Secondary blade battery

Abstract

The utility model provides a secondary blade battery, which is characterized in that a pin is provided with a pole connector and a tab connector, and the pole connector is connected with the tab connector in a bending manner; the naked battery cell is of a rectangular structure, a positive electrode lug and a negative electrode lug are connected to the naked battery cell, and the positive electrode lug and the negative electrode lug are located on the side wall of the same side of the naked battery cell; a notch is formed in the middle of the soft connecting piece, and the pole assembly and the pole connector are connected with the soft connecting piece in a welded mode; the pin is 7-shaped and is divided into two parts by bending, the first part is used for being welded with a naked battery cell tab and used for collecting current and leading out, the second part is connected with the top cover assembly through the soft connecting piece, the pole columns are located on the two sides of the battery cell, the inner naked battery cell tab is located on the same side edge, the distance between the positive tab and the negative tab is reduced, and the reliability of the battery cell is improved. On the premise that the appearance of a conventional blade cell is not changed, the effect of reducing the internal resistance of the cell is achieved.

Description

Technical Field

[0001] The utility model relates to the field of lithium ion batteries, in particular to a secondary blade battery. Background Art

[0002] With the development of new energy, the requirements for energy density of existing batteries are further improved. New energy power batteries are usually secondary batteries, which means that after the battery is discharged, the active material can be activated by charging and the battery can continue to be used.

[0003] At present, blade batteries have been widely used in the fields of hybrid vehicles and electric vehicles. They have the advantages of high energy density and high safety. In the existing blade battery structure, the positive and negative electrodes are generally welded on both sides with ears on both sides. However, this method has a large distance between the positive and negative ears. The ions on the positive and negative electrodes need to pass through the entire length of the electrode to be conductive, resulting in a higher internal resistance of the battery cell, affecting the performance characteristics of the battery cell.

[0004] To this end, we propose a secondary blade battery to solve the problem of high internal resistance of the battery. Utility Model Content

[0005] The purpose of the utility model is to solve the shortcomings of the prior art. In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0006] A secondary blade battery comprises: a pin, wherein the pin is provided with a pole connector and a pole ear connector, and the pole connector is bent and connected to the pole ear connector; a top cover assembly, wherein the top cover assembly comprises a top cover sheet, a lower plastic assembled on the bottom of the top cover sheet, and a pole assembly penetrating the top cover sheet and the lower plastic; a bare cell, wherein the bare cell is a rectangular structure, and a positive pole ear and a negative pole ear are connected to the bare cell, and the positive pole ear and the negative pole ear are located on the same side wall of the bare cell; a soft connector, wherein a notch is opened in the middle of the soft connector, and the pole assembly and the pole connector are respectively welded and connected to the soft connector.

[0007] Further preferably, the positive electrode tab and the negative electrode tab are respectively connected to the tab connector by welding.

[0008] Further preferably, a weld mark is provided on the flexible connector by ultrasonic pre-welding; when the battery cell is short-circuited, the notch position can be melted in time to cause the battery cell to be short-circuited, thereby avoiding safety risks such as fire and explosion after the battery cell is short-circuited.

[0009] Further preferably, it also includes: an aluminum shell, which is a round-shaped structure with openings on both sides; a bare battery cell, which is accommodated in the aluminum shell; and a top cover assembly, which is assembled on the openings of the aluminum shell.

[0010] It is further preferred that the opening of the aluminum shell is located at a short side of the aluminum shell.

[0011] Compared with the prior art, the beneficial effects of the utility model are:

[0012] The pin of the utility model is in the shape of "7", which is divided into two parts by bending. The first part is used for welding with the bare cell pole ear for current collection and extraction, and the second part is connected to the top cover assembly through a soft connector. The poles are located on both sides of the cell, and the internal bare cell pole ears are located on the same side, which reduces the distance between the positive and negative pole ears, and realizes the effect of reducing the internal resistance of the cell without changing the appearance of the conventional blade cell.

