CN113745757B - Preparation method of lithium battery safety diaphragm material - Google Patents
Preparation method of lithium battery safety diaphragm material Download PDFInfo
- Publication number
- CN113745757B CN113745757B CN202111047590.XA CN202111047590A CN113745757B CN 113745757 B CN113745757 B CN 113745757B CN 202111047590 A CN202111047590 A CN 202111047590A CN 113745757 B CN113745757 B CN 113745757B
- Authority
- CN
- China
- Prior art keywords
- imogolite
- diaphragm material
- lithium battery
- density polyethylene
- nano powder
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
- H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
- H01M50/403—Manufacturing processes of separators, membranes or diaphragms
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
- H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
- H01M50/409—Separators, membranes or diaphragms characterised by the material
- H01M50/411—Organic material
- H01M50/414—Synthetic resins, e.g. thermoplastics or thermosetting resins
- H01M50/417—Polyolefins
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Secondary Cells (AREA)
- Battery Electrode And Active Subsutance (AREA)
Abstract
The invention discloses a preparation method of a lithium battery safety diaphragm material, which comprises the following steps: step 1, weighing an imogolite modified substance and mixing the imogolite modified substance with white oil to obtain a mixed modified liquid; step 2, weighing high-density polyethylene particles, placing the high-density polyethylene particles into a stirring mixer, and adding the mixed modification liquid to obtain a high-density polyethylene mixture; step 3, placing the high-density polyethylene mixture into a double-screw extruder, extruding, casting the mixture onto the surface of a cooling roller, and forming a casting sheet to obtain a diaphragm material blank; and 4, stretching the blank of the diaphragm material, and then sequentially drying, shaping and rolling to obtain the lithium battery safety diaphragm material. The invention effectively solves the problems of low melting point and poor size stability of the polyolefin diaphragm by improving the prior process method, the preparation process of the method is simple and convenient, the prepared diaphragm material has high safety, and simultaneously, the wettability and the air permeability of the diaphragm material are increased.
Description
Technical Field
The invention relates to the field of battery diaphragms, in particular to a preparation method of a lithium battery safety diaphragm material.
Background
The lithium battery mainly comprises a positive electrode, a negative electrode, a diaphragm and electrolyte, wherein the diaphragm provides a passage for lithium ions, and the performance of the diaphragm directly determines the interface structure and the resistance of the battery, so that the diaphragm of the lithium battery is one of the most important materials in the lithium battery, and the preparation of a microporous membrane which is safe, environment-friendly and low in cost is a difficult point in the production process. Lithium battery separators need to be balanced in terms of safety, functionality, cost and the like, which is the development direction and research focus of lithium battery separators in the future. At present, the most widely used battery diaphragm is a polyolefin microporous membrane, but because the polyolefin diaphragm has low melting point and poor dimensional stability, severe thermal shrinkage can be generated when the temperature of the battery is higher than 150 ℃, so that the positive electrode and the negative electrode of the battery are in contact with each other to cause short circuit, and potential safety hazards are caused.
In order to improve the safety of the diaphragm, a plurality of coating diaphragms prepared by coating inorganic filler on the surface of a polyolefin diaphragm appear in recent years, and although the inorganic filler has excellent high-temperature resistance and thermal stability, the acting force between the inorganic filler coating and a base film is poor; in addition, the coating modification of the inorganic filler often causes the porosity of the base film to be reduced, and the charge and discharge performance of the battery is influenced.
Disclosure of Invention
Aiming at the problems that the acting force between an inorganic filler coating and a base film is poor frequently and the porosity of the base film is reduced frequently due to the coating modification of the inorganic filler in the prior art, the invention provides a preparation method of a lithium battery safety diaphragm material.
The purpose of the invention is realized by adopting the following technical scheme:
a preparation method of a lithium battery safety diaphragm material comprises the following steps:
step 1, weighing an imogolite modified substance, mixing the imogolite modified substance with white oil, and fully dispersing to obtain a mixed modified liquid;
step 2, weighing high-density polyethylene particles, placing the high-density polyethylene particles in a stirring mixer, heating until the high-density polyethylene particles are completely molten, slowly adding the mixed modified solution, and stirring and dispersing uniformly to obtain a high-density polyethylene mixture;
step 3, placing the high-density polyethylene mixture into a double-screw extruder, extruding, casting the mixture onto the surface of a cooling roller, and forming a casting sheet to obtain a diaphragm material blank;
step 4, carrying out primary stretching treatment on the diaphragm material blank, then extracting the diaphragm material blank by using dichloromethane, carrying out secondary stretching treatment, and then sequentially carrying out drying, shaping and rolling to obtain the lithium battery safety diaphragm material;
The imogolite modified substance is obtained by performing cross-linking modification on imogolite nano powder serving as a base material.
