Secondary battery top cover

Abstract

The utility model provides a secondary battery top cover, which is characterized in that a pole is provided with a step, and the pole sequentially penetrates through a lower plastic, a top cover sheet and a riveting block and is riveted with the riveting block; the sealing ring is connected to the pole in a sleeving mode, and the sealing ring is located between the pole step and the top cover piece; the upper plastic cement is formed in a gap among the riveting block, the top cover sheet and the pole in an injection molding manner and is positioned on the surface of the top cover sheet, buckling devices which are matched with each other are arranged between the riveting block and the upper plastic cement, and the riveting block and the upper plastic cement are connected in a buckling manner by the buckling devices; according to the utility model, the buckling device is arranged between the riveting block and the upper plastic cement, and the outer side wall of the riveting block and the upper plastic cement are buckled and fixed through the buckling device, so that the riveting block has enough rigidity and strength to resist upwarp and deformation, the contact area is ensured, and the resistance value of the top cover resistor is kept stable.

Description

Technical Field

[0001] This utility model relates to the field of lithium-ion batteries, and in particular to a top cover for a secondary battery. Background Technology

[0002] With the development of new energy sources, the energy density requirements of existing batteries are further increasing. New energy power batteries are usually secondary batteries, which are batteries that can be used again after being discharged by recharging to activate the active materials.

[0003] The rapid development of lithium batteries, with high capacity and high rate becoming the industry's mainstream, presents new challenges to individual battery cells. High rate means increased overcurrent, requiring a larger welding area for the module to meet temperature rise requirements. Therefore, the size of the terminal block on the top cover of the battery cell's mechanical components also needs to be increased. This has led to the emergence of eccentric riveting structures. While the eccentric structure allows for a larger area of ​​the riveting block while maintaining the same terminal block size, increasing the welding area with the module, the eccentricity between the riveting block and the terminal block causes severe warping at the distal end of the riveting block, reducing the contact area with the upper plastic layer and resulting in excessively high resistance values.

[0004] To address this issue, we propose a secondary battery top cover to solve the problem of the far end of the rivet block lifting up. Utility Model Content

[0005] The purpose of this utility model is to overcome the shortcomings of the existing technology. To achieve the above objective, this utility model adopts the following technical solution:

[0006] A secondary battery top cover includes: a top cover sheet, with recessed grooves at both ends of its upper surface, and a through hole in each groove; a lower plastic piece fitted onto the lower surface of the top cover sheet; a rivet block mounted above the recessed grooves; a terminal post with a step, the terminal post passing sequentially through the lower plastic piece, the top cover sheet, and the rivet block and being riveted to the rivet block; a sealing ring fitted onto the terminal post, the sealing ring being located between the terminal post step and the top cover sheet; and an upper plastic piece injection molded into the gap between the rivet block, the top cover sheet, and the terminal post and located on the surface of the top cover sheet, wherein a mutually cooperating snap-fit ​​device is provided between the rivet block and the upper plastic piece, the snap-fit ​​device fastening and connecting the rivet block and the upper plastic piece.

[0007] More preferably, the buckling device comprises an undercut groove and a buckle post. The undercut grooves are evenly distributed on the outer wall surface of the rivet block. The undercut grooves are tapered grooves that are narrow on the outside and wide on the inside. The buckle post is a tapered post that is injection molded from the upper plastic into the undercut groove.

[0008] More preferably, the buckling device comprises a boss and a slot, the boss being arranged around the bottom of the rivet block, the outer wall of the rivet block forming a step with the boss, and the slot being a clearance groove formed by the upper plastic injection molding covering the rivet block and the boss.

[0009] More preferably, the buckling device consists of a recess and a rib. The recess is formed on the outer wall surface of the rivet block and is an inwardly concave arc-shaped groove. The rib is a hemisphere formed by injection molding of the upper plastic into the recess.

[0010] More preferably, the buckling device comprises a countersunk platform and a pressure block, wherein the top of the pressure block is provided with a countersunk platform, the countersunk platform and the outer wall of the pressure block form a step, and the pressure block is an extension block of the upper plastic injection molding pressed on the countersunk platform.

