Functional current collector and preparation process thereof

Abstract

The invention discloses a functional current collector and a preparation process thereof, and relates to the technical field of functional current collectors. The functional current collector comprises a base film layer, a bottom layer attached to at least one side of the base film layer, a metal layer arranged on one side, far away from the base film layer, of the bottom layer, and a protective layer on the outermost layer; wherein the base membrane layer is obtained by mixing and casting a polymer base material and modified particles; the modified particles are soft particles or modified porous silicon dioxide, the particle size of the soft particles is 0.1-5.0 [mu] m, the ball indentation hardness is smaller than or equal to 200 MPa, and the soft particles can be specifically one or more of polystyrene, styrene-divinyl benzene copolymer, polysiloxane, polymethyl methacrylate, polylactic acid-glycolic acid copolymer, carboxymethyl cellulose and chitosan.

Description

Technical Field

[0001] The present invention relates to the technical field of functional current collectors, and in particular to a functional current collector and a preparation process thereof. Background Art

[0002] At present, composite current collectors based on polymer membranes have received widespread attention and application in the new energy industry. The preparation of this composite current collector usually adopts the method of physical vapor deposition (PVD) to deposit a layer of metal on a polymer film (such as polyester, polyolefin, etc.), thereby preparing a composite current collector with good conductivity. Compared with traditional current collectors, composite current collectors based on polymer membranes have the characteristics of low cost, light weight, and good internal insulation. These characteristics enable the composite current collector to reduce the cost of the battery and improve the energy density and safety of the battery when used in the battery;

[0003] Usually, in order to improve the adhesion between the base film and the metal layer in the composite current collector, a base layer is set between the base film and the metal layer. However, the base film contains an additive - rigid granular silica, which is easy to squeeze the base layer during the electrode rolling process, causing defects. Then, it is easy to corrode under the condition of immersion in battery electrolyte, resulting in separation of the base film and the metal layer, causing battery performance degradation. Summary of the Invention

[0004] The purpose of the present invention is to provide a functional current collector and a preparation process thereof to solve the problems raised in the prior art.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A functional current collector, comprising a base film layer, a primer layer attached to at least one side of the base film layer, a metal layer disposed on the primer layer and away from the base film layer, and an outermost protective layer;

[0007] The base film layer includes a polymer substrate and modified particles; the modified particles are soft particles or modified porous silica; the mass of the modified particles accounts for 0.5%-2% of the base film layer; the thickness of the base film layer is 1μm-10μm;

[0008] Preferably, the polymer substrate is at least one of polypropylene, polyethylene, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyimide, polypropylene, polyvinyl chloride, polyvinylidene fluoride, polytetrafluoroethylene, polyphenylene sulfide, polyphenylene oxide and polyamide;

[0009] The particle size of soft particles is 0.1μm-5.0μm, and the ball indentation hardness is ≤200MPa;

[0010] Preferably, the soft particles are one or more combinations of polystyrene, styrene-divinylbenzene copolymer, polysiloxane, polymethyl methacrylate, polylactic acid-glycolic acid copolymer, carboxymethyl cellulose, and chitosan;

[0011] The base layer is one or more combinations of aluminum oxide, silicon oxide, titanium oxide, nickel, chromium, titanium, nickel-chromium alloy, nickel-chromium-copper alloy, and silicon-aluminum alloy; the number of base layers on at least one side is ≥1; and the thickness of the base layer is 3nm-30nm;

[0012] The metal layer is one of copper, aluminum, copper alloy, and aluminum alloy; the thickness of the metal layer is 500nm-2000nm;

[0013] The protective layer comprises any one or more of nickel, chromium, nickel-based alloy, copper-based alloy, copper oxide, aluminum oxide, nickel oxide, chromium oxide, cobalt oxide, graphite, carbon black, copper-chromium oxide, carbon nano-quantum dots, carbon nanotubes, carbon nanofibers and graphene; the thickness of the protective layer is 10nm-80nm;

[0014] The preparation steps of modified porous silica are as follows:

[0015] Step s1: cetyltrimethylammonium bromide is placed in an ethanol aqueous solution, the pH is adjusted to 12 with ammonia water, and then stirred to dissolve, tetraethyl orthosilicate is added, stirred for 10-12 hours, and then centrifuged and washed, dried to obtain silica, mixed with urea and deionized water to dissolve, acid solution is added dropwise to adjust the pH to 0.8-1.2, and then stirred at 500-600 rpm and formaldehyde is added, stirred for 30-50 seconds, and then allowed to stand overnight, 3-aminopropyltriethoxysilane and ammonia water are added to adjust the pH to 3-4, and the mixture is allowed to stand for 4-6 hours, filtered, washed, dried, and calcined to obtain porous silica;

[0016] Step s2: taking the porous silica prepared in step s1, deionized water, styrene, divinylbenzene and an emulsifying agent are added in sequence, heated to 60-70°C and stirred for emulsification for 30 minutes, then potassium persulfate is added and the temperature is raised to 80-90°C, reacted for 2-3 hours, filtered, washed and dried to obtain modified porous silica;

[0017] Preferably, the mass ratio of hexadecyltrimethylammonium bromide to tetraethyl orthosilicate is 1:(0.5-2.0); the amount ratio of silicon dioxide, urea, formaldehyde and 3-aminopropyltriethoxysilane is 1g:6g:12mL:2mL; the amount ratio of porous silica, styrene, divinylbenzene and potassium persulfate is 1g:0.45mL:0.05mL:0.02g; the calcination temperature is 600-700°C, and the calcination time is 5-8h;

[0018] A preparation process of a functional current collector, the specific steps are as follows:

[0019] Step 1: The crystallized and dried polyethylene terephthalate is mixed with soft particles, melt-extruded and cast into a thick sheet, and the thick sheet is sequentially stretched longitudinally and transversely, and then heat-treated and rolled up to obtain a base film layer;

[0020] Step 2: After forming a base layer on both sides of the base film layer, transfer it to a vacuum evaporation chamber, melt the metal, and form a metal layer on the upper and lower sides of the base film containing the base layer. After cooling, place it in a dipping solution for dipping, take it out and squeeze it to remove the liquid, and dry it to form a protective layer to obtain the functional current collector;

[0021] A preparation process of a functional current collector, the specific process steps are as follows:

[0022] Step 1: Mixing the crystallized and dried polyethylene terephthalate with modified porous silica, melt-extruding and casting into a thick sheet, sequentially stretching the thick sheet longitudinally and transversely, heat-treating and then winding it to obtain a base film layer;

[0023] Step 2: After forming a base layer on both sides of the base film layer, transfer it to a vacuum evaporation chamber, melt the metal, and form a metal layer on the upper and lower sides of the base film containing the base layer. After cooling, place it in the dipping liquid for dipping, take it out and squeeze to remove the liquid, and dry it to form a protective layer to obtain the functional current collector.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1. Use porous soft particles to replace the rigid silica particles in the composite current collector base film, thereby avoiding the defects caused by silica extrusion in the base layer during the electrode rolling process and the delamination of the base film and metal layer caused by electrolyte immersion.

