CN113611983A - Composite diaphragm slurry, preparation method thereof and battery diaphragm - Google Patents

Composite diaphragm slurry, preparation method thereof and battery diaphragm Download PDF

Info

Publication number
CN113611983A
CN113611983A CN202110880716.5A CN202110880716A CN113611983A CN 113611983 A CN113611983 A CN 113611983A CN 202110880716 A CN202110880716 A CN 202110880716A CN 113611983 A CN113611983 A CN 113611983A
Authority
CN
China
Prior art keywords
polymer
ceramic particles
diaphragm
composite
slurry
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.)
Pending
Application number
CN202110880716.5A
Other languages
Chinese (zh)
Inventor
齐爱
汤云
夏海潮
张杨
张鹏
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.)
Hunan Shuopu New Material Co ltd
Original Assignee
Hunan Shuopu New Material Co ltd
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 Hunan Shuopu New Material Co ltd filed Critical Hunan Shuopu New Material Co ltd
Priority to CN202110880716.5A priority Critical patent/CN113611983A/en
Publication of CN113611983A publication Critical patent/CN113611983A/en
Pending legal-status Critical Current

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
    • H01M50/409—Separators, membranes or diaphragms characterised by the material
    • H01M50/446—Composite material consisting of a mixture of organic and inorganic materials
    • 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
    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • 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
    • H01M50/449—Separators, membranes or diaphragms characterised by the material having a layered structure
    • 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
    • H01M50/489—Separators, membranes, diaphragms or spacing elements inside the cells, characterised by their physical properties, e.g. swelling degree, hydrophilicity or shut down properties
    • 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
    • H01M50/489—Separators, membranes, diaphragms or spacing elements inside the cells, characterised by their physical properties, e.g. swelling degree, hydrophilicity or shut down properties
    • H01M50/491—Porosity
    • 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 composite diaphragm slurry and a composite diaphragm, and belongs to the technical field of lithium ion battery diaphragm production. A composite membrane comprises the following raw materials: 10-20 parts of polymer-coated ceramic particles, 10-25 parts of deionized water, 0.01-0.1 part of dispersant, 1-3 parts of binder and 0.01-1 part of auxiliary agent; the preparation method of the polymer-coated ceramic particles comprises the following steps: uniformly mixing a polymer, ceramic particles and a dispersing agent, and then preparing the polymer-coated ceramic particles by a spray drying method in an inert atmosphere; the polymer is one or 2 of polyisophthaloyl metaphenylene diamine and polyimide. The lithium ion battery prepared by the composite diaphragm has better rate and safety performance. The coating layer adopted by the invention has good wettability and liquid retention to the electrolyte, and is beneficial to improving the multiplying power and long cycle performance of the battery.

