Cell extraction tab, battery, and electric vehicle

Abstract

The cell pull-out tab (10), battery, and electric vehicle include a heat-conducting member (13), a main body (11) electrically connected to positive and negative electrode posts (40) of the battery, and two extending branches (12) bent and extending from one end of the main body (11) and electrically connected to tabs (21) of an electrode body (20) in the battery, respectively. The two extending branches (12) are spaced apart to form an attachment gap (14), and the heat-conducting member (13) is located on the side of the two extending branches (12) away from the electrode body (20) and at least partially covers the attachment gap (14).

Description

Technical Field

[0001] (Cross - reference to related applications) This application claims the priority of a patent application with an application date of June 28, 2020, an application number of 202021216701.6, and a title of "Cell Lead - out Tab, Battery, and Electric Vehicle", and all of its contents are incorporated herein by reference.

[0002] This application relates to the field of electric vehicles, and particularly to cell lead - out tabs, batteries, and electric vehicles.

Background Art

[0003] Currently, high - power batteries such as HEV (Hybrid Electric Vehicle) or mHEV (Mild Hybrid Electric Vehicle) use a full - tab design. Since HEV / mHEV batteries have high requirements for power performance and always need to meet the requirement of charging and discharging at a high rate, the heat generation of the battery becomes large, which may cause the following problems: (1) Due to the large amount of heat generation, the deterioration of the battery is accelerated, and the cycle / storage life is shortened; (2) Heat accumulates and it is difficult to dissipate heat, causing safety risks; (3) The thermal conductivity of the battery itself is low, external liquid cooling is required, resulting in high energy consumption and high carbon emissions. How to improve the heat dissipation performance of the battery has become the main direction of current battery design.

Summary of the Invention

[0004] This application provides a cell lead - out tab with excellent heat dissipation performance, and improves its heat dissipation performance by installing a heat - conducting member in the mounting gap between two extending branches of the cell lead - out tab.

[0005] The cell extraction tab according to one aspect of the present application includes a heat conduction member, a main body electrically connected to the positive and negative electrode posts of the battery, and two extending branches bent and extending from one end of the main body and electrically connected to the tabs of the electrode body of the battery respectively. The two extending branches are installed at intervals to form an installation gap. The heat conduction member is installed on the side of the two extending branches away from the electrode body and at least partially covers the installation gap. The electrode body is formed by winding a positive electrode sheet, a separator, and a negative electrode sheet. Tabs for current conduction drawn from the positive and negative electrode sheets are provided on both sides of the wound electrode body. In order to improve the output power of the electrode body and reduce the internal resistance, generally, a plurality of tabs are integrally crimped to form a full tab design. The cell extraction tab electrically connects the crimped tabs to the positive and negative electrode posts outside the housing. The electrical connection method between the cell extraction tab and the tab is to weld them to both sides of the tab by the two extending branches. Due to the requirements of battery assembly, it is necessary to form an installation gap by installing the two extending branches at intervals, and this installation gap is used for battery assembly. In the present application, a heat conduction member is installed on the side of the installation gap away from the electrode body. The heat conduction member substantially increases the heat dissipation area of the cell extraction tab and improves the heat dissipation effect of the cell extraction tab. Specifically, the heat conduction member may be a single heat dissipation sheet, a single heat dissipation mesh, or other heat dissipable structures, and is not specifically limited here. Installing the heat conduction member in the installation gap is a reasonable utilization of the space structure, which increases the heat dissipation area of the cell extraction tab and improves the heat dissipation effect without affecting the operation of the electrode body.

[0006] In one embodiment, the heat conduction member completely covers the installation gap. In the embodiment, by completely covering the installation gap, the heat dissipation area is maximally increased and the heat dissipation effect is maximally improved.

[0007] In one embodiment, both ends of the heat conduction member are respectively connected to two of the extending branches. Both ends of the heat conduction member are respectively adhered to two of the extending branches. Specific adhesion methods vary. An adhesive may be applied to both ends of the heat conduction member, and then both ends may be adhered to the extending branches. Alternatively, both ends of the heat conduction member may be respectively placed on the extending branches, and then a tape may be wrapped around to fix the heat conduction member in the mounting gap.

