A breathable pressure relief tab and method of processing the same

Abstract

The application discloses a kind of breathable pressure relief tab and its processing method, comprising: metal conductor and functional film, the metal conductor upper and lower two sides are equipped with functional film, metal conductor surface is equipped with exhaust passage or the functional film between the both sides of metal conductor is equipped with exhaust passage;Functional film includes breathable functional film, sealing functional film;Exhaust passage includes single-channel type, multi-channel type and dumbbell channel type, one end of exhaust passage is connected in the inside of electric core, and the other end of exhaust passage is designed in the exposed end of tab.The application guarantees excellent sealing performance, and then guarantees the packaging interface of electric core, improves the reliability and service life of electric core;Functional film material can maintain better deformation rate under high temperature condition, so as to avoid the collapse of film material, effectively guarantee breathable channel;Gas generated in the inside of electric core can be orderly discharged under the condition of pressure difference, so as to maintain low pressure in the inside of electric core, improve the reliability of electric core.

Description

Technical Field

[0001] This invention relates to the field of new energy batteries (lithium-ion, sodium-ion, and semi-solid, solid, etc. batteries encapsulated using tabs), specifically a breathable pressure-relieving tab and its processing method. Background Technology

[0002] Existing electrode tabs generally include metal components and sealing membranes. The number of sealing membranes is generally one or one, i.e., a single-stage membrane or a single-channel membrane, and there is no exhaust channel.

[0003] When the electrode tabs are packaged in an aluminum-plastic bag to form a battery cell, side reactions are inevitable during the cycle of use. These side reactions are usually accompanied by the generation of gas. As the gas accumulates, the internal pressure of the battery cell increases. When a certain limit is reached, it will break through the weak point of the aluminum-plastic bag packaging area, causing leakage. In severe cases, this can cause safety hazards, resulting in incalculable losses for both the battery cell manufacturer and the customer. Therefore, the release of internal pressure is crucial for the safety of the battery cell.

[0004] Existing hard-shell battery cells typically have an explosion-proof valve on the cover plate. When the internal pressure of the battery cell reaches a certain threshold, the explosion-proof valve is triggered to release the pressure.

[0005] However, since the casing of the pouch cell is made of soft material and the cell is initially under a certain vacuum pressure, explosion-proof valves or vent valves can only be installed in the area near the top seal. Due to the area limitation, this is difficult to achieve at present. Therefore, venting and depressurizing pouch cells is an urgent problem to be solved.

[0006] Therefore, we propose a breathable pressure relief electrode and its processing method to solve the problems mentioned above. Summary of the Invention

[0007] The purpose of this invention is to provide a breathable pressure relief electrode tab and its processing method to solve the problems mentioned in the background art.

[0008] To achieve the above objectives, the present invention provides the following technical solution: a breathable pressure relief electrode tab, comprising: a metal conductor and a functional membrane, wherein the metal conductor is provided with functional membranes on both the upper and lower surfaces, and an exhaust channel is provided on the surface of the metal conductor or an exhaust channel is provided between the functional membranes on both sides of the metal conductor;

[0009] Functional membranes include breathable functional membranes and sealing functional membranes;

[0010] The exhaust channels include single-channel, multi-channel, and dumbbell-channel types. One end of the exhaust channel is connected to the inside of the battery cell, that is, it is designed at the welding end of the electrode tab, close to the welding position between the electrode plate and the electrode tab. The other end of the exhaust channel is designed at the exposed end of the electrode tab, that is, outside the top seal of the battery cell. The exhaust channel at the exposed end is connected to the exhaust channel at the internal welding end.

[0011] Preferably, the functional membrane is mainly composed of a sealing functional membrane, which includes a heat-sealing layer, a breathable layer, and a metal-affinity layer. The metal-affinity layer wraps around a metal conductor, the breathable layer wraps around the outside of the metal-affinity layer, and the heat-sealing layer wraps around the outside of the breathable layer.

[0012] Preferably, the functional membrane is mainly composed of a breathable functional membrane and a sealing functional membrane, with the breathable functional membrane wrapped around the outside of the sealing functional membrane;

[0013] The breathable functional membrane includes an outer heat-sealing layer, a breathable layer, and an inner heat-sealing layer. The sealing functional membrane includes a heat-sealing layer, a high-temperature functional layer, and a metal-friendly layer.