Preferably, the high density polyethylene has a molecular weight of 20 to 50 ten thousand.
Preferably, the preparation method of the imogolite modified product comprises the following steps:
s1, weighing 2, 5-pyridinedicarboxaldehyde, mixing with deionized water, stirring for dissolving, adding activated imogolite nano powder, performing uniform ultrasonic treatment, pouring into a reaction kettle with polytetrafluoroethylene as a lining material, heating to 120-150 ℃, performing heat preservation treatment for 8-12 h, cooling to room temperature, centrifuging to collect lower-layer precipitate, washing for 3-5 times by using pure water, and performing vacuum drying treatment to obtain 2, 5-pyridinedicarboxaldehyde/imogolite; wherein the mass ratio of the 2, 5-pyridinedicarboxaldehyde, the activated imogolite nano powder to the deionized water is 1: 3-6: 10-15;
s2, weighing polyacrylamide and ethylene glycol, mixing, stirring for dissolving, adding 2-pyridylaldehyde/imogolite, uniformly dispersing, sequentially adding triethylsilane and trifluoroacetic acid while stirring, heating to 100-120 ℃ after adding, stirring for reacting for 15-18 h, cooling to room temperature, centrifuging, collecting lower-layer precipitates, washing for 3-5 times by using pure water, and performing vacuum drying treatment to obtain an imogolite modified substance; wherein the mass ratio of the polyacrylamide to the 2-pyridylaldehyde to the imogolite to the ethylene glycol is 1: 3.2-5.6: 8-10; the mass ratio of the triethylsilane to the trifluoroacetic acid to the polyacrylamide is 2: 4-6: 10-15.
Preferably, the preparation process of the activated imogolite nano-powder comprises the following steps: placing the imogolite nano powder in an acid liquor for ultrasonic treatment for 2-3 h, then washing the imogolite nano powder to be neutral by using pure water, and drying the imogolite nano powder to obtain activated imogolite nano powder; the acid solution comprises 1-2 mol/L sulfuric acid solution or nitric acid solution, and the mass ratio of the imogolite nano powder to the acid solution is 1: 5-10.
More preferably, the imogolite nano-powder has a particle size of 50 to 200 nm.
Preferably, in the step 1, the mass ratio of the imogolite modified substance to the white oil is 1: 8-12.
Preferably, in the step 1, the mixing temperature of the imogolite modified product and the white oil is 135-155 ℃, and the dispersion time is 0.5-1 h.
Preferably, in the step 2, the temperature of the stirring mixer is set to be 140-150 ℃.
Preferably, in the step 2, after the mixed modification liquid is completely added, the stirring is continued for 0.2-0.5 h.
Preferably, in the step 3, the temperature of the roll surface is 20-40 ℃.
Preferably, in the step 4, the temperature of the first stretching treatment is 50-70 ℃, and the temperature of the second stretching treatment is 100-120 ℃.
Preferably, in the step 4, the first stretching treatment is transverse stretching and then longitudinal stretching, wherein the transverse stretching magnification is 2-3 times, and the longitudinal stretching magnification is 1.5-2 times.
Preferably, in the step 4, the second stretching treatment is transverse stretching, wherein the transverse stretching ratio is 1.5 to 2 times.
Preferably, in the step 4, the drying condition is vacuum drying, the drying temperature is 45-55 ℃, and the setting temperature is 110-120 ℃.
Preferably, the thickness of the lithium battery safety diaphragm material is 10-50 mu m.
The beneficial effects of the invention are as follows:
1. the invention discloses a preparation method of a lithium battery safety diaphragm material, which effectively solves the problems of low melting point and poor size stability of a polyolefin diaphragm by improving the prior process method.
2. According to the safety diaphragm material for the lithium battery, the high-density polyethylene is used as a base material, imogolite is used as an inorganic filler to improve the high temperature resistance of the safety diaphragm material, the method for coating the inorganic filler layer on the surface of the porous polyethylene membrane in the market is abandoned, the inorganic filler is fused with the polyethylene, and the fusion of the general inorganic filler and the polyethylene cannot enhance the performance but also can weaken the service life of the polyethylene as the diaphragm. In the process of combining with polyethylene, the pore-forming agent white oil is combined firstly, and then dichloromethane is used for extraction and washing, so that the pore channel is formed.
3. Although high density polyethylene is excellent in hardness, tensile strength and creep property and improved in heat resistance to a certain extent as compared with ordinary polyethylene, it is still insufficient in shrinkage resistance, and particularly, it is deteriorated by thermal oxidation to significantly reduce the air permeability, and therefore it is necessary to modify it. The imogolite modifier prepared by the invention not only enhances the mechanical strength of the high-density polyethylene, but also enhances the high temperature resistance and shrinkage resistance of the high-density polyethylene, so that the finally prepared diaphragm material has better safety.
