CN108172734B - Preparation method of novel three-layer composite diaphragm of lithium-sulfur battery - Google Patents

Preparation method of novel three-layer composite diaphragm of lithium-sulfur battery Download PDF

Info

Publication number
CN108172734B
CN108172734B CN201611112972.5A CN201611112972A CN108172734B CN 108172734 B CN108172734 B CN 108172734B CN 201611112972 A CN201611112972 A CN 201611112972A CN 108172734 B CN108172734 B CN 108172734B
Authority
CN
China
Prior art keywords
diaphragm
lithium
layer composite
nano
sulfur battery
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
Application number
CN201611112972.5A
Other languages
Chinese (zh)
Other versions
CN108172734A (en
Inventor
刘久清
崔金强
李劼
赖延清
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Central South University
Original Assignee
Central South University
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Central South University filed Critical Central South University
Priority to CN201611112972.5A priority Critical patent/CN108172734B/en
Publication of CN108172734A publication Critical patent/CN108172734A/en
Application granted granted Critical
Publication of CN108172734B publication Critical patent/CN108172734B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

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
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y30/00—Nanotechnology for materials or surface science, e.g. nanocomposites
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • 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
    • 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

Abstract

The invention discloses a preparation method of a novel three-layer composite diaphragm of a lithium-sulfur battery, which comprises the following steps: mixing high molecular polymer and solvent capable of dissolving polymer, curing, stirring and defoaming to obtain uniform bubble-free casting solution. And pouring the obtained uniform bubble-free casting solution onto the surface of a commercial lithium ion battery diaphragm, scraping the film into a wet film by using a scraper, pre-evaporating the wet film in air, immersing the wet film into a mixed coagulating bath, exchanging the wet film in the mixed coagulating bath to obtain a primary formed diaphragm, immersing the primary formed diaphragm into a non-solvent for exchanging, taking out the primary formed diaphragm, and airing to obtain a two-layer composite diaphragm. Surface modified nano Si3N4the particles, binder, NMP were ground in a mortar to give a well-ground mixture. And (3) blade-coating the fully ground mixture on the surfaces of the two layers of composite diaphragms by using a scraper to obtain the three layers of composite diaphragms.

