Composite cover plate structure of double-pole symmetrical lithium ion square battery

Abstract

The utility model relates to the technical field of lithium ion batteries, and particularly discloses a double-pole symmetric lithium ion square battery composite cover plate structure which comprises a cover plate, a positive pole double-hole square end plate, a negative pole double-hole square end plate, a positive pole insulation injection molding part, a negative pole insulation injection molding part, a positive pole rivet, a negative pole rivet, an explosion-proof sheet and an explosion-proof membrane, square bosses are arranged on the left side and the right side of the upper end of the cover plate, round through holes are formed in the upper ends of the square bosses, two first counterbores are symmetrically formed in the upper end of the positive electrode double-hole square end plate, and two second counterbores are symmetrically formed in the upper end of the negative electrode double-hole square end plate; according to the utility model, the number of parts is small, the internal resistance of the battery is small, the overcurrent of the battery is increased by the plurality of poles, the output efficiency of the battery is improved, and meanwhile, the number of parts is small, so that the assembly process can be reduced, and the production efficiency can be improved by the assembly process.

Description

TECHNICAL FIELD

[0001] The utility model relates to lithium ion battery technical field, concretely is a kind of bipolar post symmetry lithium ion square battery composite cover plate structure. BACKGROUND

[0002] With the adjustment and development of energy strategy, lithium ion battery is applied in many fields with its excellent performance, such as electric vehicle and engineering machinery. At present, the development of lithium ion battery is mainly concentrated in power and energy storage, which puts forward higher requirements for the capacity and power of battery. Battery structure is the basis for ensuring battery energy transmission and safe use. In order to improve the energy output of battery, the traditional tab lead-out structure has been replaced by pole post structure. At present, the connection mode of pole post structure is nut snap ring connection. The repeated tightening of nut can cause the pole post to loosen, which can cause the tab and pole piece to break, resulting in internal short circuit of battery. In addition, although the pole post and cover plate integrated type can solve the problem of pole post loosening, the defect is that the laser welding is easy to pierce the cover plate, which affects the sealing of battery.

[0003] In view of the above problems, patent CN107887534A designs a kind of bipolar post lead-out negative electrode structure, main structure includes cover plate, square end plate, insulating sheet and bipolar post structure, less than traditional structure, process is simple, but the dependence of the negative electrode structure on insulating sheet is strong, and the sealing and safety need to be improved. Patent CN107833989A provides a convex plate integrated positive electrode structure, which mainly stretches out a convex plate structure from the cover plate to form a positive pole end plate. Although its structure is simple, the cover plate and aluminum shell are welded in one piece, and the aluminum shell is easy to be charged after battery charging, which increases the risk of battery short circuit. UTILITY MODEL CONTENTS

[0004] The utility model aims at providing a kind of bipolar post symmetry lithium ion square battery composite cover plate structure to solve the problems raised in the above background.

[0005] To achieve the above purpose, the utility model provides the following technical scheme: a kind of bipolar post symmetry lithium ion square battery composite cover plate structure, comprising: cover plate, positive electrode double-hole square end plate, negative electrode double-hole square end plate, positive electrode insulating injection molding, negative electrode insulating injection molding, positive electrode post rivet, negative electrode post rivet, explosion-proof sheet and explosion-proof membrane;

[0006] The upper end of the cover plate is provided with square convex platform on left and right sides, and the upper end of the square convex platform is provided with circular through hole, the upper end of the positive electrode double-hole square end plate is symmetrically provided with two countersunk holes one, and the upper end of the negative electrode double-hole square end plate is symmetrically provided with two countersunk holes two;

[0007] The positive electrode post rivet and the negative electrode post rivet are provided with two, and respectively from below to above, sequentially pass through the circular through hole on the cover plate and the countersunk hole two on the positive electrode double-hole square end plate or the negative electrode double-hole square end plate.

[0008] Preferably, the upper end of the positive pole rivet and the negative pole rivet is riveted with the positive double-hole square end plate and the negative double-hole square end plate by using a pneumatic riveting machine, and the fixed part is in the countersunk hole one or the countersunk hole two.

