Lithium-ion battery and battery pack

Abstract

The application provides a lithium ion battery and a battery pack. The lithium ion battery comprises a steel shell, a cap, a battery cell, a current collecting disc and a rivet. The steel shell is formed with a communicating accommodation cavity and a first avoiding hole. The cap is arranged and fixedly connected to the steel shell in correspondence with the opening of the accommodation cavity. The battery cell is arranged in the accommodation cavity. One side of the battery cell is provided with a negative tab structure. The current collecting disc is arranged in the accommodation cavity and is riveted to the steel shell. The current collecting disc is also electrically connected to the negative tab structure. The current collecting disc is provided with a second avoiding hole. The rivet is sequentially arranged in the first avoiding hole and the second avoiding hole. The first end of the rivet abuts against the current collecting disc. The second end of the rivet abuts against the outer side of the steel shell, so that the current collecting disc is riveted to the steel shell through the rivet. In this way, the negative tab structure is electrically connected to the outside through the negative pole, avoiding the electrical connection of the negative tab structure to the outside through resistance welding, thereby avoiding the problems of virtual welding, tab bending and welding slag splashing, and reducing the self-discharge of the battery cell.

Description

Technical Field

[0001] This invention relates to the technical field of lithium-ion batteries, and in particular to a lithium-ion battery and battery pack. Background Technology

[0002] Large cylindrical lithium-ion batteries are widely used in power tools, backup power supplies, lawn lights, solar lights, rechargeable two-wheeled vehicles, and toy models. For these batteries, the bottom of the steel casing is electrically connected to the negative electrode tab via resistance welding, allowing the negative electrode tab to connect to the outside through the casing. However, resistance welding is prone to problems such as incomplete soldering, tab bending, and solder slag spatter, leading to a higher risk of self-discharge and consequently, poorer performance of the lithium-ion battery. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a lithium-ion battery and battery pack with lower cell self-discharge, thereby resulting in higher performance of the lithium-ion battery.

[0004] The objective of this invention is achieved through the following technical solution:

[0005] A lithium-ion battery, comprising:

[0006] A steel shell, wherein the steel shell forms a receiving cavity and a first clearance hole, and the receiving cavity is connected to the first clearance hole;

[0007] A cap, which is correspondingly provided to the opening of the receiving cavity and fixedly connected to the steel shell;

[0008] A battery cell, wherein the battery cell is disposed within the accommodating cavity, and a negative electrode tab structure is provided on one side of the battery cell;

[0009] A current collector, disposed within the accommodating cavity, the current collector being electrically connected to the negative electrode tab structure, and the current collector having a second clearance hole; and

[0010] The rivets are sequentially inserted into the first clearance hole and the second clearance hole. The first end of the rivet abuts against the manifold, and the second end of the rivet abuts against the outside of the steel shell and forms a negative terminal post, so that the manifold is riveted to the steel shell by the rivets.

[0011] In one embodiment, the collector plate has a receiving groove on the side opposite to the first clearance hole, and the receiving groove is connected to the receiving cavity and the second clearance hole respectively; the first end of the rivet abuts against the groove wall of the receiving groove.

[0012] In one embodiment, the lithium-ion battery further includes a seal that covers and connects to the rivet, and the seal elastically abuts against the wall of the first clearance hole so that the rivet is sealed to the wall of the first clearance hole through the seal.

[0013] In one embodiment, the diameter of the first clearance hole is equal to the outer diameter of the rivet before riveting, and the diameter of the second clearance hole is equal to the outer diameter of the rivet before riveting.

[0014] In one embodiment, the seal is a silicone structure.

[0015] In one embodiment, the cap is welded to the steel shell; and / or,

[0016] The negative electrode ear structure is a full electrode ear structure.

[0017] In one embodiment, the cap has a positive electrode through hole.

[0018] In one embodiment, the steel shell is a cylindrical structure.

[0019] In one embodiment, the opening of the accommodating cavity is circular, and the cap is circular, so that the cap fits the opening of the accommodating cavity.

[0020] A battery pack includes a plurality of lithium-ion batteries as described in any of the above embodiments, wherein the plurality of lithium-ion batteries are electrically connected in sequence.

[0021] Compared with the prior art, the present invention has at least the following advantages:

[0022] In the aforementioned lithium-ion battery, the first end of the rivet abuts against the current collector, making the rivet electrically connected to the current collector. The second end of the rivet abuts against the outside of the steel shell, causing the second end of the rivet to protrude from the outside of the steel shell and form a negative electrode post. In this way, the negative electrode tab structure is electrically connected to the outside through the negative electrode post, avoiding the need to connect the negative electrode tab structure to the outside through resistance welding. This avoids problems such as poor welding, electrode tab bending, and welding slag splashing, resulting in lower self-discharge of the cell and improved performance of the lithium-ion battery. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1This is a schematic diagram of the structure of a lithium-ion battery according to one embodiment;

[0025] Figure 2 for Figure 1 A magnified schematic diagram of point A in the lithium-ion battery shown;

[0026] Figure 3 for Figure 1 Another schematic diagram of a lithium-ion battery structure is shown.