[0013] The soft connector of the utility model has a high degree of bending freedom and does not require the use of bending equipment. It can be naturally bent and transitioned as the top cover enters the shell. In addition, different numbers of soft connections can be selected according to the cell capacity and overcurrent requirements to achieve precise cost control. When the cell is short-circuited, the notch position can be melted in time to cause the cell to be short-circuited, thereby avoiding safety risks such as fire and explosion after the cell is short-circuited. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a structural schematic diagram of the utility model when the pin is connected to the flexible connector;

[0015] Figure 2 It is a structural schematic diagram of the soft connector of the utility model;

[0016] Figure 3 It is a structural schematic diagram of the top cover assembly of the utility model;

[0017] Figure 4 It is a schematic structural diagram of a bare battery cell of the utility model;

[0018] Figure 5 It is a schematic diagram of the assembly structure of the utility model.

[0019] In the figure: pin 1, flexible connector 2, weld mark 21, notch 22, top cover assembly 3, bare battery cell 4, positive electrode ear 41, negative electrode ear 42, aluminum shell 5. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments.

[0021] Reference Figure 1-Figure 5 , a secondary blade battery, comprising:

[0022] Pin 1, wherein the pin 1 is provided with a pole connector and a tab connector, and the pole connector is bent and connected with the tab connector;

[0023] A top cover assembly 3, the top cover assembly 3 comprising a top cover sheet, a lower plastic assembled on the bottom of the top cover sheet, and a pole assembly penetrating the top cover sheet and the lower plastic;

[0024] A bare battery cell 4, wherein the bare battery cell 4 is a rectangular structure, and a positive electrode ear 41 and a negative electrode ear 42 are connected to the bare battery cell 4, and the positive electrode ear 41 and the negative electrode ear 42 are located on the same side wall of the bare battery cell 4;

[0025] A flexible connecting piece 2 is provided with a notch 22 in the middle of the flexible connecting piece 2, and the pole assembly and the pole connector are respectively connected to the flexible connecting piece 2 by welding.

[0026] In the embodiment: the soft connector has a high degree of freedom in bending, and no bending equipment is required. It can be naturally bent and transitioned as the top cover enters the shell. In addition, different numbers of soft connector layers can be selected according to the cell capacity and overcurrent requirements to achieve precise cost control. When the cell is short-circuited, the notch position can be melted in time to cause the cell to be short-circuited, thereby avoiding safety risks such as fire and explosion after the cell is short-circuited.

[0027] In the embodiment: pin 1 is divided into a positive pin and a negative pin, the positive pin and the negative pin are in a "7" shape, and are divided into two parts by bending. The first part is used for welding with the bare battery cell tab for current collection and lead-out, and the second part is welded with the soft connector 2. After completion, pin 1 is fixed to the bare battery cell 4 by gluing.

[0028] The positive electrode tab 41 and the negative electrode tab 42 are respectively connected to the tab connector by welding for current collection and extraction.

[0029] The flexible connecting piece 2 is provided with a welding mark 21 by ultrasonic pre-welding.

[0030] In the embodiment: the flexible connecting piece 2 needs to be ultrasonically pre-welded to form a weld mark 21, and then laser welded to the top cover pole is performed on this basis, and the laser weld mark needs to fall within the pre-weld weld mark 21 to improve the welding strength.

[0031] A secondary blade battery also includes: an aluminum shell 5, which is a round-shaped structure with openings on both sides; a bare battery cell 4, which is accommodated in the aluminum shell 5; and a top cover assembly 3, which is assembled on the opening of the aluminum shell 5.

[0032] The opening of the aluminum shell 5 is located at the short side of the aluminum shell 5 .

[0033] In the embodiment: the bare battery cell is placed into the shell with the positive electrode in the front direction; after the shell is placed, the negative electrode top cover assembly 3 is welded first, and then the soft connector 2 and the positive electrode top cover assembly 3 are welded and fixed. Before welding, the soft connector 2 needs to be ultrasonically pre-welded to form a weld mark, and then laser welded to the top cover pole is performed on this basis, and the laser weld mark needs to fall within the pre-weld weld mark; finally, the positive electrode top cover is welded and fixed to the aluminum shell.

[0034] In the embodiment: In the first step of the utility model, the soft connector 2 is ultrasonically pre-welded to form a weld mark, and this weld mark is mainly used to gather the soft connector 2 to facilitate subsequent laser welding; in the second step, the soft connector 2 is welded and fixed to the positive electrode pin. This welding can be completed by ultrasonic welding alone, or the soft connector 2 is ultrasonically pre-welded to form a weld mark, and then laser welding is performed in this weld mark; relative to hard connection, the soft connector 2 has a higher degree of freedom in bending, and no bending equipment is required. It can be naturally bent and transitioned as the top cover enters the shell, and different layers of soft connections can be selected according to the cell capacity and overcurrent requirements to achieve precise cost control. When the cell is short-circuited, the notch 22 position can be melted in time to cause the cell to be short-circuited, thereby avoiding safety risks such as fire and explosion after the cell is short-circuited; in the third step, the positive ear 41 and the negative ear 42 of the bare cell 4 are welded and fixed to the negative electrode pin and the positive electrode pin respectively. This welding is similar to the first step. The second step is similar, and there are also two ways; the fourth step is to flip the negative pin and the positive pin 90°, and the pin is close to the bare battery cell 4, and then use adhesive tape to stick and fix it to prevent the pin from shaking. First, it prevents the pin from shaking and contacting the aluminum shell during the shell insertion process, generating metal chips and causing micro-short circuits inside the battery cell. Second, it prevents the pin from shaking and pulling the battery cell tabs, causing the tabs to break and affecting the battery cell capacity; the fifth step is to wrap the bare battery cell 4 with an insulating sheet, and put side support plates at both ends to facilitate shell insertion and protect the bare battery cell 4 from friction with the aluminum shell 5 during the shell insertion process. Will not wear; the sixth step, after completing the shell insertion, the negative top cover assembly 3 is first welded and packaged with the aluminum shell 5, and then the soft connector 2 is laser welded and fixed to the positive electrode column, and the laser weld mark must fall on the weld mark, which can avoid adverse phenomena such as welding explosion points; finally, the positive top cover assembly 3 and the aluminum shell 5 are welded and packaged on the other side.

[0035] In terms of appearance, the poles are located on both sides of the battery cell, and the internal bare battery cell ears are located on the same side, reducing the distance between the positive and negative ears, thereby reducing the internal resistance of the battery cell without changing the appearance of the conventional blade battery cell.

Claims

1. A secondary blade battery, characterized in that: include: A pin, wherein the pin is provided with a pole connector and a tab connector, and the pole connector is bent and connected with the tab connector; A top cover assembly, the top cover assembly comprising a top cover sheet, a lower plastic assembled on the bottom of the top cover sheet, and a pole assembly penetrating the top cover sheet and the lower plastic; A bare cell, wherein the bare cell is a rectangular structure, and is connected to a positive electrode ear and a negative electrode ear, and the positive electrode ear and the negative electrode ear are located on the same side wall of the bare cell; A flexible connecting piece is provided with a notch in the middle of the flexible connecting piece, and the pole assembly and the pole connector are respectively connected to the flexible connecting piece by welding.

2. A secondary blade battery according to claim 1, characterized in that: The positive electrode tab and the negative electrode tab are respectively connected to the tab connector by welding.

3. A secondary blade battery according to claim 1, characterized in that: The flexible connecting piece is provided with welding marks by ultrasonic pre-welding.

4. A secondary blade battery according to any one of claims 1 to 3, characterized in that: Also includes: The aluminum shell is a circular structure with openings on both sides; A bare battery cell, contained in the aluminum shell; A top cover assembly is assembled on the opening of the aluminum shell.

5. A secondary blade battery according to claim 4, characterized in that: The opening of the aluminum shell is located at a short side of the aluminum shell.

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