[0014] The metal-affinity layer of the sealing functional membrane is located on the surface of the metal conductor. Outside the metal-affinity layer of the sealing functional membrane are, in sequence, the high-temperature functional layer of the sealing functional membrane and the heat-sealing layer of the sealing functional membrane. Outside the heat-sealing layer of the sealing functional membrane are, in sequence, the inner heat-sealing layer of the breathable functional membrane, the breathable layer of the breathable functional membrane, and the outer heat-sealing layer of the breathable functional membrane.

[0015] Preferably, the breathable functional membrane is wrapped around the edge of the sealing functional membrane, the edge of the breathable functional membrane is pressed together, and the inner heat-sealing layer of the breathable functional membrane seals the edge of the sealing functional membrane.

[0016] Preferably, the breathable functional membrane covers the edge of the sealing functional membrane.

[0017] Compared with the prior art, the beneficial effects of the present invention are:

[0018] 1. The metal-affinity layer of the sealing functional membrane used for the tabs is modified to contain polar groups such as carboxyl, hydroxyl, double bond, carbonyl, and amino groups. Therefore, the metal-affinity layer of the sealing functional membrane has strong polarity, similar to that of metal. Thus, the sealing functional membrane and the metal form a strong adhesion interface through chemical bonds, thereby ensuring excellent sealing performance, which in turn ensures the encapsulation interface of the battery cell and improves the reliability and service life of the battery cell.

[0019] 2. The breathable membrane of the tab is made of polyolefin material, which is a multi-melting-point material. The low-melting-point layer is conducive to the fusion of the breathable membrane with the sealing membrane of the tab, as well as the fusion with the PP layer of the aluminum-plastic bag. This layer also has the function of conducting air but not water. The high-melting-point layer is the breathable layer of the breathable membrane. It can maintain the deformation rate of the membrane material under high temperature conditions and prevent the membrane material from collapsing.

[0020] 3. The tabs and aluminum-plastic bag packaging form the battery cell. Under certain usage time or extreme conditions (such as long-term high-temperature operation), the sealing film of the tabs can ensure the reliability of the bonding interface, thereby ensuring the reliability of the battery cell seal. When the battery cell is used in cycles, when the gas produced by the side reaction accumulates to a certain level (or when there is a certain pressure difference with the external environment), the internal pressure of the battery cell will be slowly released, thereby ensuring a low internal pressure of the battery cell, ultimately ensuring the safety performance of the battery cell packaging area, thereby improving the reliability of the battery cell and extending its service life. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of the present invention;

[0022] Figure 2 For the present invention Figure 1 Side view;

[0023] Figure 3 This is a schematic diagram of the structure of the exhaust channel designed for the metal conductor in this invention;

[0024] Figure 4 This is a schematic diagram of the multi-channel exhaust channel design for the metal conductor in this invention;

[0025] Figure 5 This is a schematic diagram of the dumbbell-shaped exhaust channel designed for the metal conductor in this invention;

[0026] Figure 6 This is a schematic diagram of the structure of the functional membrane side wing exhaust channel and the functional membrane in this invention;

[0027] Figure 7 This is a schematic diagram of the structure of Embodiment 1 of the present invention;

[0028] Figure 8 This is a schematic diagram of the structure of Embodiment 2 of the present invention;

[0029] Figure 9 This is a schematic diagram of the structure of Embodiment 3 of the present invention;

[0030] Figure 10 This is a schematic diagram of the structure of Embodiment 4 of the present invention;

[0031] Figure 11This is a schematic diagram showing the peel strength results of the Ni / Cu breathable pressure relief electrode tab in Example 1 of the present invention;

[0032] Figure 12 This is a schematic diagram showing the peel strength results of the Al breathable pressure relief electrode tab in Embodiment 2 of the present invention.

[0033] In the diagram: 1. Metal conductor; 2. Exhaust channel; 3. Functional membrane; 5. Outer heat-sealing layer of the breathable functional membrane; 6. Breathable layer of the breathable functional membrane; 7. Inner heat-sealing layer of the breathable functional membrane; 8. Heat-sealing layer of the sealing functional membrane; 9. High-temperature functional layer of the sealing functional membrane; 10. Metal-friendly layer of the sealing functional membrane; 15. Heat-sealing layer of both the sealing and breathable functional membranes; 16. Breathable layer of both the sealing and breathable functional membranes; 17. Metal-friendly layer of both the sealing and breathable functional membranes. Detailed Implementation

[0034] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] Please see Figure 1-6 The present invention provides a technical solution: a breathable pressure relief electrode, comprising: a metal conductor 1 and a functional membrane 3, wherein the metal conductor 1 is provided with functional membranes 3 on both the upper and lower surfaces, and an exhaust channel 2 is provided on the surface of the metal conductor 1 or an exhaust channel 2 is provided between the functional membranes 3 on both sides of the metal conductor 1.