Detailed Description
For the purpose of more clearly illustrating the present invention and more clearly understanding the technical features, objects and advantages of the present invention, the technical solutions of the present invention will now be described in detail below, but the present invention should not be construed as being limited to the implementable scope of the present invention.
The traditional high-temperature-resistant inorganic material cannot meet the market requirements, the acting force between the prepared inorganic filler coating and the base film is not strong enough, and the inorganic particle coating layer easily blocks micropores of the base film, so that the porosity of the coated diaphragm is reduced, the air permeability of the diaphragm is poor, and the diaphragm needs to be optimized and modified. According to the invention, imogolite which is rare in the market is selected as a high-temperature resistant base material, the imogolite is a natural nano mineral and has a single-wall tubular nano structure, a coiled gibbsite plate forms an outer tube framework, and the inner side of the tube is an orthosilicic acid group.
The process for the preparation of the imogolite modification according to the invention and the possible related principles are explained as follows:
firstly, activating imogolite by using an acid solution to activate active functional groups on the surface of the imogolite, then performing surface modification by using 2, 5-pyridinedicarboxaldehyde containing a dialdehyde group to obtain 2, 5-pyridinedicarboxaldehyde/imogolite with the 2, 5-pyridinedicarboxaldehyde coated on the surface, then combining polyacrylamide with excellent thermal stability with the 2, 5-pyridinedicarboxaldehyde/imogolite, and under the catalysis of a triethylsilane-trifluoroacetic acid system, activating the aldehyde group (-CHO) on the 2, 5-pyridinedicarboxaldehyde/imogolite and an amide group (-CO-NH) in the polyacrylamide2) And (3) an imide group (-CO-NH-) is generated through the reaction, so that the polyacrylamide is coated outside the 2, 5-pyridinedicarboxaldehyde/imogolite, and the polyacrylamide and the imogolite are crosslinked through the imide group, so that the stability can be improved. And polyacrylamide itselfThe modified imogolite water-soluble polymer has strong water solubility, and after reaction treatment, the solubility of the modified imogolite water-soluble polymer in water is reduced, but the hydrophilic property of the modified imogolite water-soluble polymer is still kept, so that the wettability of a diaphragm material on an electrolyte can be ensured, the chemical stability of 2, 5-pyridinedicarboxaldehyde is strong, and the obtained product after modification of the imogolite is more stable. In addition, the invention also finds that the service life of the battery diaphragm is longer and the electrical cycle performance is enhanced after the imogolite modifier is used for modifying the polyethylene.
The invention is further described below with reference to the following examples.
Example 1
A preparation method of a lithium battery safety diaphragm material comprises the following steps:
step 1, weighing an imogolite modified substance, mixing the imogolite modified substance with white oil, wherein the mixing temperature is 145 ℃, and fully dispersing for 0.8h to obtain a mixed modified liquid; wherein the mass ratio of the imogolite modified substance to the white oil is 1: 10;
step 2, weighing high-density polyethylene particles, placing the high-density polyethylene particles into a stirring mixer, heating to 145 ℃ for complete melting, slowly adding the mixed modification solution, and continuously stirring and dispersing for 0.4h to obtain a high-density polyethylene mixture;
step 3, placing the high-density polyethylene mixture in a double-screw extruder, extruding, casting to the roll surface of a cooling roller with the temperature of 30 ℃, and obtaining a diaphragm material blank after casting sheet forming;
step 4, performing primary stretching treatment on the diaphragm material blank at the temperature of 60 ℃, then extracting by using dichloromethane, performing secondary stretching treatment at the temperature of 110 ℃, and then sequentially drying, shaping and rolling to obtain a lithium battery safety diaphragm material with the thickness of 10-50 microns; wherein, the first stretching treatment is transverse stretching and then longitudinal stretching, the transverse stretching multiplying power is 2.5 times, and the longitudinal stretching multiplying power is 1.8 times; the second stretching treatment was transverse stretching with a stretching magnification of 1.8 times.