[0027] Figure 4 for Figure 3 A magnified schematic diagram of point B in the lithium-ion battery shown.

[0028] Figure 5 for Figure 1 The flowchart shown illustrates the steps of a lithium-ion battery manufacturing method. Detailed Implementation

[0029] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0030] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly attached to the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0032] This application provides a lithium-ion battery, which includes a steel shell, a cap, a battery cell, a current collector, and rivets. The steel shell has a receiving cavity and a first clearance hole, which are connected. The cap is correspondingly disposed to the opening of the receiving cavity and fixedly connected to the steel shell. The battery cell is disposed in the receiving cavity, and a negative electrode tab structure is provided on one side of the battery cell. The current collector is disposed in the receiving cavity and riveted to the steel shell. The current collector is also electrically connected to the negative electrode tab structure. The current collector has a second clearance hole. The rivets are sequentially inserted through the first clearance hole and the second clearance hole. The first end of the rivet abuts against the current collector, and the second end of the rivet abuts against the outside of the steel shell, so that the current collector is riveted to the steel shell by the rivets.

[0033] In the aforementioned lithium-ion battery, the first end of the rivet abuts against the current collector, making the rivet electrically connected to the current collector. The second end of the rivet abuts against the outside of the steel shell, causing the second end of the rivet to protrude from the outside of the steel shell and form a negative electrode post. In this way, the negative electrode tab structure is electrically connected to the outside through the negative electrode post, avoiding the need to connect the negative electrode tab structure to the outside through resistance welding. This avoids problems such as poor welding, electrode tab bending, and welding slag splashing, resulting in lower self-discharge of the cell and improved performance of the lithium-ion battery.

[0034] To better understand the technical solution and beneficial effects of this application, the following detailed description is provided in conjunction with specific embodiments:

[0035] like Figure 1 and Figure 2 As shown, a lithium-ion battery 10 of one embodiment includes a steel shell 100, a cap 200, a battery cell 300, a current collector 400, and rivets 500. The steel shell 100 has a receiving cavity 101 and a first clearance hole 102, which are connected. The cap 200 is correspondingly disposed to the opening of the receiving cavity 101 and fixedly connected to the steel shell 100. The battery cell 300 is disposed in the receiving cavity 101, and a negative electrode tab structure 310 is provided on one side of the battery cell 300. The collector plate 400 is disposed in the accommodating cavity 101. The collector plate 400 is also electrically connected to the negative electrode ear structure 310. The collector plate 400 has a second clearance hole 401. The rivet 500 is sequentially inserted into the first clearance hole 102 and the second clearance hole 401. The first end of the rivet 500 abuts against the collector plate 400, and the second end of the rivet 500 abuts against the outside of the steel shell 100 and forms a negative electrode post 510, so that the collector plate 400 is riveted to the steel shell 100 by the rivet 500.

[0036] like Figure 1 and Figure 2As shown, in this embodiment, the battery cell 300 is fixed inside the accommodating cavity 101. A blank foil area is provided on one side of the battery cell 300, so that a negative electrode tab structure 310 is formed on one side of the battery cell 300. The first end of the rivet 500 abuts against the current collector 400, making the rivet 500 electrically connected to the current collector 400. The second end of the rivet 500 abuts against the outer side of the steel shell 100, causing the second end of the rivet 500 to protrude beyond the outer side of the steel shell 100 and form a negative electrode post 510. This allows the negative electrode tab structure 310 to be electrically connected to the outside through the negative electrode post 510 of the rivet 500.

[0037] In the aforementioned lithium-ion battery 10, the first end of the rivet 500 abuts against the current collector 400, making the rivet 500 electrically connected to the current collector 400. The second end of the rivet 500 abuts against the outer side of the steel shell 100, making the second end of the rivet 500 protrude from the outer side of the steel shell 100 and form a negative electrode post 510. In this way, the negative electrode tab structure 310 is electrically connected to the outside through the negative electrode post 510, avoiding the need to connect the negative electrode tab structure 310 to the outside through resistance welding. This avoids problems such as poor welding, tab bending, and welding slag spatter, resulting in a smaller self-discharge of the cell 300 and improving the performance of the lithium-ion battery 10.

[0038] like Figure 2 As shown, in one embodiment, the collector plate 400 has a receiving groove 402 on the side opposite to the first clearance hole 102. The receiving groove 402 is connected to the receiving cavity 101 and the second clearance hole 401 respectively, and the first end of the rivet 500 abuts against the groove wall of the receiving groove 402. In this embodiment, both the receiving cavity 101 and the receiving groove 402 contain electrolyte, which increases the capacity of the electrolyte and improves the performance of the battery cell 300.