[0009] Preferably, the positive pole rivet is made of aluminum alloy, and the negative pole rivet is made of red copper; the upper end of the positive pole rivet is a positive pole upper cylinder, and the lower end is a positive pole lower square platform; the upper end of the negative pole rivet is a negative pole upper cylinder, and the lower end is a negative pole lower square platform.

[0010] Preferably, the positive pole lower square platform and the negative pole lower square platform are clamped at the lower end of the cover plate.

[0011] Preferably, the positive double-hole square end plate and the cover plate are provided with a positive insulating injection molding part, which wraps around the four sides and the bottom of the positive double-hole square end plate, and the side surface of the positive pole upper cylinder and the upper surface of the positive pole lower square platform.

[0012] Preferably, the negative double-hole square end plate and the cover plate are provided with a negative insulating injection molding part, which wraps around the four sides and the bottom of the negative double-hole square end plate, and the side surface of the negative pole upper cylinder and the upper surface of the negative pole lower square platform.

[0013] Preferably, the upper end structure of the cover plate is symmetrically arranged along the center line of the cover plate.

[0014] Preferably, the lower end of the middle part of the cover plate is fixedly installed with an explosion-proof sheet, and the upper end is attached with an explosion-proof film.

[0015] Compared with the prior art, the utility model has the advantages that:

[0016] 1. The positive pole rivet and the negative pole rivet are respectively made of red copper and aluminum rivet structure, and are riveted with the positive double-hole square end plate and the negative double-hole square end plate by using a pneumatic riveting machine, without the need of laser welding, thereby saving the welding cost and the risk of liquid leakage after welding.

[0017] 2. The utility model has the advantages that the double-pole riveting structure is stable in structure and can increase the overcurrent passage, thereby improving the output power and the charging speed of the battery.

[0018] 3. The utility model has the advantages that the double-pole structure is divided into an upper cylindrical structure and a lower square platform structure, is simple in structure, low in processing cost, has a large contact area during the assembly of the battery, and is suitable for large-current charging and discharging.

[0019] 4. The utility model has the advantages that the insulating injection molding part is an integral part, can avoid the dependence on multiple insulating sheets, enhances the sealing property, reduces the assembly process of the parts, and improves the production efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0020] Fig. 1 The whole structure of the utility model is shown in the figure;

[0021] Fig. 2 The whole structure of the utility model is shown in the figure;

[0022] In the figure: 1, positive pole double-hole square end plate; 2, positive pole insulation injection molding; 3, cover plate; 4, positive pole column rivet; 5, explosion-proof sheet; 6, negative pole column rivet; 7, negative pole insulation injection molding; 8, negative pole double-hole square end plate; 9, explosion-proof film; 101, counterbore hole one; 301, circular through hole; 302, square boss; 401, positive pole column upper cylinder; 402, positive pole column lower end square table; 601, negative pole column upper cylinder; 602, negative pole column lower end square table; 801, counterbore hole two. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical scheme of the utility model carry out clearly, completely describe, and the advantage is more clear and distinct, the following combining the figure carries out further detailed explanation to the utility model embodiment. It should be understood that the specific embodiments described here are part of the embodiments of the utility model, not all embodiments, only to explain the embodiments of the utility model, and not for limiting the embodiments of the utility model, all other embodiments obtained by the ordinary skill in the art without creative labor are within the scope of the utility model protection.

[0024] Please refer to Figs. 1-2 The utility model provides a kind of technical scheme: a kind of bipolar column symmetrical lithium ion square battery composite cover plate structure, comprising: cover plate 3, positive pole double-hole square end plate 1, negative pole double-hole square end plate 8, positive pole insulation injection molding 2, negative pole insulation injection molding 7, positive pole column rivet 4, negative pole column rivet 6, explosion-proof sheet 5 and explosion-proof film 9, square boss 302 is arranged in the upper end left and right sides of cover plate 3, square boss 302 is formed by stamping, two circular through holes 301 are symmetrically opened in the upper end of square boss 302, and the diameter of circular through hole 301 is greater than the diameter of positive pole column rivet 4 and negative pole column rivet 6.

