Tab, battery cell and battery

Abstract

The utility model discloses a tab, battery cell and battery, the tab comprises a tab body, at least one of two opposite sides of the tab body in the width direction is connected with a heat conducting sheet, and the heat conducting sheet is used for absorbing heat from the tab body and dissipating the heat. According to the tab provided by the utility model, at least one of the two opposite side edges in the width direction of the tab body is connected with the heat-conducting fin, and when the battery is rapidly charged and discharged, the tab and the part for welding the tab absorb heat from the tab through the heat-conducting fin and dissipate the heat, so that the heat dissipation performance of the tab is improved; and the stability of the performance of the battery cell is ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of lithium batteries, in particular to a tab, a battery core and a battery. Background Art

[0002] Lithium-ion batteries, as a widely used secondary battery, have the advantages of fast charging, high specific energy, no memory effect and long service life.

[0003] However, when lithium-ion batteries are rapidly charged and discharged, the tabs in the lithium-ion batteries will continuously conduct current, causing the tabs and the welded tabs to heat up rapidly, and the current conduction capacity will be weakened, thereby affecting the stability of the battery cell performance. Utility Model Content

[0004] The main purpose of the utility model is to provide a tab, which aims to solve the problem that when the battery is rapidly charged and discharged, the tab and the welding part of the tab quickly heat up, thereby weakening the current conductivity of the tab and affecting the stability of the battery core performance.

[0005] To achieve the above-mentioned purpose, the present invention provides a tab, which includes:

[0006] The tab body has at least one side of two opposite sides in the width direction of the tab body connected to a heat conducting sheet, and the heat conducting sheet is used to absorb heat from the tab body and dissipate the heat.

[0007] In some embodiments, one of the tab body and the thermal conductive sheet is provided with a groove, and the other is provided with a protrusion adapted to the groove, and the thermal conductive sheet is embedded in the groove through the protrusion to achieve connection with the tab body.

[0008] In some embodiments, the thickness of the thermal conductive sheet is less than or equal to the thickness of the tab body.

[0009] In some embodiments, two opposite sides of the tab body in the width direction are connected to heat conducting plates.

[0010] In some embodiments, the tab body has a first non-glue section, a glue section, and a second non-glue section divided along its length, and the glue section is used for attaching tab glue.

[0011] In some embodiments, the thermal conductive sheet is located at at least one of the first non-adhesive section and the second non-adhesive section.

[0012] In some embodiments, the thermally conductive sheet is an insulating thermally conductive sheet.

[0013] In some embodiments, the thermally conductive sheet is a thermally conductive silicone grease sheet or a thermally conductive silicone rubber sheet; and / or,

[0014] The thermal conductivity of the thermally conductive sheet is greater than 3W / (m*k).

[0015] The present invention also provides a battery cell, which comprises a positive electrode sheet, a separator and a negative electrode sheet stacked and wound together, wherein the separator is arranged between the positive electrode sheet and the negative electrode sheet;

[0016] The positive electrode sheet is connected to a positive electrode tab, the negative electrode sheet is connected to a positive electrode tab, and at least one of the positive electrode tab and the negative electrode tab includes the tab as described above.

[0017] The utility model also provides a battery, which includes a shell and the aforementioned battery core, wherein the battery core is arranged in the shell.

[0018] The tab provided by the utility model has a heat conducting sheet connected to at least one of the two opposite sides in the width direction of the tab body. When the battery is rapidly charged and discharged, the tab and the portion where the tab is welded absorb heat from the tab through the heat conducting sheet and dissipate the heat, thereby improving the heat dissipation performance of the tab and ensuring the stability of the battery core performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic structural diagram of a tab in one embodiment of the present invention;

[0020] Figure 2 Schematic diagram of the structure of the tab in another embodiment of the present invention.