[0039] like Figure 2 As shown, in one embodiment, the lithium-ion battery 10 further includes a sealing member 600, which covers and is connected to the rivet 500. The sealing member 600 elastically abuts against the wall of the first clearance hole 102. That is, the sealing member 600 covers and is connected to the portion of the rivet 500 corresponding to the first clearance hole 102, and the sealing member elastically abuts against the wall of the first clearance hole 102, so that the rivet 500 is sealed to the wall of the first clearance hole 102 through the sealing member 600, thereby preventing the electrolyte in the accommodating cavity 101 from leaking through the gap between the rivet 500 and the steel shell 100, thus improving the performance of the lithium battery.

[0040] In one embodiment, the diameter of the first clearance hole 102 is equal to the outer diameter of the rivet 500 before riveting, and the diameter of the second clearance hole 401 is equal to the outer diameter of the rivet 500 before riveting, so that the rivet 500 can pass through the first clearance hole 102 and the second clearance hole 401 more smoothly, thereby improving the efficiency of riveting.

[0041] In one embodiment, the seal 600 is a silicone structure to seal the gap between the rivet 500 and the steel shell 100. In one embodiment, the cap 200 is welded to the steel shell 100 to improve the connection strength between the cap 200 and the steel shell 100.

[0042] In one embodiment, the negative electrode structure 310 is an all-electrode structure. Of course, in another embodiment, the negative electrode structure 310 can also be a multi-electrode structure.

[0043] like Figure 1 As shown, in one embodiment, the cap 200 has a positive electrode through-hole 201, through which the positive electrode is inserted and insulated from the cap 200. In one embodiment, the steel shell 100 has a cylindrical structure. In one embodiment, the opening of the accommodating cavity 101 is circular, and the cap 200 is circular, so that the cap 200 fits the opening of the accommodating cavity 101, making the structure of the lithium-ion battery 10 more compact.

[0044] like Figure 3 and Figure 4 As shown, in one embodiment, the lithium-ion battery 10 further includes an elastic sealing plug 800. During formation, the elastic sealing plug 800 passes through the first clearance hole 102 and the second clearance hole 401, and during formation, the elastic sealing plug 800 is respectively sleeved with the steel shell 100 and the current collector 400, so that the elastic sealing plug 800 seals the first clearance hole 102 during formation, and at the same time, the current collector 400 is electrically connected to the steel shell 100 through the elastic sealing plug 800 during formation, so that the lithium-ion battery 10 can be formed.

[0045] In this embodiment, before the lithium-ion battery 10 is filled with electrolyte, an elastic sealing plug 800 is inserted into the first clearance hole 102 and the second clearance hole 401 during formation. This allows the elastic sealing plug 800 to seal the first clearance hole 102 during formation, while simultaneously ensuring that the current collector 400 is electrically connected to the steel shell 100 through the elastic sealing plug 800 during formation. After the lithium-ion battery 10 completes formation, gas is generated inside, resulting in a higher internal pressure and consequently lower safety. Formation also consumes some electrolyte. At this point, the elastic sealing plug 800 is removed, allowing the lithium-ion battery 10 to release gas through the first clearance hole 102, reducing the internal pressure and improving its safety. Then, electrolyte is added through the first clearance hole 102, filling the cavity and improving battery performance. Finally, the current collector 400 is riveted to the steel shell 100.

[0046] like Figure 4As shown, in one embodiment, the elastic sealing plug 800 includes a conductive plug body 810, a first abutment portion 820, and a second abutment portion 830. The first abutment portion 820 and the second abutment portion 830 are respectively connected to both ends of the conductive plug body 810, and both the first abutment portion 820 and the second abutment portion 830 protrude from the outer side of the conductive plug body 810. The second abutment portion 830 is an elastic structure. Further, the conductive plug body 810 is located in the second clearance hole 401 and sleeved with the current collector 400, so that the current collector 400 is electrically connected to the conductive plug body 810. The conductive plug body 810 is located in the first clearance hole 102 and sleeved with the steel shell 100, so that the conductive plug body 810 is electrically connected to the steel shell 100. Thus, the current collector 400 is electrically connected to the steel shell 100 through the conductive plug body 810, so that the lithium-ion battery 10 is ready for formation. Furthermore, the first abutting portion 820 elastically abuts against the inner wall of the receiving groove 402, and the second abutting portion 830 elastically abuts against the inner surface of the steel shell 100, so that the elastic sealing plug 800 seals the first clearance hole 102, preventing electrolyte leakage through the first clearance hole 102 during formation, thereby improving the performance of the lithium-ion battery 10. It is understood that the conductive plug 810 can be metal or other existing conductive materials. The first abutting portion 820 and the second abutting portion 830 can be silicone structures, rubber structures, or other existing elastic structures.

[0047] In one embodiment, the portion of the rivet 500 corresponding to the second clearance hole 401 is provided with a silver plating layer, so that the rivet 500 contacts the inner wall of the second clearance hole 401 through the silver plating layer, thereby improving the conductivity of the rivet 500 and thus improving the performance of the lithium-ion battery.