Description

Preparation method of novel three-layer composite diaphragm of lithium-sulfur battery
Technical Field
the invention relates to a preparation method of a diaphragm for a lithium-sulfur battery, and belongs to the field of lithium-sulfur battery materials.
Background
with the continuous development of scientific technology and the improvement of the living standard of people, people put forward higher demands on the development of secondary lithium batteries, particularly in the aspect of high-performance electric vehicles, the high-performance electric vehicles need to have extremely high energy storage and transmission systems, the lithium-sulfur batteries are batteries assembled by taking metal lithium as a negative electrode, elemental sulfur or a sulfur-containing composite material as a positive electrode and ether organic matters as electrolyte, and the batteries of the system have theoretical specific energy up to 2600Wh/kg and are far higher than the lithium-ion secondary batteries commercially used at present. The lithium sulfur battery is considered to be an energy storage battery for the next generation of electric vehicles and smart grids with great potential due to the characteristics of high specific energy, low cost and environmental friendliness, but has the problems of low reversible capacity and poor cycle and rate capability performance due to low conductivity of sulfur element and shuttle effect of polysulfide in the reaction process. Most of the research on lithium-sulfur batteries in the academic community currently focuses on the positive electrode, and mainly aims to realize coating of sulfur by designing different nano materials as a conductive framework so as to inhibit the dissolution and shuttling of polysulfide. The separator, which is one of the important organized parts of the battery, plays a decisive role in the performance of the battery and is called the "third electrode" of the battery. Most of the currently commonly used lithium-sulfur battery diaphragms are traditional olefin diaphragms, mainly polypropylene (PP) microporous membranes and Polyethylene (PE) microporous membranes. The thickness, the strength and the porosity of the lithium-sulfur battery are difficult to be considered, and the high temperature resistance and the high current resistance charging and discharging performance of the lithium-sulfur battery are poor, so that the lithium-sulfur battery has huge potential safety hazards when being applied to a power lithium-sulfur battery. Meanwhile, due to the complexity of the charge-discharge reaction process and the diversity of the electrolyte of the lithium-sulfur battery, the traditional polyolefin diaphragm can not well inhibit the diffusion of polysulfide which is an intermediate product of the lithium-sulfur battery. Therefore, the development of higher quality separator materials is also one of the important directions for improving the overall performance of lithium-sulfur batteries.
disclosure of Invention
aiming at the defect that the shuttle effect of the conventional lithium-sulfur battery diaphragm cannot be inhibited, the invention aims to provide the preparation method of the novel lithium-sulfur battery composite diaphragm.
in order to achieve the above object, the present invention provides a method for preparing a composite separator for a lithium-sulfur battery, comprising the steps of:
(1) surface modified nano Si3N4Preparation of the particles: taking a certain amount of nano Si3N4Adding powder, a mercaptosilane coupling agent and toluene into a three-neck flask, ultrasonically dispersing for 10-60min, stirring the dispersed solution for 20-36h at 100-150 ℃, then vacuum drying the solution for 10-20h at 40-70 ℃ to obtain nano particles, and performing Soxhlet extraction on the obtained nano particles for 50-60h in a Soxhlet extractor by using dichloromethane at 45-55 ℃; dispersing the extracted nano particles in 66.7% hydrogen peroxide, stirring and reacting at 75-85 deg.C for 3-5h, vacuum filtering, and drying to obtain surface-modified nano Si3N4Particles;
(2) Preparing a casting solution: mixing a high molecular polymer and a solvent capable of dissolving the polymer, curing at 60-80 ℃ for 12-24h, stirring for 24-36h, standing and defoaming for 24-48h, setting a temperature gradient during standing, and preserving heat for a period of time to fully defoam to obtain a uniform bubble-free casting solution;
(3) Preparing a three-layer composite diaphragm: flatly laying a commercial lithium ion battery diaphragm on a smooth and clean glass plate, pouring the obtained uniform bubble-free casting solution onto the surface of the commercial lithium ion battery diaphragm, scraping the commercial lithium ion battery diaphragm into a wet film by using a scraper, controlling the thickness of the wet film to be 30-50 mu m, pre-evaporating the obtained wet film in the air for 5s-30min, immersing the wet film into a mixed solidification bath, exchanging the wet film in the mixed solidification bath for 1-10min to obtain a primary formed diaphragm, immersing the prepared primary formed diaphragm into deionized water for 6-24h, taking out, and airing to obtain a two-layer composite diaphragm;
Weighing a certain mass of the surface-modified nano Si prepared in the step (1)3N4Grinding the particles and the binder in a mortar for 30-60min, adding a certain amount of N-methylpyrrolidone (NMP) and continuing grinding for 15-30min to obtain a fully ground mixture. And (3) taking the fully ground mixture as an inorganic coating, coating the inorganic coating on the surfaces of the two layers of composite diaphragms by using a scraper, and controlling the thickness of the coating to be a certain thickness to obtain the three layers of composite diaphragms.
The mercaptosilane coupling agent is one of 3-mercaptopropyltriethoxysilane and 3-mercaptopropyltrimethoxysilane;
The nano Si3N4The proportion of powder, mercaptosilane coupling agent and toluene is 1 g: (1.8-9.5 g): (100-200 ml);
the high-molecular polymer is polyvinylidene fluoride (PVDF) and Polyacrylonitrile (PAN), the mass concentration of the polymer is 10-25%, and the mass ratio of the PVDF to the PAN is (1: 1-9: 1).
The solvent capable of dissolving the polymer is one of N, N-dimethylformamide, N-methylpyrrolidone and N, N-dimethylacetamide.
The solvent capable of dissolving the polymer is one of dimethylformamide, N-methylpyrrolidone, dimethyl sulfoxide and dimethylacetamide.
The temperature gradient during standing and defoaming is reduced to 5-20 ℃/h, and the heat preservation time is 30-60 min.
The wet film is pre-evaporated in air for a time of 5 seconds to 30 minutes.
The composition of the mixed coagulation bath is as follows: water and one of dimethylformamide, N-methylpyrrolidone, dimethyl sulfoxide, dimethylacetamide and triethyl phosphate, wherein the content of water is 60-90% vol%.
Surface-modified nano Si in the inorganic coating3N4The mass ratio of the particles to the binder to the NMP is 1: (0.1-0.5): (1-5);
The binder is one of polyvinyl alcohol, polytetrafluoroethylene and sodium polyvinylidene fluoride carboxymethyl cellulose.
the thickness of the inorganic coating is 3-15 mu m.
The invention has the following advantages:
1. Surface-modified nano Si in the invention3N4The particles having-SO on their surface3 -ionic group, -SO3 -The presence of ionic groups not only makes Li possible+Easy to pass through and the shuttle effect of polysulfide is inhibited;
2. The polymer layer in the middle of the composite diaphragm prepared by the invention has the effect of gel electrolyte, so that the diaphragm has high porosity and liquid absorption rate, and-C ≡ N in PAN and polysulfide have high binding energy, and shuttle of polysulfide can be effectively inhibited;
3. The presence of the inorganic layer on the surface of the three-layer composite diaphragm prepared by the invention obviously improves the tensile strength and heat resistance of the diaphragm, thereby improving the stability and safety of the diaphragm.
Drawings
FIG. 1 is an SEM image of an inorganic coating on the surface of a separator prepared by the method.
Detailed Description
the invention is illustrated by the following non-limiting examples.
Mixing nano Si3N4Adding powder, a mercaptosilane coupling agent and toluene into a three-neck flask, ultrasonically dispersing and stirring at a certain temperature, then carrying out vacuum drying on the solution to obtain nano particles, and carrying out Soxhlet extraction on the obtained nano particles in a Soxhlet extractor by using dichloromethane; dispersing the extracted nano particles in hydrogen peroxide, stirring, filtering, and drying to obtain surface-modified nano Si3N4And (3) granules. Mixing high molecular polymer and solvent capable of dissolving polymer, curing, stirring and defoaming to obtain the invented productto obtain uniform bubble-free casting solution. And pouring the obtained uniform bubble-free casting solution onto the surface of a commercial lithium ion battery diaphragm, scraping the film into a wet film by using a scraper, pre-evaporating the prepared wet film in air, immersing the wet film into a mixed coagulating bath, exchanging the wet film in the mixed coagulating bath to obtain a primary formed diaphragm, immersing the prepared primary formed diaphragm into a non-solvent for exchanging, taking out, and airing to obtain a two-layer composite diaphragm. Surface modified nano Si3N4the particles, binder, NMP were ground in a mortar to give a well-ground mixture. And (3) coating the prepared fully ground mixture on the surfaces of the two layers of composite membranes by using a scraper to obtain the three layers of composite membranes.
