Lithium battery and self-puncturing connection structure of pole and adapter plate for lithium battery

Abstract

The invention discloses a self-puncturing connection structure of a pole and an adapter plate for a lithium battery and the lithium battery. According to the scheme, a self-locking riveting structure of metal cold connection is formed between the pole and the adapter plate based on a self-puncturing form. According to the scheme provided by the invention, the self-locking riveting structure of metal cold connection is adopted between the pole and the adapter plate, so that the requirement on the cleanliness of the surface of a part is effectively reduced, and metal foreign matters are not generated in the connection process, so that the service life, safety and other performances of the lithium battery are prevented from being influenced.

Description

Technical Field

[0001] The invention relates to a power battery, and in particular to a connection structure between a pole and a switching piece in a lithium battery. Background Art

[0002] In the production and assembly process of existing lithium batteries, the pole and the adapter plate need to be fixedly connected. At present, laser welding or ultrasonic welding is often used to achieve fixed connection between the pole 1 and the adapter plate 2 of the lithium battery, such as Figure 1 shown.

[0003] However, both of these two methods have corresponding problems in actual application and cannot meet actual needs.

[0004] If laser welding is used, it is not suitable for welding between dissimilar materials, and the welding process has high requirements on cleanliness and matching clearance, which is prone to welding defects, such as insufficient penetration, penetration, and explosion holes. Welding slag may also be generated during the welding process, which has a great impact on the life and safety performance of lithium batteries.

[0005] If ultrasonic welding is used, indentations will be produced on the surface of the parts, which is not conducive to the subsequent welding process. Welding slag may also be produced, affecting the life and safety of the lithium battery.

[0006] It can be seen that how to effectively overcome the problems existing in the fixed connection between the pole and the adapter plate based on welding is a problem that needs to be solved urgently in the art. Summary of the invention

[0007] In view of the problem that the pole and the adapter in the existing lithium battery are fixedly connected by laser welding or ultrasonic welding, which affects the life and safety of the lithium battery, the purpose of the present invention is to provide a self-puncture connection structure between the pole and the adapter for a lithium battery, thereby completely abandoning the laser welding or ultrasonic welding scheme, thereby avoiding the impact on the life and safety of the lithium battery and ensuring the service life and safety of the lithium battery; on this basis, the present invention further provides a safe lithium battery

[0008] In order to achieve the above-mentioned purpose, the self-puncture connection structure of the pole and the adapter plate for lithium batteries provided by the present invention includes a pole and an adapter plate, and a self-locking riveted structure of metal cold connection is formed between the pole and the adapter plate based on the self-puncture form.

[0009] In some embodiments of the present invention, the pole is made of copper, aluminum or a copper-aluminum composite pole.

[0010] In some embodiments of the present invention, the first end of the pole for connecting with the adapter plate forms a hollow self-piercing riveted portion arranged around the central axis, and the hollow self-piercing riveted portion can penetrate the adapter plate and expand to form a self-locking riveted structure between the adapter plate.

[0011] In some embodiments of the present invention, a connection portion on the adapter sheet that cooperates with the pole forms a countersunk structure.

[0012] In some embodiments of the present invention, the second end portion of the pole is configured to form an expansion riveted connection structure with the riveting block.

[0013] In order to achieve the above-mentioned purpose, the lithium battery provided by the present invention includes a lithium battery body and at least one group of poles and adapter plates arranged on the lithium battery body, wherein a self-locking riveted structure of metal cold connection is formed between the poles and the adapter plates based on a self-puncture form.

[0014] In some embodiments of the present invention, the first end of the pole for connecting with the adapter plate forms a hollow self-piercing riveted portion arranged around the central axis, and the hollow self-piercing riveted portion can penetrate the adapter plate and expand to form a self-locking riveted structure between the adapter plate.

[0015] In some embodiments of the present invention, a connection portion on the adapter sheet that cooperates with the pole forms a countersunk structure.

[0016] In some embodiments of the present invention, the pole is fixed on the top cover plate in the lithium battery body through the cooperation of the second end with the rivet block.

[0017] In some embodiments of the present invention, the second end portion of the pole is configured to form an expansion riveted connection structure with the riveting block.