Description

Composite diaphragm slurry, preparation method thereof and battery diaphragm
Technical Field
The invention relates to the technical field of preparation of lithium ion battery materials, in particular to composite diaphragm slurry and a lithium ion battery diaphragm.
Background
The lithium ion battery has the advantages of high working voltage, high specific energy and specific power, small self-discharge, no memory effect, good cycle stability, environmental protection and the like, and thus the lithium ion battery rapidly occupies the energy storage market in various fields. With the thinning of 3C digital products and the application of lithium ion batteries in the fields of electric vehicles, energy storage power stations, and the like, people have made higher requirements on electrochemical performance, especially safety performance. The diaphragm is used as one of four key materials of the lithium ion battery, plays a role in preventing the direct contact of the positive electrode and the negative electrode in the lithium ion battery and allowing lithium ions to freely pass through, and plays a vital role in the electrochemical performance, particularly the safety performance of the lithium ion battery. The ideal diaphragm material needs to have the characteristics of high porosity, high heat resistance, high melting point, high strength and good wettability to electrolyte, and in the actual use process, the diaphragm material with a single component cannot simultaneously meet the requirements. The commercial microporous polyolefin diaphragm has the defects of poor thermal stability and poor wettability to electrolyte, and is improved by preparing a composite diaphragm through surface modification or coating at present.
The polyolefin diaphragm coating modification process is relatively simple, inorganic or organic materials are compounded with the base film through the simple coating process, the complementation between the material properties is realized, and the performance is greatly improved compared with the traditional polyolefin diaphragm. The inorganic ceramic coating diaphragm has small shrinkage at high temperature, can improve the wettability of the diaphragm to electrolyte, reduce the oxidation of the diaphragm and is beneficial to improving the comprehensive performance of the lithium ion battery. However, the interface bonding problem between the ceramic phase and the base membrane causes ceramic powder to fall off and block the pore canal of the diaphragm due to weak interface bonding force between the two phases in the using process. The affinity of the polymer PVDF coating with the pole piece and the diaphragm is better than that of the inorganic material coating, the flexibility is good, but the thermal stability is poor. The mixed coating process combines the advantages of ceramic coating and polymer coating, and can obviously improve the comprehensive performance of the diaphragm, however, the mixed coating slurry of PVDF and ceramic is difficult to be uniformly dispersed in the same system, so that the coating particles of the diaphragm are not uniformly dispersed, the current density of the battery is not uniform in the charging and discharging process, and the electrochemical performance and the safety performance of the battery are influenced.
The prior art CN 108666511 a discloses a high temperature resistant polymer modified ceramic diaphragm and application thereof, which comprises a porous base membrane, at least one side of the porous base membrane is coated with a ceramic layer, and the surface and the inside of pores of the ceramic layer and the inside of pores of the porous base membrane and the side which is not coated with the ceramic layer are polymerized with a high temperature resistant polymer layer in situ. The method is characterized in that a high-temperature-resistant polymer protective layer is coated on the surface and the pores of a ceramic layer, the surface and the inside of the pores of a porous base film in situ by a pyrrole, thiophene and aniline monomer through an in-situ polymerization method, so that the ceramic layer, the polymer layer and the base film form an organic whole. Thereby improving the thermal dimensional stability of the modified ceramic diaphragm and ensuring that the modified ceramic diaphragm does not shrink at the high temperature of 200 ℃. And still keep stronger mechanical properties, can effectively obstruct positive negative pole contact, ensure the security performance of battery. However, the polymer of the separator is conductive, which leads to an increased probability of internal short circuits and cell self-discharge.
The prior art CN 108023050A discloses a poly (m-phenylene isophthalamide) coated lithium ion battery diaphragm, which comprises a base film and slurry adhered to the film surface of one side or two sides of the base film, wherein the slurry is coating slurry containing the poly (m-phenylene isophthalamide), the problem that the high temperature resistance, the heat shrinkage resistance and the strength of the coated diaphragm cannot meet the requirements under a certain temperature condition in the prior art is solved, the poly (m-phenylene isophthalamide) coated lithium ion battery diaphragm is provided, the high temperature resistance and the high temperature shrinkage resistance of the poly (m-phenylene isophthalamide) coated lithium ion battery diaphragm are good, the safety is greatly improved, the poly (m-phenylene isophthalamide) coated diaphragm is suitable for an electric automobile lithium battery, but the poly (m-phenylene isophthalamide) coated diaphragm is prepared by a low-temperature solution method, and the preparation cost is overhigh.