The preparation method of the imogolite modifier in the step 1 comprises the following steps:
s1, placing imogolite nano powder with the particle size of 50-200 nm in acid liquor for ultrasonic treatment for 2.5 hours, then washing the imogolite nano powder to be neutral by using pure water, and drying the imogolite nano powder to obtain activated imogolite nano powder; wherein the acid solution comprises 1.5mol/L sulfuric acid solution or nitric acid solution, and the mass ratio of the imogolite nano powder to the acid solution is 1: 8;
s2, weighing 2, 5-pyridinedicarboxaldehyde, mixing with deionized water, stirring for dissolving, adding activated imogolite nano powder, performing uniform ultrasonic treatment, pouring into a reaction kettle with polytetrafluoroethylene as a lining material, heating to 135 ℃, performing heat preservation treatment for 10 hours, cooling to room temperature, centrifuging to collect lower-layer precipitate, washing for 3-5 times by using pure water, and performing vacuum drying treatment to obtain 2, 5-pyridinedicarboxaldehyde/imogolite; wherein the mass ratio of the 2, 5-pyridinedicarboxaldehyde, the activated imogolite nano powder to the deionized water is 1:4: 12;
s3, weighing polyacrylamide and ethylene glycol, mixing, stirring for dissolving, adding 2-pyridylaldehyde/imogolite, uniformly dispersing, sequentially adding triethylsilane and trifluoroacetic acid while stirring, heating to 110 ℃ after adding, stirring for reacting for 16 hours, cooling to room temperature, centrifuging, collecting lower-layer precipitates, washing for 3-5 times by using pure water, and performing vacuum drying treatment to obtain an imogolite modified substance; wherein the mass ratio of the polyacrylamide to the 2-pyridylaldehyde to the imogolite to the ethylene glycol is 1:4.8: 9; the mass ratio of the triethylsilane to the trifluoroacetic acid to the polyacrylamide is 2:5: 13.
Example 2
A preparation method of a lithium battery safety diaphragm material comprises the following steps:
step 1, weighing an imogolite modified substance, mixing the imogolite modified substance with white oil, wherein the mixing temperature is 135 ℃, and fully dispersing for 0.5h to obtain a mixed modified liquid; wherein the mass ratio of the imogolite modified substance to the white oil is 1: 8;
step 2, weighing high-density polyethylene particles, placing the high-density polyethylene particles in a stirring mixer, heating to 140 ℃ to completely melt, slowly adding a mixed modification solution, and continuously stirring and dispersing for 0.2h to obtain a high-density polyethylene mixture;
step 3, placing the high-density polyethylene mixture in a double-screw extruder, extruding, casting to the roll surface of a cooling roller with the temperature of 20 ℃, and obtaining a diaphragm material blank after casting sheet forming;
step 4, performing primary stretching treatment on the diaphragm material blank at the temperature of 50 ℃, extracting by using dichloromethane, performing secondary stretching treatment at the temperature of 100 ℃, and then sequentially drying, shaping and rolling to obtain a lithium battery safety diaphragm material with the thickness of 10-50 microns; wherein, the first stretching treatment is transverse stretching and then longitudinal stretching, the transverse stretching multiplying power is 2 times, and the longitudinal stretching multiplying power is 1.5 times; the second stretching treatment was transverse stretching with a stretching magnification of 1.5 times.
The preparation method of the imogolite modifier in the step 1 comprises the following steps:
s1, placing imogolite nano powder with the particle size of 50-200 nm in acid liquor for ultrasonic treatment for 2 hours, then washing the imogolite nano powder to be neutral by using pure water, and drying the imogolite nano powder to obtain activated imogolite nano powder; wherein the acid solution comprises 1mol/L sulfuric acid solution or nitric acid solution, and the mass ratio of the imogolite nano powder to the acid solution is 1: 5;
s2, weighing 2, 5-pyridinedicarboxaldehyde, mixing with deionized water, stirring for dissolving, adding activated imogolite nano powder, uniformly performing ultrasonic treatment, pouring into a reaction kettle with polytetrafluoroethylene as a lining, heating to 120 ℃, performing heat preservation for 8 hours, cooling to room temperature, centrifuging, collecting lower-layer precipitate, washing for 3-5 times by using pure water, and performing vacuum drying treatment to obtain 2, 5-pyridinedicarboxaldehyde/imogolite; wherein the mass ratio of the 2, 5-pyridinedicarboxaldehyde, the activated imogolite nano powder to the deionized water is 1:3: 10;
s3, weighing polyacrylamide and ethylene glycol, mixing, stirring for dissolving, adding 2-pyridylaldehyde/imogolite, uniformly dispersing, sequentially adding triethylsilane and trifluoroacetic acid while stirring, heating to 100 ℃ after adding, stirring for reacting for 15 hours, cooling to room temperature, centrifuging, collecting lower-layer precipitates, washing for 3-5 times by using pure water, and performing vacuum drying treatment to obtain an imogolite modified substance; wherein the mass ratio of the polyacrylamide to the 2-pyridylaldehyde to the imogolite to the ethylene glycol is 1:3.2: 8; the mass ratio of the triethylsilane to the trifluoroacetic acid to the polyacrylamide is 2:4: 10.