[0018] The connection scheme between the pole and the adapter in the lithium battery provided by the present invention completely abandons thermal connection forms such as laser welding or ultrasonic welding, and innovatively adopts a self-locking riveted structure of metal cold connection between the pole and the adapter, which effectively reduces the cleanliness requirements for the surface of the parts, and no metal foreign matter is generated during the connection process, thereby avoiding affecting the life and safety performance of the lithium battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0020] Figure 1 This is an example diagram of the connection structure between the pole and the adapter in an existing lithium battery;

[0021] Figure 2 This is a diagram showing an example of the structure of the pole and the adapter in the lithium battery of the present invention;

[0022] Figure 3 It is a three-dimensional example diagram of the connection structure between the pole and the adapter in the lithium battery of the example of the present invention;

[0023] Figure 4 It is a front view of the connection structure between the pole and the adapter in the lithium battery of the example of the present invention;

[0024] Figure 5 An exploded view of the connection structure between the pole and the adapter in the lithium battery of the example of the present invention;

[0025] Figure 6 This is an example diagram of the state change of the pole undergoing expansion and riveting connection in an example of the present invention;

[0026] Figure 7 This is an example diagram of the state change of the self-locking riveting of the pole in the example of the present invention. DETAILED DESCRIPTION

[0027] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below with reference to specific diagrams.

[0028] As is known to all, the existing lithium battery poles and adapters are connected by thermal connection solutions such as laser welding or ultrasonic welding. The solution of the present invention overcomes this technical prejudice and completely abandons the use of thermal connection forms such as laser welding or ultrasonic welding. Instead, it innovates the self-locking riveting process of metal cold connection between the pole and the adapter. Under the premise of ensuring the reliability of the connection between the pole and the adapter, it effectively avoids the problems caused by the thermal connection solution, thereby avoiding affecting the life and safety performance of the lithium battery.

[0029] On this basis, in order to cooperate with the self-locking riveted structure of the metal cold connection between the pole and the adapter, the pole in the scheme of the present invention preferably adopts a copper pole, an aluminum pole or a copper-aluminum composite pole. At the same time, the corresponding adapter is selected based on the physical properties of the material of the pole.

[0030] The present invention is described in detail below.

[0031] See also Figure 2 , which shows an example diagram of the structure between the lithium battery pole 100 and the adapter 200 in the solution of the present invention.

[0032] The pole 100 and the adapter 200 in the solution of the present invention are configured to form a self-locking riveted structure based on a self-puncture form to form a metal cold connection, thereby realizing a stable and reliable metal cold connection structure between the pole 100 and the adapter 200.

[0033] Specifically, the pole 100 includes a pole body 110, and a flange portion 120 for matching and fixing is formed on the outer side of the pole body 110. The specific structure of the flange portion 120 is not limited here, and can be determined according to actual needs. For example, the flange portion 120 here can adopt a two-stage stepped flange structure.

[0034] Furthermore, the first end portion 130 of the pole 110 for connecting with the adapter plate 200 forms a hollow self-piercing riveted portion 140 arranged around the central axis. The hollow self-piercing riveted portion 140 can penetrate the adapter plate 200 and expand in all directions, thereby forming a stable self-locking riveted structure with the adapter plate 200.

[0035] As a further explanation, the hollow self-piercing riveted portion 140 on the pole 110 preferably has a hollow structure with a "U"-shaped cross-section, wherein the port outlet is in a trumpet-shaped shape, which facilitates self-piercing and expands outwardly to form a self-locking riveted structure after self-piercing is completed.

[0036] Furthermore, the main wall thickness t1 of the hollow self-piercing riveted portion 140 is uniform, and the main wall thickness t1 of the hollow self-piercing riveted portion 140 is specifically adapted to the material strength of the adapter plate 200 and the pole 100 , and the thickness t2 of the adapter plate 200 .

[0037] As a specific description, in order to form an effective self-locking riveting without material piercing, and in view of the different elongation at break of materials in different heat treatment states, the following setting scheme is preferably adopted in this scheme:

[0038] (1) If the material strengths of the adapter plate 200 and the pole 100 are both greater than 150 MPa, the material thickness of the pole riveted position feature t1=(0.8-1.6)t2, where t2 is the material thickness of the adapter plate 200 riveted position feature;

[0039] (2) If the material strengths of the adapter plate 200 and the pole 100 are both less than 150 MPa, the material thickness of the pole riveted position feature t1=(0.6-1.2)t2, where t2 is the material thickness of the adapter plate 200 riveted position feature;

[0040] (3) If the material strength of the adapter plate 200 is less than 150 MPa and the material strength of the pole 100 is greater than 150 MPa, the material thickness t1 of the characteristic riveted position of the pole is equal to (0.6-1.4) t2, where t2 is the material thickness of the characteristic riveted position of the adapter plate 200.