[0021] Description of Figure Numbers:

[0022] Label name Label name 110 Ji Er body 111 The first non-glue section 112 Glue section 113 The second non-glue section 120 thermal conductive sheet 130 Ear glue 121 convex part 114 groove

[0023] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the schemes in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0025] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0026] It should also be noted that when an element is referred to as being "fixed on" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or there may be an intermediate element.

[0027] In addition, the descriptions of "first," "second," etc. in this utility model are for descriptive purposes only and should not be understood as indicating or implying their relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions between the various embodiments can be combined with each other, but this must be based on the fact that they can be implemented by ordinary technicians in this field. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by this utility model.

[0028] The present invention provides a tab, referring to Figure 1 , the tabs include:

[0029] The tab body 110 has at least one side of two opposite sides in the width direction of the tab body 110 connected thereto with a heat conducting sheet 120 . The heat conducting sheet 120 is used to absorb heat from the tab body 110 and dissipate the heat.

[0030] The tab body 110 is a component in the battery used to collect current and will be welded to the current collector. Before welding the tab body 110 to the current collector, a heat conducting sheet 120 is connected to the side of the tab body 110 to dissipate heat from the tab body 110. In a specific application, the heat conducting sheet 120 can be connected to any one of the two opposite sides of the tab body 110, or to both opposite sides of the tab body 110. Optionally, the length of the heat conducting sheet 120 is less than or equal to the length of the tab body 110.

[0031] The tab provided by the present invention has a heat conducting sheet 120 connected to at least one of two opposite sides of the tab body 110 in the width direction. When the battery is rapidly charging or discharging, the tab and the area where the tab is welded absorb heat from the tab through the heat conducting sheet and dissipate the heat, thereby improving the heat dissipation performance of the tab and ensuring the stability of the battery cell performance. In addition, it also reduces the safety risks of battery cells caused by overheating.

[0032] Reference Figure 2In some embodiments, one of the tab body 110 and the thermally conductive sheet 120 is provided with a groove 114, and the other is provided with a protrusion 121 that matches the groove 114. The thermally conductive sheet 120 is embedded in the groove 114 via the protrusion 121 to achieve connection with the tab body 110. In this embodiment, optionally, the tab body 110 may be provided with the groove 114 and the thermally conductive sheet 120 may be provided with the protrusion 121; or, the tab body 110 may be provided with the protrusion 121 and the thermally conductive sheet 120 may be provided with the groove 114. Taking the example of a groove 114 provided on the tab body 110 and a protrusion 121 provided on the thermal conductive sheet 120, the groove 114 is located on the side of the tab body 110 for connecting to the thermal conductive sheet 120, and the groove 114 extends along the length direction of the tab body 110, while the protrusion 121 is located correspondingly on the side of the thermal conductive sheet 120 for connecting to the tab body 110. The thermal conductive sheet 120 is embedded in the groove 114 of the tab body 110 through the protrusion 121 thereon, and is then connected to the tab body 110.

[0033] Among them, the heat conducting sheet 120 and the tab body 110 increase the contact area between the two through the concave-convex cooperation of the groove 114 and the convex part 121, thereby increasing the heat conduction area, thereby improving the thermal conductivity of the heat conducting sheet 120 and achieving better heat dissipation effect; and, the heat conducting sheet 120 and the tab body 110 are tightly combined, and the connection is more stable.

[0034] In some embodiments, the thickness of the thermal conductive sheet 120 is less than or equal to the thickness of the tab body 110 .

[0035] The heat conducting sheet 120 is connected to the side of the tab body 110 to absorb heat from the tab body 110 and dissipate the heat. The heat conducting sheet 120 is in uniform contact with the side of the tab body 110. This uniform contact ensures that when heat is transferred from the tab body 110 to the heat conducting sheet 120, there will be no uneven heat transfer, thereby improving the overall heat conduction efficiency of the heat conducting sheet 120. Optionally, the thickness of the heat conducting sheet 120 is less than the thickness of the tab body 110, or the thickness of the heat conducting sheet 120 is equal to the thickness of the tab body 110.