[0036] Functional membrane 3 includes a breathable functional membrane and a sealing functional membrane;

[0037] The breathable functional membrane includes an outer heat-sealing layer 5, a breathable layer 6, and an inner heat-sealing layer 7.

[0038] The sealing functional membrane includes a heat-sealing layer 8, a high-temperature functional layer 9, and a metal-friendly layer 10.

[0039] The sealing and breathable membrane includes a heat-sealing layer 15, a breathable layer 16, and a metal-friendly layer 17.

[0040] The metal-affinity layer 10 of the sealing functional membrane and the metal-affinity layer 17 of the sealing and breathable functional membrane are made of modified polyolefin material containing polar groups such as carboxyl, hydroxyl, double bond, carbonyl, amino, etc., with a melting point of generally 140℃~170℃ and strong adhesion to metal.

[0041] The breathable layer 6 of the breathable functional membrane is made of polyolefin or modified polyolefin material with a melting point above 160℃;

[0042] The high-temperature functional layer 9 of the sealing functional membrane is made of polyolefin material or modified polyolefin material with a melting point of 160℃ or above.

[0043] The breathable layer 16 of the sealing and breathable membrane is made of polyolefin or modified polyolefin material with a melting point above 160℃ and excellent breathability.

[0044] The exhaust channel 2 includes single-channel, multi-channel, and dumbbell-channel types. One end of the exhaust channel 2 is connected to the inside of the battery cell, that is, it is designed at the welding end of the electrode tab, close to the welding position between the electrode sheet and the electrode tab. The exhaust channel 2 at the electrode tab welding end is not covered with polymer membrane material, such as sealing functional membrane material, breathable functional membrane material, etc., to ensure the excellent breathability of the exhaust channel 2. The other end of the exhaust channel 2 is designed at the exposed end of the electrode tab, that is, outside the top seal of the battery cell. The exhaust channel 2 at the exposed end is connected to the exhaust channel at the internal welding end. The exhaust channel 2 at the exposed end needs to be sealed to prevent water vapor and other substances in the outside air from entering the battery cell, thereby affecting the service life of the battery cell.

[0045] The sealing material for the exposed exhaust channel 2 can be a polymer membrane or welded to the vent valve. This polymer membrane has good air permeability and is unidirectional, meaning that under a certain pressure difference, gas can pass through the fixed surface of the membrane. During the cycle of the battery cell, when the gas generated by the side reaction accumulates to a certain level (or when there is a certain pressure difference with the outside environment), the pressure inside the battery cell will be slowly released, thereby ensuring a low pressure inside the battery cell and ultimately ensuring the safety performance of the battery cell packaging area, thereby improving the reliability of the battery cell and extending its service life.

[0046] The metal conductor 1 is made of high-purity aluminum, aluminum plated with nickel, high-purity copper, copper plated with nickel, high-purity nickel, copper-aluminum alloy, aluminum-nickel alloy and other metal materials. Its main function is to be a carrier of energy transfer.

[0047] Functional membrane 3 is made of polyolefin material and has sealing, insulation and breathability functions;

[0048] After the tabs are encapsulated in the aluminum-plastic bag, the ventilation function of the functional membrane 3 is not affected and is unidirectional. Under certain pressure difference conditions, the gas is discharged, thereby maintaining a low internal pressure state inside the cell, improving the reliability of the cell and extending its service life.

[0049] Example 1

[0050] Please see Figure 7This invention provides a technical solution: a breathable pressure relief electrode tab, comprising a functional membrane 3. The functional membrane 3 is mainly composed of a sealing functional membrane and a breathable functional membrane. The sealing functional membrane includes a heat-sealing layer 15, a breathable layer 16, and a metal-affinity layer 17. The metal-affinity layer 17 encapsulates a metal conductor 1. The breathable layer 16 is wrapped around the outside of the metal-affinity layer 17. The heat-sealing layer 15 is wrapped around the outside of the breathable layer 16.

[0051] Example 2

[0052] Please see Figure 8 The present invention provides a technical solution, a breathable pressure relief electrode, including a functional membrane 3, wherein the functional membrane 3 is mainly composed of a breathable functional membrane and a sealing functional membrane, and the breathable functional membrane is wrapped around the outside of the sealing functional membrane.