[0011] More preferably, the four corners of the settling tank are provided with through holes.

[0012] More preferably, the upper plastic is injection molded with a positioning post that mates with the second through hole.

[0013] More preferably, the top cover plate has a waist-shaped groove, an explosion-proof valve is installed in the waist-shaped groove, and a protective plate is provided at the top of the explosion-proof valve.

[0014] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0015] This invention provides a snap-fit ​​device between the rivet block and the upper plastic. The snap-fit ​​device secures the outer wall of the rivet block to the upper plastic, giving the rivet block sufficient rigidity to resist warping and deformation, thereby ensuring the contact area and keeping the resistance value of the top cover stable. Attached Figure Description

[0016] Figure 1 This is an exploded view of the present invention;

[0017] Figure 2 This is an assembly diagram of the present invention;

[0018] Figure 3 This is a cross-sectional view of the present invention;

[0019] Figure 4 Schematic diagram of the latching device Figure 1 ;

[0020] Figure 5 Schematic diagram of the latching device Figure 2 ;

[0021] Figure 6 Schematic diagram of the latching device Figure 3 ;

[0022] Figure 7 Schematic diagram of the latching device Figure 4 .

[0023] In the diagram: 1. Top cover plate; 2. Lower plastic; 3. Sealing ring; 4. Pole post; 5. Upper plastic; 6. Riveting block; 7. Explosion-proof valve; 8. Protective plate; 11. Slot; 12. Through hole one; 13. Through hole two; 61. Inverted groove; 51. Buckle post; 62. Boss; 52. Slot; 63. Recess; 53. Rib; 64. Slot; 54. Pressing block. Detailed Implementation

[0024] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0025] Reference Figures 1-3 A secondary battery top cover includes: a top cover sheet 1, with recessed grooves 11 at both ends of its upper surface, and a through hole 12 formed within each recessed groove 11; a lower plastic 2, which is fitted onto the lower surface of the top cover sheet 1; a rivet block 6, which is mounted above the recessed grooves 11; and a terminal post 4, which has a step and passes sequentially through the lower plastic 2, the top cover sheet 1, and the rivet block 6, and is connected to the rivet block 6. Riveting; sealing ring 3, which is sleeved on the pole post 4 and located between the step of the pole post 4 and the top cover plate 1; upper plastic 5, which is injection molded in the gap between the riveting block 6, the top cover plate 1 and the pole post 4 and located on the surface of the top cover plate 1, and a mutually cooperating snap-fit ​​device is provided between the riveting block 6 and the upper plastic 5, the snap-fit ​​device fastening and connecting the riveting block 6 and the upper plastic 5.

[0026] In this embodiment: the pole 4 includes a positive pole and a negative pole, which are respectively installed on both sides of the top cover plate 1. First, the lower surface of the top cover plate 1 is fixed to the lower plastic 2 by heat fusion through the undercut hole. The groove 11 on the upper surface of the top cover plate 1 is fitted with the rivet block 6. In this embodiment, both the groove 11 and the rivet block 6 are rectangular structures. After the pole 4 is fitted with the sealing ring 3, it is inserted into the mounting holes of the lower plastic 2, the top cover plate 1 and the rivet block 6 in sequence. The pole 4 then injection molds the gap between the rivet block 6, the top cover plate 1 and the pole 4 to form the upper plastic 5. At this time, the bottom stepped surface of the pole 4 presses against the bottom limit of the lower plastic 2. Then, the top of the pole 4 is riveted to form a mounting platform and welded to fix the pole 4 and the rivet block 6.

[0027] Reference Figure 4The buckling device consists of an undercut groove 61 and a buckle post 51. The undercut groove 61 is evenly distributed on the outer wall surface of the rivet block 6. The undercut groove 61 is a tapered groove that is narrow on the outside and wide on the inside. The buckle post 51 is a tapered post that is injection molded by the upper plastic 5 into the undercut groove 61.