[0026] 2. The rigid granular silica was replaced with modified porous silica prepared in the experiment. Compared with the rigid granular silica, the porous structure can act as a stress buffer, reducing the defects caused by the rigid material during the electrode rolling. The porous silica was amino-treated and calcined to achieve nitrogen doping, which enhanced the conductivity while improving the subsequent polymerization of styrene monomers and optimizing the interface bonding. The polystyrene soft coating was formed on the surface of the porous silica by emulsion polymerization, which improved the compatibility and reduced the defects caused by rolling.

[0027] 3. The functionalized current collector prepared by the present invention includes a base film layer, a primer layer, a metal layer and a protective layer. By optimizing the composition of the base film layer and the composition design of the primer layer, the vacuum-evaporated metal layer and the protective layer, the service life of the current collector is jointly improved. DETAILED DESCRIPTION

[0028] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0029] In the experiment, polyethylene terephthalate was purchased from Sinopec Yizheng Chemical Fiber Co., Ltd., model FG611;

[0030] Example 1: This example provides a process for preparing a functional current collector, which specifically includes the following steps:

[0031] Step 1: Place polyethylene terephthalate in a crystallizer and treat it at a crystallization temperature of 150°C for 60 minutes, then transfer it to a drying tower and treat it at a drying temperature of 160°C for 160 minutes;

[0032] Step 2: Take the polyethylene terephthalate after crystallization and drying and mix it with polystyrene in a mass percentage of 99%:1, then convey it to a twin-screw extruder, heat and melt at a temperature of 280°C, filter it with the help of a metering pump, extrude it through a die head, cast it onto a casting roller, and cool it to 30°C. The casting roller is cooled and formed into a thick sheet, and the thick sheet is longitudinally stretched and transversely stretched in sequence, and then transferred to an 80°C oven for heat treatment. After air cooling in the platform area, it enters the winding system through a traction system for film winding to obtain a base film layer; wherein the longitudinal stretching is preheated at 70°C, the longitudinal stretching is carried out at a stretch ratio of 3:1 at 110°C, and the stretching is completed. After cooling at 40°C; the transverse stretching is preheated at 80°C, the longitudinal stretching is carried out at a stretch ratio of 3:1 at 110°C, and the stretching is completed. After cooling at 40°C;

[0033] Step 3: The prepared base film is placed in a magnetron sputtering machine, with nickel-chromium alloy as the target material, argon as the gas source, the flow rate is 80 mL / min, and the pressure in the cabin is 0.1 Pa. A primer layer is magnetron sputtered on either side of the base film layer. After the primer layer is prepared, it is transferred to a vacuum evaporation cabin, and high-purity copper wire (purity of 99.99%) is evaporated in a vacuum coating chamber at a high temperature of 1600°C. The evaporated copper atoms pass through a cooling system and are deposited on the upper and lower sides of the base film containing the primer layer to form a metal layer. After cooling, it is placed in a dipping solution for dipping. After the dipping is completed, it is taken out and squeezed to remove the liquid, and then placed in a 60°C oven to dry the protective layer to obtain the functional current collector;

[0034] Among them, the polystyrene has a particle size of 0.5 μm and a ball indentation hardness of 120 MPa, and is purchased from Zhongke Keyou; the thickness of the base film layer is 4.5 μm; the base layer is a nickel-chromium alloy (the mass ratio of nickel to chromium is 80:20) with a thickness of 5 nm; the thickness of the metal layer is 1 μm; the thickness of the protective layer is 10 nm; and the dipping liquid is a 0.5 g / L potassium dichromate aqueous solution.

[0035] Example 2: basically the same as Example 1, except that the soft granular polystyrene is replaced with polymethyl methacrylate, specifically comprising the following steps:

[0036] Step 1: Place polyethylene terephthalate in a crystallizer and treat it at a crystallization temperature of 150°C for 60 minutes, then transfer it to a drying tower and treat it at a drying temperature of 160°C for 160 minutes;

[0037] Step 2: Take the polyethylene terephthalate after crystallization and drying and mix it with polymethyl methacrylate in a mass percentage of 99%:1, then convey it to a twin-screw extruder, heat and melt at a temperature of 280°C, filter it with the help of a metering pump, extrude it through a die head, cast it onto a casting roller, and cool it to 30°C. The casting roller is cooled and formed into a thick sheet, and the thick sheet is longitudinally stretched and transversely stretched in sequence, and then transferred to an 80°C oven for heat treatment. After air cooling in the platform area, it enters the winding system through a traction system for film winding to obtain a base film layer; wherein the longitudinal stretching is preheated at 70°C, the longitudinal stretching is carried out at a stretch ratio of 3:1 at 110°C, and the stretching is completed. After cooling at 40°C; the transverse stretching is preheated at 80°C, the longitudinal stretching is carried out at a stretch ratio of 3:1 at 110°C, and the stretching is completed. After cooling at 40°C;

[0038] Step 3: The prepared base film is placed in a magnetron sputtering machine, with nickel-chromium alloy as the target material, argon as the gas source, the flow rate is 80 mL / min, and the pressure in the cabin is 0.1 Pa. A primer layer is magnetron sputtered on either side of the base film layer. After the primer layer is prepared, it is transferred to a vacuum evaporation cabin, and high-purity copper wire (purity of 99.99%) is evaporated in a vacuum coating chamber at a high temperature of 1600°C. The evaporated copper atoms pass through a cooling system and are deposited on the upper and lower sides of the base film containing the primer layer to form a metal layer. After cooling, it is placed in a dipping solution for dipping. After the dipping is completed, it is taken out and squeezed to remove the liquid, and then placed in a 60°C oven to dry the protective layer to obtain the functional current collector;

[0039] Among them, the polymethyl methacrylate has a particle size of 1.0 μm and a ball indentation hardness of 150 MPa, and is purchased from Zhongke Keyou; the thickness of the base film layer is 4.5 μm; the thickness of the primer layer is 5 nm; the thickness of the metal layer is 1 μm; the thickness of the protective layer is 10 nm; and the dipping liquid is a 0.5 g / L potassium dichromate aqueous solution.

[0040] Example 3: basically the same as Example 1, except that the particle size of polystyrene is adjusted to 5 μm, specifically comprising the following steps:

[0041] Step 1: Place polyethylene terephthalate in a crystallizer and treat it at a crystallization temperature of 150°C for 60 minutes, then transfer it to a drying tower and treat it at a drying temperature of 160°C for 160 minutes;

[0042] Step 2: Take the polyethylene terephthalate after crystallization and drying and mix it with polystyrene in a mass percentage of 99%:1, then convey it to a twin-screw extruder, heat and melt at a temperature of 280°C, filter it with the help of a metering pump, extrude it through a die head, cast it onto a casting roller, and cool it to 30°C. The casting roller is cooled and formed into a thick sheet, and the thick sheet is longitudinally stretched and transversely stretched in sequence, and then transferred to an 80°C oven for heat treatment. After air cooling in the platform area, it enters the winding system through a traction system for film winding to obtain a base film layer; wherein the longitudinal stretching is preheated at 70°C, the longitudinal stretching is carried out at a stretch ratio of 3:1 at 110°C, and the stretching is completed. After cooling at 40°C; the transverse stretching is preheated at 80°C, the longitudinal stretching is carried out at a stretch ratio of 3:1 at 110°C, and the stretching is completed. After cooling at 40°C;

[0043] Step 3: The prepared base film is placed in a magnetron sputtering machine, with nickel-chromium alloy as the target material, argon as the gas source, the flow rate is 80 mL / min, the pressure in the cabin is 0.1 Pa, and a primer layer is magnetron sputtered on either side of the base film layer; after the primer layer is prepared, it is transferred to a vacuum evaporation cabin, and high-purity copper wire (purity of 99.99%) is evaporated in a vacuum coating chamber at a high temperature of 1600°C. The evaporated copper atoms pass through a cooling system and are deposited on the upper and lower sides of the base film containing the primer layer to form a metal layer. After cooling, it is placed in a dipping solution for dipping. After the dipping is completed, it is taken out and squeezed to remove the liquid, and then placed in a 60°C oven to dry the protective layer to obtain the functional current collector;

[0044] Among them, the polystyrene has a particle size of 5 μm and a ball indentation hardness of 120 MPa, and is purchased from Zhongke Keyou; the thickness of the base film layer is 4.5 μm; the thickness of the primer layer is 5 nm; the thickness of the metal layer is 1 μm; the thickness of the protective layer is 10 nm; and the dipping liquid is a 0.5 g / L potassium dichromate aqueous solution.

[0045] Example 4: basically the same as Example 1, except that polystyrene is replaced with modified porous silica particles. The specific steps are as follows:

[0046] Step 1: Place polyethylene terephthalate in a crystallizer and treat it at a crystallization temperature of 150°C for 60 minutes, then transfer it to a drying tower and treat it at a drying temperature of 160°C for 160 minutes;

[0047] Step 2: Take the polyethylene terephthalate after crystallization and drying and the modified porous silica in a mass percentage of 99%:1% and mix them evenly, then transport them to a twin-screw extruder, heat and melt at a temperature of 280°C, filter with the help of a metering pump, extrude through a die head, cast onto a casting roller, and cool the casting roller at 30°C to form a thick sheet. The thick sheet is longitudinally stretched and transversely stretched in sequence, and then transferred to an 80°C oven for heat treatment. After air cooling in the platform area, it enters the winding system through a traction system for film winding to obtain a base film layer; wherein the longitudinal stretching is preheated at 70°C, the longitudinal stretching is carried out at a stretch ratio of 3:1 at 110°C, and the stretching is completed and then cooled at 40°C; the transverse stretching is preheated at 80°C, the longitudinal stretching is carried out at a stretch ratio of 3:1 at 110°C, and the stretching is completed and then cooled at 40°C;

[0048] Step 3: The prepared base film is placed in a magnetron sputtering machine, with nickel-chromium alloy as the target material, argon as the gas source, the flow rate is 80 mL / min, the pressure in the cabin is 0.1 Pa, and a primer layer is magnetron sputtered on either side of the base film layer; after the primer layer is prepared, it is transferred to a vacuum evaporation cabin, and high-purity copper wire (purity of 99.99%) is evaporated in a vacuum coating chamber at a high temperature of 1600°C. The evaporated copper atoms pass through a cooling system and are deposited on the upper and lower sides of the base film containing the primer layer to form a metal layer. After cooling, it is placed in a dipping solution for dipping. After the dipping is completed, it is taken out and squeezed to remove the liquid, and then placed in a 60°C oven to dry the protective layer to obtain the functional current collector;

[0049] The thickness of the base film layer is 4.5 μm; the thickness of the primer layer is 5 nm; the thickness of the metal layer is 1 μm; the thickness of the protective layer is 10 nm; and the dipping liquid is a 0.5 g / L potassium dichromate aqueous solution.

[0050] The preparation steps of modified porous silica are as follows:

[0051] Step s1: 7.30 g of hexadecyltrimethylammonium bromide was placed in 100 ml of ethanol aqueous solution, the pH was adjusted to 12 with ammonia water, and then stirred to dissolve, 4.17 g of tetraethyl orthosilicate was added, stirred for 10 h, and then centrifuged and washed, and dried to obtain silica, 1 g of silica was mixed and dissolved with 6 g of urea and 50 mL of deionized water, acid was added dropwise to adjust the pH to 1.2, and then stirred at 500 rpm and 12 mL of formaldehyde was added, stirred for 50 s, and then allowed to stand overnight, 2 mL of 3-aminopropyltriethoxysilane and ammonia water were added to adjust the pH to 3, and allowed to stand for 5 h, filtered, washed, dried, and then calcined at 650° C. for 8 h to obtain porous silica;

[0052] Step s2: Take 1 g of the porous silica prepared in step s1, add 19.45 mL of deionized water, 0.45 mL of styrene, 0.05 mL of divinylbenzene and 0.05 mL of sodium lauryl sulfate in sequence, heat to 60°C, stir and emulsify for 30 minutes, add 0.02 g of potassium persulfate, heat to 80°C, react for 2 hours, filter, wash and dry to obtain modified porous silica.

[0053] Example 5: basically the same as Example 1, except that the metal layer material is replaced with aluminum. The specific steps are as follows:

[0054] Step 1: Place polyethylene terephthalate in a crystallizer and treat it at a crystallization temperature of 150°C for 60 minutes, then transfer it to a drying tower and treat it at a drying temperature of 160°C for 160 minutes;

[0055] Step 2: Take the polyethylene terephthalate after crystallization and drying and mix it with polystyrene in a mass percentage of 99%:1, then convey it to a twin-screw extruder, heat and melt at a temperature of 280°C, filter it with the help of a metering pump, extrude it through a die head, cast it onto a casting roller, and cool it to 30°C. The casting roller is cooled and formed into a thick sheet, and the thick sheet is longitudinally stretched and transversely stretched in sequence, and then transferred to an 80°C oven for heat treatment. After air cooling in the platform area, it enters the winding system through a traction system for film winding to obtain a base film layer; wherein the longitudinal stretching is preheated at 70°C, the longitudinal stretching is carried out at a stretch ratio of 3:1 at 110°C, and the stretching is completed. After cooling at 40°C; the transverse stretching is preheated at 80°C, the longitudinal stretching is carried out at a stretch ratio of 3:1 at 110°C, and the stretching is completed. After cooling at 40°C;

[0056] Step 3: Place the prepared base film in a magnetron sputtering machine, use nickel-chromium alloy as the target material, argon as the gas source, the flow rate is 80 mL / min, the pressure in the cabin is 0.1 Pa, and magnetron sputter a primer layer on either side of the base film layer; after the primer layer is prepared, transfer it to a vacuum evaporation cabin, and evaporate high-purity aluminum wire (purity of 99.99%) in a vacuum coating chamber at a high temperature of 1400°C. The evaporated aluminum atoms pass through a cooling system and are deposited on the upper and lower sides of the base film containing the primer layer to form a metal layer. After cooling, place it in a dipping solution for dipping. After dipping, take it out and squeeze it to remove the liquid, and then place it in a 60°C oven to dry the protective layer to obtain the functional current collector;

[0057] Among them, the polystyrene has a particle size of 0.5 μm and a ball indentation hardness of 120 MPa, and is purchased from Zhongke Keyou; the thickness of the base film layer is 4.5 μm; the base layer is a nickel-chromium alloy (the mass ratio of nickel to chromium is 80:20) with a thickness of 5 nm; the thickness of the metal layer is 1 μm; the thickness of the protective layer is 10 nm; and the dipping liquid is a 0.5 g / L potassium dichromate aqueous solution.

[0058] Example 6: basically the same as Example 1, except that the particle size of polystyrene is 0.1 μm; the specific steps are as follows:

[0059] Step 1: Place polyethylene terephthalate in a crystallizer and treat it at a crystallization temperature of 150°C for 60 minutes, then transfer it to a drying tower and treat it at a drying temperature of 160°C for 160 minutes;

[0060] Step 2: Take the polyethylene terephthalate after crystallization and drying and mix it with polystyrene in a mass percentage of 99%:1, then convey it to a twin-screw extruder, heat and melt at a temperature of 280°C, filter it with the help of a metering pump, extrude it through a die head, cast it onto a casting roller, and cool it to 30°C. The casting roller is cooled and formed into a thick sheet, and the thick sheet is longitudinally stretched and transversely stretched in sequence, and then transferred to an 80°C oven for heat treatment. After air cooling in the platform area, it enters the winding system through a traction system for film winding to obtain a base film layer; wherein the longitudinal stretching is preheated at 70°C, the longitudinal stretching is carried out at a stretch ratio of 3:1 at 110°C, and the stretching is completed. After cooling at 40°C; the transverse stretching is preheated at 80°C, the longitudinal stretching is carried out at a stretch ratio of 3:1 at 110°C, and the stretching is completed. After cooling at 40°C;

[0061] Step 3: The prepared base film is placed in a magnetron sputtering machine, with nickel-chromium alloy as the target material, argon as the gas source, the flow rate is 80 mL / min, the pressure in the cabin is 0.1 Pa, and a primer layer is magnetron sputtered on either side of the base film layer; after the primer layer is prepared, it is transferred to a vacuum evaporation cabin, and high-purity copper wire (purity of 99.99%) is evaporated in a vacuum coating chamber at a high temperature of 1600°C. The evaporated copper atoms pass through a cooling system and are deposited on the upper and lower sides of the base film containing the primer layer to form a metal layer. After cooling, it is placed in a dipping solution for dipping. After the dipping is completed, it is taken out and squeezed to remove the liquid, and then placed in a 60°C oven to dry the protective layer to obtain the functional current collector;

[0062] Among them, the polystyrene has a particle size of 0.1 μm and a ball indentation hardness of 120 MPa, and is purchased from Zhongke Keyou; the thickness of the base film layer is 4.5 μm; the base layer is a nickel-chromium alloy (the mass ratio of nickel to chromium is 80:20) with a thickness of 5 nm; the thickness of the metal layer is 1 μm; the thickness of the protective layer is 10 nm; and the dipping liquid is a 0.5 g / L potassium dichromate aqueous solution.

[0063] Example 7: basically the same as Example 1, except that the particle size of polystyrene is 0.05 μm; the specific steps are as follows:

[0064] Step 1: Place polyethylene terephthalate in a crystallizer and treat it at a crystallization temperature of 150°C for 60 minutes, then transfer it to a drying tower and treat it at a drying temperature of 160°C for 160 minutes;

[0065] Step 2: Take the polyethylene terephthalate after crystallization and drying and mix it with polystyrene in a mass percentage of 99%:1, then convey it to a twin-screw extruder, heat and melt at a temperature of 280°C, filter it with the help of a metering pump, extrude it through a die head, cast it onto a casting roller, and cool it to 30°C. The casting roller is cooled and formed into a thick sheet, and the thick sheet is longitudinally stretched and transversely stretched in sequence, and then transferred to an 80°C oven for heat treatment. After air cooling in the platform area, it enters the winding system through a traction system for film winding to obtain a base film layer; wherein the longitudinal stretching is preheated at 70°C, the longitudinal stretching is carried out at a stretch ratio of 3:1 at 110°C, and the stretching is completed. After cooling at 40°C; the transverse stretching is preheated at 80°C, the longitudinal stretching is carried out at a stretch ratio of 3:1 at 110°C, and the stretching is completed. After cooling at 40°C;