Example 3
A preparation method of a lithium battery safety diaphragm material comprises the following steps:
step 1, weighing an imogolite modified substance, mixing the imogolite modified substance with white oil, wherein the mixing temperature is 155 ℃, and fully dispersing for 1 hour to obtain a mixed modified liquid; wherein the mass ratio of the imogolite modified substance to the white oil is 1: 12;
step 2, weighing high-density polyethylene particles, placing the high-density polyethylene particles in a stirring mixer, heating to 150 ℃, completely melting, slowly adding the mixed modified solution, and continuously stirring and dispersing for 0.5 hour to obtain a high-density polyethylene mixture;
step 3, placing the high-density polyethylene mixture in a double-screw extruder, extruding, casting to a roller surface of a cooling roller with the temperature of 40 ℃, and obtaining a diaphragm material blank after casting sheet forming;
step 4, performing primary stretching treatment on the diaphragm material blank at the temperature of 70 ℃, extracting by using dichloromethane, performing secondary stretching treatment at the temperature of 120 ℃, and then sequentially drying, shaping and rolling to obtain a lithium battery safety diaphragm material with the thickness of 10-50 microns; wherein, the first stretching treatment is transverse stretching and then longitudinal stretching, the transverse stretching multiplying power is 3 times, and the longitudinal stretching multiplying power is 2 times; the second stretching treatment was transverse stretching with a stretching magnification of 2.
The preparation method of the imogolite modifier in the step 1 comprises the following steps:
s1, placing imogolite nano powder with the particle size of 50-200 nm in acid liquor for ultrasonic treatment for 3 hours, then washing the imogolite nano powder to be neutral by using pure water, and drying the imogolite nano powder to obtain activated imogolite nano powder; wherein the acid solution comprises 2mol/L sulfuric acid solution or nitric acid solution, and the mass ratio of the imogolite nano powder to the acid solution is 1: 10;
s2, weighing 2, 5-pyridinedicarboxaldehyde, mixing with deionized water, stirring for dissolving, adding activated imogolite nano powder, uniformly performing ultrasonic treatment, pouring into a reaction kettle with polytetrafluoroethylene as a lining material, heating to 150 ℃, performing heat preservation treatment for 12 hours, cooling to room temperature, centrifuging to collect lower-layer precipitate, washing for 3-5 times by using pure water, and performing vacuum drying treatment to obtain 2, 5-pyridinedicarboxaldehyde/imogolite; wherein the mass ratio of the 2, 5-pyridinedicarboxaldehyde, the activated imogolite nano powder to the deionized water is 1:6: 15;
s3, weighing polyacrylamide and ethylene glycol, mixing, stirring for dissolving, adding 2-pyridylaldehyde/imogolite, uniformly dispersing, sequentially adding triethylsilane and trifluoroacetic acid while stirring, heating to 120 ℃ after adding, stirring for reacting for 18 hours, cooling to room temperature, centrifuging, collecting lower-layer precipitates, washing for 3-5 times by using pure water, and performing vacuum drying treatment to obtain an imogolite modified substance; wherein the mass ratio of polyacrylamide, 2-pyridylaldehyde/imogolite to ethylene glycol is 1:5.6: 10; the mass ratio of the triethylsilane to the trifluoroacetic acid to the polyacrylamide is 2:6: 15.
Comparative example 1
A preparation method of a lithium battery safety diaphragm material comprises the following steps:
step 1, weighing imogolite and mixing the imogolite with white oil, wherein the mixing temperature is 145 ℃, and fully dispersing for 0.8h to obtain a mixed modification liquid; wherein the mass ratio of imogolite to white oil is 1: 10;
step 2, weighing high-density polyethylene particles, placing the high-density polyethylene particles in a stirring mixer, heating to 145 ℃ to completely melt the high-density polyethylene particles, slowly adding the mixed modified solution, and continuously stirring and dispersing for 0.4h to obtain a high-density polyethylene mixture;
step 3, placing the high-density polyethylene mixture into a double-screw extruder, extruding, casting to the roll surface of a cooling roller with the temperature of 30 ℃, and obtaining a diaphragm material blank after casting sheet forming;
step 4, performing primary stretching treatment on the diaphragm material blank at the temperature of 60 ℃, then extracting by using dichloromethane, performing secondary stretching treatment at the temperature of 110 ℃, and then sequentially drying, shaping and rolling to obtain a lithium battery safety diaphragm material with the thickness of 10-50 mu m; wherein the first stretching treatment comprises transverse stretching and longitudinal stretching, the transverse stretching multiplying power is 2.5 times, and the longitudinal stretching multiplying power is 1.8 times; the second stretching treatment was transverse stretching with a stretching magnification of 1.8 times.
