Tab and battery and electrochemical device comprising the same

Abstract

This invention provides a tab and a battery and electrochemical device including the tab. The tab of this invention includes a substrate layer and metal conductive layers disposed on both sides of the substrate layer. An anti-oxidation coating is deposited on the surface of the metal conductive layers. The thickness of the metal conductive layers gradually increases from the cell connection end to the external lead end. Nanoscale heat sinks are dispersed in the substrate layer, and a micropore array is distributed in the metal conductive layer. The tab of this invention, through triple protection of "thermophysical isolation (substrate layer + coating), controllable melting (gradient metal layer), and increased impedance (micropores + substrate permeation)," effectively suppresses the safety risk of high-temperature external short circuits in lithium-ion batteries. Compared with traditional tab improvement schemes (adhesive coating, multi-layer metal, ordinary ceramic coating), it offers more comprehensive safety performance and more controllable failure modes. This invention also provides a battery and electrochemical device including the tab.

Description

Technical Field

[0001] This invention belongs to the technical field of lithium-ion batteries and related electrochemical devices, specifically relating to tabs and batteries and electrochemical devices including them. Background Technology

[0002] In the actual use of lithium-ion batteries, safety performance has always been a key factor restricting their further promotion. Especially under extreme conditions such as high temperature and external short circuit, the battery is prone to thermal runaway, which can not only damage the battery itself, but also cause serious safety accidents such as fire and explosion, threatening the life and property safety of users.

[0003] Traditional lithium-ion batteries using metal tabs (such as copper and aluminum tabs) exhibit significant structural defects and safety hazards in high-temperature external short-circuit scenarios. When a battery experiences a high-temperature external short circuit, the current becomes highly concentrated on the electrode plate in the area corresponding to the tab, causing a rapid increase in temperature in that area and potentially triggering thermal runaway and fire. Simultaneously, the sudden increase in current density can cause the local temperature of the tab to far exceed the metal's melting point, leading to tab melting and metal splattering, further exacerbating the severity of the safety accident. This issue has become a core weakness of traditional metal tabs in battery safety applications.

[0004] To improve the safety performance of traditional electrode tabs, various optimization solutions have been proposed in the industry, but all have functional limitations and fail to fundamentally solve the problem. For example, coating the electrode surface with adhesive only forms a simple protective layer on the surface and cannot prevent heat conduction to the inside of the cell, making it difficult to prevent internal components from failing due to heat. Electrodes formed by stacking multiple metal layers can only improve the conductivity of the electrode tabs, but do not provide thermal isolation, and problems such as current density and localized overheating still occur at high temperatures. The solution of coating the electrode surface with ceramic mainly serves to prevent corrosion, but ceramic materials are prone to cracking at high temperatures, losing their protective effect and failing to cope with the risk of thermal runaway. Therefore, how to start from the electrode structure itself and achieve thermal physical isolation and risk suppression through internal regulation has become a key technical problem that urgently needs to be solved to improve the safety performance of lithium-ion batteries. Summary of the Invention

[0005] This invention aims to at least solve one of the aforementioned technical problems existing in the prior art. To this end, this invention provides an electrode tab that, through triple protection of "thermophysical isolation (substrate layer + coating), controllable melting (gradient metal layer), and increased impedance (micropores + substrate exudation)," can effectively suppress the safety risk of high-temperature external short circuits in lithium-ion batteries. Compared with the single improvement schemes of traditional electrode tabs (adhesive coating, multi-layer metal, ordinary ceramic coating), it has more comprehensive safety performance and more controllable failure modes.

[0006] The present invention also provides a battery.

[0007] The present invention also provides an electrochemical device.

[0008] A first aspect of the present invention provides a tab, comprising a substrate layer and a metal conductive layer disposed on both sides of the substrate layer, wherein an anti-oxidation coating is deposited on the surface of the metal conductive layer, the thickness of the metal conductive layer gradually increases from the cell connection end to the external lead end, nano heat sinks are dispersed in the substrate layer, and a micropore array is distributed in the metal conductive layer.

[0009] The present invention relates to a technical solution for a electrode, which has at least the following beneficial effects: In this invention, the thickness of the conductive metal layer on the tab gradually increases from the cell connection end to the external lead end. This means that the heat capacity of the metal layer at the cell end is smaller and more easily melted, forming a melting zone. When a high-temperature external short circuit occurs, melting will preferentially occur in the thin metal layer near the cell, rather than the thick outer layer. This prevents molten material from splashing outwards and precisely cuts off the connection between the cell and the external circuit, solving the defects of traditional homogeneous tabs where "the melting location is uncontrollable and easily leads to secondary safety problems."