[0048] It is understandable that when the current collector 400 is electrically connected to the steel shell 100, the steel shell 100 is more likely to be electrically connected to the positive terminal, which makes the lithium battery more prone to short circuit and reduces the safety performance of the lithium-ion battery 10.

[0049] Therefore, such as Figure 2As shown, in one embodiment, the rivet 500 is a double-drum pull rivet, that is, the rivet 500 has a first expansion portion 520 and a second expansion portion 530 protruding from it. The first expansion portion 520 and the second expansion portion 530 are spaced apart. The first expansion portion 520 is located between the bottom end of the manifold 400 and the steel shell 100. The sealing member 600 is an insulating structure. The sealing member 600 also covers and is connected to the first expansion portion 520. The sealing member 600 also elastically abuts against the manifold 400 and the steel shell 100 respectively. That is, the first expansion portion 520 abuts against the manifold 400 and the steel shell 100 respectively through the sealing member 600. The second expansion portion 530 protrudes from the side of the manifold 400 away from the bottom end of the steel shell 100. That is, the second expansion portion 530 protrudes from the side of the manifold 400 away from the first expansion portion 520, and the second expansion portion 530 abuts against the manifold 400. In this embodiment, since the sealing element 600 is an insulating structure, it can block the electrical connection. Furthermore, since the rivet 500 is sealed to the wall of the first clearance hole 102 through the sealing element 600, it is insulated from the wall of the first clearance hole 102. Also, since the first expansion portion 520 abuts against the current collector 400 and the steel shell 100 respectively through the sealing element 600, the current collector 400 is insulated from the first expansion portion 520. Thus, the current collector 400 is insulated from the steel shell 100. In other words, the sealing element 600 blocks the electrical connection between the current collector 400 and the steel shell 100, making the steel shell 100 uncharged and suppressing short circuits caused by the electrical connection between the steel shell 100 and the positive electrode post, thereby improving the safety performance of the lithium-ion battery 10.

[0050] However, due to the small contact area between the seal 600 and the collector plate 400, the gap between the collector plate 400 and the bottom of the steel shell 100 is relatively large. Furthermore, since the seal 600 is an elastic structure, the collector plate 400 is prone to shaking. Consequently, the edge of the collector plate 400 is more likely to touch the bottom of the steel shell 100, making it impossible to completely prevent the steel shell 100 from becoming energized. This still poses a risk of short circuit due to the steel shell 100 being electrically connected to the positive terminal.

[0051] Therefore, as Figure 2As shown, in one embodiment, the lithium-ion battery 10 further includes an insulating sheet 700. The outer diameter of the insulating sheet 700 is adapted to the inner diameter of the accommodating cavity 101. The insulating sheet 700 is disposed within the accommodating cavity 101, and its opposite sides abut against the bottom end of the steel shell 100 and the current collector 400, respectively. The insulating sheet 700 has a third clearance hole 701, which is respectively provided with a first clearance hole 102 and a second clearance hole 401. A rivet 500 is sequentially inserted through the first clearance hole 102, the third clearance hole 701, and the second clearance hole 401. The first enlarged portion 520 is correspondingly provided with the third clearance hole 701. In this embodiment, since the outer diameter of the insulating sheet 700 is adapted to the inner diameter of the accommodating cavity 101, and the opposite sides of the insulating sheet 700 abut against the bottom end of the steel shell 100 and the current collector 400 respectively, the contact area of ​​the current collector 400 is increased, while the gap between the current collector 400 and the bottom end of the steel shell 100 is reduced. This makes the positional stability of the current collector 400 higher, avoiding the current collector 400 from contacting the steel shell 100 after displacement, thereby avoiding the steel shell 100 from becoming charged, and thus avoiding the risk of short circuit caused by the steel shell 100 being electrically connected to the positive terminal post. This makes the safety performance of the lithium-ion battery 10 better.

[0052] In order for the insulating sheet 700 to provide stable support for the current collector 400, in one embodiment, the insulating sheet 700 is a rigid structure, such as a rigid plastic structure, a ceramic structure, or other existing rigid structures with insulating properties.

[0053] It is understandable that when the first enlarged portion 520 expands, the seal 600 risks compressing the insulating sheet 700, making the seal 600 more prone to deformation problems such as arching. This, in turn, causes uneven stress on the current collector 400 connected to the seal 600, making the current collector 400 more susceptible to damage and displacement, thus reducing the performance of the lithium-ion battery 10. Therefore, in one embodiment, the size of the third clearance hole 701 is larger than the size of the portion of the seal 600 corresponding to the first enlarged portion 520, so that there is a gap between the insulating sheet 700 and the seal 600. In this embodiment, after the first expansion portion 520 expands, there is a gap between the insulating sheet 700 and the sealing member 600, which prevents the sealing member 600 from directly pressing against the insulating sheet 700 after the first expansion portion 520, suppressing the deformation of the insulating sheet 700, thereby making the current collector 400 more uniformly stressed, suppressing damage to the current collector 400, and improving the positional stability of the current collector 400, thereby improving the performance of the lithium-ion battery 10.

