CN113206345A - Para-aramid nanofiber/inorganic nanoparticle composite coating enhanced polyolefin battery diaphragm and preparation method thereof - Google Patents
Para-aramid nanofiber/inorganic nanoparticle composite coating enhanced polyolefin battery diaphragm and preparation method thereof Download PDFInfo
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Abstract
The invention discloses a polyolefin battery diaphragm reinforced by a para-aramid nano-fiber/inorganic nano-particle composite coating and a preparation method thereof, wherein aramid nano-fiber with excellent film forming effect and mechanical property is utilizedPreparation of ANFs/Al by combining fibers with inorganic nano aluminum oxide and silicon dioxide2O3、ANFs/SiO2The dispersion liquid is added with a layer of film on the surface of a commercial polyolefin diaphragm by using a coating or spin coating mode, so that the advantages of the para-aramid nano-fiber film-forming property and an intermolecular network cross-linking structure are fully exerted, the problems of poor temperature resistance, wrinkling and thermal shrinkage caused by temperature rise of the current commercial polyolefin diaphragm are solved, the problems of the aperture size of the diaphragm and the surface hydrophobicity of the diaphragm are solved, the thermal stability, the cycle service life and the excellent electrochemical property of the polyolefin diaphragm are improved, and the application requirements of the fields of high-performance lithium ion batteries, lithium sulfur batteries and the like on the diaphragm can be met.
Description
Technical Field
The invention relates to a battery diaphragm, in particular to a para-aramid nano-fiber/inorganic nano-particle composite coating reinforced polyolefin battery diaphragm and a preparation method thereof.
Background
The diaphragm is used as one of four main components of the battery, and has the main functions of directly separating the positive electrode and the negative electrode of the battery to prevent the short circuit of the battery, ensuring the free transmission of ions between the positive electrode and the negative electrode in the battery and directly separating the positive electrode and the negative electrode of the battery to prevent the short circuit of the battery. Although the battery diaphragm is an inert material, the battery diaphragm does not directly participate in the electrochemical reaction of the battery, and has no direct influence on the energy storage and output of the battery, the safety and the electrical performance of the battery can be greatly influenced by the quality of the physical performance of the battery diaphragm, and the free movement of ions in the battery can be ensured. At present, microporous polyolefin diaphragms (PE, PP and PP/PE) widely used have excellent chemical stability, simple preparation process, low cost and uniform pore size distribution, but the diaphragms have extremely poor heat resistance and are easy to shrink and melt by heating, thereby causing short circuit of batteries and causing accidents such as fire, explosion and the like; and the affinity of the diaphragm to the electrolyte is poor, and the electrolyte can soak the diaphragm only in a long time, so that the assembly cost of the battery is greatly increased.
The existing commercial polyolefin battery diaphragm is mainly prepared by bonding inorganic nanoparticles on the surface of a diaphragm through an adhesive to obtain a reinforced polyolefin composite diaphragm. (1) The invention patent CN111883721A proposes that inorganic nano polymer, polyolefin base material, plasticizer and antioxidant are co-extruded at high temperature by a double-screw extruder to obtain cast sheets, and then the cast sheets are subjected to biaxial stretching and heat setting to obtain inorganic nano polymer modified polyolefin lithium battery diaphragm, but the method has complex process and various used components, and influences the transmission speed of lithium ions of the diaphragm; (2) in the invention patent CN111725468A, a polyolefin diaphragm is soaked by small molecular lithium salt/ethanol solutions with different concentrations, and then a silicon dioxide inorganic nanoparticle/binder mixed solution is coated on the surface of the soaked polyolefin diaphragm to prepare a silicon dioxide inorganic nanoparticle reinforced polyolefin diaphragm, but the polyolefin diaphragm prepared by the method has poor mechanical properties, and inorganic nanoparticles are easy to fall off in the using process; (3) the invention patent CN111244361A proposes a modified polyolefin diaphragm with an ordered mesoporous silica coating on the surface of the polyolefin diaphragm, and a preparation method and application thereof, but the preparation process of the composite diaphragm is complex, and the use of adhesives and thickeners has a great influence on the diaphragm performance.
The para-aramid fiber has the characteristics of high strength, high modulus, high toughness, high temperature resistance and light specific gravity, has good impact resistance, chemical stability, flame retardance and insulativity, is an important raw material in high-end fields of aerospace, national defense, electronic communication, petrochemical industry and the like, and is widely applied to high-end fields of individual protection, bulletproof armor, rubber products, friction materials, insulating paper and the like. para-Aramid nano-fibers (ANFs) are used as a novel nano polymer fiber material developed in recent years, and the excellent mechanical property and thermal stability of the conventional macroscopic para-Aramid fibers are reserved; meanwhile, due to the unique nanoscale structure, the large length-diameter ratio and the large specific surface area, the composite reinforcing effect which cannot be realized by macroscopic aramid fibers is brought to the composite material, the composite material becomes one of reinforcing construction units with great application potential for constructing high-performance composite materials, and plays an important role in interface reinforcement and material toughening. In the field of nano composite material reinforcement, the problems of poor interface bonding force of aramid fiber and resin and the like and low material strength and the like caused by the defects of smooth surface, few active groups, strong chemical inertness and the like of the traditional macroscopic aramid fiber can be obviously improved. The ANFs are used as the reinforcing material of the composite material, and due to the fact that the ANFs have more active functional groups on the surface, larger specific surface area and more uniform distribution state in a matrix, the strength, modulus and toughness of the resin-based composite material can be remarkably and synergistically enhanced, so that the ANFs become a novel nano material which has application potential and can realize synergistic enhancement of comprehensive properties of polymers. Meanwhile, a network interweaving structure formed by hydrogen bond combination between ANFs has an excellent film forming effect, the formed film has the advantages of high strength, high temperature resistance, transparency, good flexibility and the like, and the film has certain application potential and development prospect in the fields of electrical insulation, battery diaphragms, adsorption filtration, flexible electrodes, structural weight reduction, biological tissues and the like. The application research of ANFs in the field of composite material reinforcement has become one of the research hotspots and development trends in the field of polymer nano fibers at home and abroad.