[0053] The breathable functional membrane includes an outer heat-sealing layer 5, a breathable layer 6, and an inner heat-sealing layer 7. The sealing functional membrane includes a heat-sealing layer 8, a high-temperature functional layer 9, and a metal-friendly layer 10.

[0054] The metal-affinity layer 10 of the sealing functional membrane is located on the surface of the metal conductor 1. The outer side of the metal-affinity layer 10 of the sealing functional membrane is successively the high-temperature functional layer 9 of the sealing functional membrane and the heat-sealing layer 8 of the sealing functional membrane. The outer side of the heat-sealing layer 8 of the sealing functional membrane is successively the inner heat-sealing layer 7 of the breathable functional membrane, the breathable layer 6 of the breathable functional membrane, and the outer heat-sealing layer 5 of the breathable functional membrane.

[0055] Example 3

[0056] Please see Figure 9 The present invention provides a technical solution, a breathable pressure relief electrode tab, including a functional membrane 3, the functional membrane 3 mainly composed of a breathable functional membrane and a sealing functional membrane, the breathable functional membrane wrapping around the edge of the sealing functional membrane, the edge of the breathable functional membrane being pressed together, and the inner heat sealing layer 7 of the breathable functional membrane sealing the edge of the sealing functional membrane.

[0057] Example 4

[0058] Please see Figure 10 The present invention provides a technical solution, a breathable pressure relief electrode tab, including a functional membrane 3, wherein the functional membrane 3 is mainly composed of a breathable functional membrane and a sealing functional membrane, and the breathable functional membrane covers the edge of the sealing functional membrane.

[0059] The process flow is as follows:

[0060] Metal foil and functional film materials, processing and forming, metal chamfering, metal surface treatment, metal surface lamination with functional film materials, fusion processing;

[0061] Metal foil rolls and functional film rolls are precisely cut into specified sizes using a rolling shearing machine. The sides of the precisely cut metal are then beveled to thin them, and the beveled metal is then surface-treated (including electroplating and passivation). Finally, the functional film and the surface-treated metal are fused together and encapsulated.

[0062] The specific process flow for the surface treatment is as follows:

[0063] Unwinding, ultrasonic degreasing, first-stage hot degreasing, third-stage water washing, second-stage hot degreasing, third-stage water washing, drying, activation, electroplating, water washing, drying, first-stage passivation treatment, third-stage water washing, drying, second-stage passivation treatment, third-stage water washing, drying, rewinding;

[0064] The unwinding material is a continuous strip of metal foil after processing and beveling the sides.

[0065] The degreasing agent is an alkaline degreasing agent;

[0066] The activation treatment is acid washing activation;

[0067] The electroplating process is the electroplating of a Ni layer;

[0068] The passivation treatment is either a chromium coating treatment or a silane coating treatment.

[0069] The secondary passivation treatment is either a chromium coating treatment or a silane coating treatment.

[0070] The winding device includes automatic correction and positioning functions.

[0071] The fusion processing flow is as follows:

[0072] Unwinding, guiding, height positioning, correction, shaping, primary positioning, sealing film punching, preheating and pressing sealing film, venting, high-temperature encapsulation, primary shaping, secondary positioning, breathable film punching, preheating and pressing breathable film, high-temperature hot pressing, secondary shaping, side wing film material precision cutting, pulling, pressing, and unloading.

[0073] The unwinding material is a continuous strip of metal foil after processing and surface treatment.

[0074] The height positioning refers to the control of the height position of the material belt by the upper and lower height roller devices.

[0075] The correction device is an infrared optical sensing positioning and correction device;

[0076] The shaping process involves multi-level upper and lower silicone roller pressing.

[0077] The primary positioning is precise positioning using a positioning groove of the same specification as the metal.

[0078] The sealing membrane is punched using a die-cutting knife and a vacuum device;

[0079] The preheated and sealed functional membrane and the exhaust are heated by resistance wire.

[0080] The high-temperature encapsulation is achieved through magnetic heating or electric heating.

[0081] The primary forming process involves a copper plate device equipped with cooling water.

[0082] The secondary positioning is an infrared optical sensing positioning device;

[0083] The breathable functional membrane is punched using a die-cutting device;

[0084] The preheated and breathable functional membrane is heated by resistance wire.

[0085] The breathable functional membrane is hot-pressed at high temperature using a resistance wire heating method;

[0086] The secondary shaping is a copper plate resistance wire heating device;

[0087] The side wing membrane material is precision-cut using a precise positioning die-cutting method;

[0088] The material feeding mode is servo feeding mode;

[0089] The pressing material is a template made of metal plate and silicone.

[0090] The blanking process involves high-temperature encapsulation of metal materials and functional films, followed by die-cutting into individual breathable and pressure-relief tabs.

[0091] The process flow for the functional membrane material is as follows:

[0092] Feeding, extrusion, casting, winding, and slitting;

[0093] The feeding process involves feeding raw materials into the first hopper of the sealing functional membrane, feeding modified polyolefin particles into the second hopper, and feeding modified polyolefin particles or low-melting-point polyolefin particles into the third hopper.

[0094] Modified polyolefin particles or low-melting-point polyolefin particles are added to the first hopper of the breathable functional membrane, modified high-melting-point polyolefin particles are added to the second hopper, and low-melting-point polyolefin particles are added to the third hopper.

[0095] The first, second, and third hoppers mentioned above are the feeding ports of the casting machine.

[0096] The extrusion is the melt extrusion of polyolefin particles inside a screw extruder;

[0097] The casting sheet is a thick sheet of a certain thickness cast from extruded polyolefin fluid through the gap of the die lip;

[0098] The winding process involves casting a thick sheet of film and then winding it into a film roll using an automatic tension wheel.

[0099] The slit film material is then cut into fixed dimensions using a circular blade.

[0100] The gas-permeable pressure-relieving tab of Example 1 was placed in a mixture of 1.0 mol / L LiPF6, V EC V DMC V EMC = 1:1:1 (containing 1000ppm water) or mixed reagent 1.0mol / L LiPF6,V EC V DEC V EMC The reliability of the ratio 1:1:1 (containing 1000ppm water) is shown in the appendix. Figure 11 and 12 As shown.

[0101] As analyzed in the above embodiments, the metal used for the tab in Example 1, after undergoing special surface treatment, has no dirt or stains on its surface, and an oxide film of a certain thickness is formed on the metal surface. This film has strong corrosion resistance. After modification, the metal-affinity layer 10 of the sealing functional membrane and the metal-affinity layer 17 of the sealing and breathable functional membrane for the tab contain polar groups, such as carboxyl, hydroxyl, double bond, carbonyl, amino, etc. Therefore, the metal-affinity layer 10 of the sealing functional membrane and the metal-affinity layer 17 of the sealing and breathable functional membrane have strong polarity, similar to the polarity of metal. Thus, the sealing functional membrane and the metal form a strong adhesion interface through chemical bonds, thereby ensuring excellent sealing performance, and thus ensuring the encapsulation interface of the battery cell, improving the reliability and service life of the battery cell.

[0102] The breathable pressure relief tab from Example 1 was sealed with an Al pocket bag to form a sealed shell, and 200g of a mixed reagent of 1.0mol / L LiPF6 was injected. EC V DMC V EMC = 1:1:1 (containing 1000ppm water) or mixed reagent 1.0mol / L LiPF6,V EC V DEC V EMC =1:1:1 (containing 1000ppm water), baked at a constant temperature of 85℃, and the deformation of the sealed shell was observed:

[0103]

[0104] In Example 1, the breathable pressure-relieving tabs and Al Pocket bag packaging are used to fabricate a battery cell. Under certain usage time or extreme conditions (such as prolonged high-temperature operation), the sealing membrane of the tabs ensures the reliability of the bonding interface, thereby guaranteeing the reliability of the battery cell's seal. During the battery cell's cyclic use, when the gases generated by side reactions accumulate to a certain level (or when there is a certain pressure difference with the external environment), the internal pressure of the battery cell will be slowly released through the breathable membrane, thus ensuring a lower internal pressure and ultimately guaranteeing the safety performance of the battery cell's packaging area. This improves the battery cell's reliability and lifespan.

[0105] The contents not described in detail in this specification are existing technologies known to those skilled in the art.

[0106] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A breathable pressure relief electrode, comprising: A metal conductor (1) and a functional membrane (3), characterized in that: the metal conductor (1) is provided with a functional membrane (3) on both the upper and lower surfaces, and an exhaust channel (2) is provided on the surface of the metal conductor (1) or an exhaust channel (2) is provided between the functional membranes (3) on both sides of the metal conductor (1); Functional membranes (3) include breathable functional membranes and sealing functional membranes; The exhaust channel (2) includes single-channel type, multi-channel type and dumbbell channel type. One end of the exhaust channel (2) is connected to the inside of the cell, that is, it is designed at the welding end of the electrode tab, close to the welding position of the electrode plate and the electrode tab. The other end of the exhaust channel (2) is designed at the exposed end of the electrode tab, that is, outside the top seal of the cell. The exhaust channel (2) at the exposed end is connected to the exhaust channel at the internal welding end. The functional membrane (3) is mainly composed of a sealing functional membrane, which includes a heat-sealing layer (15), a breathable layer (16), and a metal-friendly layer (17). The metal-friendly layer (17) of the sealing functional membrane wraps around the metal conductor (1), and the breathable layer (16) of the sealing functional membrane is wrapped around the outside of the metal-friendly layer (17). The heat-sealing layer (15) of the sealing functional membrane is wrapped around the outside of the breathable layer (16). The functional membrane (3) is mainly composed of a breathable functional membrane and a sealing functional membrane, with the breathable functional membrane wrapped around the outside of the sealing functional membrane; The breathable functional membrane includes an outer heat-sealing layer (5), a breathable layer (6), and an inner heat-sealing layer (7) of the breathable functional membrane. The sealing functional membrane includes a heat-sealing layer (8), a high-temperature functional layer (9), and a metal-friendly layer (10) of the sealing functional membrane. The metal-affinity layer (10) of the sealing functional membrane is located on the surface of the metal conductor (1). The outer side of the metal-affinity layer (10) of the sealing functional membrane is successively the high-temperature functional layer (9) of the sealing functional membrane and the heat-sealing layer (8) of the sealing functional membrane. The outer side of the heat-sealing layer (8) of the sealing functional membrane is successively the inner heat-sealing layer (7) of the breathable functional membrane, the breathable layer (6) of the breathable functional membrane and the outer heat-sealing layer (5) of the breathable functional membrane. The breathable functional membrane is wrapped around the edge of the sealing functional membrane, the edge of the breathable functional membrane is pressed together, and the inner heat sealing layer (7) of the breathable functional membrane seals the edge of the sealing functional membrane. The breathable membrane covers the edge of the sealing membrane.

2. A processing method for the breathable pressure relief electrode tab according to claim 1, characterized in that, The processing steps are as follows: Metal foil and functional film materials, processing and forming, metal chamfering, metal surface treatment, metal surface lamination with functional film materials, fusion processing; Metal foil rolls and functional film rolls are precisely cut into specified sizes using a rolling shearing machine. The sides of the precisely cut metal are then beveled to thin them, and the beveled metal is then surface-treated. Finally, the functional film and the surface-treated metal are fused together and encapsulated.

3. A method for processing the breathable pressure relief electrode tab as described in claim 2, characterized in that, The specific process flow for the surface treatment is as follows: Unwinding, ultrasonic degreasing, first-stage hot degreasing, third-stage water washing, second-stage hot degreasing, third-stage water washing, drying, activation, electroplating, water washing, drying, first-stage passivation treatment, third-stage water washing, drying, second-stage passivation treatment, third-stage water washing, drying, rewinding; The material used for unwinding is a continuous strip of metal foil after being processed and shaped and having its sides beveled. The degreasing agent used in the ultrasonic degreasing is an alkaline degreasing agent; The activation treatment is acid washing activation; The electroplating process is the electroplating of a Ni layer; The passivation treatment is either a chromium coating treatment or a silane coating treatment. The secondary passivation treatment is either a chromium coating treatment or a silane coating treatment. The winding device includes automatic correction and positioning functions.

4. A method for processing the breathable pressure relief electrode tab as described in claim 2, characterized in that, The process flow for the functional membrane material is as follows: Feeding, extrusion, casting, winding, and slitting; The feeding process involves feeding raw materials into the first hopper of the sealing functional membrane, feeding modified polyolefin particles into the second hopper, and feeding modified polyolefin particles or low-melting-point polyolefin particles into the third hopper. Modified polyolefin particles or low-melting-point polyolefin particles are added to the first hopper of the breathable functional membrane, modified high-melting-point polyolefin particles are added to the second hopper, and low-melting-point polyolefin particles are added to the third hopper. The first, second, and third hoppers are the feeding ports of the casting machine. The extrusion is the melt extrusion of polyolefin particles inside a screw extruder; The casting sheet is a thick sheet formed by extruding polyolefin fluid through the gap of the die lip; The winding process involves winding a cast thick film into a film roll using an automatic tension wheel.

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