[0036] In some embodiments, heat conducting sheets 120 are provided on two opposite sides of the tab body 110 in the width direction. As can be seen from the aforementioned description of the heat conducting sheets 120, the heat conducting sheets 120 are used to absorb heat from the tab body 110 and dissipate the heat. When heat conducting sheets 120 are provided on two opposite sides of the tab body 110 in the width direction, the heat generated by the tab body 110 can be dissipated simultaneously from the heat conducting sheets 120 on both sides, thereby accelerating the heat dissipation rate of the tab body 110 and effectively improving the heat dissipation efficiency of the heat conducting sheets 120.

[0037] In some embodiments, the tab body 110 has a first non-glue section 111 , a glue section 112 and a second non-glue section 113 divided along its length direction. The glue section 112 is used for attaching the tab glue 130 .

[0038] Among them, the tab glue 130 is pasted on the tab body 130 along the width direction of the tab body 110, and the two ends extend along the width direction of the tab body 110. The tab glue 130 can fix the tab body 110 on the pole piece and has sealing properties, which can prevent electrolyte leakage or external contaminants from entering the battery. Normally, the tab body 110 is firmly fixed on the pole piece by hot-melting the tab glue 130. When melted at high temperature, the tab glue 130 will be deformed. Therefore, in order to ensure the sealing length, the length of the tab glue 130 is greater than the width of the tab body 110.

[0039] In some embodiments, at least one of the first non-adhesive section 111 and the second non-adhesive section 113 is provided with a thermal conductive sheet 120. Optionally, the first non-adhesive section 111 is provided with a thermal conductive sheet 120. When the battery is rapidly charged or discharged, the tab body 110 and the portion where the tab is welded heat rapidly rise in temperature. The thermal conductive sheet 120 absorbs the heat of the tab body 110 and dissipates the heat to the external environment, thereby ensuring the stability of the battery cell performance. Alternatively, the second non-adhesive section 113 is provided with a thermal conductive sheet. When the battery is rapidly charged or discharged, the tab body 110 and the portion where the tab is welded heat rapidly rise in temperature. The thermal conductive sheet 120 absorbs the heat of the portion where the tab is welded and conducts the heat to the first non-adhesive section 111 of the tab body, and the heat is dissipated through the first non-adhesive section 111.

[0040] In some embodiments, the thermal conductive sheet 120 is an insulating thermal conductive sheet. It can be seen from the aforementioned thermal conductive sheet 120 that the thermal conductive sheet 120 is part of the tab. The tab is usually a relatively thin sheet and is prone to bending when subjected to external force. If the bent tab accidentally touches the tab, it will cause a short circuit and cause a safety accident. In this embodiment, the thermal conductive sheet 120 uses an insulating thermal conductive sheet. Even if the tab body 110 bends and accidentally touches the tab, it will not cause a short circuit, thereby avoiding the occurrence of safety accidents. In addition, the thermal conductive sheets 120 arranged on the opposite sides of the tab body 110 can also, to a certain extent, play a role in fixing the tab body 110, preventing the tab body 110 from bending when subjected to external force and contacting the tab to cause a short circuit, thereby avoiding the occurrence of safety accidents.