[0041] Furthermore, the second end 150 on the pole 110 for connecting with the lithium battery body is configured to form a rivet connection structure with the corresponding rivet block, thereby forming a fixed connection structure with the lithium battery body, and then being fixedly set on the lithium battery body.

[0042] As a further explanation, the second end portion 150 of the pole 110 is configured as a cylindrical step structure as a whole, thereby facilitating the formation of a stable expansion riveted connection structure with the corresponding riveting block.

[0043] The specific structural form of the adapter sheet 200 is not limited in the solution of the present invention and can be determined according to actual needs.

[0044] In order to cooperate with the self-piercing of the pole 110 , the adapter 200 forms a countersunk hole structure 220 at the connecting portion 210 that cooperates with the pole 100 , so as to facilitate cooperation with the hollow self-piercing riveting portion 140 of the pole 100 .

[0045] When the thus formed lithium battery pole 100 is arranged with the adapter 200, the pole 100 cooperates with the corresponding rivet block based on its second end 150 to form a rivet connection structure between the two, and cooperates with the flange portion 120 on the pole 100 to achieve the fixed arrangement of the pole 100 on the lithium battery body.

[0046] On the basis, the first end portion 130 of the pole 100 cooperates with the connecting portion 210 on the adapter plate 200 based on the hollow self-piercing riveted portion 140 thereon. Under the action of external force, the hollow self-piercing riveted portion 140 can penetrate the connecting portion 210 of the adapter plate 200 and simultaneously expand outward to the surroundings while cooperating with the flange portion 120 on the pole 100, and contact and press the surface of the adapter plate 200, and then form a stable self-locking riveted structure with the adapter plate 200; thereby forming a stable and reliable metal cold connection structure between the pole 100 and the adapter plate 200.

[0047] The entire fixed connection process is a metal cold connection form, without any hot connection form, which effectively reduces the cleanliness requirements for the surface of the parts, and no metal foreign matter will be generated during the connection process, so it will not affect the life and safety of the lithium battery and other performance.

[0048] The present invention is further described below through specific application examples.

[0049] Here, a bipolar column structure in which a negative electrode column assembly and a positive electrode column assembly are arranged on the top cover 30 of the lithium battery body is taken as an example.

[0050] See also Figure 3 and Figure 4In this example, a negative electrode column assembly 10 and a positive electrode column assembly 20 are respectively arranged at both ends of the top cover 30 of the lithium battery body, wherein the negative electrode column in the negative electrode column assembly 10 and the top cover 30 are fixedly connected based on a riveting connection structure, and the negative electrode column and the negative electrode adapter are fixedly connected based on a self-locking riveting structure; similarly, the positive electrode column in the positive electrode column assembly 20 and the top cover 30 are fixedly connected based on a riveting connection structure, and the positive electrode column and the positive electrode adapter are fixedly connected based on a self-locking riveting structure.

[0051] See also Figure 5 The top cover 30 in this example is specifically composed of a top cover plate 31 , a first internal insulating plastic part 32 , a second internal insulating plastic part 33 , an explosion-proof valve 34 and a protective sheet 35 .

[0052] The top cover plate 31 is rectangular in shape as a whole, and has a first connection hole 31 a and a second connection hole 31 b formed at both ends thereof for connecting the negative electrode column assembly and the positive electrode column assembly.

[0053] On this basis, in order to improve the stability of the fixed connection with the negative electrode pole assembly and the positive electrode pole assembly, this example forms corresponding first placement groove structures 31c and second placement groove structures 31d inwardly around the first connection hole 31a and the second connection hole 31b respectively to match the first connection hole 31a and the second connection hole 31b.

[0054] The specific structural forms of the first placement groove structure 31c and the second placement groove structure 31d are not limited here, and can be determined according to actual needs. As an example, a square placement groove structure is preferred here.

[0055] On this basis, a placement hole 31 f for placing the explosion-proof valve 34 is formed in the middle of the top cover plate 31 , and the placement hole 31 f is adapted to the explosion-proof valve 34 and the protection sheet 35 .

[0056] Furthermore, the explosion-proof valve 34 is mounted in the mounting hole 31f on the top cover plate 31 through a welding structure. The structure of the explosion-proof valve 34 and the specific mounting welding structure are not limited here and can be determined according to actual needs.