Comparative example 2
A preparation method of a lithium battery safety diaphragm material comprises the following steps:
step 1, weighing an imogolite modified substance, mixing the imogolite modified substance with white oil, wherein the mixing temperature is 145 ℃, and fully dispersing for 0.8h to obtain a mixed modified liquid; wherein the mass ratio of the imogolite modified substance to the white oil is 1: 10;
step 2, weighing high-density polyethylene particles, placing the high-density polyethylene particles in a stirring mixer, heating to 145 ℃ to completely melt the high-density polyethylene particles, slowly adding the mixed modified solution, and continuously stirring and dispersing for 0.4h to obtain a high-density polyethylene mixture;
step 3, placing the high-density polyethylene mixture into a double-screw extruder, extruding, casting to the roll surface of a cooling roller with the temperature of 30 ℃, and obtaining a diaphragm material blank after casting sheet forming;
step 4, performing primary stretching treatment on the diaphragm material blank at the temperature of 60 ℃, then extracting by using dichloromethane, performing secondary stretching treatment at the temperature of 110 ℃, and then sequentially drying, shaping and rolling to obtain a lithium battery safety diaphragm material with the thickness of 10-50 microns; wherein the first stretching treatment comprises transverse stretching and longitudinal stretching, the transverse stretching multiplying power is 2.5 times, and the longitudinal stretching multiplying power is 1.8 times; the second stretching treatment was transverse stretching with a stretching magnification of 1.8 times.
The preparation method of the imogolite modifier in the step 1 comprises the following steps:
s1, placing imogolite nano powder with the particle size of 50-200 nm in acid liquor for ultrasonic treatment for 2.5 hours, then washing the imogolite nano powder to be neutral by using pure water, and drying the imogolite nano powder to obtain activated imogolite nano powder; wherein the acid solution comprises 1.5mol/L sulfuric acid solution or nitric acid solution, and the mass ratio of the imogolite nano powder to the acid solution is 1: 8;
s2, weighing polyacrylamide and ethylene glycol, mixing, stirring for dissolving, adding activated imogolite nano powder, uniformly dispersing, sequentially adding triethylsilane and trifluoroacetic acid while stirring, heating to 110 ℃ after the addition is finished, stirring for reacting for 16 hours, cooling to room temperature, centrifuging, collecting lower-layer precipitates, washing for 3-5 times by using pure water, and performing vacuum drying treatment to obtain the imogolite modified substance; wherein the mass ratio of the polyacrylamide, the activated imogolite nano powder and the ethylene glycol is 1:4.8: 9; the mass ratio of the triethylsilane to the trifluoroacetic acid to the polyacrylamide is 2:5: 13.
For more clearly illustrating the invention, the membrane materials prepared in examples 1 to 3 and comparative examples 1 to 2 were prepared to have a thickness of (20 ± 0.1) μm, and the tensile strength, the air permeability, the thermal shrinkage rate and the ionic conductivity were measured according to the GB/T1040.3-2006 standard, and the thermal shrinkage rate, the thermal shrinkage rate and the ionic conductivity were measured according to the GB/T36363-2018 standard, and the thermal shrinkage rate was the shrinkage rate after 1h of treatment at 150 ℃.
The results are shown in table 1:
table 1 comparison of the properties of different separator materials
As can be seen from Table 1, the film disclosed in the embodiments 1-3 of the invention has better mechanical strength and air permeability, higher film breaking temperature, lower thermal shrinkage and smaller contact angle with water while maintaining the pore closing temperature of 130 ℃, which indicates that the film has better high temperature resistance, air permeability, safety and wettability.
Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present invention, and not for limiting the protection scope of the present invention, although the present invention is described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions can be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.