The prior art CN 107134556B discloses a lithium ion battery separator, which is formed by coating a functional polymer layer on one or both surfaces of a polyolefin microporous membrane, wherein the functional polymer layer is an insoluble microporous functional polymer layer formed by coating, pore-forming, ultraviolet curing, washing, drying and other processes of polyaryletherketone coating liquid. The prepared lithium ion battery diaphragm has the advantages of low water absorption, low energy consumption for subsequent use, excellent high temperature resistance, good heat-resistant dimensional stability, excellent electrolyte resistance and high safety, and also has the advantages of high puncture strength and flame retardance. However, the surface of the polyaryletherketone diaphragm is hydrophobic, so that the infiltration and absorption of electrolyte are not facilitated, and the liquid absorption rate and the liquid retention rate of the diaphragm are influenced.
Spray drying is a process in which the material to be dried is dispersed into fine, fog-like particles by mechanical action, and the particles (increasing the area of water evaporation and accelerating the drying process) are contacted with hot air to instantaneously remove most of the water and dry the solid matter in the material into powder. The spray drying method has the characteristics of rapid reaction, strong continuous production capacity, easy change of drying conditions to adjust the product quality standard, high product purity and uniform particle size.
The spray drying method is applied to surface coating of positive and negative electrode materials in material preparation in the field of batteries, and the coating application of ceramic materials is less.
Disclosure of Invention
The invention aims to provide composite diaphragm slurry, and the prepared ceramic coating diaphragm keeps low closed pore temperature, and simultaneously improves the thermal stability, the electrolyte wettability, the affinity with a pole piece and the adhesion of a coating layer of the diaphragm.
In order to achieve the purpose, the invention adopts the technical scheme that:
a composite separator slurry comprises the following raw materials: 10-20 parts of polymer-coated ceramic particles, 10-25 parts of deionized water, 0.01-0.1 part of dispersant I, 1-3 parts of binder and 0.01-1 part of auxiliary agent;
the polymer-coated ceramic particles comprise a polymer, ceramic particles and a No. two dispersing agent; the mass ratio of the polymer to the ceramic particles to the second dispersant is 0.01-0.5: 1: 0.005-0.02;
the polymer is one or 2 of polyisophthaloyl metaphenylene diamine and polyimide.
Preferably, the preparation method of the polymer-coated ceramic particles comprises the following steps: uniformly mixing a polymer, ceramic particles and a second dispersing agent, and preparing the polymer-coated ceramic particles by a spray drying method in an inert atmosphere;
preferably, the preparation method of the polymer-coated ceramic particles further comprises dissolving the polymer in an organic solvent to form a polymer solution in advance, adding the ceramic particles and the dispersing agent, and uniformly mixing.
According to the technological requirements of a spray drying method, a polymer is dissolved into a solution in advance, and the solution is sprayed on the outer surface of the ceramic more uniformly than the solution is sprayed directly.
The two polymers of polyisophthaloyl metaphenylene diamine and polyimide are selected, and the fundamental reason is that: the polymer has high temperature resistance and good wettability to electrolyte, and needs to be suitable for a lithium ion battery system.
The polyisophthaloyl metaphenylene diamine and the polyimide are high temperature resistant, the polyisophthaloyl metaphenylene diamine is aromatic polyamide, the skeleton of the polyisophthaloyl metaphenylene diamine is provided with a metabenzamide branch chain, the metaphenylene diamine has thermal resistance of up to 400 ℃, and a diaphragm using the material can improve the safety performance of a battery due to high flame retardant property. In addition, the polarity of the carbonyl group is relatively high, so that the separator has high wettability in the electrolyte. The polyimide has good high temperature resistance, strong polarity, good wettability to electrolyte and good liquid absorption rate of the manufactured diaphragm.
Preferably, the organic solvent is a polar organic solvent.
Polar organic solvents have better solubility for polymers.
Preferably, the organic solvent is one or more of nitrogen methyl pyrrolidone, dimethyl acetamide, dimethyl formamide, acetone and dimethyl sulfoxide.
Preferably, the mass concentration of the polymer in the polymer solution is 0.5-10%.
Preferably, the mass ratio of the polymer to the ceramic particles to the second dispersant is 0.01-0.3: 1: 0.005-0.02.
Too high a ratio of polymer to ceramic can result in too thick a coating, which can affect the passage of lithium ions, and if the ratio is too low, incomplete or insignificant coating can occur. The amount of dispersant is determined by the quality of the ceramic. The surface of the ceramic nano-particle has a limited area for the dispersant to adsorb, and after the dispersant is saturated and adsorbed on the surface of the particle, redundant unadsorbed dispersant chains are changed back to pass through the action of a bridge, so that the originally dispersed particles are agglomerated again, the flocculation phenomenon is produced, the stability is poor, the nano-slurry is increased in viscosity and thickened, and the performances of the original nano-slurry are reduced.
Preferably, the solid content of the polymer solution (mass ratio of the polymer, the ceramic particles and the dispersant to the polymer solution) is 8% to 15%.
If the solid content is too high, the viscosity of the solution system is high, and the dispersibility is poor. If the solids content is too low, the spray drying process takes a long time.
Preferably, the dispersant is BYK-LPN 25432.
Preferably, the mixing is uniform stirring, the stirring speed is 100-500 rpm/min, and the stirring time is 1-5 hours.
Preferably, the spray drying adopts a closed circulation system, nitrogen is used as inert protective gas, the spray drying temperature is 80-300 ℃, and the spray pressure is 0.05-5 MPa. The feed rate is precisely controlled by the feed system, preferably at a rate of 50-1000 ml/h.
Preferably, the ceramic particles are one or a mixture of Al2O3, SiO2, TiO2 and boehmite;
Al2O3、SiO2、TiO2boehmite is a ceramic material which is actually applied to the production of coating membranes at present, has the function of improving the heat shrinkage of polyolefin membranes, and SiO2Readily water-absorbent, TiO2As the noble metal, alumina and boehmite can be preferably used.
Preferably, the D50 of the ceramic particles is 0.6 to 1.2 μm.
In the case of the spray drying method, the influence of the particle size of the ceramic particles is large. Through a plurality of tests, the film formed by the particle size within the range is uniform, and the performance of the obtained battery diaphragm is optimal.
Preferably, the binder is an aqueous binder, and comprises one or more of Styrene Butadiene Rubber (SBR), polyvinyl alcohol (PVA), polyethylene oxide (PEO), sodium carboxymethyl cellulose (CMC), ethylene-vinyl acetate copolymer (EVA), Polyurethane (PU), and acrylate.
The aqueous binder can be used for preparing slurry by using water as a solvent, and is environment-friendly.
Preferably, the adjuvant further comprises a thickener.
Preferably, the thickener is sodium carboxymethyl cellulose.
The preparation method of the composite diaphragm slurry comprises the following steps: and mixing the ceramic particles coated by the polymer, deionized water, a dispersing agent, a binder and an auxiliary agent at a stirring speed of 300-700 rpm for 90-180 min to obtain the composite diaphragm slurry.
The invention also claims a battery diaphragm, which is prepared by coating the composite diaphragm slurry on a base film and drying, wherein the base film is a wet Polyethylene (PE) diaphragm, the thickness of the base film is 5-14 mu m, the coating thickness is 2-5 mu m, and the drying temperature is 40-80 ℃.
The invention has the following advantages:
1. the invention adopts a nitrogen protection spray drying method to coat polymer macromolecules on the surface of an inorganic ceramic material, and forms a thin soft polymer coating layer on the surface of the inorganic ceramic material, wherein the polymer coating layer is beneficial to improving the interface bonding force between the inorganic ceramic material and a base film, inhibiting ceramic powder from falling off, and avoiding the ceramic powder from blocking a diaphragm pore channel. Meanwhile, the affinity of the diaphragm coating and the lithium ion battery pole piece is improved through the ceramic particles coated by the polymer. The lithium ion battery prepared by the composite diaphragm has better rate and safety performance.
2. The coating layer has good heat resistance and high heat stability compared with the traditional polymer coating film. The conventional coating diaphragm and the base film have poor wettability to the electrolyte, and the coating layer adopted by the invention has good wettability and liquid retention to the electrolyte, thereby being beneficial to improving the multiplying power and long cycle performance of the battery.
3. The agglomeration of the ceramic material is reduced after the surface is coated and modified. Compared with the conventional mixed coating ceramic, the modified ceramic coating slurry has good uniformity, the coated composite diaphragm coating particles are uniformly dispersed, the current density of the battery is uniformly distributed in the charging and discharging processes, the polarization of the battery is reduced, and the safety performance is improved.
4. The preparation method is simple, has good matching degree with the prior art, has high equipment automation degree, and is suitable for industrial production.
Detailed Description
The invention is further described below with reference to specific preferred embodiments. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments that can be derived by one of ordinary skill in the art from the embodiments given herein are intended to be within the scope of the present invention. All the raw materials of the invention are commercial products.
Example 1:
0.5g of Polyimide (PI) powder (molecular weight is 60000-85000) is dissolved in 77g of dimethylacetamide, and the mixture is heated and stirred uniformly at 60 ℃ to prepare a polymer solution. To the polymer solution were added 0.1g of a dispersant (BYK-LPN 25432) and 10g of Al2O3And (3) uniformly stirring the powder (D50 is 0.6-1.2 mu m) to prepare precursor slurry. The rotation speed of stirring and mixing is 400rpm/min, and the stirring time is 2 h.
And (2) passing the precursor slurry through a fully-closed spray dryer, adopting nitrogen as inert gas, drying and conveying the slurry in an oxidation-resistant environment of a closed circulation system, wherein the atomization drying temperature is 90 ℃, the atomization pressure is 0.2MPa, and the feeding speed is 100ml/h, so that the polymer-coated ceramic particles with the particle size of 0.7-1.6 mu m are prepared.
Coating the polymer on the ceramic particles according to the mass ratio: deionized water: cellulose ether dispersants: sodium carboxymethylcellulose: acrylate adhesive 38%: 45%: 0.1%: 8.4%: 7.5 percent of modified ceramic coating slurry is prepared, and the mixture is stirred for 3 hours at the stirring speed of 390rpm/min to prepare the uniform modified ceramic coating slurry.
The sodium carboxymethylcellulose used was CMC 2200.