[0057] On this basis, the protection sheet 35 is fixedly arranged on the placement hole 31f on the top cover plate 31 through a bonding structure in the direction of the first surface of the top cover plate 31 to cover the explosion-proof valve 34 and protect the explosion-proof valve 34. The structure and specific arrangement of the protection sheet 35 are not limited here and can be determined according to actual needs.

[0058] The first internal insulating plastic part 32 and the second internal insulating plastic part 33 in the top cover 30 are integrally matched with the second surface of the top cover plate 31. At the same time, corresponding connecting through holes 32a and 33a are respectively provided on the first internal insulating plastic part 32 and the second internal insulating plastic part 33 at positions corresponding to the first connecting hole 31a and the second connecting hole 31b on the top cover plate 31; furthermore, corresponding mounting grooves 32b and 33b are respectively provided on the first internal insulating plastic part 32 and the second internal insulating plastic part 33 at positions corresponding to the mounting hole 31f on the top cover plate 31. The mounting grooves 32b and 33b here can be matched with the explosion-proof valve 34 by cooperating with each other.

[0059] The first internal insulating plastic part 32 and the second internal insulating plastic part 33 of such a structure are arranged on the second surface of the top cover plate 31 in cooperation with each other, and the connecting through hole 32a on the first internal insulating plastic part 32 corresponds to the first connecting hole 31a on the top cover plate 31, and the connecting through hole 33a on the second internal insulating plastic part 33 corresponds to the second connecting hole 31b on the top cover plate 31; the placement groove 32b on the first internal insulating plastic part 32 cooperates with the placement groove 33b of the second internal insulating plastic part 33, just covering the explosion-proof valve 34 placed in the placement hole 31f on the top cover plate 31.

[0060] With respect to the top cover 30 of the above structure, the negative electrode post assembly 10 in this embodiment is specifically composed of a negative electrode post 11, a negative electrode adapter plate 12, a first sealing ring 13, a first external insulating plastic part 14 and a negative electrode rivet block 15 which cooperate with each other.

[0061] The overall structure of the negative pole 11 and the negative electrode adapter 12 in the negative pole assembly 10 is the same as the pole and adapter structure described above, and will not be repeated here. The negative pole 11 is preferably made of aluminum or copper or a copper-aluminum composite material; the negative electrode adapter 12 has a riveted portion 12a formed at the end.

[0062] The first sealing ring 13 in the negative electrode pole assembly 10 is a T-shaped sealing ring, which is integrally adapted to the connecting through hole 32a on the first internal insulating plastic part 32 and can be placed therein; at the same time, the internal through hole of the first sealing ring 13 is adapted to the second end of the negative electrode pole 11 and can be inserted therein.

[0063] The overall structure of the first external insulating plastic part 14 in the negative pole assembly 10 is adapted to the first placement groove structure 31c on the top cover plate 31, and can be placed therein. At the same time, a placement groove 14a adapted to the negative rivet block 15 is formed on the upper surface of the first external insulating plastic part 14, and a limiting step 14b is formed at the corner of the placement groove 14a, which is used to limit the negative rivet block 15 placed therein in the circumferential direction, so as to ensure the stability and reliability of the expansion and riveting cooperation between the negative rivet block 15 and the negative pole 11.

[0064] Furthermore, a through hole 14c is provided on the first external insulating plastic member 14 at the bottom of the receiving groove 14a, and the through hole 14c is adapted to the second end of the negative electrode column 11 and can be arranged therein.

[0065] The overall structure of the negative rivet block 15 in the negative electrode pole assembly 10 is compatible with the placement groove 14a on the first external insulating plastic part 14 and can be placed therein; at the same time, a connecting through hole 15a is formed in the middle of the negative rivet block 15, and the connecting through hole 15a is compatible with the second end of the negative electrode pole 11, so as to form a riveted connection structure.

[0066] When the negative electrode pole assembly 10 of such structure is assembled and fixed with the top cover 30, the first sealing ring 13 is placed in the connecting through hole 32a on the first internal insulating plastic part 32; and the first external insulating plastic part 14 is placed in the first placement groove structure 31c on the top cover plate 31.