[0054] However, due to the gap between the insulating sheet 700 and the sealing member 600, electrolyte tends to accumulate within this gap. Furthermore, because this gap is adjacent to the first recessed hole 102, the first recessed hole 102 has a significant leakage potential. Therefore, in one embodiment, the lithium-ion battery 10 further includes a flexible insulating filler 900. The flexible insulating filler 900 is located within the third recessed hole 701 and connected to the insulating sheet 700. The flexible insulating filler 900 is also connected to the sealing member 600. That is, the flexible insulating filler 900 is positioned within the gap between the insulating sheet 700 and the sealing member 600 to prevent electrolyte accumulation near the first recessed hole 102. This means that any leakage of electrolyte through the first recessed hole 102 must also be blocked by the flexible insulating filler 900, reducing the risk of leakage through the first recessed hole 102 and improving the performance of the lithium-ion battery 10. In this embodiment, the flexible insulating filler 900 is a flexible material with insulating properties, such as silicone, rubber, or other existing materials that are both insulating and flexible.

[0055] It is understandable that, in order to ensure that the flexible insulating filler 900 fills the gap between the insulating sheet 700 and the sealing member 600, the flexible insulating filler 900 needs to elastically abut against both the insulating sheet 700 and the sealing member 600. This results in the flexible insulating filler 900 applying a certain elastic force to the insulating sheet 700, leading to a small deformation of the insulating sheet 700. However, due to the small size of the lithium-ion battery 10, even a small deformation of the insulating sheet 700 has a significant impact on the lithium-ion battery 10. To minimize the deformation of the insulating sheet 700, in one embodiment, the flexible insulating filler 900 has a plurality of spaced deformation holes 901. In this embodiment, after the first expansion portion 520 expands, the sealing member 600 covering and connected to the first expansion portion 520 abuts against the soft insulating filler 900, causing the soft insulating filler 900 to deform towards the multiple deformation holes 901. This reduces the amount of deformation of the soft insulating filler 900 towards the insulating sheet 700, thereby reducing the force exerted by the soft insulating filler 900 on the insulating sheet 700, and thus reducing the deformation of the insulating sheet 700. This results in a more uniform stress distribution on the current collector 400 and higher positional stability of the current collector 400, thereby improving the performance of the lithium-ion battery 10. Moreover, even if electrolyte enters into each deformation hole 901, the hole walls of each deformation hole 901 prevent the electrolyte from flowing to the first clearance hole 102, thus preventing the deformation holes 901 from increasing the risk of leakage from the first clearance hole 102.

[0056] Furthermore, each deformation hole 901 penetrates the flexible insulating filler 900, meaning each deformation hole 901 is a through hole, which makes the deformation of the flexible insulating filler 900 more uniform. This, in turn, makes the force exerted by the flexible insulating filler 900 on the insulating sheet 700 more uniform, thus ensuring that the insulating sheet 700 is subjected to more uniform force, avoiding the problem of the insulating sheet 700 cracking or even being scrapped. This ensures that the insulating sheet 700 can play its role in blocking the electrical connection between the current collector 400 and the steel shell 100.

[0057] This application also provides a battery pack, including a plurality of the above-described lithium-ion batteries 10, wherein the plurality of lithium-ion batteries 10 are electrically connected in sequence. Figure 1 and Figure 2 As shown, in one embodiment, the lithium-ion battery 10 includes a steel shell 100, a cap 200, a battery cell 300, a current collector 400, and rivets 500. The steel shell 100 has a communicating accommodating cavity 101 and a first clearance hole 102. The cap 200 is correspondingly disposed and fixedly connected to the opening of the accommodating cavity 101. The battery cell 300 is disposed in the accommodating cavity 101. A negative electrode tab structure 310 is provided on one side of the battery cell 300. The current collector 400... The current collector 400 is disposed in the accommodating cavity 101 and is also electrically connected to the negative electrode ear structure 310. The current collector 400 has a second clearance hole 401. The rivet 500 passes through the first clearance hole 102 and the second clearance hole 401 in sequence. The first end of the rivet 500 abuts against the current collector 400, and the second end of the rivet 500 abuts against the outside of the steel shell 100 and forms a negative electrode post 510, so that the current collector 400 is riveted to the steel shell 100 by the rivet 500.

[0058] like Figure 1 and Figure 2 As shown, in this embodiment, the battery cell 300 is fixed inside the accommodating cavity 101. A blank foil area is provided on one side of the battery cell 300, so that a negative electrode tab structure 310 is formed on one side of the battery cell 300. The first end of the rivet 500 abuts against the current collector 400, making the rivet 500 electrically connected to the current collector 400. The second end of the rivet 500 abuts against the outer side of the steel shell 100, causing the second end of the rivet 500 to protrude beyond the outer side of the steel shell 100 and form a negative electrode post 510. This allows the negative electrode tab structure 310 to be electrically connected to the outside through the negative electrode post 510 of the rivet 500.