[0025] Two counterbore holes one 101 are symmetrically arranged in the upper end of positive pole double-hole square end plate 1, and two counterbore holes two 801 are symmetrically arranged in the upper end of negative pole double-hole square end plate 8, so that the riveting of the pole column is facilitated in the later period, the structure and size of counterbore hole one 101 and counterbore hole two 801 are the same, the diameter of counterbore hole one 101 and counterbore hole two 801 is the same as the diameter of circular through hole 301 and greater than the diameter of positive pole column rivet 4 and negative pole column rivet 6, so as to facilitate the upper end of positive pole column rivet 4 and negative pole column rivet 6 to pass through.

[0026] The positive pole rivet 4 and the negative pole rivet 6 are both provided with two, the positive pole rivet 4 passes through the circular through hole 301 on the cover plate 3 and the countersunk hole one 101 on the positive pole double-hole square end plate 1 from bottom to top in sequence, the negative pole rivet 6 passes through the circular through hole 301 on the cover plate 3 and the countersunk hole two 801 on the negative pole double-hole square end plate 8 from bottom to top in sequence, the upper end of the positive pole rivet 4 and the negative pole rivet 6 is riveted with the positive pole double-hole square end plate 1 and the negative pole double-hole square end plate 8 by using a pneumatic riveting machine, the upper end fixed part of the positive pole rivet 4 is in the countersunk hole one 101, the upper end fixed part of the negative pole rivet 6 is in the countersunk hole two 801, and a reverse round table which is matched with the upper part of the countersunk hole is formed after riveting, and meanwhile the positive pole lower end square table 402 and the negative pole lower end square table 602 are clamped at the lower end of the cover plate 3.

[0027] The positive pole rivet 4 is made of aluminum alloy, and the negative pole rivet 6 is made of red copper; the upper end of the positive pole rivet 4 is a positive pole upper cylinder 401, and the lower end is a positive pole lower end square table 402; the upper end of the negative pole rivet 6 is a negative pole upper cylinder 601, and the lower end is a negative pole lower end square table 602.

[0028] The positive pole double-hole square end plate 1 and the cover plate 3 are provided with a positive pole insulation injection molding part 2, the positive pole insulation injection molding part 2 wraps around the four sides and the bottom of the positive pole double-hole square end plate 1 and the side surface of the positive pole upper cylinder 401 and the upper surface of the positive pole lower end square table 402, the positive pole insulation injection molding part 2 is integrally formed, the negative pole double-hole square end plate 8 and the cover plate 3 are provided with a negative pole insulation injection molding part 7, the negative pole insulation injection molding part 7 wraps around the four sides and the bottom of the negative pole double-hole square end plate 8 and the side surface of the negative pole upper cylinder 601 and the upper surface of the negative pole lower end square table 602, the negative pole insulation injection molding part 7 is integrally formed, the insulation injection molding part plays a fixed anti-loose role, and the insulation injection molding part separates the positive pole double-hole square end plate and the cover plate 3 to play an insulation role, and separates the positive pole rivet and the cover plate 3 to play an insulation role.

[0029] The upper end structure of the cover plate 3 is symmetrically arranged along the center line of the cover plate 3, and a set of molds can be used for the positive pole and the negative pole, so that the mold opening cost can be saved, the middle part of the cover plate 3 is provided with an explosion-proof sheet 5 which is fixedly installed at the lower end, and an explosion-proof film 9 is attached to the upper end to ensure the safety of the battery in use.

[0030] The utility model discloses few parts, battery internal resistance is smaller, multiple pole increases battery overcurrent, improves the output efficiency of battery, and fewer parts can reduce assembly process, and assembly technology improves production efficiency.