[0041] In some embodiments, the thermal conductive sheet 120 is a thermal conductive silicone sheet or a thermal conductive silicone sheet. In this embodiment, the thermal conductive sheet 120 is a thermal conductive silicone sheet or a thermal conductive silicone sheet. Both the thermal conductive silicone sheet and the thermal conductive silicone sheet have good thermal conductivity. When the battery is rapidly charged or discharged, they can quickly absorb the heat generated by the tab body 110 and dissipate it to the external environment. In addition, when the battery cell is packaged, the temperature at the tab body 110 packaging is usually lower than 200°C. ℃ ， Thermally conductive silicone grease sheets and thermally conductive silicone sheets can withstand temperatures of 250°C for a long time without drying out or cracking, and can intermittently withstand temperatures of 300°C, thus avoiding the problem of poor packaging due to high temperature resistance during packaging. And / or, in some embodiments, the thermal conductivity of the thermal conductive sheet 120 is greater than 3W / (m*k). It should be noted that thermal conductivity is one of the important indicators for measuring thermal conductivity effects, indicating the ability of the thermal conductive sheet 120 to conduct heat. The higher the thermal conductivity, the stronger the ability of the thermal conductive sheet 120 to conduct heat under the same temperature gradient. When the thermal conductivity of the thermal conductive sheet 120 is greater than 3W / (m*k), a better thermal conductivity effect can be achieved. For example, a thermal conductive sheet 120 made of polyimide.

[0042] The present invention also provides a battery cell, which includes a positive electrode sheet, a separator and a negative electrode sheet stacked and wound together, wherein the separator is arranged between the positive electrode sheet and the negative electrode sheet;

[0043] The positive electrode sheet is connected to the positive electrode tab, and the negative electrode sheet is connected to the positive electrode tab. At least one of the positive electrode tab and the negative electrode tab includes the tab as described in the above embodiment.

[0044] The specific structure of the tab refers to the above embodiments. Since the battery cell adopts all the technical solutions of all the above embodiments, it has at least all the technical effects brought by the technical solutions of the above embodiments, which will not be described one by one here.

[0045] The present invention also provides a battery comprising a housing and the aforementioned battery cell, the battery cell being disposed within the housing. The specific structure of the battery cell is similar to that of the aforementioned embodiments. Since the present battery utilizes all the technical solutions of all the aforementioned embodiments, it at least exhibits all the technical effects of the aforementioned embodiments, and therefore will not be further detailed here.

[0046] The above description is only part or preferred embodiments of the present invention. Neither the text nor the drawings can limit the scope of protection of the present invention. All equivalent structural transformations made by using the contents of the present invention specification and drawings under the overall concept of the present invention, or direct / indirect application in other related technical fields are included in the scope of protection of the present invention.

Claims

1. A tab, characterized in that: include: A tab body, wherein at least one of two opposite sides of the tab body in a width direction is connected to a heat conducting sheet, the heat conducting sheet being used to absorb heat from the tab body and dissipate the heat; One of the tab body and the heat conducting sheet is provided with a groove, and the other is provided with a convex portion adapted to the groove, and the heat conducting sheet is embedded in the groove through the convex portion to achieve connection with the tab body.

2. The tab according to claim 1, wherein: The thickness of the heat conducting sheet is less than or equal to the thickness of the tab body.

3. The tab according to claim 1, wherein: The two opposite sides of the tab body in the width direction are both connected with heat conducting plates.

4. The tab according to claim 1, wherein: The tab body has a first non-glue section, a glue section and a second non-glue section divided along its length direction, and the glue section is used for attaching tab glue.

5. The tab according to claim 4, characterized in that: The heat conducting sheet is located at at least one of the first non-adhesive section and the second non-adhesive section.

6. The tab according to claim 1, wherein: The heat conducting sheet is an insulating heat conducting sheet.

7. The tab according to claim 1, wherein: The thermally conductive sheet is a thermally conductive silicone grease sheet or a thermally conductive silica gel sheet; and / or, The thermal conductivity of the thermally conductive sheet is greater than 3W / (m*k).

8. A battery cell, characterized in that: It includes a positive electrode sheet, a separator and a negative electrode sheet stacked and wound together, wherein the separator is arranged between the positive electrode sheet and the negative electrode sheet; The positive electrode sheet is connected to a positive electrode tab, the negative electrode sheet is connected to a positive electrode tab, and at least one of the positive electrode tab and the negative electrode tab comprises the tab according to any one of claims 1 to 7.

9. A battery, characterized in that: The invention comprises a shell and the battery cell according to claim 8, wherein the battery cell is arranged in the shell.

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