The modified ceramic coating slurry is uniformly coated on a PE base film by adopting a gravure coating mode, the coating thickness is 2 mu m, and the coating film is dried at 60 ℃ to prepare the composite diaphragm with good safety. The composite diaphragm has good thermal stability, 1.9 percent of thermal shrinkage at 150 ℃ for 1 hour in the MD direction, 1.8 percent of thermal shrinkage in the TD direction, 158N/m of peel strength, 155s/100cc of air permeability and 215 percent of electrolyte liquid absorption rate.
Manufacturing a battery: and (2) adopting a soft package lithium ion battery, and packaging the prepared composite diaphragm, a ternary positive pole piece (a conventional NMC111 material), a graphite negative pole piece and an electrolyte group (in the electrolyte, 1mol/L LiPF6EC/EMC/DEC is 1:1:1+ 1% VC) into the lithium ion battery. And (3) testing electrical properties: and (3) normal-temperature circulation: at 25 ℃, constant current charge-discharge circulation of 1C/1C, 3.0 to 4.2V; high-temperature circulation: and (3) performing constant current charge and discharge cycles at 55 ℃ and 3.0-4.2V at 1C/1C. The capacity retention rate of the battery prepared by the composite diaphragm after 500 times of normal temperature circulation is 93.2%, and the capacity retention rate of the battery prepared by the composite diaphragm after 500 times of 55 ℃ circulation is 86.7%.
Example 2:
0.1g of Polyimide (PI) powder (molecular weight is 60000-85000) is dissolved in 74.07g of dimethylacetamide, and the mixture is heated and stirred uniformly at 60 ℃ to prepare a polymer solution. 0.1g of a dispersant (BYK-LPN 25432) and 10g of Al2O3 powder (D50 is 0.6-1.2 μm) were added to the polymer solution, and the mixture was stirred uniformly to prepare a precursor slurry, and the other preparation was the same as in example 1.
Example 3:
1g of Polyimide (PI) powder (molecular weight is 60000-85000) is dissolved in 80.67g of dimethylacetamide, and the mixture is heated and stirred uniformly at 60 ℃ to prepare a polymer solution. 0.1g of a dispersant (BYK-LPN 25432) and 10g of Al2O3 powder (D50 is 0.6-1.2 μm) were added to the polymer solution, and the mixture was stirred uniformly to prepare a precursor slurry, and the other preparation was the same as in example 1.
Example 4:
0.5g of PMIA powder (molecular weight of 80000-100000) is dissolved in 77g of dimethylacetamide, and the mixture is heated and stirred uniformly at 60 ℃ to prepare a polymer solution. 0.1g of dispersant (BYK-LPN 25432) and 10g of Al2O3 powder (D50 is 0.6-1.2 mu m) are added into the polymer solution and stirred uniformly to prepare precursor slurry. The other preparation was the same as in example 1.
Comparative example 1
Mixing Al according to mass ratio2O3Powder lot: deionized water: cellulose ether dispersants: sodium carboxymethylcellulose: acrylate adhesive 38%: 45%: 0.1%: 8.4%: 7.5 percent of ceramic coating slurry is prepared, and the mixture is stirred for 3 hours at the stirring speed of 390rpm/min to prepare uniform ceramic coating slurry.
Uniformly coating the ceramic coating slurry on a PE (polyethylene) base film by adopting a gravure coating mode, coating the PE base film to a thickness of 2 mu m, and drying the coating film at 60 ℃ to obtain the conventional Al2O3The separator is coated.
Comparative example 2:
modifying polymers with Al2O3(Polymer-modified ceramic particles) by Al2O3(ceramic particles) were simply mixed with the same amount of PI (or PMIA) as in example 1, and the other preparation was the same as in example 1.
However, as a result of the test, it was found that Al is not modified2O3(ceramic particles) and the same amount of PI as in example 1 were not uniformly mixed.
Experimental testing
The performance test of the diaphragm adopts the GB/T36363-2018 standard, wherein the thermal shrinkage temperature test temperature is set to be 150 ℃, and the rest operations are carried out according to the standard.
The cells prepared in examples 1-4 and comparative example 1 were subjected to cycle performance testing using a charge and discharge NEWARE3000 cell tester:
and (3) normal-temperature circulation: and (3) performing constant current charge and discharge cycles at 25 ℃ and 1C/1C and 3.0-4.2V.
High-temperature circulation: and (3) performing constant current charge and discharge cycles at 55 ℃ and 3.0-4.2V at 1C/1C.
The cycle performance of the battery is evaluated by a capacity retention rate (500-cycle discharge capacity/initial capacity), and the higher the capacity retention rate under the same condition, the better the cycle stability.
Results of the experiment
The performance test results of the separators prepared by the methods of examples 1 to 4 and comparative examples 1 to 2 and the lithium ion batteries assembled by the separators are shown in table 1.
Table 1 results of performance tests of separators prepared by the methods described in examples 1 to 4 and comparative example and lithium ion batteries assembled with the separators
Figure BDA0003191923520000071
Figure BDA0003191923520000081
As shown in Table 1, compared with comparative example 1, the four patterns of membranes prepared in examples 1-4 have less than 5% thermal shrinkage performance at 150 ℃ for 1h in the transverse direction and the longitudinal direction, high peel strength and good air permeability. Compared with the conventional diaphragm, the thermal shrinkage performance and the electrolyte liquid absorption rate are obviously improved, and the cycle capacity retention rate of the assembled lithium ion battery is improved.
The above description is only for the preferred embodiment of the present application and should not be taken as limiting the present application in any way, and although the present application has been disclosed in the preferred embodiment, it is not intended to limit the present application, and those skilled in the art should understand that they can make various changes and modifications within the technical scope of the present application without departing from the scope of the present application, and therefore all the changes and modifications can be made within the technical scope of the present application.