[0067] On this basis, the second end of the negative electrode column assembly 10 is sequentially passed through the first sealing ring 13, the first connection hole 31a on the top cover plate 31, and the through hole 14c on the first external insulating plastic part 14, and inserted into the connecting through hole 15a of the negative riveting block 15, at which time the flange portion on the negative electrode column 11 abuts against the surface of the first internal insulating plastic part 32; in this state, the second end of the negative electrode column 11 inserted in the connecting through hole 15a on the negative riveting block 15 is subjected to expansion riveting operation, so that an expansion riveting connection structure is formed between the second end of the negative electrode column 11 and the negative riveting block 15, and then the negative riveting block 15, the first external insulating plastic part 14, the top cover plate 31, the first internal insulating plastic part 32, the first sealing ring 13 and the negative electrode column 11 are sequentially fixedly connected together, as shown in FIG. Figure 6 shown.

[0068] At the same time, the flange portion on the negative electrode column 11 presses against the first sealing ring 13 to form a sealing structure between the negative electrode column 11 and the first internal insulating plastic component 32 .

[0069] For the negative electrode post 11 fixedly arranged on the top cover plate 31, the rivet portion 12a on the negative electrode adapter 12 is arranged corresponding to the hollow self-piercing rivet portion on the first end of the negative electrode post 11. On this basis, through the riveting operation, the hollow self-piercing rivet portion can penetrate the rivet portion 12a of the adapter 12 and expand around, and the formed expansion portion presses the outer surface of the adapter 12, and then forms a stable self-locking riveted structure between the negative electrode post 11 and the adapter 12, such as Figure 7 shown.

[0070] Furthermore, with respect to the top cover 30 of the above structure, the positive electrode post assembly 20 in this example is specifically composed of a positive electrode post 21, a positive electrode adapter 22, a second sealing ring 23, a second external insulating plastic part 24 and a positive electrode rivet block 25 that cooperate with each other.

[0071] The composition and arrangement of the specific components in the positive electrode column assembly 20 are the same as those of the negative electrode column assembly 10 described above, and will not be elaborated here.

[0072] The positive electrode post 21 in the positive electrode post assembly 20 is preferably made of aluminum.

[0073] It can be seen that in this example, the negative electrode pole assembly 10 and the positive electrode pole assembly 20 are fixedly connected to the top cover 30 based on the metal cold connection structure (the expansion rivet connection structure between the pole and the rivet block); at the same time, the poles in the negative electrode pole assembly 10 and the positive electrode pole assembly 20 and the adapter are fixedly connected based on the self-locking rivet structure of metal cold connection. The entire fixed connection structure completely abandons the thermal connection form, effectively ensuring the life and safety of the lithium battery.

[0074] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A self-puncture connection structure between a pole and an adapter for a lithium battery, characterized in that: The invention comprises a pole and an adapter plate, wherein a self-locking riveting structure of a metal cold connection is formed between the pole and the adapter plate based on a self-puncture form.

2. The self-puncture connection structure of the lithium battery pole and the adapter according to claim 1, characterized in that: The pole is made of copper, aluminum or a copper-aluminum composite pole.

3. The self-puncture connection structure of the lithium battery pole and the adapter according to claim 1, characterized in that: The first end of the pole used for connecting with the adapter plate forms a hollow self-piercing riveted portion arranged around the central axis, and the hollow self-piercing riveted portion can penetrate the adapter plate and expand to form a self-locking riveted structure with the adapter plate.

4. The self-puncture connection structure between the lithium battery pole and the adapter according to claim 3, characterized in that: The connecting portion on the adapter sheet that matches the pole forms a countersunk hole structure.

5. The self-puncture connection structure between the lithium battery pole and the adapter according to claim 3, characterized in that: The second end portion of the pole is configured to form an expansion riveted connection structure with the riveting block.

6. A lithium battery, comprising a lithium battery body and at least one set of poles and adapters arranged on the lithium battery body, characterized in that: A self-locking riveting structure of a metal cold connection is formed between the pole and the adapter plate based on a self-puncture form.

7. The lithium battery according to claim 6, characterized in that: The first end of the pole used for connecting with the adapter plate forms a hollow self-piercing riveted portion arranged around the central axis, and the hollow self-piercing riveted portion can penetrate the adapter plate and expand to form a self-locking riveted structure with the adapter plate.

8. The lithium battery according to claim 7, characterized in that: The connecting portion on the adapter sheet that matches the pole forms a countersunk hole structure.

9. The lithium battery according to claim 7, characterized in that: The pole is fixed on the top cover plate in the lithium battery body through the second end portion in cooperation with the rivet block.

10. The lithium battery according to claim 9, characterized in that: The second end portion of the pole is configured to form an expansion riveted connection structure with the riveting block.

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