[0028] In this embodiment: an undercut groove 61 is formed on the outer wall and bottom surface of the rivet block 6. The undercut groove 61 is an isosceles trapezoidal structure that is narrow on the outside and wide on the inside. Then, an upper plastic 5 is injection molded, and a snap post 51 that mates with the undercut groove 61 is formed on the upper plastic 5. Through the snap-fit ​​engagement of the undercut groove 61 and the snap post 51, the upper plastic 5 is fully in contact with and fixed to the rivet block 6, so that the rivet block 6 has sufficient rigidity to resist the warping deformation at the far end, thereby ensuring the contact area and keeping the resistance value of the top cover stable. However, the deepest part of the undercut groove 61 on the bottom surface of the rivet block 6 is at a distance H≥3mm from the upper surface of the rivet block 6, in order to ensure that the module has sufficient thickness for welding.

[0029] Reference Figure 5 The buckling device consists of a boss 62 and a slot 52. The boss 62 is arranged around the bottom of the rivet block 6, and the outer wall of the rivet block 6 forms a step with the boss 62. The slot 52 is a clearance groove formed by the upper plastic 5 injection molding covering the rivet block 6 and the boss 62.

[0030] In this embodiment: A ring of protrusions 62 is provided at the bottom of the rivet block 6. The protrusions 62 are integrally formed with the rivet block 6, so that the outer side wall of the rivet block 6 forms a step. The injection-molded upper plastic 5 covers the bottom and outer side wall of the rivet block 6. Through the snap-fit ​​cooperation between the protrusions 62 and the slots 52, the upper plastic 5 and the rivet block 6 are fully in contact and fixed, so that the rivet block 6 has sufficient rigidity to resist the warping deformation at the far end, thereby ensuring the contact area and keeping the resistance value of the top cover stable.

[0031] Reference Figure 6 The buckling device consists of a recess 63 and a rib 53. The recess 63 is formed on the outer wall surface of the rivet block 6. The recess 63 is an inwardly concave arc-shaped groove. The rib 53 is a hemisphere that is injection molded into the recess 63 by the upper plastic 5.

[0032] In the embodiment: a semi-circular recess 63 is provided on the side wall of the rivet block 6. The injection-molded upper plastic 5 has a raised rib 53 formed on its inner side wall that cooperates with the recess 63. Through the snap-fit ​​cooperation between the recess 63 and the raised rib 53, the upper plastic 5 and the rivet block 6 are fully in contact and fixed, so that the rivet block 6 has sufficient rigidity to resist the warping deformation at the far end, thereby ensuring the contact area and keeping the resistance value of the top cover stable.

[0033] In another embodiment: First, the upper plastic 5 is made into a finished product. During assembly, the rivet block 6 is manually clamped to the upper plastic 5. Then, the fitted upper plastic 5 and rivet block 6 are installed in the groove 11 of the top cover plate 1. After the pole post 4 is fitted with the sealing ring 3, it is inserted into the mounting holes of the lower plastic 2, the top cover plate 1, the upper plastic 5 and the rivet block 6 in sequence. Then, the top of the pole post 4 is riveted to form a mounting platform and welded to fix the pole post 4 to the rivet block 6.

[0034] Reference Figure 7 The buckling device consists of a countersunk platform 64 and a pressure block 54. The top of the pressure block 6 is provided with a countersunk platform 64, and the countersunk platform 64 forms a step with the outer wall of the pressure block 6. The pressure block 54 is an extension block that is injection molded by the upper plastic 5 and pressed against the countersunk platform 64.

[0035] In this embodiment: A recessed platform 64 is formed on the upper end of the outer wall of the rivet block 6. The recessed platform 64 and the outer wall of the rivet block 6 form a stepped structure. The injection-molded upper plastic 5 forms an extended pressing block 54 on the recessed platform 64. Through the snap-fit ​​cooperation between the recessed platform 64 and the pressing block 54, the upper plastic 5 and the rivet block 6 are fully in contact and fixed, so that the rivet block 6 has sufficient rigidity to resist the warping deformation at the far end, thereby ensuring the contact area and keeping the resistance value of the top cover stable.