Claims (10)

1. The composite diaphragm slurry is characterized by comprising the following raw materials: 10-20 parts of polymer-coated ceramic particles, 10-25 parts of deionized water, 0.01-0.1 part of dispersant I, 1-3 parts of binder and 0.01-1 part of auxiliary agent;
the polymer-coated ceramic particles comprise a polymer, ceramic particles and a No. two dispersing agent; the mass ratio of the polymer to the ceramic particles to the second dispersant is 0.01-0.5: 1: 0.005-0.02;
the polymer is one or 2 of polyisophthaloyl metaphenylene diamine and polyimide.
2. The composite separator slurry according to claim 1, wherein the polymer-coated ceramic particles are prepared by a method comprising: the polymer, the ceramic particles and the second dispersant are uniformly mixed, and then the polymer-coated ceramic particles are prepared by a spray drying method in an inert atmosphere.
3. The composite separator slurry according to claim 2, wherein the preparation method of the polymer-coated ceramic particles further comprises dissolving the polymer in an organic solvent in advance to form a polymer solution, adding the ceramic particles and a dispersing agent, and uniformly mixing.
4. The composite separator slurry according to claim 2, wherein the solid content of the polymer solution is 8% to 15%.
5. The composite separator slurry according to claim 2, wherein said organic solvent is a polar organic solvent; preferably, the organic solvent is one or more of nitrogen methyl pyrrolidone, dimethyl acetamide, dimethyl formamide, acetone and dimethyl sulfoxide.
6. The composite diaphragm slurry of claim 1, wherein the spray drying adopts a closed circulation system, nitrogen is used as inert protective gas, the spray drying temperature is 80-300 ℃, and the spray pressure is 0.05-5 MPa. The feed rate is precisely controlled by the feed system, preferably at a rate of 50-1000 ml/h.
7. The composite separator slurry according to claim 1, wherein said ceramic particles are one or a mixture of Al2O3, SiO2, TiO2, boehmite; preferably, the D50 of the ceramic particles is 0.6 to 1.2 μm.
8. The composite separator slurry according to claim 1, wherein said binder is an aqueous binder comprising one or more of Styrene Butadiene Rubber (SBR), polyvinyl alcohol (PVA), polyethylene oxide (PEO), sodium carboxymethylcellulose (CMC), Ethylene Vinyl Acetate (EVA), Polyurethane (PU), acrylates.
9. The method of preparing a composite separator slurry according to any one of claims 1 to 8, comprising: and mixing the ceramic particles coated by the polymer, deionized water, a dispersing agent, a binder and an auxiliary agent at a stirring speed of 300-700 rpm for 90-180 min to obtain the composite diaphragm slurry.
10. The battery diaphragm is characterized in that the battery diaphragm is prepared by coating composite diaphragm slurry on a base film and drying, wherein the base film is a wet Polyethylene (PE) diaphragm, the thickness of the base film is 5-14 mu m, the coating thickness is 2-5 mu m, and the drying temperature is 40-80 ℃.
CN202110880716.5A 2021-08-02 2021-08-02 Composite diaphragm slurry, preparation method thereof and battery diaphragm Pending CN113611983A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202110880716.5A CN113611983A (en) 2021-08-02 2021-08-02 Composite diaphragm slurry, preparation method thereof and battery diaphragm