[0066] Step 3: Place the prepared base film in a magnetron sputtering machine, use nickel-chromium alloy as the target material, argon as the gas source, the flow rate is 80 mL / min, the pressure in the cabin is 0.1 Pa, and magnetron sputter a primer layer on either side of the base film layer; after the primer layer is prepared, transfer it to a vacuum evaporation cabin, and evaporate high-purity copper wire (purity of 99.99%) in a vacuum coating chamber at a high temperature of 1600°C. The evaporated copper atoms pass through a cooling system and are deposited on the upper and lower sides of the base film containing the primer layer to form a metal layer. After cooling, place it in a dipping solution for dip coating. After the dipping is completed, take it out and squeeze it to remove the liquid, and then place it in a 60°C oven to dry the protective layer to obtain the functional current collector;

[0067] Among them, the polystyrene has a particle size of 0.05 μm and a ball indentation hardness of 120 MPa, and is purchased from Zhongke Keyou; the thickness of the base film layer is 4.5 μm; the base layer is a nickel-chromium alloy (the mass ratio of nickel to chromium is 80:20) with a thickness of 5 nm; the thickness of the metal layer is 1 μm; the thickness of the protective layer is 10 nm; and the dipping liquid is a 0.5 g / L potassium dichromate aqueous solution.

[0068] Example 8: basically the same as Example 1, except that the particle size of polystyrene is 5.5 μm; the specific steps are as follows:

[0069] Step 1: Place polyethylene terephthalate in a crystallizer and treat it at a crystallization temperature of 150°C for 60 minutes, then transfer it to a drying tower and treat it at a drying temperature of 160°C for 160 minutes;

[0070] Step 2: Take the polyethylene terephthalate after crystallization and drying and mix it with polystyrene in a mass percentage of 99%:1, then convey it to a twin-screw extruder, heat and melt at a temperature of 280°C, filter it with the help of a metering pump, extrude it through a die head, cast it onto a casting roller, and cool it to 30°C. The casting roller is cooled and formed into a thick sheet, and the thick sheet is longitudinally stretched and transversely stretched in sequence, and then transferred to an 80°C oven for heat treatment. After air cooling in the platform area, it enters the winding system through a traction system for film winding to obtain a base film layer; wherein the longitudinal stretching is preheated at 70°C, the longitudinal stretching is carried out at a stretch ratio of 3:1 at 110°C, and the stretching is completed. After cooling at 40°C; the transverse stretching is preheated at 80°C, the longitudinal stretching is carried out at a stretch ratio of 3:1 at 110°C, and the stretching is completed. After cooling at 40°C;

[0071] Step 3: The prepared base film is placed in a magnetron sputtering machine, with nickel-chromium alloy as the target material, argon as the gas source, the flow rate is 80 mL / min, the pressure in the cabin is 0.1 Pa, and a primer layer is magnetron sputtered on either side of the base film layer. After the primer layer is prepared, it is transferred to a vacuum evaporation cabin, and high-purity copper wire (purity of 99.99%) is evaporated in a vacuum coating chamber at a high temperature of 1600°C. The evaporated copper atoms pass through a cooling system and are deposited on the upper and lower sides of the base film containing the primer layer to form a metal layer. After cooling, it is placed in a dipping solution for dipping. After the dipping is completed, it is taken out and squeezed to remove the liquid, and then placed in a 60°C oven to dry the protective layer to obtain the functional current collector;

[0072] Among them, the polystyrene has a particle size of 5.5 μm and a ball indentation hardness of 120 MPa, and is purchased from Zhongke Keyou; the thickness of the base film layer is 4.5 μm; the base layer is a nickel-chromium alloy (the mass ratio of nickel to chromium is 80:20) with a thickness of 5 nm; the thickness of the metal layer is 1 μm; the thickness of the protective layer is 10 nm; and the dipping liquid is a 0.5 g / L potassium dichromate aqueous solution.

[0073] Example 9: basically the same as Example 2, except that the particle size of polymethyl methacrylate is 0.5 μm and the ball indentation hardness is 200 MPa. Specifically, the following steps are included:

[0074] Step 1: Place polyethylene terephthalate in a crystallizer and treat it at a crystallization temperature of 150°C for 60 minutes, then transfer it to a drying tower and treat it at a drying temperature of 160°C for 160 minutes;

[0075] Step 2: Take the polyethylene terephthalate after crystallization and drying and mix it with polymethyl methacrylate in a mass percentage of 99%:1, then convey it to a twin-screw extruder, heat and melt at a temperature of 280°C, filter it with the help of a metering pump, extrude it through a die head, cast it onto a casting roller, and cool it to 30°C. The casting roller is cooled and formed into a thick sheet, and the thick sheet is longitudinally stretched and transversely stretched in sequence, and then transferred to an 80°C oven for heat treatment. After air cooling in the platform area, it enters the winding system through a traction system for film winding to obtain a base film layer; wherein the longitudinal stretching is preheated at 70°C, the longitudinal stretching is carried out at a stretch ratio of 3:1 at 110°C, and the stretching is completed. After cooling at 40°C; the transverse stretching is preheated at 80°C, the longitudinal stretching is carried out at a stretch ratio of 3:1 at 110°C, and the stretching is completed. After cooling at 40°C;

[0076] Step 3: The prepared base film is placed in a magnetron sputtering machine, with nickel-chromium alloy as the target material, argon as the gas source, the flow rate is 80 mL / min, the pressure in the cabin is 0.1 Pa, and a primer layer is magnetron sputtered on either side of the base film layer. After the primer layer is prepared, it is transferred to a vacuum evaporation cabin, and high-purity copper wire (purity of 99.99%) is evaporated in a vacuum coating chamber at a high temperature of 1600°C. The evaporated copper atoms pass through a cooling system and are deposited on the upper and lower sides of the base film containing the primer layer to form a metal layer. After cooling, it is placed in a dipping solution for dipping. After the dipping is completed, it is taken out and squeezed to remove the liquid, and then placed in a 60°C oven to dry the protective layer to obtain the functional current collector;

[0077] Among them, the particle size of polymethyl methacrylate is 0.5μm, the ball indentation hardness is 200MPa, and it is purchased from Zhongke Keyou; the thickness of the base film layer is 4.5μm; the base layer is nickel-chromium alloy (the mass ratio of nickel and chromium is 80:20), with a thickness of 5nm; the thickness of the metal layer is 1μm; the thickness of the protective layer is 10nm; the dipping liquid is 0.5g / L potassium dichromate aqueous solution.