Claims (8)
1. The preparation method of the lithium battery safety diaphragm material is characterized by comprising the following steps of:
step 1, weighing an imogolite modified substance, mixing the imogolite modified substance with white oil, and fully dispersing to obtain a mixed modified liquid;
step 2, weighing high-density polyethylene particles, placing the high-density polyethylene particles in a stirring mixer, heating until the high-density polyethylene particles are completely molten, slowly adding a mixed modification solution, and stirring and dispersing uniformly to obtain a high-density polyethylene mixture;
Step 3, placing the high-density polyethylene mixture in a double-screw extruder, extruding, casting to the surface of a cooling roller, and obtaining a diaphragm material blank after casting sheet forming;
step 4, carrying out primary stretching treatment on the diaphragm material blank, then extracting the diaphragm material blank by using dichloromethane, carrying out secondary stretching treatment, and then sequentially carrying out drying, shaping and rolling to obtain the lithium battery safety diaphragm material;
the imogolite modified substance is obtained by performing cross-linking modification on imogolite nano powder serving as a base material;
the preparation method of the imogolite modified substance comprises the following steps:
s1, weighing 2, 5-pyridinedicarboxaldehyde, mixing with deionized water, stirring for dissolving, adding activated imogolite nano powder, performing uniform ultrasonic treatment, pouring into a reaction kettle with polytetrafluoroethylene as a lining material, heating to 120-150 ℃, performing heat preservation treatment for 8-12 h, cooling to room temperature, centrifuging to collect lower-layer precipitate, washing for 3-5 times by using pure water, and performing vacuum drying treatment to obtain 2, 5-pyridinedicarboxaldehyde/imogolite; wherein the mass ratio of the 2, 5-pyridinedicarboxaldehyde, the activated imogolite nano powder to the deionized water is 1: 3-6: 10-15;
s2, weighing polyacrylamide and ethylene glycol, mixing, stirring for dissolving, adding 2-pyridylaldehyde/imogolite, uniformly dispersing, sequentially adding triethylsilane and trifluoroacetic acid while stirring, heating to 100-120 ℃ after adding, stirring for reacting for 15-18 h, cooling to room temperature, centrifuging, collecting lower-layer precipitates, washing for 3-5 times by using pure water, and performing vacuum drying treatment to obtain an imogolite modified substance; wherein the mass ratio of the polyacrylamide to the 2-pyridylaldehyde to the imogolite to the ethylene glycol is 1: 3.2-5.6: 8-10; the mass ratio of the triethylsilane to the trifluoroacetic acid to the polyacrylamide is 2: 4-6: 10-15;
The preparation process of the activated imogolite nano powder comprises the following steps: placing the imogolite nano powder in an acid liquor for ultrasonic treatment for 2-3 h, then washing the imogolite nano powder to be neutral by using pure water, and drying the imogolite nano powder to obtain activated imogolite nano powder; the acid solution comprises 1-2 mol/L sulfuric acid solution or nitric acid solution, and the mass ratio of the imogolite nano powder to the acid solution is 1: 5-10.
2. The preparation method of the lithium battery safety separator material as claimed in claim 1, wherein in the step 1, the mass ratio of the imogolite modifier to the white oil is 1: 8-12.
3. The method for preparing the lithium battery safety diaphragm material according to claim 1, wherein in the step 1, the mixing temperature of the imogolite modifier and the white oil is 135-155 ℃, and the dispersion time is 0.5-1 h.
4. The method for preparing a lithium battery safety separator material according to claim 1, wherein in the step 2, the temperature of the stirring mixer is set to be 140 to 150 ℃.
5. The method for preparing a lithium battery safety diaphragm material according to claim 1, wherein in the step 2, after the mixed modification liquid is completely added, the stirring is continued for 0.2-0.5 h.
6. The method for preparing a lithium battery safety diaphragm material according to claim 1, wherein in the step 4, the temperature of the first stretching treatment is 50-70 ℃, and the temperature of the second stretching treatment is 100-120 ℃.
7. The method for preparing a lithium battery safety diaphragm material according to claim 1, wherein in the step 4, the first stretching treatment is transverse stretching and then longitudinal stretching, wherein the transverse stretching ratio is 2-3 times, and the longitudinal stretching ratio is 1.5-2 times.