[0059] In the aforementioned battery pack, the first end of the rivet 500 abuts against the current collector 400, making the rivet 500 electrically connected to the current collector 400. The second end of the rivet 500 abuts against the outer side of the steel shell 100, making the second end of the rivet 500 protrude from the outer side of the steel shell 100 and form a negative electrode post 510. In this way, the negative electrode tab structure 310 is electrically connected to the outside through the negative electrode post 510, avoiding the need to connect the negative electrode tab structure 310 to the outside through resistance welding. This avoids problems such as poor welding, tab bending, and welding slag spatter, resulting in a smaller self-discharge of the cell 300 and improving the performance of the lithium-ion battery 10.

[0060] like Figures 2 to 5 As shown, this application also provides a method for manufacturing a lithium-ion battery 10, used to manufacture the lithium-ion battery 10 described in any of the above embodiments. The method for manufacturing the lithium-ion battery 10 includes:

[0061] S101: Provides a flexible sealing plug 800.

[0062] In this embodiment, the elastic sealing plug 800 has an elastic structure, and the elastic sealing plug 800 has a better sealing effect.

[0063] S103: The elastic sealing plug 800 is respectively inserted into the first clearance hole 102 and the second clearance hole 401 of the steel shell 100, so that the elastic sealing plug 800 is sleeved with the steel shell 100 and the collector plate 400 respectively, thereby sealing the first clearance hole 102 with the elastic sealing plug 800, and simultaneously making the elastic sealing plug 800 and the collector plate 400 electrically connected to the steel shell 100 through the elastic sealing plug 800.

[0064] In this embodiment, the elastic sealing plug 800 passes through the first clearance hole 102 and the second clearance hole 401. The elastic sealing plug 800 is sleeved with the steel shell 100 and the current collector 400 respectively, so that the current collector is electrically connected to the steel shell 100 through the elastic sealing plug 800, thereby enabling the lithium-ion battery 10 to be energized and formed. The two ends of the elastic sealing plug 800 elastically abut against the inner wall of the receiving groove 402 and the outer surface of the steel shell 100 respectively, so that the elastic sealing plug 800 seals the first clearance hole 102, preventing electrolyte leakage through the first clearance hole 102.

[0065] S105: Perform a liquid injection operation on the steel shell 100 to fill the accommodating cavity 101 with electrolyte.

[0066] In this embodiment, electrolyte is injected through the positive terminal through-hole 201 of the cap 200 to fill the accommodating cavity 101 with electrolyte.

[0067] S107: Seal the cap 200 to the steel shell 100.

[0068] In this embodiment, the cap 200 is first placed in the opening of the accommodating cavity 101, and then the cap 200 is sealed to the steel shell 100 to prevent the electrolyte from overflowing through the opening of the accommodating cavity 101.

[0069] S109: Form the lithium-ion battery 10 to activate the lithium-ion battery 10.

[0070] In this embodiment, the lithium-ion battery 10 is charged for the first time, which activates the cell 300. During this process, a stable solid electrolyte interface film is formed on the surface of the negative electrode.

[0071] S111: Pull out the elastic sealing plug 800 to allow the gas inside the lithium-ion battery 10 to be released through the first clearance hole.

[0072] In this embodiment, during the formation of the lithium-ion battery 10, some electrolyte is consumed and gas is generated. First, the first clearance hole 102 is turned upward, and then the sealing plug is pulled out to release the gas inside the lithium-ion battery 10, thereby reducing the internal pressure of the lithium-ion battery 10.

[0073] S113: Perform electrolyte replenishment through the first clearance hole 102 to refill the accommodating cavity 101 with electrolyte.

[0074] In this embodiment, electrolyte is injected through the first clearance hole 102 so that the electrolyte can refill the accommodating cavity 101, thereby improving the performance of the lithium-ion battery 10.

[0075] S115: The rivet 500 is sequentially inserted into the first clearance hole 102 and the second clearance hole 401 so that the second enlarged part 530 of the rivet 500 protrudes from one side of the collector plate 400 and the rivet 500 abuts against the outside of the steel shell 100, wherein the rivet 500 is a blind rivet 500.

[0076] In this embodiment, the second enlarged portion 530 of the rivet 500 protrudes from the side of the manifold 400 away from the bottom end of the steel shell 100, and the rivet 500 abuts against the outer side of the steel shell 100, so that the rivet 500 is fixed to the steel shell 100 and the manifold 400.

[0077] S117: Perform a core-pulling operation on the rivet 500 so that the second expansion portion 530 of the rivet 500 expands and abuts against one side of the manifold 400, thereby making the manifold 400 riveted to the steel shell 100.

[0078] In this embodiment, the second expansion portion 530 of the rivet 500 is expanded by the core-pulling riveting operation, so that both ends of the rivet 500 abut against the outside of the collector plate 400 and the steel shell 100 respectively, thereby making the collector plate 400 riveted to the steel shell 100 by the rivet 500, and at the same time, the collector plate 400 is electrically connected to the rivet 500, thereby making the collector plate 400 electrically connected to the outside through the negative terminal 510 of the rivet 500.

[0079] The aforementioned manufacturing method of the lithium-ion battery 10, by removing the elastic sealing plug 800 after formation, releases the gas generated inside the lithium battery, reducing the internal pressure and improving the safety performance of the lithium-ion battery 10. Furthermore, electrolyte is replenished through the first clearance hole 102 after formation, allowing the electrolyte to refill the lithium battery, thus improving the performance of the lithium-ion battery 10. In addition, the first end of the rivet 500 abuts against the current collector 400, electrically connecting the rivet 500 to the current collector 400, and the second end of the rivet 500 abuts against the outer side of the steel shell 100, protruding from the outer side of the steel shell 100 and forming a negative electrode post 510. This allows the negative electrode tab structure 310 to be electrically connected to the outside via the negative electrode post 510, avoiding the need for resistance welding. This prevents problems such as incomplete soldering, tab bending, and welding slag spatter, resulting in lower self-discharge of the cell 300 and improving the performance of the lithium-ion battery 10.

[0080] In one embodiment, when rivets 500 are sequentially inserted into the first clearance hole 102 and the second clearance hole 401, so that the second enlarged portion 530 of the rivet 500 protrudes from one side of the collector plate 400 and abuts against the outside of the steel shell 100, wherein the rivet 500 is a pull rivet 500, a sealing member 600 is covered and connected to the rivet 500, and the sealing member 600 elastically abuts against the hole wall of the first clearance hole 102. That is, the sealing member 600 covers and connects to the portion of the rivet 500 corresponding to the first clearance hole 102, and the sealing member elastically abuts against the hole wall of the first clearance hole 102, so that the rivet 500 is sealed and connected to the hole wall of the first clearance hole 102 through the sealing member 600, thereby preventing the electrolyte in the accommodating cavity 101 from leaking through the gap between the rivet 500 and the steel shell 100, thus improving the performance of the lithium battery.

[0081] Furthermore, in the step of sequentially inserting the rivet 500 into the first clearance hole 102 and the second clearance hole 401, so that the second enlarged portion 530 of the rivet 500 protrudes from one side of the manifold 400 and abuts against the outer side of the steel shell 100, wherein the rivet 500 is a double-drum blind rivet, the first enlarged portion 520 of the rivet 500 is located between the manifold 400 and the steel shell 100, and the sealing member 600 is an insulating structure, and the sealing member 600 also covers and connects to the first enlarged portion 520.

[0082] Furthermore, in the step of performing a core-pulling operation on the rivet 500 so that the second expansion portion 530 of the rivet 500 expands and abuts against one side of the manifold 400, thereby riveting the manifold 400 to the steel shell 100, the first expansion portion 520 of the rivet 500 also expands so that the seal 600 elastically abuts against the manifold 400 and the steel shell 100 respectively. In this embodiment, since the sealing element 600 is an insulating structure, it can block the electrical connection. Furthermore, since the rivet 500 is sealed to the wall of the first clearance hole 102 through the sealing element 600, it is insulated from the wall of the first clearance hole 102. Also, since the first expansion portion 520 abuts against the current collector 400 and the steel shell 100 respectively through the sealing element 600, the current collector 400 is insulated from the first expansion portion 520. Thus, the current collector 400 is insulated from the steel shell 100. In other words, the sealing element 600 blocks the electrical connection between the current collector 400 and the steel shell 100, making the steel shell 100 uncharged and suppressing short circuits caused by the electrical connection between the steel shell 100 and the positive electrode post, thereby improving the safety performance of the lithium-ion battery 10.

[0083] In one embodiment, after the step of replenishing liquid through the first clearance hole 102 and before the step of sequentially inserting the rivet 500 through the first clearance hole 102 and the second clearance hole 401, the manufacturing method of the lithium-ion battery 10 further includes: silver plating the portion of the rivet 500 that contacts the hole wall of the second clearance hole 401 to improve the conductivity of the rivet 500, thereby improving the performance of the lithium-ion battery 10.

[0084] like Figure 4As shown, in one embodiment, the elastic sealing plug 800 includes a conductive plug body 810, a first abutment portion 820, and a second abutment portion 830. The first abutment portion 820 and the second abutment portion 830 are respectively connected to both ends of the conductive plug body 810, and both the first abutment portion 820 and the second abutment portion 830 protrude from the outer side of the conductive plug body 810. The second abutment portion 830 is an elastic structure. Further, the conductive plug body 810 is located in the second clearance hole 401 and sleeved with the current collector 400, so that the current collector 400 is electrically connected to the conductive plug body 810. The conductive plug body 810 is located in the first clearance hole 102 and sleeved with the steel shell 100, so that the conductive plug body 810 is electrically connected to the steel shell 100. Thus, the current collector 400 is electrically connected to the steel shell 100 through the conductive plug body 810, so that the lithium-ion battery 10 is ready for formation. Furthermore, the first abutting portion 820 elastically abuts against the inner wall of the receiving groove 402, and the second abutting portion 830 elastically abuts against the inner surface of the steel shell 100, so that the elastic sealing plug 800 seals the first clearance hole 102, preventing electrolyte leakage through the first clearance hole 102 during formation, thereby improving the performance of the lithium-ion battery 10. It is understood that the conductive plug 810 can be metal or other existing conductive materials. The first abutting portion 820 and the second abutting portion 830 can be silicone structures, rubber structures, or other existing elastic structures.