[0078] Example 10: basically the same as Example 2, except that the particle size of polymethyl methacrylate is 0.5 μm and the ball indentation hardness is 220 MPa. Specifically, the following steps are included:

[0079] Step 1: Place polyethylene terephthalate in a crystallizer and treat it at a crystallization temperature of 150°C for 60 minutes, then transfer it to a drying tower and treat it at a drying temperature of 160°C for 160 minutes;

[0080] Step 2: Take the polyethylene terephthalate after crystallization and drying and mix it with polymethyl methacrylate in a mass percentage of 99%:1, then convey it to a twin-screw extruder, heat and melt at a temperature of 280°C, filter it with the help of a metering pump, extrude it through a die head, cast it onto a casting roller, and cool it to 30°C. The casting roller is cooled and formed into a thick sheet, and the thick sheet is longitudinally stretched and transversely stretched in sequence, and then transferred to an 80°C oven for heat treatment. After air cooling in the platform area, it enters the winding system through a traction system for film winding to obtain a base film layer; wherein the longitudinal stretching is preheated at 70°C, the longitudinal stretching is carried out at a stretch ratio of 3:1 at 110°C, and the stretching is completed. After cooling at 40°C; the transverse stretching is preheated at 80°C, the longitudinal stretching is carried out at a stretch ratio of 3:1 at 110°C, and the stretching is completed. After cooling at 40°C;

[0081] Step 3: Place the prepared base film in a magnetron sputtering machine, use nickel-chromium alloy as the target material, argon as the gas source, the flow rate is 80 mL / min, the pressure in the cabin is 0.1 Pa, and magnetron sputter a primer layer on either side of the base film layer; after the primer layer is prepared, transfer it to a vacuum evaporation cabin, and evaporate high-purity copper wire (purity of 99.99%) in a vacuum coating chamber at a high temperature of 1600°C. The evaporated copper atoms pass through a cooling system and are deposited on the upper and lower sides of the base film containing the primer layer to form a metal layer. After cooling, place it in a dipping solution for dip coating. After the dipping is completed, take it out and squeeze it to remove the liquid, and then place it in a 60°C oven to dry the protective layer to obtain the functional current collector;

[0082] Among them, the particle size of polymethyl methacrylate is 0.5μm, the ball indentation hardness is 220MPa, and it is purchased from Zhongke Keyou; the thickness of the base film layer is 4.5μm; the base layer is nickel-chromium alloy (the mass ratio of nickel to chromium is 80:20), with a thickness of 5nm; the thickness of the metal layer is 1μm; the thickness of the protective layer is 10nm; the dipping liquid is 0.5g / L potassium dichromate aqueous solution.

[0083] Comparative Example 1: As a control experiment of Example 1, the soft particles were replaced with unmodified porous silica particles. The specific steps are as follows:

[0084] Step 1: Place polyethylene terephthalate in a crystallizer and treat it at a crystallization temperature of 150°C for 60 minutes, then transfer it to a drying tower and treat it at a drying temperature of 160°C for 160 minutes;

[0085] Step 2: Take the polyethylene terephthalate after crystallization and drying and mix it with silicon dioxide in a mass percentage of 99%:1%, then transport it to a twin-screw extruder, heat and melt it at a temperature of 280°C, filter it with the help of a metering pump, extrude it through a die head, cast it onto a casting roller, and cool it to 30°C. The casting roller is cooled and formed into a thick sheet, and the thick sheet is longitudinally stretched and transversely stretched in sequence, and then transferred to an 80°C oven for heat treatment. After air cooling in the platform area, it enters the winding system through a traction system for film winding to obtain a base film layer; wherein the longitudinal stretching is preheated at 70°C, the longitudinal stretching is carried out at a stretch ratio of 3:1 at 110°C, and the stretching is completed. After cooling at 40°C; the transverse stretching is preheated at 80°C, the longitudinal stretching is carried out at a stretch ratio of 3:1 at 110°C, and the stretching is completed. After cooling at 40°C;

[0086] Step 3: placing the above-prepared base film in a magnetron sputtering machine, using nickel-chromium alloy as the target material, argon as the gas source, the flow rate is 80 mL / min, the pressure in the cabin is 0.1 Pa, and a primer layer is magnetron sputtered on either side of the base film layer; after the primer layer is prepared, it is transferred to a vacuum evaporation cabin, and high-purity copper wire is evaporated in a vacuum coating chamber at a high temperature of 1600°C. The evaporated copper atoms pass through a cooling system and are deposited on the upper and lower sides of the base film containing the primer layer to form a metal layer. After cooling, it is placed in a dipping liquid for dipping. After the dipping is completed, it is taken out and squeezed to remove the liquid, and then placed in a 60°C oven to dry the protective layer to obtain the functional current collector;

[0087] Among them, the preparation method of silica is the same as the preparation method of porous silica in Example 4, except that step s2 is not implemented; the thickness of the base film layer is 4.5 μm; the thickness of the primer layer is 5 nm; the thickness of the metal layer is 1 μm; the thickness of the protective layer is 10 nm; and the dipping liquid is a 0.5 g / L potassium dichromate aqueous solution.

[0088] Comparative Example 2: As a control experiment of Example 5, the soft particles were replaced with unmodified porous silica particles. The specific steps are as follows:

[0089] Step 1: Place polyethylene terephthalate in a crystallizer and treat it at a crystallization temperature of 150°C for 60 minutes, then transfer it to a drying tower and treat it at a drying temperature of 160°C for 160 minutes;

[0090] Step 2: Take the polyethylene terephthalate after crystallization and drying and mix it with silicon dioxide in a mass percentage of 99%:1%, then transport it to a twin-screw extruder, heat and melt it at a temperature of 280°C, filter it with the help of a metering pump, extrude it through a die head, cast it onto a casting roller, and cool it to 30°C. The casting roller is cooled and formed into a thick sheet, and the thick sheet is longitudinally stretched and transversely stretched in sequence, and then transferred to an 80°C oven for heat treatment. After air cooling in the platform area, it enters the winding system through a traction system for film winding to obtain a base film layer; wherein the longitudinal stretching is preheated at 70°C, the longitudinal stretching is carried out at a stretch ratio of 3:1 at 110°C, and the stretching is completed. After cooling at 40°C; the transverse stretching is preheated at 80°C, the longitudinal stretching is carried out at a stretch ratio of 3:1 at 110°C, and the stretching is completed. After cooling at 40°C;

[0091] Step 3: Place the prepared base film in a magnetron sputtering machine, use nickel-chromium alloy as the target material, argon as the gas source, the flow rate is 80 mL / min, the pressure in the cabin is 0.1 Pa, and magnetron sputter a primer layer on either side of the base film layer; after the primer layer is prepared, transfer it to a vacuum evaporation cabin, and evaporate high-purity aluminum wire (purity of 99.99%) in a vacuum coating chamber at a high temperature of 1400°C. The evaporated aluminum atoms pass through a cooling system and are deposited on the upper and lower sides of the base film containing the primer layer to form a metal layer. After cooling, place it in a dipping solution for dipping. After dipping, take it out and squeeze it to remove the liquid, and then place it in a 60°C oven to dry the protective layer to obtain the functional current collector;

[0092] Among them, the preparation method of silica is the same as the preparation method of porous silica in Example 4, except that step s2 is not implemented; the thickness of the base film layer is 4.5 μm; the base layer is a nickel-chromium alloy (the mass ratio of nickel to chromium is 80:20) with a thickness of 5 nm; the thickness of the metal layer is 1 μm; the thickness of the protective layer is 10 nm; and the dipping liquid is a 0.5 g / L potassium dichromate aqueous solution.

[0093] Above, some parameters adjusted in Examples 1-10 and Comparative Examples 1-2 are tabulated and sorted, as shown in the following table:

[0094] Table 1

[0095] Modified particles and particle size Ball indentation hardness of modified particles MPa Metal layer type Example 1 Commercially available polystyrene, 0.5 μm 120 Cu Example 2 Commercially available polymethyl methacrylate, 1.0 μm 150 Cu Example 3 Commercially available polystyrene, 5 μm 120 Cu Example 4 Modified porous silica / Cu Example 5 Commercially available polystyrene, 0.5 μm 120 Al Example 6 Commercially available polystyrene, 0.1 μm 120 Cu Example 7 Commercially available polystyrene, 0.05 μm 120 Cu Example 8 Commercially available polystyrene, 5.5 μm 120 Cu Example 9 Commercially available polymethyl methacrylate, 0.5 μm 200 Cu Example 10 Commercially available polymethyl methacrylate, 0.5 μm 220 Cu Comparative Example 1 Porous silica / Cu Comparative Example 2 Porous silica / Al

[0096] Detection test

[0097] 1. Adhesion:

[0098] (1) Adhesion between polymer film and metal layer before rolling: A layer of Permacel P-94 double-sided tape was adhered to a 1 mm thick aluminum foil, and the current collectors prepared in Examples 1-10 and Comparative Examples 1-2 were adhered on top of the double-sided tape. A layer of ethylene acrylic acid copolymer film (DuPont) was covered on top of the current collector. 0903, thickness of 50 μm), and then at 1.3×10 5 N / m 2 , hot pressing at 120℃ for 10s, cooling to room temperature (25℃), and cutting into 150mm×15mm strips; finally, the ethylene acrylic acid copolymer film of the sample strip was fixed to the upper fixture of the tensile machine, and the rest was fixed to the lower fixture. After fixing, the two were peeled at an angle of 180° and a speed of 100mm / min to test the peeling force, that is, the adhesion between the polymer film and the metal layer. The data are recorded in Table 2; (2) Adhesion between the polymer film and the metal layer after rolling: ① Rolling: Coat a layer of 80 microns of electrode material (the positive electrode material is LiNi) on the surface of the prepared current collector 0.8 Mn 0.1 Co 0.1 O2 (NCM811), carbon nanotubes, and polyvinylidene fluoride, with a ratio of 95:3:2; the negative electrode material is artificial graphite, carbon black, and polyvinylidene fluoride, with a ratio of 96:2:2, to prepare the electrode. The electrode is then rolled. For the positive electrode, the linear pressure is 3000N / mm, and the compaction density is 3.5g / cm 3 For the negative electrode, the line pressure is 1000N / mm and the compaction density is 1.5g / cm 3 ② Stripping of electrode materials: Place the prepared electrode sheet in an ethanol solution and soak for 2 hours to allow the electrode material to swell, then remove the electrode material on the surface of the electrode sheet to obtain the rolled current collector; continue to follow the stripping method (1) to obtain the adhesion between the polymer film and the metal layer after rolling, and the data are recorded in Table 2;

[0099] 2. Battery capacity retention rate:

[0100] The current collectors prepared in Examples 1-4, Examples 6-10 and Comparative Example 1 were used as negative electrode current collectors, and 12 μm thick aluminum foil was used as positive electrode current collector. The positive electrode material was LiNi 0.8 Mn 0.1 Co 0.1 O2 (NCM811), carbon nanotubes, and polyvinylidene fluoride, with a ratio of 95:3:2; the negative electrode material is artificial graphite, carbon black, and polyvinylidene fluoride, with a ratio of 96:2:2. Alumina ceramic coated polyethylene is used as the separator, with a thickness of 25μm; the electrolyte is 1mol·L -1A carbonate solution of LiPF6, wherein the solvent is propylene carbonate, ethylene carbonate, and ethyl methyl carbonate in a mass ratio of 1:1:1; the above materials are assembled into a battery according to the process, and the battery is cycled and discharged 800 times at 45°C, at a charge and discharge rate of 1C, in a voltage range of 3.0V to 4.2V. The battery capacity retention rate after cyclic charge and discharge is recorded in the table below. The current collector prepared in Example 5 and Comparative Example 2 is used as the positive electrode current collector, a 6-micron thick electrolytic copper foil is used as the negative electrode current collector, and the positive electrode material is LiNi 0.8 Mn 0.1 Co 0.1 O2 (NCM811), carbon nanotubes and polyvinylidene fluoride, the ratio of the three is 95:3:2; the negative electrode material is artificial graphite, carbon black and polyvinylidene fluoride, the ratio of the two is 96:2:2. Alumina ceramic coated polyethylene is used as a separator with a thickness of 25μm; the electrolyte is 1mol·L -1 A carbonate solution of LiPF6, wherein the solvent is propylene carbonate, ethylene carbonate, and ethyl methyl carbonate in a mass ratio of 1:1:1; the above materials are assembled into a battery according to the process, and the battery is cycled and discharged 800 times at 45°C, at a charge and discharge rate of 1C, within a voltage range of 3.0V to 4.2V. The battery capacity retention after cyclic charge and discharge is recorded in the following Table 2.