[0008] In one embodiment, one end of the heat conduction member is connected to one side surface of the tab. In this embodiment, in order to more firmly attach the heat conduction member, one end of the heat conduction member can be connected to one side surface of the tab by welding. The other end of the heat conduction member is bent to cover the mounting gap.

[0009] In one embodiment, the extending direction of the main body portion is the first direction, the extending directions of the two extending branches are the second direction, and in the third direction, the two extending branches are arranged opposite to each other with a gap therebetween. The first direction, the second direction, and the third direction are perpendicular to each other. The two extending branches arranged with a gap in the third direction form a mounting gap, and the cell extraction tab can be adapted according to the structural design of the electrode body.

[0010] In one embodiment, the surface of one of the extending branches is bonded to one side surface of the tab, and the surface of the other extending branch is bonded to the other side surface of the tab. The surfaces of the two extending branches are respectively bonded to both side surfaces of the tab. Such a board surface bonding design increases the power of current transmission and, on the other hand, also increases the heat dissipation capacity of the extending branches.

[0011] In one embodiment, the cell extraction tab is located at an end of the extending branch away from the main body portion and further includes a connecting portion connecting the two extending branches. The design of the connecting portion connects the two extending branches and ensures its stability.

[0012] In one embodiment, the plate surface is connected to the tab by welding. The welding method here may be ultrasonic welding or laser welding, thereby ensuring the flatness and stability of the structure.

[0013] In one embodiment, the extending branch is connected to the tab by ultrasonic welding or laser welding.

[0014] In one embodiment, the heat conduction member is made of a metal material.

[0015] In one embodiment, a side spacer made of an insulating material for separating the heat conduction member from the housing of the battery is installed on the tab.

[0016] In one embodiment, the heat conduction member is made of a heat conduction silicone material.

[0017] In one embodiment, the heat conduction member is made of a composite ceramic material.

[0018] In one embodiment, the composite ceramic material includes a mixture of plastic and a high heat conductivity material.

[0019] In one embodiment, the heat conduction member is made of a carbon-based material.

[0020] In one embodiment, the carbon-based material includes a heat dissipation layer and a heat conduction insulating layer.

[0021] The battery according to the second aspect of the present application includes a housing, an electrode body, and the cell lead tab. The cell lead tab and the electrode body are electrically connected to form an electrode body assembly, and the electrode body assembly is housed in the housing. In an embodiment, the cell lead tab is electrically connected to the tab of the electrode body, and both are housed inside the housing. Specifically, the housing includes a lower housing having an accommodation space and a cover plate. The cell lead tab is disposed in the accommodation space, and a positive electrode terminal and a negative electrode terminal are installed on the cover plate. The tab is connected to the positive and negative electrode terminals via the cell lead tab.

[0022] The electric vehicle according to the third aspect of the present application includes the above battery. The cell lead tab of the battery according to the above embodiment has an excellent heat dissipation effect, can effectively solve the heat dissipation problem when the electrode body operates, and can avoid the abnormal use of the electric vehicle due to overheating of the electrode body in the battery.

[0023] By installing a heat conduction member in the mounting gap between the two extending branches of the cell lead tab according to the embodiment of the present application, the heat dissipation area of the cell lead tab can be increased and its heat dissipation performance can be improved without affecting the operation of the cell lead tab.

Brief Description of the Drawings

[0024]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Mode for Carrying Out the Invention

[0025] Hereinafter, specific embodiments of the present application will be described in detail with reference to the drawings.

[0026] The present application provides a cell extraction tab 10, and the cell extraction tab 10 can be widely applied to the assembly of batteries. To explain the characteristics of the cell extraction tab 10 in the solution means in more detail, refer to FIGS. 1 to 5 together.