8. The method for preparing a lithium battery safety diaphragm material according to claim 1, wherein in the step 4, the second stretching treatment is transverse stretching, wherein the transverse stretching rate is 1.5-2 times.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111047590.XA CN113745757B (en) | 2021-09-07 | 2021-09-07 | Preparation method of lithium battery safety diaphragm material |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111047590.XA CN113745757B (en) | 2021-09-07 | 2021-09-07 | Preparation method of lithium battery safety diaphragm material |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113745757A CN113745757A (en) | 2021-12-03 |
| CN113745757B true CN113745757B (en) | 2022-06-28 |
Family
ID=78736951
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111047590.XA Active CN113745757B (en) | 2021-09-07 | 2021-09-07 | Preparation method of lithium battery safety diaphragm material |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113745757B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114032000B (en) * | 2021-12-13 | 2022-06-14 | 安徽漫画树涂料有限公司 | Inorganic aldehyde-removing fireproof water-based paint |
| CN114304824B (en) * | 2022-01-14 | 2023-11-17 | 北京华夏理想证章有限公司 | Durable wear-resistant souvenir badge and preparation method thereof |
| CN115108817B (en) * | 2022-06-17 | 2023-04-18 | 无锡畾田陶瓷科技有限公司 | Environment-friendly wear-resistant ceramic brick and preparation process thereof |
Family Cites Families (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH11130900A (en) * | 1997-10-27 | 1999-05-18 | Asahi Chem Ind Co Ltd | Finely porous polyethylene membrane |
| KR20080029428A (en) * | 2006-09-29 | 2008-04-03 | 도레이새한 주식회사 | Method of manufacturing polyolefin microporous films |
| CN102064299A (en) * | 2010-12-25 | 2011-05-18 | 佛山塑料集团股份有限公司 | Polyolefin multi-layer porous diaphragm for lithium ion battery and preparation method thereof |
| EP2849258A4 (en) * | 2012-05-09 | 2015-12-30 | Hitachi Chemical Co Ltd | Separator for electrochemical element and fabrication method for same |
| CN103865093B (en) * | 2012-12-18 | 2016-04-20 | 中国第一汽车股份有限公司 | A kind of lithium ion battery separator process for surface preparation |
| CN106784528A (en) * | 2016-12-27 | 2017-05-31 | 深圳市星源材质科技股份有限公司 | A kind of preparation method of lithium battery diaphragm |
| CN109742298B (en) * | 2019-01-08 | 2024-07-12 | 桑顿新能源科技有限公司 | Porous ceramic diaphragm slurry, preparation method thereof, battery diaphragm and battery |
| CN112350025B (en) * | 2019-08-09 | 2022-08-05 | 江苏厚生新能源科技有限公司 | Organic/inorganic hybrid microporous diaphragm and application thereof |
| CN110911617A (en) * | 2019-12-10 | 2020-03-24 | 安徽新衡新材料科技有限公司 | High-toughness polyolefin lithium ion battery diaphragm and preparation method thereof |
| CN112259904A (en) * | 2020-09-28 | 2021-01-22 | 河北金力新能源科技股份有限公司 | High-strength low-shrinkage lithium ion battery diaphragm and preparation method thereof |
-
2021
- 2021-09-07 CN CN202111047590.XA patent/CN113745757B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN113745757A (en) | 2021-12-03 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN113745757B (en) | Preparation method of lithium battery safety diaphragm material | |
| JP5176318B2 (en) | Aromatic polyamide porous film, method for producing aromatic polyamide porous film, and secondary battery | |
| CN111477816A (en) | Lithium ion battery diaphragm and preparation method thereof | |
| CN106450115B (en) | Inorganic coating bacteria cellulose porous membrane and preparation method thereof | |
| CN106229445A (en) | A kind of lithium ion battery separator and preparation method thereof and lithium ion battery | |
| CN114725616A (en) | Inorganic hybrid aramid nanofiber membrane, preparation method and application of inorganic hybrid aramid nanofiber membrane in lithium battery | |
| CN112448098A (en) | Electrostatic spinning polyimide-based nanofiber porous membrane and preparation method and application thereof | |
| JP3681720B2 (en) | Polyolefin microporous membrane | |
| CN106531929A (en) | Drying process of ceramic coated bacterial cellulose porous thin film | |
| CN112670668B (en) | Ultra-high molecular weight polyethylene lithium battery diaphragm and preparation method thereof | |
| CN112952295B (en) | Polyolefin-cellulose composite diaphragm and preparation method thereof | |
| CN112259909B (en) | Lithium ion battery composite diaphragm with multifunctional alternate segmented coating | |
| CN113328202B (en) | Honeycomb high-porosity and large-aperture lithium battery diaphragm and preparation method thereof | |
| CN116190908A (en) | Diaphragm for lithium battery and preparation method thereof | |
| CN113764825B (en) | Lithium battery diaphragm material and preparation method thereof | |
| CN114709558A (en) | High-heat-resistance polyamide-imide composite diaphragm and preparation method thereof | |
| CN110212138B (en) | Enhanced polypropylene diaphragm, preparation method and application | |
| CN115566359A (en) | Ion-conducting polymer composite lithium battery diaphragm and preparation method thereof | |
| CN114696035A (en) | Cellulose-based composite diaphragm for lithium ion battery and preparation method thereof | |
| KR101377476B1 (en) | Menufacturing Method of Meta-Aramid Based Porous Membrane for Secondary Battery and Porous Membrane thereby | |
| CN115693024A (en) | Composite separator, electrochemical device, electronic apparatus, and mobile terminal | |
| CN111933873A (en) | Diaphragm with uniform aperture and preparation method thereof | |
| CN111192993A (en) | Polyimide diaphragm of lithium battery and preparation method thereof | |
| CN115863912A (en) | High-performance ternary lithium battery diaphragm and production process thereof | |
| KR102051636B1 (en) | Microporous separator using glass wool and prepatarion method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |