

[0045] That is: when H1 is 0.8mm, H3 can be 0.096mm or 0.13mm or 0.176mm; when H1 is 0.9mm, H3 can be 0.108mm or 0.15mm or 0.198mm; when H1 is 1mm, H3 can be 0.12mm or 0.18mm or 0.22mm. When W3 is 0.5mm, W41 is 0.2mm or 0.25mm or 0.3mm; when W3 is 0.6mm, W41 is 0.24mm or 0.3mm or 0.36mm; when W3 is 0.7mm, W41 is 0.28mm or 0.35mm or 0.42mm.

[0046] In addition, it should be noted that in other embodiments, the thickness H1 of the limiting part 51 is 0.8-1mm, and the slot width W3 is 0.5-0.7mm, and if the cross section of the glue tank 52 is not a regular trapezoidal face, the area S of the cross section of the glue tank 52 can be limited to 0.04-0.1㎡ to ensure that the glue content in the glue tank 52 is appropriate.

[0047] In addition, the cylindrical battery of the specific embodiment of the utility model, the cylindrical battery comprises a battery cell, a cylindrical shell, and the end cover assembly of any one of the above embodiments, and the assembly mode between the end cover assembly, the battery cell, and the cylindrical shell can refer to the prior art.

[0048] The above-mentioned matters not mentioned are applicable to the prior art.

[0049] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the utility model, and not to limit them. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacements for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the utility model.

Claims

1. An end cap assembly, characterized by, The end cover assembly comprises: The top cover sheet (1) is downwardly abutted against the explosion-proof sheet (2), the inner rubber ring (3) is arranged at the bottom of the explosion-proof sheet (2), the lower end plate (4) is arranged at the bottom of the inner rubber ring (3), the outer insulating ring (5) is provided with a limiting portion (51), the explosion-proof sheet (2) is downwardly abutted against the limiting portion (51), a glue containing groove (52) is formed on the abutting end face of the limiting portion (51), and the side portion bottom end of the limiting portion (51) is provided with an anti-overflow portion (53) which is arranged in the central direction of the outer insulating ring (5).

2. The end cap assembly of claim 1, wherein, The overall radial width W0 of the outer insulating ring (5) at the anti-overflow portion (53) is 2-4 mm, the radial distance from the center of the glue containing groove (52) to the outer side wall of the outer insulating ring (5) is W1, and W1 is 34-48% of W0.

3. The end cap assembly of claim 1, wherein, The abutting end face of the limiting portion (51) is divided into a first end face (54) and a second end face (55) by the glue containing groove (52), the first end face (54) is located outside the second end face (55) with respect to the center of the outer insulating ring (5), the overall radial width W0 of the outer insulating ring (5) at the anti-overflow portion (53) is 2-4 mm, the radial distance from the center of the second end face (55) to the end portion of the anti-overflow portion (53) which faces the central direction of the outer insulating ring (5) is W2, and W2 is 36-46% of W0.

4. The end cap assembly of claim 3, wherein, The notch width W3 of the glue containing groove (52) is 0.5-0.7 mm, the width of the second end face (55) is W4, and W4 is 75-95% of W3.

5. The end cap assembly of claim 1, wherein, The overall radial width W0 of the outer insulating ring (5) at the anti-overflow portion (53) is 2-4 mm, the radial width of the anti-overflow portion (53) is W5, and W5 is 26-38% of W0.

6. The end cap assembly of claim 1, wherein, The thickness H1 of the limiting portion (51) is 0.8-1 mm, the thickness of the anti-overflow portion (53) is H2, and H2 is 28-46% of H1.

7. The end cap assembly of claim 1, wherein, The thickness H1 of the limiting portion (51) is 0.8-1 mm, and the groove depth of the glue containing groove (52) is H3, and H3 is 12-22% of H1.

8. The end cap assembly of claim 1, wherein, The area S of the cross section of the glue containing groove (52) is 0.04-0.1 m2.

9. The end cap assembly of claim 1, wherein, The cross section of the glue containing groove (52) is trapezoidal, the notch width W3 of the glue containing groove (52) is 0.5-0.7 mm, and the groove bottom width W41 of the glue containing groove (52) is 40-60% of W3.

10. A cylindrical battery, characterized by The cylindrical battery comprises a battery cell, a cylindrical shell, and the end cover assembly according to any one of claims 1-9.

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