[0027] As shown in FIGS. 1 and 2, it is a schematic configuration diagram showing the attachment of the cell lead tab 10 and the electrode body 20. FIG. 1 is a schematic configuration diagram when the cell lead tab 10 hides the heat conduction member 13. The cell lead tab 10 includes a main body portion 11 externally connected to the positive and negative electrode posts 40, and two extending branches 12 drawn from the main body portion 11. The two extending branches 12 are each electrically connected to the electrode body 20. As shown in FIG. 3, the two extending branches 12 are installed at intervals to form an attachment gap 14. The attachment gap 14 here is a preset space for welding the cell lead tab 10 and the tab 21 later, facilitating the arrangement of the welding tool. A heat conduction member 13 is installed on the side of the electrode body 20 away from the attachment gap 14. The electrode body 20 in the embodiment is generally formed by winding a positive electrode sheet, a separator, and a negative electrode sheet. On both sides of the wound electrode body 20, there are tabs 21 for current conduction drawn from the positive and negative electrode sheets. In order to improve the output power of the electrode body 20 and reduce the internal resistance, generally, a plurality of tabs 21 are integrally crimped to form a full tab design. The cell lead tab 10 electrically connects the crimped tabs 21 to the external positive and negative electrode posts 40. The electrical connection method between the cell lead tab 10 and the tab 21 is to weld them to both sides of the tab 21 by the two extending branches 12. As shown in FIG. 3, due to the requirements of battery installation, it is necessary to install the two extending branches 12 at intervals to form an attachment gap 14. As shown in FIG. 2, in the design of this embodiment, a heat conduction member 13 is installed on the side of the electrode body 20 away from the attachment gap 14. The heat conduction member 13 at least partially covers the attachment gap 14, substantially increasing the heat dissipation area of the cell lead tab 10 and improving the heat dissipation effect of the cell lead tab 10. Note that the heat conduction member 13 may be a single heat dissipation sheet, a single heat dissipation mesh, or other heat dissipable structures, and is not specifically limited here. Installing the Thermal conduction member 13 in the attachment gap is a reasonable utilization of the space structure, increasing the heat dissipation area of the cell lead tab 10 and improving the heat dissipation effect without affecting the operation of the electrode body 20.

[0028] Specifically, as shown in FIGS. 1 and 3, the extending direction of the main body portion 11 is the first direction X, the extending directions of the two extending branches 12 are the second direction Y, and in the third direction Z, the two extending branches 12 are installed opposite to each other with a gap therebetween, and the first direction X, the second direction Y, and the third direction Z are perpendicular to each other.

[0029] In one specific embodiment, as shown in FIGS. 2, 3, and 4, the heat conduction member 13 completely covers the mounting gap 14. In the embodiment, the heat conduction member 13 completely covers the mounting gap 14 between the extending branches 12, thereby increasing the heat dissipation area of the entire cell extraction tab 10 and maximizing the heat dissipation effect. In the technical solution of the present application, the mounting gap 14 between the two extending branches 12 can be reasonably utilized to increase the heat dissipation area of the cell extraction tab 10. Therefore, in this embodiment, the heat conduction member 13 completely covers the mounting gap 14 to improve the heat dissipation effect as much as possible.

[0030] In one specific embodiment, as shown in FIGS. 2, 3, and 4, the direction in which the two extending branches 12 face each other is the third direction Z, and both ends of the heat conduction member 13 in the third direction Z are respectively connected to the two extending branches 12. Specifically, both ends of the heat conduction member 13 in the third direction Z are respectively adhered to the two extending branches 12, and the adhesion method here is various. Adhesive can be applied to both ends of the heat conduction member 13, and then both ends can be adhered to the extending branches 12 to completely cover the mounting gap 14. Both ends of the heat conduction member 13 can be respectively hung on the extending branches 12, and then a tape can be wound around to fix the heat conduction member 13 to the extending branches 12 to completely cover the mounting gap 14.