[0010] The conductive metal layer contains a microporous array. At high temperatures, the substrate layer (polymer material) enters a viscous flow state, permeating through the microporous array and covering the surface of the metal layer or filling the micropores. On the one hand, the permeated substrate increases the contact resistance between the tab and the test fixture; on the other hand, the filling of the micropores reduces the effective conductive area of ​​the metal layer, further reducing the short-circuit current density. This suppresses thermal runaway from two dimensions: "cutting off the circuit" and "reducing the current," breaking through the single failure mode of traditional tabs that "only rely on melting to cut off the circuit."

[0011] The substrate layer contains nano heat sinks, which have excellent lateral thermal conductivity and can form a continuous thermal conductivity network within the substrate layer. Combined with the expanded heat dissipation area of ​​the wave-shaped structure, it can quickly disperse the high temperature generated in the local area of ​​the electrode (such as the current-intensive area) to the surrounding area, avoiding the melting and splashing caused by the "sudden rise in local temperature" of traditional electrodes, and reducing the risk of thermal runaway from the source.

[0012] Traditional metal tabs are prone to oxidation at high temperatures, which can lead to a sharp drop in conductivity or structural embrittlement. The surface of the metal conductive layer is coated with an anti-oxidation coating, which can protect the metal layer from oxidation in high-temperature environments and ensure that the tab can maintain stable conductivity before directional melting (avoiding premature current interruption due to oxidation). At the same time, it can prevent the metal layer from reacting with the air to produce harmful gases when it melts, thus improving safety redundancy.

[0013] In summary, the tab of this invention, through the triple protection of "thermophysical isolation (substrate layer + coating), controllable melting (gradient metal layer), and increased impedance (micropores + substrate exudation)," can effectively suppress the safety risk of high-temperature external short circuits in lithium-ion batteries. Compared with the single improvement scheme of traditional tabs (adhesive coating, multi-layer metal, ordinary ceramic coating), it has more comprehensive safety performance and more controllable failure modes.

[0014] In some embodiments, the thermal conductivity of the substrate layer is ≤0.5 W / m·K.

[0015] In some embodiments, the melting point of the substrate layer is ≥250°C.

[0016] The thermal conductivity and melting point of the substrate layer are within the above range, which can ensure thermal barrier effect at high temperature and maintain a certain structural integrity.

[0017] In some embodiments, the substrate layer is wavy, which can increase the heat dissipation area compared to a planar substrate layer.

[0018] In some embodiments, the thickness of the substrate layer ranges from 30 to 80 μm.

[0019] If the substrate layer is too thin, the heat insulation effect will be poor; if the substrate layer is too thick, the conductivity of the tabs will not be met.

[0020] In some embodiments, the nano-heat sink is present in the substrate layer at a content of 5-10 wt%.

[0021] If the content is less than 5wt%, the improvement in thermal conductivity is limited and hot spots cannot be effectively dispersed; if the content is greater than 10wt%, the viscosity of the substrate increases dramatically and the tensile strength decreases.

[0022] The substrate contains nano-heat sinks, which can improve lateral heat dissipation and accelerate the dissipation of local high temperatures.

[0023] In some embodiments, the nanoscale heat sink comprises boron nitride nanosheets.

[0024] In some embodiments, the lateral dimensions of the boron nitride nanosheets are 200-500 nm.

[0025] "Lateral dimension" refers to the dimension between the two points with the greatest distance on the nanosheet plane.

[0026] If the lateral dimension is less than 200 nm, it is easy to agglomerate in the substrate, resulting in poor thermal conductivity network connectivity; if the lateral dimension is greater than 500 nm, there is a risk of penetrating the substrate surface, which can easily damage the metal layer deposition and significantly reduce the in-plane thermal conductivity.

[0027] The pore size of the micropore array is 5~10um.

[0028] In some embodiments, the substrate layer is made of at least one of polyimide, polyetheretherketone, and polyphenylene sulfide.

[0029] In some embodiments, the metallic conductive layer includes a copper layer or an aluminum layer.

[0030] At high temperatures, the viscous matrix material seeps out, increasing the internal resistance of the test fixture and reducing the current. The edges of the metal layer are sealed with laser welding to prevent the metal layer from peeling off.

[0031] In some embodiments, the thickness of the metal conductive layer is 3~20 μm.