Example 1: (1) surface modified nano Si3N4Preparation of the particles: taking 1g of nano Si3N4adding powder, 1.8g of 3-mercaptopropyltriethoxysilane and 100ml of toluene into a three-neck flask, ultrasonically dispersing for 10min, stirring the dispersed solution at 100 ℃ for 20h, then vacuum drying the solution at 40 ℃ for 10h to obtain nano particles, and performing Soxhlet extraction on the obtained nano particles in a Soxhlet extractor by using dichloromethane at 45 ℃ for 50 h; dispersing the extracted nano particles in 66.7 mass percent hydrogen peroxide, stirring and reacting for 3 hours at 75 ℃, filtering, drying to obtain the surface modified nano Si3N4Particles;
(2) Preparing a casting solution: weighing 2.5g of PVDF and 2.5g of PAN, dissolving in 45g N, N-dimethylformamide, curing at 60 ℃ for 12h, stirring for 24h, standing for defoaming for 24h, setting the temperature gradient to be reduced to 5 ℃/h during standing, and preserving heat for 30min for full defoaming to obtain a uniform bubble-free casting solution;
(3) Preparing a three-layer composite diaphragm: laying a commercial lithium ion battery diaphragm on a smooth and clean glass plate, pouring the obtained uniform bubble-free casting film liquid onto the surface of the commercial lithium ion battery diaphragm, scraping the commercial lithium ion battery diaphragm into a wet film by using a scraper, controlling the thickness of the film to be 30 mu m, pre-evaporating the prepared wet film in the air for 5s, then soaking the prepared wet film into a mixed coagulation bath of water and N, N-dimethylformamide, wherein the water content is 60 vol%, exchanging the wet film in the mixed coagulation bath for 1min to obtain a primary formed diaphragm, then soaking the obtained primary formed diaphragm into deionized water for exchanging for 6h, taking out and airing to obtain a two-layer composite diaphragm;
Weighing 1g of the surface-modified nano Si prepared in the step (1)3N4The granules, 0.1g polyvinyl alcohol, were ground in a mortar for 30min, then 1g N-methyl pyrrolidone (NMP) was added and grinding was continued for 15min to give a well-ground mixture. Taking the prepared fully ground mixture as an inorganic coating, and blade-coating the inorganic coating on the surfaces of the two layers of composite membranes by using a scraper, and controlling the thickness of the coating to be 3 mu m to obtain three layers of composite membranes;
(4) The obtained three-layer composite diaphragm assembled lithium-sulfur battery has a positive electrode made of a sulfur/carbon nanotube composite material with the sulfur content of 70wt%, a negative electrode made of metal lithium, and an electrolyte made of 1M LiTFSI and 0.4M LiNO3Dissolved in a solvent at a volume ratio of 1: 1, 1-Dioxolane (DOL) and Dimethoxyethane (DME), and testing the electrochemical performance of the cell;
The physical and chemical properties of the three-layer composite diaphragm prepared by the method are as follows: the porosity of the three-layer composite membrane is 67%, the liquid absorption rate is 246%, the tensile strength is 16.8MPa, the shrinkage rate of the composite membrane at 175 ℃ is less than 5%, and the ionic conductivity is 1.8mScm-1The capacity of the battery after 100 cycles under the multiplying power of 0.5C is 918mAh/g, and the coulombic efficiency is about 99%.
Example 2: (1) surface modified nano Si3N4preparation of the particles: taking 1g of nano Si3N4Adding powder, 9.5g of 3-mercaptopropyltrimethoxysilane and 200ml of toluene into a three-neck flask, ultrasonically dispersing for 60min, stirring the dispersed solution at 150 ℃ for 36h, then drying the solution at 70 ℃ in vacuum for 20h to obtain nano particles, and performing Soxhlet extraction on the obtained nano particles in a Soxhlet extractor by using dichloromethane at 55 ℃ for 60 h; dispersing the extracted nano particles in 66.7 mass percent hydrogen peroxide, stirring and reacting for 5 hours at 85 ℃, filtering, drying to obtain the surface modified nano Si3N4And (3) granules.
(2) Preparing a casting solution: weighing 9g of PVDF and 1g of PAN, dissolving in 40g N-methyl pyrrolidone, mixing, curing at 80 ℃ for 24h, stirring for 36h, standing and defoaming for 48h, setting the temperature gradient to be 20 ℃/h during standing, and preserving heat for 60min to fully defoam to obtain the uniform bubble-free casting solution.
(3) preparing a three-layer composite diaphragm: laying a commercial lithium ion battery diaphragm on a smooth and clean glass plate, pouring the obtained uniform bubble-free casting solution onto the surface of the commercial lithium ion battery diaphragm, scraping the commercial lithium ion battery diaphragm into a wet film by using a scraper, controlling the thickness of the film to be 50 mu m, pre-evaporating the prepared wet film in air for 1min, and then immersing the film into a mixed coagulation bath, wherein the mixed coagulation bath comprises water and N-methyl pyrrolidone, the content of the water is 90 vol%, exchanging the film in the mixed coagulation bath for 10min to obtain a primary formed diaphragm, then immersing the obtained primary formed diaphragm into deionized water for exchanging for 24h, taking out, and airing to obtain two layers of composite diaphragms;