[0036] Furthermore, the upper surface of the upper plastic 5 pressure block 54 and the upper surface of the rivet block 6 have a dimension D≥0.2mm, ensuring that the rivet block 6 is higher than the upper plastic 5, thus ensuring that it can be placed flat during conventional welding of the sheet metal.

[0037] The four corners of the settling tank 11 are provided with through holes 13, and the upper plastic 5 is injection molded with positioning posts that cooperate with the through holes 13.

[0038] In this embodiment, the number and position of the second through holes 13 in the two side recesses 11 can be the same or different. There is one second through hole 13, which is set at the corner of the recess 11. There can also be two second through holes 13, which can be set at adjacent corners or diagonally opposite corners of the recess 11. There can also be three or four second through holes 13, which are located at the corners of the recess 11. By opening the second through holes 13 on the surface of the recess 11, when the upper plastic 5 is injection molded, the upper plastic 5 will be injection molded to form positioning posts that cooperate with the second through holes 13, thereby improving the firmness and stability between the upper plastic 5 and the top cover plate 1.

[0039] The top cover plate 1 has a waist-shaped groove, and an explosion-proof valve 7 is installed in the waist-shaped groove. A protective plate 8 is provided at the top of the explosion-proof valve 7.

[0040] In the embodiment: when the secondary battery generates gas due to overcharging, over-discharging or overheating, causing excessive internal pressure in the secondary battery, the explosion-proof valve 7 and the protective plate 8 are destroyed, allowing the gas formed inside the secondary battery to be discharged to the outside through the through hole of the explosion-proof valve 7.

[0041] This invention provides a snap-fit ​​device between the rivet block and the upper plastic. The snap-fit ​​device secures the outer wall of the rivet block to the upper plastic, giving the rivet block sufficient rigidity to resist warping and deformation, thereby ensuring the contact area and keeping the resistance value of the top cover stable.

Claims

1. A top cover for a secondary battery, characterized in that, include: The top cover plate has grooves at both ends on its upper surface, and a through hole is formed in each groove. The lower plastic piece is fitted onto the lower surface of the top cover sheet; A rivet pressing block is installed above the sink groove; The electrode post has a step and passes through the lower plastic, the top cover plate and the rivet block in sequence and is riveted to the rivet block. A sealing ring, which is fitted onto the pole post and is located between the pole post step and the top cover plate; The upper plastic is injection molded in the gap between the rivet block, the top cover plate and the pole and located on the surface of the top cover plate. A buckling device is provided between the rivet block and the upper plastic to fasten and connect the rivet block and the upper plastic.

2. The secondary battery top cover according to claim 1, characterized in that, The buckling device consists of an undercut groove and a buckle post. The undercut grooves are evenly distributed on the outer wall surface of the rivet block. The undercut grooves are tapered grooves that are narrow on the outside and wide on the inside. The buckle post is a tapered post that is injection molded into the undercut groove by the upper plastic.

3. The secondary battery top cover according to claim 1, characterized in that, The buckling device consists of a boss and a slot. The boss is arranged around the bottom of the rivet block, and the outer wall of the rivet block forms a step with the boss. The slot is a clearance groove formed by the upper plastic injection molding covering the rivet block and the boss.

4. The secondary battery top cover according to claim 1, characterized in that, The buckling device consists of a recess and a rib. The recess is formed on the outer wall surface of the rivet block and is an inwardly concave arc-shaped groove. The rib is a hemisphere formed by injection molding of the upper plastic into the recess.

5. A secondary battery top cover according to claim 1, characterized in that, The buckling device consists of a countersunk platform and a pressure block. The top of the pressure block is provided with a countersunk platform, which forms a step with the outer wall of the pressure block. The pressure block is an extension block that is pressed onto the countersunk platform by the upper plastic injection molding.

6. A secondary battery top cover according to claim 1, characterized in that, The settling tank has two through holes at its four corners.

7. A secondary battery top cover according to claim 6, characterized in that, The upper plastic is injection molded with a positioning post that mates with the second through hole.

8. A secondary battery top cover according to claim 1, characterized in that, The top cover plate has an oblong groove, an explosion-proof valve is installed in the oblong groove, and a protective plate is provided at the top of the explosion-proof valve.

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