[0032] If the metal layer is too thin, the conductivity will be poor, increasing the cell impedance; if the metal layer is too thick, the heat insulation effect will be weakened.

[0033] In some embodiments, the material of the antioxidant coating includes ZrB2-SiC ceramic.

[0034] In some embodiments, the thickness of the antioxidant coating is 0.1~1.5 μm.

[0035] In some embodiments, the thickness of the antioxidant coating is 0.5~1.0 μm.

[0036] A second aspect of the present invention provides a method for preparing electrode tabs, comprising the following steps: S1: Prepare the substrate layer and fabricate a metal conductive layer on both sides of the substrate layer; S2: Deposit an anti-oxidation coating on the surface of the metal conductive layer.

[0037] One technical solution of the present invention relating to the preparation method of electrode tabs has at least the following beneficial effects: The preparation method of the present invention does not require expensive equipment and complex process control, the reaction conditions are not harsh, the raw materials are readily available, the production cost is low, and it is easy to industrialize.

[0038] A third aspect of the present invention provides a battery comprising the tabs of the first aspect of the present invention.

[0039] One of the technical solutions of the present invention concerning batteries has at least the following beneficial effects: The polymer matrix layer of the tabs can efficiently dissipate heat laterally and block heat conduction into the cell. The metal conductive layers on both sides can achieve directional melting to avoid splashing of molten material. They can also increase internal resistance and reduce short-circuit current through the seepage of viscous matrix at high temperatures. The high-melting-point anti-oxidation coating on the surface of the metal layer can protect the metal layer from oxidation at excessively high temperatures without affecting conductivity. These features work together to effectively suppress the risk of thermal runaway due to high-temperature external short circuits in the battery, ensure the integrity of the internal structure of the cell, and take into account the normal conductivity and reliability of the battery.

[0040] A fourth aspect of the present invention provides an electrochemical device comprising the battery of the third aspect of the present invention.

[0041] One of the technical solutions of the present invention concerning an electrochemical device has at least the following beneficial effects: The electrochemical device of the present invention indirectly achieves significant beneficial effects because its battery is equipped with a composite structure tab that has multi-dimensional safety and performance optimization: the battery tab achieves efficient heat dissipation and heat resistance through a polymer matrix layer, achieves directional melting and current control through a metal conductive layer, and ensures conductivity stability at high temperatures through an anti-oxidation coating on the surface of the metal layer. This effectively suppresses the risk of high-temperature external short-term thermal runaway, ensures the integrity of its own structure, and takes into account conductivity performance. As a result, electrochemical devices (such as various electronic devices) using this battery can obtain more reliable safety protection during use, avoid device failure or damage due to battery safety issues, maintain stable power supply performance of the device, and ensure the overall safety and reliability of the device operation. Attached Figure Description

[0042] Figure 1 This is a front view of the electrode tab in the embodiment.

[0043] Figure 2 This is a cross-sectional schematic diagram of the electrode tab in the embodiment. Detailed Implementation

[0044] Terminology definition: The "tab" is a core conductive component of a lithium-ion battery, responsible for conducting current from inside the cell to the external circuit while ensuring the battery's internal safety and sealing. It is not only a crucial factor affecting battery performance but also a key breakthrough for upgrading high-power, high-safety battery technology.

[0045] "Cell connection end" refers to the end of the tab that is close to and directly connected to the electrode (positive or negative electrode) inside the lithium-ion battery cell.

[0046] "External lead end" is a specific functional end of the safety tab of the composite structure of this invention. Specifically, it refers to the end of the tab that is far from the inside of the lithium-ion battery cell and directly connected to the external lead of the battery (or external circuit / test fixture).

[0047] "Micropore array" refers to a collection of tiny pores with a uniform diameter of 5-10 μm distributed according to a specific pattern on the outer thick metal layer (i.e., the metal conductive layer near the external lead end) of the composite structure safety tab of this invention. This micropore array is not merely a structural design, but has a functional purpose: its core purpose is to allow the polymer matrix layer of the tab (which is in a viscous flow state at high temperatures) to seep out in the event of a high-temperature external short circuit in the battery. The seeped viscous flow matrix can cover the surface of the metal layer or fill the micropores, increasing the contact resistance between the tab and the test fixture on the one hand, and reducing the effective conductive area of ​​the metal layer on the other, thereby reducing the short-circuit current. Combined with the gradient thickening design of the metal layer, it achieves a dual safety guarantee of "directional melting + impedance increase", which is one of the key structures for suppressing the risk of high-temperature external short circuits in batteries.