Weighing 1g of the surface-modified nano Si prepared in the step (1)3N4The granules, 0.5g of polytetrafluoroethylene, were ground in a mortar for 60min, and then 5g N-methylpyrrolidone (NMP) was added and grinding was continued for 30min to give a well-ground mixture. Taking the prepared fully ground mixture as an inorganic coating, and blade-coating the inorganic coating on the surfaces of the two layers of composite membranes by using a scraper, and controlling the thickness of the coating to be 15 mu m to obtain three layers of composite membranes;
(4) The obtained three-layer composite diaphragm assembled lithium-sulfur battery has a positive electrode made of a sulfur/carbon nanotube composite material with the sulfur content of 70wt%, a negative electrode made of metal lithium, and an electrolyte made of 1M LiTFSI and 0.4M LiNO3Dissolved in a solvent at a volume ratio of 1: 1, 1-Dioxolane (DOL) and Dimethoxyethane (DME), and testing the electrochemical performance of the cell;
The physical and chemical properties of the three-layer composite diaphragm prepared by the method are as follows: the porosity of the three-layer composite membrane is 65%, the liquid absorption rate is 236%, the tensile strength is 15.4MPa, the shrinkage rate of the composite membrane at 175 ℃ is less than 5%, and the ionic conductivity is 2.1mScm-1The capacity of the battery is 892mAh/g after the battery is circulated for 100 circles under the multiplying power of 0.5C, and the coulombic efficiency is about 99%.
Example 3: (1) surface modified nano Si3N4Preparation of the particles: taking 1g of nano Si3N4The powder, 6.7g of 3-mercaptopropyltriethoxysilane, 150ml of toluene were added to a three-necked flask and the mixture was super-heatedPerforming acoustic dispersion for 140min, stirring the dispersed solution at 120 ℃ for 30h, then performing vacuum drying on the solution at 55 ℃ for 15h to obtain nano particles, and performing Soxhlet extraction on the obtained nano particles in a Soxhlet extractor by using dichloromethane at 50 ℃ for 55 h; dispersing the extracted nano particles in 66.7 mass percent hydrogen peroxide, stirring and reacting for 4 hours at the temperature of 80 ℃, filtering, drying to obtain the surface modified nano Si3N4Particles;
(2) Preparing a casting solution: weighing 5.6g of PVDF and 1.4g of PAN, dissolving in 42g N, mixing, curing at 70 ℃ for 20h, stirring for 30h, standing for defoaming for 36h, setting the temperature gradient to be reduced to 15 ℃/h during standing, and preserving heat for 40min to fully defoam to obtain a uniform bubble-free casting solution;
(3) Preparing a three-layer composite diaphragm: laying a commercial lithium ion battery diaphragm on a smooth and clean glass plate, pouring the obtained uniform bubble-free casting film liquid onto the surface of the commercial lithium ion battery diaphragm, scraping the commercial lithium ion battery diaphragm into a wet film by using a scraper and controlling the thickness of the film to be 45 mu m, pre-evaporating the prepared wet film in the air for 30s, then soaking the prepared wet film into a mixed coagulation bath of water and dimethylacetamide, exchanging the wet film in the mixed coagulation bath for 5min to obtain a primary formed diaphragm, then soaking the obtained primary formed diaphragm into deionized water for exchanging for 12h, taking out, and airing to obtain two layers of composite diaphragms;
Weighing 1g of the surface-modified nano Si prepared in the step (1)3N4The granules, 0.2g polyvinylidene fluoride, were ground in a mortar for 40min, then 2g N-methyl pyrrolidone (NMP) was added and grinding continued for 20min to give a well-ground mixture. Taking the obtained fully ground mixture as an inorganic coating, and blade-coating the inorganic coating on the surfaces of the two layers of composite membranes by using a scraper, and controlling the thickness of the coating to be 5 mu m to obtain three layers of composite membranes;
(4) The obtained three-layer composite diaphragm assembled lithium-sulfur battery has a positive electrode made of a sulfur/carbon nanotube composite material with the sulfur content of 70wt%, a negative electrode made of metal lithium, and an electrolyte made of 1M LiTFSI and 0.4M LiNO3Dissolved in a solvent at a volume ratio of 1: 1, 1-Dioxolane (DOL) and Dimethoxyethane (DME), and testing the electrochemical performance of the cell;
The physical and chemical properties of the three-layer composite diaphragm prepared by the method are as follows: the porosity of the three-layer composite diaphragm is 75%, the liquid absorption rate reaches 287%, the tensile strength is 18.4MPa, the shrinkage rate of the composite diaphragm at 175 ℃ is less than 5%, and the ionic conductivity is 2.32mScm-1The capacity of the battery is 1050mAh/g after the battery is circulated for 100 circles under the multiplying power of 0.5C, and the coulombic efficiency is about 99%.