[0031] In one specific embodiment, as shown in FIGS. 3, 4, and 5, the direction in which the two extending branches 12 face each other is the third direction Z. One end of the heat conduction member 13 in the third direction Z is connected to one side of the tab 21. Specifically, in order to more firmly attach the heat conduction member 13, in this embodiment, one end of the heat conduction member 13 can be connected to one side surface of the tab 21 by welding, and the other end of the heat conduction member 13 can be bent to cover the mounting gap 14. In another specific embodiment, both ends of the heat conduction member 13 can be fixedly connected to both ends of the tab 21 by a tape. In addition, no matter in what way the heat conduction member 13 and the tab 21 are connected, the heat conduction member 13 needs to completely cover the mounting gap 14.

[0032] In one specific embodiment, as shown in FIG. 6, the surface of one extending branch 12 is bonded to one side surface of the tab 21, and the surface of the other extending branch 12 is bonded to the other side surface of the tab 21. Such a bonding design increases the power of current transmission and, on the other hand, also increases the heat dissipation capacity of the extending branch 12.

[0033] In one specific embodiment, as shown in FIGS. 3 and 6, a connecting portion 16 for connecting the two extending branches 12 is installed at an end of the extending branch 12 away from the main body portion 11. The design of the connecting portion 16 connects the two extending branches 12 and ensures the structural stability thereof.

[0034] In one specific embodiment, as shown in FIG. 6, the plate surface of the extending branch 12 is connected to the tab 21 by welding. The welding method here may be ultrasonic welding or laser welding, thereby ensuring the flatness and stability of the structure.

[0035] It should be noted that in this application, the heat conduction member is made of a material having excellent heat conduction performance.

[0036] Specifically, the heat conduction member is made of a metallic material, and the metallic material here may be, for example, one or more of aluminum, brass, tough pitch copper, steel, and iron. After selecting the heat conduction member made of the metallic material, side spacers can be added to the tabs. Generally, the side spacers are fitted to the side tab ends. Since the side spacers are made of an insulating plastic material such as PP or PE, it is possible to prevent the heat conduction member made of the metallic material from coming into contact with the battery housing, and avoid problems such as electric leakage and short circuit.

[0037] Specifically, the heat conduction member is made of a heat conductive silicone material. The heat conductive silicone material is an insulating heat conductive material and may be, for example, one or more of aluminum oxide, silicon oxide, magnesium oxide, zinc oxide, aluminum nitride, Boron nitride, silicon carbide and the like. Since the heat conduction member using the heat conductive silicone material has excellent insulation performance, it is possible to avoid accidents such as short circuit or electric leakage caused by the installation of the heat conduction member.

[0038] Specifically, the heat conduction member is made of a composite ceramic material. The composite ceramic here is mainly a mixture of plastic and a high heat conductivity material. The plastic may be one or more of PP (polypropylene) and PE (polyethylene), and the high heat conductivity material may be one or more of aluminum oxide, silicon oxide, magnesium oxide, zinc oxide, aluminum nitride, Boron nitride, silicon carbide and the like. The heat conduction member using the composite ceramic material not only satisfies the heat dissipation requirement but also has no risk of short circuit and electric leakage.

[0039] In one specific embodiment, the heat conduction member is made of a carbon-based material. The carbon-based material here includes a heat dissipation layer and a heat conduction insulating layer. The heat dissipation layer may be one or more of carbon-based materials such as graphene, carbon black, carbon nanotubes, and graphite, and the heat conduction insulating layer may be one or more of heat conductive silicone or composite ceramic.

[0040] As shown in FIG. 7, the battery 100 according to the second aspect of the present application includes a housing 30, an electrode body 20, and a cell lead tab 10. The cell lead tab 10 and the electrode body 20 are electrically connected and housed in the housing 30. In an embodiment, the cell lead tab is electrically connected to the tab of the electrode body, and both are housed inside the housing. Specifically, the housing includes a lower housing having an accommodation space and a cover plate. The cell lead tab is disposed in the accommodation space, positive and negative electrode posts are installed on the cover plate, and the tab is connected to the positive and negative electrode posts via the cell lead tab. The battery according to the embodiment has an excellent heat dissipation effect due to the design of the heat conduction member at the cell lead tab, and avoids the danger caused by the too high temperature of the electrode body during operation.