[0048] "Viscous flow state" refers to a physical state exhibited by the polymer matrix layer of the tab (such as polyimide, polyetheretherketone, etc.) under specific conditions.

[0049] "Wave shape" refers to a design that does not use a traditional planar structure, but is processed into a wave-like undulating shape, forming continuous arc-shaped or zigzag-shaped protrusions and depressions through the staggered heights of the surface.

[0050] "Lateral dimension" refers to the dimension between the two points with the greatest distance in the plane of the nanosheet.

[0051] "Aperture of the micro-pore array" refers to the key dimensional parameter of the tiny holes provided on the conductive metal layer (outer thick metal layer) of the electrode tab in this invention. Among them, "outer thick metal layer" means that when the electrode tab is welded on the battery cell electrode sheet, part of it will be embedded in the battery cell, so the outer side refers to the part that is not embedded in the battery cell and is located at the edge along the length direction of the electrode tab.

[0052] The following will describe the concept and technical effects of the present invention clearly and completely with reference to embodiments, so as to fully understand the purpose, features and effects of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are all within the scope of protection of the present invention.

[0053] In the description of this invention, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0054] Unless otherwise specified, "room temperature" in this invention means 25℃±5℃.

[0055] Unless otherwise specified, "about" in this invention means that the allowable error is within ±2%.

[0056] Unless otherwise specified in the examples, the procedures should be performed under standard conditions or conditions recommended by the manufacturer. Reagents or instruments whose manufacturers are not specified are all commercially available products.

[0057] It is understood that the inventive points of this invention include at least the following aspects: 1. A basic safety framework is constructed through the composite three-layer structure design. The electrode adopts a composite structure of "polymer matrix layer + two metal conductive layers on both sides + high melting point anti-oxidation coating on the surface of the metal layer". The three layers work together to form the basic functions of "thermal barrier + conductivity + anti-oxidation": (1) The polymer matrix layer (thermal conductivity ≤0.5W / m·K, melting point ≥250℃) blocks the conduction of high temperature to the inside of the cell; (2) The metal conductive layer (copper / aluminum) ensures normal conductivity; (3) The high melting point anti-oxidation coating prevents the metal layer from oxidizing at high temperature, avoids a sudden drop in conductivity or the generation of harmful gases, and breaks through the defect of "single metal layer without protection" of traditional electrode.

[0058] 2. Enhanced heat dissipation and thermal insulation are achieved through structural and material optimization of the substrate layer. The substrate layer is designed in a wave-like / corrugated shape, which significantly increases the heat dissipation area compared to the traditional planar structure and accelerates the dissipation of local high temperatures. 5~10wt% nanosheets with a lateral size of 200~500nm are dispersed in the substrate layer to form a continuous thermal conductivity network, which significantly improves the lateral heat dissipation capacity, avoids melting and splashing caused by sudden local temperature rises, and solves the problem of low heat dissipation efficiency of traditional tabs.

[0059] 3. The gradient thickness of the metal layer and the micropore array achieve a dual safety mechanism. The thickness of the metal layer increases gradually from the cell connection end to the external lead end, making the heat capacity of the metal layer at the cell end smaller and easier to melt, forming a "directional melting zone". This ensures that melting occurs preferentially on the side closer to the cell, avoiding the splashing of molten material to the outside, and solving the hidden danger of uncontrollable melting location of traditional homogeneous electrode tabs. The outer thick metal layer has a micropore array, and the viscous fluid matrix layer can seep out through the micropores at high temperatures. This increases the contact resistance between the electrode tab and the test fixture and reduces the effective conductive area of ​​the metal layer. The dual effect reduces the short-circuit current and breaks through the single failure mode of traditional electrode tabs that "only rely on melting to cut off the circuit".

[0060] 4. The edges of the metal layer are sealed by laser welding, ensuring structural stability. The laser welding sealing of the metal layer edges effectively prevents the conductive metal layer from peeling off from the substrate surface, avoiding conductive failure or safety risks caused by interlayer separation. It also compensates for the structural defects of traditional tabs, such as "weak interlayer bonding," and ensures the structural integrity of the tab under high temperature, vibration, and other operating conditions.

[0061] 5. Comprehensive safety protection is achieved through multi-mechanism synergy. By synergistically employing multiple mechanisms such as "thermophysical isolation (substrate layer + anti-oxidation coating), controllable melting (gradient metal layer), impedance increase (micropores + viscous flow matrix exudation), and structural stability (laser welding), a "triple safety guarantee" is formed. Compared with the single improvement scheme of traditional electrode tabs (such as surface coating, multi-layer metal, and ordinary ceramic coating), it can more comprehensively and controllably suppress the risk of thermal runaway due to high-temperature external short circuits in the battery, while taking into account both conductivity and structural reliability.

[0062] Test methods The thickness of the matrix layer was measured using a scanning electron microscope (SEM).

[0063] The thickness of the inner side of the metal layer was measured using a scanning electron microscope (SEM).

[0064] The thickness of the outer side of the metal layer was measured using a scanning electron microscope (SEM).

[0065] The distinction between "inner side" and "outer side" here is based on whether the tab is embedded in the battery cell; embedded tabs are considered the inner side, and non-embedded tabs are considered the outer side.

[0066] The aperture on the outer side of the metal layer was measured using a scanning electron microscope (SEM).

[0067] The following are specific embodiments of the present invention, and the technical solutions of the present invention will be further described in conjunction with the embodiments, but the present invention is not limited to these embodiments.

[0068] Example 1 refer to Figure 1 and Figure 2 As shown, a tab 100 was fabricated, with a structure centered on a 55 μm thick substrate layer 110 made of polyimide. The substrate layer has a wavy shape.

[0069] The substrate layer 110 has metal conductive layers 120 on both sides. The substrate layer 110 is made of polyimide. The metal conductive layer 120 is made of copper. An anti-oxidation coating is deposited on the surface of the metal conductive layer 120, and the anti-oxidation coating is made of ZrB2-SiC ceramic.

[0070] The thickness of the metal conductive layer 120 gradually increases from the cell connection end to the outer lead end, with an inner thickness of 4 μm and an outer thickness of 15 μm. 7 wt% boron nitride nanofibers are dispersed in the substrate layer 110, with the boron nitride nanofibers having a size of 400 nm. A micropore array 130 with a pore size of 6 μm is distributed on the outer side of the metal conductive layer 120. Figure 1 and Figure 2 In the middle, 140 is the tab adhesive, which is used to improve the sealing performance of the aluminum-plastic film on the top edge of the battery cell.

[0071] The preparation method is as follows: (1) Place boron nitride nanosheets in an ethanol solution, add silane coupling agent at a concentration of 1.5% of the mass of boron nitride nanosheets, and perform ultrasonic dispersion (power 700W, time 30min). Then stir and reflux at 70℃ for 3 hours. Finally, filter, wash and dry to obtain modified boron nitride nanosheets.

[0072] (2) The modified boron nitride nanosheets (accounting for 7wt% of the total solid mass) were added to a polyamic acid (polyimide precursor) solution and then dispersed using a high-speed shear disperser (10,000 rpm for 1 hour). Subsequently, ball milling (zirconia balls, 0.5 mm in diameter, for 4 hours) was performed to ensure nanoscale dispersion and no visible agglomeration.

[0073] (3) A uniform polyamic acid / boron nitride nanosheet slurry was coated onto a stainless steel strip using a precision casting machine, with the casting thickness controlled to 150 μm. Immediately after casting, a pressure roller with a pre-engraved wavy pattern (roller temperature 80℃) was used to imidize the film with the wavy structure, and the film was subjected to a programmed temperature increase for imidization treatment: 80℃ / 1h → 150℃ / 1h → 250℃ / 1h → 350℃ / 1h. After cooling, a wavy polyimide / boron nitride nanosheet composite substrate with a thickness of 55 μm was obtained.

[0074] (4) Deposition of a double-sided gradient metal layer to form a conductive metal layer. Deposition was performed using a dual-chamber roll-to-roll magnetron sputtering system with a base vacuum of ≤5.0×10⁻⁶. -4 Key parameters: working pressure: 0.4Pa (Ar gas), sputtering power: 10KW.

[0075] (5) Laser processing and anti-oxidation coating deposition. A micro-hole array with a diameter of 6±0.5 μm was fabricated in the outer thick metal layer using laser micro-hole processing. The process control parameters were: laser power: 2.5 W; pulse frequency: 80 kHz; scanning speed: 1000 mm / s; spot overlap rate: 80%; number of impacts: 2. After processing, a dense ceramic coating with strong adhesion was obtained using high-power pulsed magnetron sputtering. The control parameters were: background vacuum: <6.0 × 10⁻⁶. -4Pa, working gas pressure: 0.3 Pa (Ar gas), pulse power density: 500 W / cm³ 2 Pulse frequency: 500Hz, substrate bias: -50V (DC), deposition time: approximately 45min.