Claims (9)

1. A preparation method of a three-layer composite diaphragm of a lithium-sulfur battery is characterized by comprising the following steps:
(1) surface modified nano Si3N4Preparation of the particles: taking a certain amount of nano Si3N4adding powder, a mercaptosilane coupling agent and toluene into a three-neck flask, ultrasonically dispersing for 10-60min, stirring the dispersed solution for 20-36h at 100-150 ℃, then vacuum drying the solution for 10-20h at 40-70 ℃ to obtain nano particles, and performing Soxhlet extraction on the obtained nano particles for 50-60h in a Soxhlet extractor by using dichloromethane at 45-55 ℃; dispersing the extracted nano particles in 66.7% hydrogen peroxide, stirring and reacting at 75-85 deg.C for 3-5h, vacuum filtering, and drying to obtain surface-modified nano Si3N4Particles;
(2) preparing a casting solution: mixing a high molecular polymer and a solvent capable of dissolving the polymer, curing at 60-80 ℃ for 12-24h, stirring for 24-36h, standing for defoaming for 24-48h, setting temperature gradient reduction during standing, and keeping the temperature for a period of time to fully defoam to obtain a uniform bubble-free casting solution; the high molecular polymer is polyvinylidene fluoride and polyacrylonitrile, the mass concentration of the high molecular polymer is 10-25%, wherein the mass ratio of the polyvinylidene fluoride to the polyacrylonitrile is 1-9: 1;
(3) Preparing a three-layer composite diaphragm: spreading a commercial lithium ion battery diaphragm on a smooth and clean glass plate, pouring the obtained uniform bubble-free casting solution on the surface of the commercial lithium ion battery diaphragm, scraping the film into a wet film by using a scraper, controlling the thickness of the wet film to be 30-50 mu m, pre-evaporating the prepared wet film in the air for 5s-30min, immersing the film into a mixed coagulation bath, exchanging the film in the mixed coagulation bath for 1-10min to obtain a primary formed diaphragm, and then, carrying out primary forming on the prepared primary formed diaphragmimmersing the diaphragm into deionized water for exchange for 6-24h, taking out, and airing to obtain a two-layer composite diaphragm; weighing a certain mass of the surface-modified nano Si prepared in the step (1)3N4Grinding the particles and the binder in a mortar for 30-60min, adding a certain amount of N-methyl pyrrolidone, continuously grinding for 15-30min to obtain a fully ground mixture, using the prepared fully ground mixture as an inorganic coating, blade-coating the surface of the two layers of composite membranes by using a scraper, and controlling the thickness of the coating to be a certain thickness to obtain the three layers of composite membranes.
2. the method for preparing the three-layer composite separator of the lithium-sulfur battery according to claim 1, wherein the method comprises the following steps: the mercapto silane coupling agent is one of 3-mercaptopropyltriethoxysilane and 3-mercaptopropyltrimethoxysilane.
3. The method for preparing the three-layer composite separator of the lithium-sulfur battery according to claim 1, wherein the method comprises the following steps: the surface-modified nano Si3N4Nano Si in particle preparation3N4The proportion of powder, mercaptosilane coupling agent and toluene is 1 g: 1.8-9.5 g: 100-200 ml.
4. the method of claim 1, wherein the solvent capable of dissolving the polymer is one of N, N-dimethylformamide, N-methylpyrrolidone, and N, N-dimethylacetamide.
5. The method for preparing the three-layer composite diaphragm of the lithium-sulfur battery as claimed in claim 1, wherein the temperature gradient during standing defoaming is reduced to 5-20 ℃/h, and the heat preservation time is 30-60 min.
6. The method of claim 1, wherein the coagulation bath comprises: water and one or more of dimethylformamide, N-methylpyrrolidone, dimethyl sulfoxide, dimethylacetamide and triethyl phosphate, wherein the content of water is 60-90 VOL%.
7. The method for preparing the three-layer composite separator of the lithium-sulfur battery as claimed in claim 1, wherein the inorganic coating is surface-modified with nano-Si3N4The mass ratio of the particles to the binder to the N-methylpyrrolidone is 1: 0.1-0.5: 1-5.
8. the method for preparing the three-layer composite separator of the lithium-sulfur battery as claimed in claim 1, wherein the binder is one of polyvinyl alcohol, polytetrafluoroethylene, polyvinylidene fluoride and sodium carboxymethylcellulose.
9. the method for preparing a three-layer composite separator of a lithium-sulfur battery according to claim 1, wherein the thickness of the inorganic coating is 3-15 μm.
CN201611112972.5A 2016-12-07 2016-12-07 Preparation method of novel three-layer composite diaphragm of lithium-sulfur battery Active CN108172734B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201611112972.5A CN108172734B (en) 2016-12-07 2016-12-07 Preparation method of novel three-layer composite diaphragm of lithium-sulfur battery