[0101] Table 2

[0102]

[0103] Conclusion: The functional current collector and its preparation process provided by the present invention can be applied to the processing of positive and negative current collectors. It can be seen from the above data that Example 5 has better adhesion than the other examples, and the bonding strength after rolling is also relatively excellent; and Example 4 replaces polystyrene with modified porous silica, which has good adhesion, and the prepared battery has a better battery capacity retention rate than the other examples; Comparative Examples 1 and 2 replace the soft particles with unmodified porous silica materials, and the adhesion between the polymer film and the metal layer before and after rolling is significantly reduced, and the battery capacity retention rate also decreases accordingly; it can be seen that the functional current collector and its preparation process provided by the present invention have good interface bonding strength and can significantly reduce the defects caused by rolling.

[0104] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations that come within the meaning and range of equivalents of the claims be embraced therein.

Claims

1. A functional current collector, characterized in that: The functional current collector includes a base film layer, a primer layer attached to at least one side of the base film layer, a metal layer arranged on the primer layer side away from the base film layer, and an outermost protective layer.

2. A functional current collector according to claim 1, characterized in that: The base film layer includes a polymer substrate and modified particles; the modified particles are soft particles or modified porous silica; the mass of the modified particles accounts for 0.5%-2% of the base film layer; the thickness of the base film layer is 1μm-10μm.

3. A functional current collector according to claim 2, characterized in that: The polymer substrate is at least one of polypropylene, polyethylene, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyimide, polypropylene, polyvinyl chloride, polyvinylidene fluoride, polytetrafluoroethylene, polyphenylene sulfide, polyphenylene ether and polyamide.

4. A functional current collector according to claim 2, characterized in that: The soft particles have a particle size of 0.1 μm-5.0 μm and a ball indentation hardness of ≤200 MPa; the soft particles are one or more combinations of polystyrene, styrene-divinylbenzene copolymer, polysiloxane, polymethyl methacrylate, polylactic acid-glycolic acid copolymer, carboxymethyl cellulose, and chitosan.

5. The functional current collector according to claim 1, characterized in that: The bottom layer is one or more combinations of aluminum oxide, silicon oxide, titanium oxide, nickel, chromium, titanium, nickel-chromium alloy, nickel-chromium-copper alloy, and silicon-aluminum alloy; the thickness of the bottom layer is 3nm-30nm.

6. The functional current collector according to claim 1, characterized in that: The metal layer is one of copper, aluminum, copper alloy, and aluminum alloy; the thickness of the metal layer is 500nm-2000nm; the protective layer includes any one or more of nickel, chromium, nickel-based alloy, copper-based alloy, copper oxide, aluminum oxide, nickel oxide, chromium oxide, cobalt oxide, graphite, carbon black, copper-chromium oxide, carbon nano-quantum dots, carbon nanotubes, carbon nanofibers and graphene; the thickness of the protective layer is 10nm-80nm.

7. The functional current collector according to claim 2, characterized in that: The preparation steps of the modified porous silica are as follows: Step s1: cetyltrimethylammonium bromide is placed in an ethanol aqueous solution, the pH is adjusted to 12 with ammonia water, and then stirred to dissolve, tetraethyl orthosilicate is added, stirred for 10-12 hours, and then centrifuged and washed, dried to obtain silica, mixed with urea and deionized water to dissolve, acid solution is added dropwise to adjust the pH to 0.8-1.2, and then stirred at 500-600 rpm and formaldehyde is added, stirred for 30-50 seconds, and then allowed to stand overnight, 3-aminopropyltriethoxysilane and ammonia water are added to adjust the pH to 3-4, and the mixture is allowed to stand for 4-6 hours, filtered, washed, dried, and calcined to obtain porous silica; Step s2: Take the porous silica prepared in step s1, add deionized water, styrene, divinylbenzene and an emulsifying agent in sequence, heat to 60-70°C, stir and emulsify for 30 minutes, add potassium persulfate and heat to 80-90°C, react for 2-3 hours, filter, wash and dry to obtain modified porous silica.

8. The functional current collector according to claim 7, characterized in that: The mass ratio of hexadecyltrimethylammonium bromide to tetraethyl orthosilicate is 1:(0.5-2.0); the dosage ratio of silica, urea, formaldehyde and 3-aminopropyltriethoxysilane is 1g:6g:12mL:2mL; the dosage ratio of porous silica, styrene, divinylbenzene and potassium persulfate is 1g:0.45mL:0.05mL:0.02g; the calcination temperature is 600-700℃, and the calcination time is 5-8h.

9. A process for preparing a functional current collector, characterized in that: The specific process steps are as follows: Step 1: The crystallized and dried polyethylene terephthalate is mixed with soft particles, melt-extruded and cast into a thick sheet, and the thick sheet is sequentially stretched longitudinally and transversely, and then heat-treated and rolled up to obtain a base film layer; Step 2: After forming a base layer on both sides of the base film layer, transfer it to a vacuum evaporation chamber, melt the metal, and form a metal layer on the upper and lower sides of the base film containing the base layer. After cooling, place it in the dipping liquid for dipping, then take it out and squeeze it to remove the liquid, and dry it to form a protective layer to obtain the functional current collector.

10. A process for preparing a functional current collector, characterized in that: The specific process steps are as follows: Step 1: Mixing the crystallized and dried polyethylene terephthalate with modified porous silica, melt-extruding and casting into a thick sheet, sequentially stretching the thick sheet longitudinally and transversely, heat-treating and then winding it to obtain a base film layer; Step 2: After forming a base layer on both sides of the base film layer, transfer it to a vacuum evaporation chamber, melt the metal, and form a metal layer on the upper and lower sides of the base film containing the base layer. After cooling, place it in the dipping liquid for dipping, then take it out and squeeze it to remove the liquid, and dry it to form a protective layer to obtain the functional current collector.

Images