[0041] After using the cell lead tab including the heat conduction member in the battery according to this embodiment, the contact thermal resistance on the side surface of the electrode body can be greatly reduced, which will be described by comparing with a set of actual measurement data here.

[0042] The experimental steps include: (1) selecting a cell lead tab with a heat conduction member and assembling the battery; (2) adding at least three thermocouples to each surface of the outer surface of the housing to ensure the accuracy of temperature acquisition, and obtaining experimental data under the test conditions of continuously charging and discharging at 25 °C, 50% SOC battery, 6C / 10S, and stopping when the temperature of each thermocouple reaches equilibrium (the equilibrium condition is that the temperature change is 0.5 °C / 10 min); (3) removing the heat conduction member from the initial cell, testing according to the above method, and re-obtaining the experimental data; (4) calculating the contact thermal resistance in each direction of the cell by simulation based on the measured data.

[0043] The data in Table 1 below is obtained.

Table 1

[0044] As can be seen from Table 1, after adding the heat conduction member, the contact thermal resistance data on the side surface of the electrode body decreased from 0.002915 K*m 2 / W to 0.0015 K*m 2 / W, indicating that the cell lead tab with the heat conduction member according to the present application has an excellent heat dissipation effect on the electrode body.

[0045] As shown in FIG. 8, the electric vehicle 1000 according to the third aspect of the present application includes the above battery 100. The cell lead tab of the battery according to the above embodiment has an excellent heat dissipation effect, improves the heat dissipation performance of the electrode body, and avoids safety risks caused by the excessively high temperature of the electrode body. Also, when the heat dissipation performance of the electrode body itself is low, it is necessary to perform liquid cooling and temperature reduction by an external device, which substantially increases the energy consumption of the electric vehicle and causes the problem of high carbon emissions. Therefore, the present application can reduce the overall thermal resistance and reduce the energy consumption of the entire vehicle.

[0046] The above content is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A cell extraction tab including a heat conduction member, a main body portion electrically connected to the positive and negative electrode posts of a battery, two extending branches bent and extending from one end of the main body portion, and a connecting portion located at an end of the extending branches away from the main body portion and connecting the two extending branches, wherein the two extending branches are each electrically connected to a tab of an electrode body in the battery, the two extending branches are installed at intervals to form a mounting gap, the heat conduction member is made of a heat conduction silicone material or a composite ceramic material, the heat conduction member is installed on a side of the two extending branches away from the electrode body, and at least partially covers the mounting gap. A cell extraction tab characterized by this.

2. The heat conduction member completely covers the mounting gap. The cell extraction tab according to claim 1, characterized by this.

3. Both ends of the heat conduction member are each connected to the two extending branches. The cell extraction tab according to claim 2, characterized by this.

4. One end of the heat conduction member is connected to one side surface of the tab, and the other end of the heat conduction member is bent to cover the mounting gap. The cell extraction tab according to claim 2, characterized by this.

5. The extending direction of the main body portion is a first direction, the extending directions of the two extending branches are a second direction, and in a third direction, the two extending branches are installed opposite to each other at intervals, and the first direction, the second direction, and the third direction are perpendicular to each other. The cell extraction tab according to claim 3, characterized by this.

6. The surface of one of the extending branches is bonded to one side surface of the tab, and the surface of the other extending branch is bonded to the other side surface of the tab. The cell extraction tab according to claim 5, characterized by this.

7. The extended branch is connected to the tab by welding, and the cell extraction tab according to claim 6 is characterized by this.

8. A battery comprising a housing, an electrode body, and the cell extraction tab according to any one of claims 1 to 7, wherein the electrode body and the cell extraction tab are housed in the housing.

9. An electric vehicle characterized by including the battery according to claim 8.

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