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201611112972.5A CN108172734B (en) 2016-12-07 2016-12-07 Preparation method of novel three-layer composite diaphragm of lithium-sulfur battery

Publications (2)

Publication Number Publication Date
CN108172734A CN108172734A (en) 2018-06-15
CN108172734B true CN108172734B (en) 2019-12-13

Family

ID=62526048

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201611112972.5A Active CN108172734B (en) 2016-12-07 2016-12-07 Preparation method of novel three-layer composite diaphragm of lithium-sulfur battery

Country Status (1)

Country Link
CN (1) CN108172734B (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111785912B (en) * 2019-04-03 2021-12-24 中南大学 Preparation method of porous carbon cathode lithium-sulfur battery
CN111785892B (en) * 2019-04-03 2021-10-08 中南大学 Preparation method of lithium-sulfur battery composite diaphragm

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102522516A (en) * 2011-12-22 2012-06-27 中国科学院青岛生物能源与过程研究所 Asymmetric composite diaphragm for lithium ion secondary cell and preparation method thereof
CN104194146B (en) * 2014-08-06 2016-09-28 惠州市沃特新材料有限公司 Polypropene composition and preparation method thereof
CN104393215B (en) * 2014-12-01 2017-01-04 天津工业大学 Multi-layer porous battery diaphragm of component ratio continually varying in gradient and preparation method thereof

Also Published As

Publication number Publication date
CN108172734A (en) 2018-06-15

Similar Documents

Publication Publication Date Title
CN110581314B (en) Multilayer-structure composite solid electrolyte membrane, preparation method thereof and solid battery
CN110010964B (en) Porous membrane reinforced polymer-plastic crystal solid electrolyte membrane, and preparation method and application thereof
CN111653717B (en) Preparation method of composite diaphragm, composite diaphragm and lithium ion battery
CN105261721A (en) Asymmetric diaphragm and application thereof in lithium-sulfur rechargeable battery
CN105161661A (en) Composite diaphragm for lithium ion battery, preparation method of composite diaphragm, and lithium ion battery
CN101662042B (en) Polymer lithium ion battery and preparation method of diaphragm thereof
CN109841899B (en) Preparation method of three-dimensional network polymer gel electrolyte membrane based on bacterial cellulose
CN110518279B (en) Composite solid electrolyte of PEO-coated activated nanoparticles and preparation method thereof
CN109037550B (en) Method for preparing lithium battery coating diaphragm by blending organic clay mineral and polyvinylidene fluoride
Dai et al. A novel separator material consisting of ZeoliticImidazolate Framework-4 (ZIF-4) and its electrochemical performance for lithium-ions battery
Liu et al. An effective dual-channel strategy for preparation of polybenzimidazole separator for advanced-safety and high-performance lithium-ion batteries
CN105977470A (en) Silicon dioxide active carbon composite material and preparation method thereof as well as lead-carbon battery
WO2022110204A1 (en) Electrochemical device and electronic device
CN111180644A (en) Lithium ion battery diaphragm with ultrathin coating layer
CN109950487A (en) A kind of lithium sulfur battery anode material and preparation method thereof
CN111192994A (en) Heat-shrinkage-resistant polyethylene lithium battery diaphragm and preparation method thereof
CN108172734B (en) Preparation method of novel three-layer composite diaphragm of lithium-sulfur battery
CN115064764A (en) Ceramic filler modified high-conductivity wide-voltage-window composite electrolyte material, and preparation method and application thereof
CN104409770B (en) Preparation method of polymer electrolyte containing allyl functionalized ionic liquid
CN114649560A (en) Zn-MOF/PAN @ PAN composite membrane material and preparation method and application thereof
CN106450434A (en) High-voltage high-energy-density lithium ion battery
WO2023179550A1 (en) Composite oil-based separator and preparation method therefor, and secondary battery
CN112582611B (en) Application of polyacid oxide NVO in positive electrode of lithium-sulfur battery
CN112687839A (en) Pole piece, preparation method thereof and lithium ion battery
CN114204209A (en) Preparation method of secondary functionalized double-coating modified polyether sulfone lithium-sulfur battery diaphragm

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