[0031] In actual use, the mold first forms the cover plate 3 and the positive and negative double-hole end plates. The positive and negative terminal rivets are then passed through the cover plate 3 and the positive and negative double-hole end plates in sequence. The injection molding machine integrally injection molds the insulating injection parts between the positive and negative double-hole end plates and the cover plate 3, and between the cover plate 3 and the positive and negative terminal rivets, ensuring the insulation between the various parts of the combined cover plate 3. Then, a pneumatic riveting machine is used to rivet the positive and negative terminal rivets from the top. Finally, the explosion-proof sheet 5 and the explosion-proof film 9 are installed to ensure the safety of the battery. During operation, the tab connecting piece is welded to the lower surface of the positive and negative terminal rivets to form a current loop. The introduction of the double terminals can increase the battery current flow channel, enhance the battery output power, and improve the battery charging speed.

[0032] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A composite cover structure for a bipolar symmetrical lithium-ion square battery, characterized in that: include: Cover plate (3), positive electrode double hole square end plate (1), negative electrode double hole square end plate (8), positive electrode insulating injection molded part (2), negative electrode insulating injection molded part (7), positive electrode post rivet (4), negative electrode post rivet (6), explosion-proof sheet (5) and explosion-proof film (9); The cover plate (3) has square bosses (302) on both the left and right sides of the upper end. The square bosses (302) have circular through holes (301) at the upper end. The positive electrode double hole square end plate (1) has two countersunk holes (101) symmetrically opened at the upper end. The negative electrode double hole square end plate (8) has two countersunk holes (801) symmetrically opened at the upper end. Two positive electrode post rivets (4) and two negative electrode post rivets (6) are provided, and they pass through the circular through hole (301) on the cover plate (3) and the countersunk hole (801) on the positive electrode double hole square end plate (1) or the negative electrode double hole square end plate (8) respectively from bottom to top.

2. The bipolar symmetrical lithium-ion square battery composite cover structure according to claim 1, characterized in that: The upper ends of the positive terminal post rivet (4) and the negative terminal post rivet (6) are riveted together by a pneumatic riveting machine and a positive double-hole square end plate (1) and a negative double-hole square end plate (8), and the fixed part is in countersunk hole one (101) or countersunk hole two (801).

3. The bipolar symmetrical lithium-ion square battery composite cover structure according to claim 2, characterized in that: The positive terminal rivet (4) is made of aluminum alloy, and the negative terminal rivet (6) is made of copper. The upper end of the positive terminal rivet (4) is a cylindrical upper part (401) of the positive terminal and the lower end is a square platform (402) of the lower end of the positive terminal. The upper end of the negative terminal rivet (6) is a cylindrical upper part (601) of the negative terminal and the lower end is a square platform (602) of the lower end of the negative terminal.

4. The bipolar symmetrical lithium-ion square battery composite cover structure according to claim 3, characterized in that: The lower end square platform (402) of the positive electrode post and the lower end square platform (602) of the negative electrode post are snapped onto the lower end of the cover plate (3).

5. The bipolar symmetrical lithium-ion square battery composite cover structure according to claim 4, characterized in that: A positive electrode insulating injection molding part (2) is provided between the positive electrode double hole square end plate (1) and the cover plate (3). The positive electrode insulating injection molding part (2) wraps around the perimeter and bottom of the positive electrode double hole square end plate (1), as well as the side of the positive electrode post cylinder (401) and the upper surface of the positive electrode post lower end square platform (402).

6. The bipolar symmetrical lithium-ion square battery composite cover structure according to claim 5, characterized in that: A negative electrode insulating injection molding part (7) is provided between the negative electrode double hole square end plate (8) and the cover plate (3). The negative electrode insulating injection molding part (7) wraps around the perimeter and bottom of the negative electrode double hole square end plate (8), as well as the side of the cylinder (601) on the negative electrode post and the upper surface of the square platform (602) at the lower end of the negative electrode post.

7. The bipolar symmetrical lithium-ion square battery composite cover structure according to claim 6, characterized in that: The upper structure of the cover plate (3) is symmetrically arranged along the center line of the cover plate (3).

8. The bipolar symmetrical lithium-ion square battery composite cover structure according to claim 1, characterized in that: An explosion-proof sheet (5) is fixedly installed at the lower middle part of the cover plate (3), and an explosion-proof film (9) is attached to the upper part.

Images