[0076] (6) Cutting and inspection. Using a high-precision ceramic blade mold, the tabs are cut off from the roll to obtain the final tabs.

[0077] Examples 2 to 8 The differences between Example 1 and Example 2 are shown in Table 1.

[0078] Comparative Examples 1 to 10 The differences between Example 1 and Example 2 are shown in Table 1.

[0079] Table 1. Relevant parameters of the tabs in the examples and comparative examples.

[0080] Performance testing The external short-circuit failure rate and cell internal resistance of the tabs prepared in the examples and comparative examples were tested.

[0081] The external short-circuit failure rate was obtained through high-temperature external short-circuit testing.

[0082] The internal resistance of the battery cell was measured using a voltmeter.

[0083] The structure is shown in Table 2.

[0084] Table 2 Performance Test Results

[0085] According to the results in Table 2, by comparing Example 1 with Comparative Examples 1 and 2, it can be seen that when the thickness of the substrate layer is less than the required thickness, the thermal insulation performance and support strength of the substrate layer deteriorate, leading to the risk of short-circuit failure; when the thickness of the substrate layer is greater than the required thickness, the thickness of the metal layer becomes thinner, causing the tab impedance to increase and failing to meet the tab conductivity requirements.

[0086] By comparing Example 2 and Comparative Example 3, it can be seen that when the boron nitride nanosheet content is low, it cannot effectively disperse hot spots, leading to local heat concentration and causing the risk of short circuit failure.

[0087] By comparing Example 3 and Comparative Example 4, it can be seen that when the lateral size of boron nitride nanosheets is small, they agglomerate in the matrix, resulting in poor thermal conductivity network connectivity, inability to effectively disperse hot spots, and risk of short-circuit failure.

[0088] By comparing Example 1 with Comparative Examples 5 and 6, it can be seen that when the inner metal layer is thinner, the internal resistance of the cell increases and the tabs cannot meet the conductivity requirements; when the inner metal layer is thicker and the outer metal layer is thinner, the internal resistance of the cell also increases, but the increase is less than that when the inner metal layer is thinner, indicating that the inner metal layer has a greater impact on the impedance.

[0089] By comparing Example 1 with Comparative Examples 7 and 8, it can be seen that when the aperture of the array hole is large, it hinders the connection of the tab metal layer and increases the cell impedance; when the aperture of the array hole is small, it cannot guarantee good flow of the substrate viscous fluid, and there is a small risk of short circuit failure.

[0090] By comparing Example 7 and Comparative Example 8, it can be seen that conventional tabs without a substrate layer have a higher risk of short circuit.

[0091] By comparing Example 1 and Comparative Example 10, it can be seen that the heat dissipation effect of the flat substrate layer is worse than that of the wavy one, but the risk of failure is lower.

[0092] The present invention has been described in detail above with reference to the embodiments. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A tab, characterized in that, The device includes a substrate layer and metal conductive layers disposed on both sides of the substrate layer. An anti-oxidation coating is deposited on the surface of the metal conductive layer. The thickness of the metal conductive layer gradually increases from the cell connection end to the external lead end. Nanoscale heat sinks are dispersed in the substrate layer. The substrate layer is made of at least one of polyimide, polyetheretherketone, and polyphenylene sulfide. The nanoscale heat sinks are made of at least one of boron nitride nanosheets, aluminum nitride nanoparticles, graphene nanotubes, and carbon nanotubes. The anti-oxidation coating is made of ZrB2-SiC ceramic. A micropore array is distributed in the metal conductive layer.

2. The electrode tab according to claim 1, characterized in that, The thickness of the substrate layer ranges from 30 to 80 μm.

3. The electrode tab according to claim 1, characterized in that, The content of the nano heat sink in the substrate layer is 5~10wt%.

4. The electrode tab according to claim 3, characterized in that, The lateral dimension of the nano heat sink is 200~500nm.

5. The electrode tab according to claim 1, characterized in that, The pore size of the micropore array is 5~10um.

6. The electrode tab according to any one of claims 1 to 5, characterized in that, The conductive metal layer includes a copper layer or an aluminum layer; and / or, the thickness of the conductive metal layer is 3~20µm.

7. The electrode tab according to any one of claims 1 to 5, characterized in that, The thickness of the antioxidant coating is 0.5~1.0 μm.

8. A battery, characterized in that, Includes the tabs according to any one of claims 1 to 7.

9. An electrochemical device, characterized in that, Includes the battery as described in claim 8.

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