[0085] Compared with the prior art, the present invention has at least the following advantages:

[0086] In the aforementioned battery pack, the first end of the rivet 500 abuts against the current collector 400, making the rivet 500 electrically connected to the current collector 400. The second end of the rivet 500 abuts against the outer side of the steel shell 100, making the second end of the rivet 500 protrude from the outer side of the steel shell 100 and form a negative electrode post 510. In this way, the negative electrode tab structure 310 is electrically connected to the outside through the negative electrode post 510, avoiding the need to connect the negative electrode tab structure 310 to the outside through resistance welding. This avoids problems such as poor welding, tab bending, and welding slag spatter, resulting in a smaller self-discharge of the cell 300 and improving the performance of the lithium-ion battery 10.

[0087] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A lithium-ion battery, characterized in that, include: A steel shell, wherein the steel shell forms a receiving cavity and a first clearance hole, and the receiving cavity is connected to the first clearance hole; A cap, which is correspondingly provided to the opening of the receiving cavity and fixedly connected to the steel shell; A battery cell, wherein the battery cell is disposed within the accommodating cavity, and a negative electrode tab structure is provided on one side of the battery cell; A current collector, disposed within the accommodating cavity, the current collector being electrically connected to the negative electrode tab structure, and the current collector having a second clearance hole; and The rivet is sequentially inserted into the first clearance hole and the second clearance hole. The first end of the rivet abuts against the collector plate, and the second end of the rivet abuts against the outside of the steel shell and forms a negative electrode post, so that the collector plate is riveted to the steel shell by the rivet. The lithium-ion battery further includes a sealing element, which covers and is connected to the rivet. The sealing element elastically abuts against the wall of the first clearance hole, so that the rivet is sealed to the wall of the first clearance hole through the sealing element. The rivet has a first enlarged portion and a second enlarged portion, which are spaced apart. The first enlarged portion is located between the bottom end of the manifold and the steel shell. The sealing element is an insulating structure and also covers and connects to the first enlarged portion. The first enlarged portion abuts against the manifold and the steel shell through the sealing element. The second enlarged portion protrudes from the side of the manifold away from the first enlarged portion and abuts against the manifold. The lithium-ion battery further includes an insulating sheet, the outer diameter of which is adapted to the inner diameter of the accommodating cavity. The insulating sheet is disposed within the accommodating cavity, and the opposite sides of the insulating sheet abut against the bottom end of the steel shell and the current collector, respectively. The insulating sheet has a third clearance hole, which is respectively provided with the first clearance hole and the second clearance hole. The rivet is sequentially inserted through the first clearance hole, the third clearance hole, and the second clearance hole. The first enlarged portion is provided with the third clearance hole. The size of the third clearance hole is larger than the size of the portion of the seal corresponding to the first expansion portion, so that there is a gap between the insulating sheet and the seal; The lithium-ion battery further includes a flexible insulating filler, which is located within the third clearance hole and connected to the insulating sheet. The flexible insulating filler is also connected to the sealing element, so that the flexible insulating filler is disposed in the gap between the insulating sheet and the sealing element. The flexible insulating filler has a plurality of spaced deformation holes, each of which penetrates the flexible insulating filler, so that each deformation hole is a through hole.

2. The lithium-ion battery according to claim 1, characterized in that, The collector plate has a receiving groove on the side opposite to the first clearance hole, and the receiving groove is connected to the receiving cavity and the second clearance hole; the first end of the rivet abuts against the groove wall of the receiving groove.

3. The lithium-ion battery according to claim 1, characterized in that, The seal is made of silicone.

4. The lithium-ion battery according to claim 1, characterized in that, The cap is welded to the steel shell; and / or The negative electrode ear structure is a full electrode ear structure.

5. The lithium-ion battery according to claim 1, characterized in that, The cap has a positive electrode through hole.

6. The lithium-ion battery according to claim 1, characterized in that, The steel shell has a cylindrical structure.

7. The lithium-ion battery according to claim 1, characterized in that, The opening of the accommodating cavity is circular, and the cap is circular, so that the cap fits the opening of the accommodating cavity.

8. A battery pack, characterized in that, The invention includes a plurality of lithium-ion batteries as described in any one of claims 1 to 7, wherein the plurality of lithium-ion batteries are electrically connected in sequence.

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