Aluminum oxide (Al)2O3) Is a white amorphous powdery high-hardness inorganic material with a melting point of 2054 ℃, silicon dioxide (SiO)2) The composite membrane is an amorphous white powder nano particle, the particle size is 1-100 nm, the particle size and the particle size have excellent high temperature resistance and chemical stability, the ionic conductivity and the temperature resistance of the composite membrane can be obviously improved by applying the composite membrane to modification of a polyolefin membrane, but the composite membrane is difficult to disperse uniformly in a dispersion liquid and is easy to agglomerate.
Disclosure of Invention
The invention aims to provide a para-aramid nano-fiber/inorganic nano-particle composite coating reinforced polyolefin battery diaphragm and a preparation method thereof, aiming at overcoming the defects in the prior art.
In order to achieve the purpose, the invention adopts the following technical scheme:
a preparation method of a para-aramid nanofiber/inorganic nanoparticle composite coating reinforced polyolefin battery diaphragm comprises the following steps:
the method comprises the following steps: mixing and stirring para-aramid fibers, DMSO, KOH and deionized water to prepare a para-aramid nanofiber solution, wherein the mass ratio of the para-aramid fibers to the KOH is 1:1.5, the volume ratio of the DMSO to the deionized water is 25:1, and 1g of the para-aramid fibers (the concentration of the para-aramid nanofiber solution is 1%) is added into each 100mL of DMSO;
step two: adding inorganic nanoparticles into the para-aramid nano-fiber solution, and then performing ultrasonic dispersion and full stirring to obtain a uniformly dispersed para-aramid nano-fiber/inorganic nanoparticle dispersion liquid;
step three: uniformly coating the para-aramid nano-fiber/inorganic nano-particle dispersion liquid on the surface of a commercial polyolefin diaphragm by using a coating rod and a spin coater, and carrying out protonation reduction on the coated diaphragm in an aqueous solution to obtain a para-aramid nano-fiber/inorganic nano-particle reinforced polyolefin diaphragm;
step four: and drying the para-aramid nano-fiber/inorganic nano-particle reinforced polyolefin diaphragm to obtain the para-aramid nano-fiber/inorganic nano-particle composite coating reinforced polyolefin battery diaphragm.
Further, in the first step, the stirring speed is 800-1500 rpm, the stirring temperature is room temperature, and the stirring time is 4-6 hours.
Further, in the first step, the diameter of the para-aramid nano-fiber is 8-15 nm, and the length of the para-aramid nano-fiber is 3-10 μm.
Further, in the second step, the inorganic nanoparticles are hydrophilic aluminum oxide or hydrophilic silicon dioxide, the particle size of the hydrophilic aluminum oxide is 20-40 nm, the particle size of the hydrophilic silicon dioxide is 15-40 nm, and the using amount of the inorganic nanoparticles is 1% -10% of the mass of the para-aramid fibers.
Furthermore, in the second step, the ultrasonic power is 500-1500W, and the ultrasonic time is 30-60 min.
Further, the commercial polyolefin separator in step three was either commercial polyolefin monolayer separator Celgard2500 or composite separator Celgard2325, which had a thickness of 25 μm each.
Furthermore, the protonation reduction time in the third step is 3-5 hours.
Further, the thickness of the coating in the third step is 3-10 μm, when a coating rod is adopted, the length of the coating rod is 120mm, and the groove depth of the coating rod is 40 μm; when a spin coater is adopted, the spin coating speed is 1000-1500 rpm, and the spin coating time is 60-90 s.
Further, in the fourth step, the drying temperature is 105 ℃, and the drying time is 10 min.
A para-aramid nano-fiber/inorganic nano-particle composite coating reinforced polyolefin battery diaphragm is prepared by adopting the preparation method of the para-aramid nano-fiber/inorganic nano-particle composite coating reinforced polyolefin battery diaphragm.
Compared with the prior art, the invention has the following beneficial technical effects:
the invention takes the para-aramid nano-fiber, inorganic aluminum oxide and silicon dioxide as a system to prepare dispersion liquid, takes commercial single-layer Celgard2500 and three-layer polyolefin diaphragm Celgard2325 as substrates, fully exerts the characteristics of excellent film forming effect and excellent thermal property of the para-aramid nano-fiber, is combined with the aluminum oxide and the silicon dioxide to improve the ionic conductivity of the diaphragm, develops a novel diaphragm material with excellent thermal stability, heat resistance, lyophilic property and excellent electrochemical property comprehensive performance, and can meet the application in the field of batteries with high cycle stability, high safety and high multiplying power performance. According to the invention, the characteristics of excellent film forming property and high temperature resistance of the aramid nano-fiber are combined with the inorganic nano-particles, so that the ion transmission speed is increased. The invention improves the problems of large aperture, poor temperature resistance, easy shrinkage, poor affinity to electrolyte, low ionic conductivity, poor cycle stability and the like of the current commercial polyolefin diaphragm, improves the comprehensive performance of the diaphragm, improves the application field of the product, can meet the application requirements of the lithium ion battery and the lithium sulfur battery field on the diaphragm, and integrally improves the energy density, the power capacity, the cycle life and the safety performance of the battery.
The composite coating enhanced polyolefin battery diaphragm is prepared by compounding the para-aramid nano-fiber with the characteristics of excellent mechanical property and excellent film forming effect on the nano scale with inorganic nano-particle aluminum oxide and silicon dioxide, and a novel diaphragm which is excellent in temperature resistance, good in electrolyte wettability, uniform in pore size and high in ionic conductivity is obtained by adding an assembly layer on the surface of the polyolefin diaphragm by using a simple coating and spin coating method. The safety problem that the battery is ignited and exploded due to thermal shrinkage caused by temperature rise in the battery circulation process because the current commercial polyolefin diaphragm has poor temperature resistance and hydrophobic surface is solved.
Drawings
FIG. 1 is a flow chart of the preparation process of the present invention;
FIG. 2 shows Celgard2500-Al obtained in example 3 of the present invention2O3Scanning electron microscopy of the @ ANFs composite membranes; wherein (a) and (b) are Celgard2500 scanning electron micrographs, and (c) and (d) are Al2O3@ ANFs scanning Electron microscopy images;
FIG. 3 shows Celgard2325-Al obtained in example 4 of the present invention2O3Scanning electron microscopy of the @ ANFs composite membranes; wherein (a) and (b) are Celgard2325 scanning electron micrographs, and (c) and (d) are Al2O3@ ANFs scanning Electron microscopy images;
FIG. 4 shows Celgard2500-SiO obtained in example 8 of the present invention2Scanning electron microscopy of the @ ANFs composite membranes; wherein (a) and (b) are Celgard2500 scanning electron micrographs, and (c) and (d) are SiO2@ ANFs scanning Electron microscopy images;
FIG. 5 shows Celgard2325-SiO obtained in example 4 of the present invention2Scanning electron microscopy of the @ ANFs composite membranes; wherein (a) and (b) are Celgard2325 scanning electronMirror image, (c) and (d) are SiO2@ ANFs scanning Electron microscopy images;
FIG. 6 shows Al obtained in examples 3 and 4 of the present invention2O3@ ANFs composite diaphragm contact angle schematic; wherein (a)1) And (c) is Celgard2500 contact angle diagram, (a)2) And (d) is Celgard2500-Al2O3@ ANFs contact Angle diagram, (b)1) And (e) is Celgard2325 contact angle diagram, (b)2) (f) is Celgard2325-Al2O3@ ANFs contact angle diagram;
FIG. 7 shows SiO obtained in examples 8 and 9 of the present invention2@ ANFs composite diaphragm contact angle schematic; wherein (a) is Celgard2500 contact angle diagram, and (b) is Celgard2500-SiO2The contact angle diagrams of @ ANFs, (c) are Celgard2325 contact angle diagrams, and (d) are Celgard2325-SiO2@ ANFs contact Angle diagram.
Detailed Description
Embodiments of the invention are described in further detail below:
a para-aramid nano-fiber/inorganic nano-particle composite coating reinforced polyolefin battery diaphragm is prepared from the following raw materials: the commercial polyolefin single-layer diaphragm Celgard2500 and the composite diaphragm Celgard2325 are used as substrates, the mass concentration of the solution is 1% of para-aramid nano-fiber solution, and the dosage of hydrophilic aluminum oxide or hydrophilic silicon dioxide is 1% -10% of the mass of the para-aramid fiber.
Referring to fig. 1, the para-aramid nanofiber/inorganic nanoparticle composite coating reinforced polyolefin battery separator is prepared by the following method:
step (1): uniformly mixing para-aramid fiber, potassium hydroxide (KOH), dimethyl sulfoxide (DMSO) and deionized water according to a certain proportion at room temperature, stirring at the room temperature at the stirring speed of 800-1500 rpm for 4-6 hours to prepare a para-aramid nanofiber solution; the mass ratio of the para-aramid fiber to the potassium hydroxide is 1:1.5, the volume ratio of the dimethyl sulfoxide to the deionized water is 25:1, 1g of para-aramid fiber is added into each 100mL of DMSO, and the diameter of the para-aramid nanofiber is 8-15 nm, and the length of the para-aramid nanofiber is 3-10 microns;
step (2): adding inorganic nanoparticles into the para-aramid nano-fiber solution obtained in the step (1), firstly performing ultrasonic dispersion in an ultrasonic dispersion machine, and then stirring on a magnetic stirrer to obtain a uniformly dispersed and uniformly systematic para-aramid nano-fiber/inorganic nanoparticle dispersion liquid; the inorganic nano particles adopt hydrophilic aluminum oxide or hydrophilic nano silicon dioxide, wherein the particle size of the hydrophilic aluminum oxide is 20-40 nm, the particle size of the hydrophilic nano silicon dioxide is 15-40 nm, the ultrasonic power is 500-1500W, and the ultrasonic time is 30-60 min; the dosage of the inorganic nanoparticles is calculated according to the mass percent of the para-aramid nano-fiber, and the addition amount is 1-10%;
and (3): uniformly coating the para-aramid nano-fiber/inorganic nano-particle dispersion liquid obtained in the step (2) on the surface of a diaphragm by adopting a coating or spin-coating mode by taking Celgard2500 or Celgard2325 diaphragm as a substrate, and then putting the coated diaphragm into water for protonation reduction; wherein the thickness of Celgard2500 and Celgard2325 is 25 μm, the thickness of coating or spin coating is 3-10 μm, and the time of protonation reduction is 3-5 h; the length of the coating rod is 120mm, and the depth of the groove of the coating rod is 40 mu m; during spin coating, the spin coating speed is 1000-1500 rpm, and the spin coating time is 60-90 s.
And (4): drying the reinforced polyolefin diaphragm of the para-aramid nano-fiber/inorganic nano-particle composite coating obtained in the step (3) to obtain a reinforced polyolefin diaphragm; wherein the drying temperature is 105 ℃, and the drying time is 10 min.
In order to make the technical solutions of the present invention better understood and implemented by those skilled in the art, the present invention is further described below with reference to the following specific embodiments and the accompanying drawings, but the embodiments are not meant to limit the present invention.
Example 1
Step (1): taking 1g of para-aramid fiber, 1.5g of potassium hydroxide, 100ml of dimethyl sulfoxide and 4ml of deionized water, and carrying out stirring reaction at room temperature, wherein the stirring rotation speed is 800rpm, and the stirring reaction time is 4 hours, so as to obtain a uniform red aramid nanofiber solution A;
step (2): taking 50ml of the aramid nano-fiber solution obtained in the step (1), adding 1% of aluminum oxide (0.005g, particle size of 20nm) into the solution, carrying out ultrasonic treatment in a 500W ultrasonic dispersion machine for 30min, and then fully stirring and dispersing the solution in a magnetic stirrer for 24h to obtain uniformly dispersed aramid nano-fiber/aluminum oxide dispersion liquid B;
and (3): uniformly coating the aramid nano-fiber/aluminum oxide dispersion liquid B on the surface of a diaphragm (the coating thickness is 3 mu m) by using a coating rod with Celgard2500 as a substrate, and putting the diaphragm in a tap water system for protonation reduction for 3 h;
and (4): and (4) drying the reduced modified diaphragm obtained in the step (3) on a sheet making device at 105 ℃ for 10min to obtain the polyolefin battery diaphragm reinforced by the para-aramid nano-fiber/aluminum oxide composite coating.
Example 2
Step (1): taking 1g of para-aramid fiber, 1.5g of potassium hydroxide, 100ml of dimethyl sulfoxide and 4ml of deionized water, and carrying out stirring reaction at room temperature, wherein the stirring rotation speed is 1200rpm, and the stirring reaction time is 5 hours, so as to obtain a uniform red aramid nanofiber solution A;
step (2): taking 50ml of the aramid nano-fiber solution obtained in the step (1), adding 3% of aluminum oxide (0.015g, the particle size of 25nm) into the solution, carrying out ultrasonic treatment in an ultrasonic dispersion machine of 800W for 40min, and then fully stirring and dispersing the solution in a magnetic stirrer for 24h to obtain uniformly dispersed aramid nano-fiber/aluminum oxide dispersion liquid B;
and (3): uniformly coating the aramid nano-fiber/aluminum oxide dispersion liquid B on the surface of a diaphragm (the coating thickness is 5 mu m) by using a coating rod with Celgard2500 as a substrate, and putting the diaphragm in a tap water system for protonation reduction for 4 h;
and (4): and (4) drying the reduced modified diaphragm obtained in the step (3) on a sheet making device at 105 ℃ for 10min to obtain the polyolefin battery diaphragm reinforced by the para-aramid nano-fiber/aluminum oxide composite coating.
Example 3
Step (1): taking 1g of para-aramid fiber, 1.5g of potassium hydroxide, 100ml of dimethyl sulfoxide and 4ml of deionized water, and carrying out stirring reaction at room temperature, wherein the stirring rotation speed is 1500rpm, and the stirring reaction time is 6 hours, so as to obtain a uniform red aramid nanofiber solution A;
step (2): taking 50ml of the aramid nano-fiber solution obtained in the step (1), adding 5% of aluminum oxide (0.025g, the particle size of 30nm) into the solution, carrying out ultrasonic treatment in a 1200W ultrasonic dispersion machine for 50min, and then fully stirring and dispersing the solution in a magnetic stirrer for 24h to obtain uniformly dispersed aramid nano-fiber/aluminum oxide dispersion liquid B;
and (3): uniformly coating the aramid nano-fiber/aluminum oxide dispersion liquid B on the surface of a diaphragm (the coating thickness is 8 mu m) by using a coating rod with Celgard2500 as a substrate, and putting the diaphragm in a tap water system for protonation reduction for 5 hours;
and (4): and (4) drying the reduced modified diaphragm obtained in the step (3) on a sheet making device at 105 ℃ for 10min to obtain the polyolefin battery diaphragm reinforced by the para-aramid nano-fiber/aluminum oxide composite coating.
Example 4
Step (1): taking 1g of para-aramid fiber, 1.5g of potassium hydroxide, 100ml of dimethyl sulfoxide and 4ml of deionized water, and carrying out stirring reaction at room temperature, wherein the stirring rotation speed is 1200rpm, and the stirring reaction time is 4 hours, so as to obtain a uniform red aramid nanofiber solution A;
step (2): taking 50ml of the aramid nano-fiber solution obtained in the step (1), adding 8% of aluminum oxide (0.04g, the particle size of 35nm) into the solution, carrying out ultrasonic treatment in a 1500W ultrasonic dispersion machine for 60min, and then fully stirring and dispersing the solution in a magnetic stirrer for 24h to obtain uniformly dispersed aramid nano-fiber/aluminum oxide dispersion liquid B;
and (3): uniformly coating the aramid nano-fiber/aluminum oxide dispersion liquid B on the surface of a diaphragm (the coating thickness is 10 mu m) by using a coating rod by using Celgard2325 as a substrate, and putting the diaphragm in a tap water system for protonation reduction for 4 hours;
and (4): and (4) drying the reduced modified diaphragm obtained in the step (3) on a sheet making device at 105 ℃ for 10min to obtain the polyolefin battery diaphragm reinforced by the para-aramid nano-fiber/aluminum oxide composite coating.
Example 5
Step (1): taking 1g of para-aramid fiber, 1.5g of potassium hydroxide, 100ml of dimethyl sulfoxide and 4ml of deionized water, and carrying out stirring reaction at room temperature, wherein the stirring rotation speed is 1000rpm, and the stirring reaction time is 6 hours, so as to obtain a uniform red aramid nanofiber solution A;
step (2): taking 50ml of the aramid nano-fiber solution obtained in the step (1), adding 10% of aluminum oxide (0.05g, the particle size of 40nm) into the solution, carrying out ultrasonic treatment in a 1500W ultrasonic dispersion machine for 40min, and then fully stirring and dispersing the solution in a magnetic stirrer for 24h to obtain uniformly dispersed aramid nano-fiber/aluminum oxide dispersion liquid B;
and (3): uniformly coating the aramid nano-fiber/aluminum oxide dispersion liquid B on the surface of a diaphragm (the coating thickness is 5 mu m) by using a coating rod by using Celgard2325 as a substrate, and putting the diaphragm in a tap water system for protonation reduction for 5 hours;
and (4): and (4) drying the reduced modified diaphragm obtained in the step (3) on a sheet making device at 105 ℃ for 10min to obtain the polyolefin battery diaphragm reinforced by the para-aramid nano-fiber/aluminum oxide composite coating.
Example 6
Step (1): taking 1g of para-aramid fiber, 1.5g of potassium hydroxide, 100ml of dimethyl sulfoxide and 4ml of deionized water, and carrying out stirring reaction at room temperature, wherein the stirring rotation speed is 800rpm, and the stirring reaction time is 4 hours, so as to obtain a uniform red aramid nanofiber solution A;
step (2): taking 50ml of the aramid nano-fiber solution obtained in the step (1), adding 1% of silicon dioxide (0.005g, the particle size is 15nm) into the solution, carrying out ultrasonic treatment in a 500W ultrasonic dispersion machine for 30min, and then fully stirring and dispersing the solution in a magnetic stirrer for 24h to obtain uniformly dispersed aramid nano-fiber/silicon dioxide dispersion liquid B;
and (3): uniformly spin-coating the aramid fiber nanofiber/silicon dioxide dispersion liquid B on the surface of a diaphragm by using a spin coater with Celgard2500 as a substrate, wherein the spin-coating speed is 1000rpm, the spin-coating time is 60s, the spin-coating thickness is 3 mu m, and the spinning solution is placed in a tap water system for protonation reduction for 3 h;
and (4): and (4) drying the reduced modified diaphragm obtained in the step (3) on a sheet making machine at 105 ℃ for 10min to obtain the polyolefin battery diaphragm reinforced by the para-aramid nano-fiber/silicon dioxide composite coating.
Example 7
Step (1): taking 1g of para-aramid fiber, 1.5g of potassium hydroxide, 100ml of dimethyl sulfoxide and 4ml of deionized water, and carrying out stirring reaction at room temperature, wherein the stirring rotation speed is 1200rpm, and the stirring reaction time is 5 hours, so as to obtain a uniform red aramid nanofiber solution A;
step (2): taking 50ml of the aramid nano-fiber solution obtained in the step (1), adding 3% of silicon dioxide (0.015g, the particle size is 30nm) into the solution, carrying out ultrasonic treatment in an ultrasonic dispersion machine of 800W for 40min, and then fully stirring and dispersing the solution in a magnetic stirrer for 24h to obtain uniformly dispersed aramid nano-fiber/silicon dioxide dispersion liquid B;
and (3): uniformly spin-coating the aramid fiber nanofiber/silicon dioxide dispersion liquid B on the surface of a diaphragm by using a spin coater with Celgard2500 as a substrate, wherein the spin-coating speed is 1200rpm, the spin-coating time is 70s, the spin-coating thickness is 5 mu m, and the spinning solution is placed in a tap water system for protonation reduction for 4 h;
and (4): and (4) drying the reduced modified diaphragm obtained in the step (3) on a sheet making machine at 105 ℃ for 10min to obtain the polyolefin battery diaphragm reinforced by the para-aramid nano-fiber/silicon dioxide composite coating.
Example 8
Step (1): taking 1g of para-aramid fiber, 1.5g of potassium hydroxide, 100ml of dimethyl sulfoxide and 4ml of deionized water, and carrying out stirring reaction at room temperature, wherein the stirring rotation speed is 1500rpm, and the stirring reaction time is 6 hours, so as to obtain a uniform red aramid nanofiber solution A;
step (2): taking 50ml of the aramid nano-fiber solution obtained in the step (1), adding 5% of silicon dioxide (0.025g, the particle size of 40nm) into the solution, carrying out ultrasonic treatment in a 1200W ultrasonic dispersion machine for 50min, and then fully stirring and dispersing the solution in a magnetic stirrer for 24h to obtain uniformly dispersed aramid nano-fiber/silicon dioxide dispersion liquid B;
and (3): uniformly spin-coating the aramid fiber nanofiber/silicon dioxide dispersion liquid B on the surface of a diaphragm by using a spin coater with Celgard2500 as a substrate, wherein the spin-coating speed is 1500rpm, the spin-coating time is 80s, the spin-coating thickness is 8 mu m, and the spinning solution is placed in a tap water system for protonation reduction for 5 h;
and (4): and (4) drying the reduced modified diaphragm obtained in the step (3) on a sheet making machine at 105 ℃ for 10min to obtain the polyolefin battery diaphragm reinforced by the para-aramid nano-fiber/silicon dioxide composite coating.
Example 9
Step (1): taking 1g of para-aramid fiber, 1.5g of potassium hydroxide, 100ml of dimethyl sulfoxide and 4ml of deionized water, and carrying out stirring reaction at room temperature, wherein the stirring rotation speed is 1200rpm, and the stirring reaction time is 4 hours, so as to obtain a uniform red aramid nanofiber solution A;
step (2): taking 50ml of the aramid nano-fiber solution obtained in the step (1), adding 8% of silicon dioxide (0.04g, the particle size is 30nm), carrying out ultrasonic treatment in a 1500W ultrasonic dispersion machine for 60min, and then fully stirring and dispersing in a magnetic stirrer for 24h to obtain uniformly dispersed aramid nano-fiber/silicon dioxide dispersion liquid B;
and (3): uniformly spin-coating the aramid fiber nanofiber/silicon dioxide dispersion liquid B on the surface of a diaphragm by using a spin coater with Celgard2325 as a substrate, wherein the spin-coating speed is 1400rpm, the spin-coating time is 90s, the spin-coating thickness is 10 mu m, and the spinning solution is placed in a tap water system for protonation reduction, and the reduction time is 4 h;
and (4): and (4) drying the reduced modified diaphragm obtained in the step (3) on a sheet making machine at 105 ℃ for 10min to obtain the polyolefin battery diaphragm reinforced by the para-aramid nano-fiber/silicon dioxide composite coating.
Example 10
Step (1): taking 1g of para-aramid fiber, 1.5g of potassium hydroxide, 100ml of dimethyl sulfoxide and 4ml of deionized water, and carrying out stirring reaction at room temperature, wherein the stirring rotation speed is 1000rpm, and the stirring reaction time is 6 hours, so as to obtain a uniform red aramid nanofiber solution A;
step (2): taking 50ml of the aramid nano-fiber solution obtained in the step (1), adding 10% of silicon dioxide (0.05g, the particle size is 15nm), carrying out ultrasonic treatment in a 1500W ultrasonic dispersion machine for 40min, and then fully stirring and dispersing in a magnetic stirrer for 24h to obtain uniformly dispersed aramid nano-fiber/silicon dioxide dispersion liquid B;
and (3): uniformly spin-coating the aramid fiber nanofiber/silicon dioxide dispersion liquid B on the surface of a diaphragm by using a spin coater with Celgard2325 as a substrate, wherein the spin-coating speed is 1500rpm, the spin-coating time is 70s, the spin-coating thickness is 5 mu m, and the diaphragm is placed in a tap water system for protonation reduction, and the reduction time is 5 h;
and (4): and (4) drying the reduced modified diaphragm obtained in the step (3) on a sheet making machine at 105 ℃ for 10min to obtain the polyolefin battery diaphragm reinforced by the para-aramid nano-fiber/silicon dioxide composite coating.
Taking examples 3 and 4 and examples 8 and 9 as examples, the aramid nanofiber/inorganic nanoparticle composite coating reinforced polyolefin battery separator prepared by the invention is detected, and scanning electron microscope results show that Celgard2500 and Celgard2325 separators have regular pore structures, wherein the average pore size of Celgard2500 is 294.12nm, the average pore size of Celgard2325 is 193.18nm, the pore size is reduced after the aramid nanofiber/inorganic nanoparticle composite coating is reinforced, but the pore size does not completely disappear, wherein the inorganic nanoparticles of aluminum oxide and silicon dioxide are uniformly distributed in the structure, which directly influences the lyophilic property and ionic conductivity of the separator; see fig. 2, 3 and 4, 5. The contact angle measurement result shows that the surface of the polyolefin diaphragm is of a hydrophobic structure, the contact angles are 129.9 degrees and 107.7 degrees, the contact angles of the diaphragm after the enhancement of the para-aramid nano-fiber/aluminum oxide composite coating reach 33.2 degrees and 29.9 degrees, the contact angles of the diaphragm after the enhancement of the para-aramid nano-fiber/silicon dioxide composite coating reach 28.6 degrees and 25.4 degrees, the hydrophobic structure is changed into a hydrophilic structure, the wetting property with electrolyte is good in the subsequent battery assembling process, the battery assembling time is shortened, and the production cost is saved; see fig. 6 and 7. The polyolefin battery diaphragm reinforced by the aramid fiber nanofiber/inorganic nanoparticle composite coating is remarkably improved in the comprehensive properties of aperture size, electrolyte wettability, heat resistance, electrochemistry and the like, and has wide application prospect and application value in the battery energy storage fields of high-performance lithium ion batteries, lithium sulfur batteries and the like.
Claims (10)
1. A preparation method of a para-aramid nanofiber/inorganic nanoparticle composite coating reinforced polyolefin battery diaphragm is characterized by comprising the following steps:
the method comprises the following steps: mixing and stirring para-aramid fibers, DMSO, KOH and deionized water to prepare a para-aramid nanofiber solution, wherein the mass ratio of the para-aramid fibers to the KOH is 1:1.5, the volume ratio of the DMSO to the deionized water is 25:1, and 1g of the para-aramid fibers is added into each 100mL of the DMSO;
step two: adding inorganic nanoparticles into the para-aramid nano-fiber solution, and then performing ultrasonic dispersion and full stirring to obtain a uniformly dispersed para-aramid nano-fiber/inorganic nanoparticle dispersion liquid;
step three: uniformly coating the para-aramid nano-fiber/inorganic nano-particle dispersion liquid on the surface of a commercial polyolefin diaphragm by using a coating rod and a spin coater, and carrying out protonation reduction on the coated diaphragm in an aqueous solution to obtain a para-aramid nano-fiber/inorganic nano-particle reinforced polyolefin diaphragm;
step four: and drying the para-aramid nano-fiber/inorganic nano-particle reinforced polyolefin diaphragm to obtain the para-aramid nano-fiber/inorganic nano-particle composite coating reinforced polyolefin battery diaphragm.
2. The preparation method of the para-aramid nanofiber/inorganic nanoparticle composite coating reinforced polyolefin battery separator as claimed in claim 1, wherein in the first step, the stirring speed is 800-1500 rpm, the stirring temperature is room temperature, and the stirring time is 4-6 hours.
3. The preparation method of the para-aramid nanofiber/inorganic nanoparticle composite coating reinforced polyolefin battery separator as claimed in claim 1, wherein in the first step, the diameter of the para-aramid nanofiber is 8-15 nm, and the length of the para-aramid nanofiber is 3-10 μm.
4. The preparation method of the para-aramid nanofiber/inorganic nanoparticle composite coating reinforced polyolefin battery diaphragm as claimed in claim 1, wherein in the second step, the inorganic nanoparticles are hydrophilic aluminum oxide or hydrophilic silicon dioxide, the particle size of the hydrophilic aluminum oxide is 20-40 nm, the particle size of the hydrophilic silicon dioxide is 15-40 nm, and the amount of the inorganic nanoparticles is 1-10% of the mass of the para-aramid fibers.
5. The preparation method of the para-aramid nanofiber/inorganic nanoparticle composite coating reinforced polyolefin battery separator as claimed in claim 1, wherein in the second step, the ultrasonic power is 500-1500W, and the ultrasonic time is 30-60 min.
6. The preparation method of the para-aramid nanofiber/inorganic nanoparticle composite coating reinforced polyolefin battery separator as claimed in claim 1, wherein the commercial polyolefin separator in step three is commercial polyolefin single-layer separator Celgard2500 or composite separator Celgard2325, and the thickness of the commercial polyolefin single-layer separator Celgard2500 or the composite separator Celgard2325 is 25 μm.
7. The preparation method of the para-aramid nanofiber/inorganic nanoparticle composite coating reinforced polyolefin battery diaphragm as claimed in claim 1, wherein the protonation reduction time in the third step is 3-5 hours.
8. The preparation method of the para-aramid nanofiber/inorganic nanoparticle composite coating reinforced polyolefin battery separator as claimed in claim 1, wherein the thickness of the coating in the third step is 3-10 μm, when a coating rod is adopted, the length of the coating rod is 120mm, and the groove depth of the coating rod is 40 μm; when a spin coater is adopted, the spin coating speed is 1000-1500 rpm, and the spin coating time is 60-90 s.
9. The preparation method of the para-aramid nanofiber/inorganic nanoparticle composite coating reinforced polyolefin battery separator as claimed in claim 1, wherein the drying temperature in the fourth step is 105 ℃, and the drying time is 10 min.
10. The para-aramid nanofiber/inorganic nanoparticle composite coating reinforced polyolefin battery diaphragm is characterized by being prepared by the preparation method of the para-aramid nanofiber/inorganic nanoparticle composite coating reinforced polyolefin battery diaphragm as claimed in any one of claims 1 to 9.
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114497882A (en) * | 2021-11-17 | 2022-05-13 | 河北金力新能源科技股份有限公司 | High-strength para-aramid diaphragm and preparation method thereof |
| CN116240748A (en) * | 2022-12-29 | 2023-06-09 | 陕西科技大学 | Basalt fiber/aramid fiber nanofiber composite paper with self-assembled layered structure and preparation method thereof |
| CN116240748B (en) * | 2022-12-29 | 2024-06-07 | 陕西科技大学 | Basalt fiber/aramid fiber nanofiber composite paper with self-assembled layered structure and preparation method thereof |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010103050A (en) * | 2008-10-27 | 2010-05-06 | Kuraray Co Ltd | Separator for lithium cell and lithium cell using it |
| KR101506944B1 (en) * | 2013-09-27 | 2015-03-30 | 주식회사 휴비스 | Battery Separator with Excellent Shut-down Function and Heat Resistance and Secondary Cell Battery Using thereof |
| CN106170878A (en) * | 2014-02-19 | 2016-11-30 | 密执安州立大学董事会 | The ion conductor of the dendrite inhibition from aromatic polyamide nanofiber of tolerance end cells condition |
| WO2017113275A1 (en) * | 2015-12-31 | 2017-07-06 | 宁波艾特米克锂电科技有限公司 | Composite nanofiber membrane for electrochemical element, preparation method and energy storage device |
| JP2017139117A (en) * | 2016-02-03 | 2017-08-10 | 旭化成株式会社 | Separator for power storage device and method for manufacturing the same |
| CN108666501A (en) * | 2018-04-26 | 2018-10-16 | 烟台泰和新材料股份有限公司 | A kind of preparation method for the p-aramid fiber membrane for polymer that can be used for lithium ion battery produced with method of electrostatic spinning |
| CN110358113A (en) * | 2019-07-03 | 2019-10-22 | 中化高性能纤维材料有限公司 | A kind of preparation method of aramid nano-fiber water-borne dispersions |
| CN111668426A (en) * | 2020-06-22 | 2020-09-15 | 欣旺达电动汽车电池有限公司 | Diaphragm and preparation method thereof, lithium ion battery and electric automobile |
-
2021
- 2021-04-21 CN CN202110431425.8A patent/CN113206345B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010103050A (en) * | 2008-10-27 | 2010-05-06 | Kuraray Co Ltd | Separator for lithium cell and lithium cell using it |
| KR101506944B1 (en) * | 2013-09-27 | 2015-03-30 | 주식회사 휴비스 | Battery Separator with Excellent Shut-down Function and Heat Resistance and Secondary Cell Battery Using thereof |
| CN106170878A (en) * | 2014-02-19 | 2016-11-30 | 密执安州立大学董事会 | The ion conductor of the dendrite inhibition from aromatic polyamide nanofiber of tolerance end cells condition |
| WO2017113275A1 (en) * | 2015-12-31 | 2017-07-06 | 宁波艾特米克锂电科技有限公司 | Composite nanofiber membrane for electrochemical element, preparation method and energy storage device |
| JP2017139117A (en) * | 2016-02-03 | 2017-08-10 | 旭化成株式会社 | Separator for power storage device and method for manufacturing the same |
| CN108666501A (en) * | 2018-04-26 | 2018-10-16 | 烟台泰和新材料股份有限公司 | A kind of preparation method for the p-aramid fiber membrane for polymer that can be used for lithium ion battery produced with method of electrostatic spinning |
| CN110358113A (en) * | 2019-07-03 | 2019-10-22 | 中化高性能纤维材料有限公司 | A kind of preparation method of aramid nano-fiber water-borne dispersions |
| CN111668426A (en) * | 2020-06-22 | 2020-09-15 | 欣旺达电动汽车电池有限公司 | Diaphragm and preparation method thereof, lithium ion battery and electric automobile |
Non-Patent Citations (1)
| Title |
|---|
| ANISH PATEL ET AL.: "《High Modulus, Thermally Stable, and Self-Extinguishing Aramid》", 《ACS APPLIED MATERIALS & INTERFACES》 * |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114497882A (en) * | 2021-11-17 | 2022-05-13 | 河北金力新能源科技股份有限公司 | High-strength para-aramid diaphragm and preparation method thereof |
| CN116240748A (en) * | 2022-12-29 | 2023-06-09 | 陕西科技大学 | Basalt fiber/aramid fiber nanofiber composite paper with self-assembled layered structure and preparation method thereof |
| CN116240748B (en) * | 2022-12-29 | 2024-06-07 | 陕西科技大学 | Basalt fiber/aramid fiber nanofiber composite paper with self-assembled layered structure and preparation method thereof |
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|---|---|
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