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202110880716.5A CN113611983A (en) 2021-08-02 2021-08-02 Composite diaphragm slurry, preparation method thereof and battery diaphragm

Publications (1)

Publication Number Publication Date
CN113611983A true CN113611983A (en) 2021-11-05

Family

ID=78306459

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202110880716.5A Pending CN113611983A (en) 2021-08-02 2021-08-02 Composite diaphragm slurry, preparation method thereof and battery diaphragm

Country Status (1)

Country Link
CN (1) CN113611983A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114497899A (en) * 2022-02-11 2022-05-13 北京宇程科技有限公司 High-temperature-resistant polymer microsphere coated modified composite diaphragm and preparation method thereof
CN114614199A (en) * 2022-03-28 2022-06-10 惠州亿纬动力电池有限公司 Diaphragm and preparation method and application thereof
CN115491737A (en) * 2022-09-14 2022-12-20 暨南大学 Method for dispersing ceramic particles in metal ceramic composite plating solution

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20110183203A1 (en) * 2010-01-27 2011-07-28 Molecular Nanosystems, Inc. Polymer supported electrodes
CN104362275A (en) * 2014-12-01 2015-02-18 东莞市卓高电子科技有限公司 Manufacturing method of lithium ion battery diaphragm as well as battery diaphragm prepared by manufacturing method and battery
CN109192903A (en) * 2018-08-20 2019-01-11 合肥国轩高科动力能源有限公司 A kind of preparation method of lithium ion battery coating modification ceramic coating membrane
CN209434275U (en) * 2018-12-28 2019-09-24 江西省通瑞新能源科技发展有限公司 A kind of Organic-inorganic composite power lithium battery diaphragm
WO2020155001A1 (en) * 2019-01-31 2020-08-06 青岛蓝科途膜材料有限公司 Lithium ion battery separator having high temperature-resistant coating and preparation method therefor
CN112531290A (en) * 2019-09-18 2021-03-19 珠海冠宇电池股份有限公司 Ceramic microsphere, diaphragm containing ceramic microsphere and lithium ion battery containing diaphragm

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20110183203A1 (en) * 2010-01-27 2011-07-28 Molecular Nanosystems, Inc. Polymer supported electrodes
CN104362275A (en) * 2014-12-01 2015-02-18 东莞市卓高电子科技有限公司 Manufacturing method of lithium ion battery diaphragm as well as battery diaphragm prepared by manufacturing method and battery
CN109192903A (en) * 2018-08-20 2019-01-11 合肥国轩高科动力能源有限公司 A kind of preparation method of lithium ion battery coating modification ceramic coating membrane
CN209434275U (en) * 2018-12-28 2019-09-24 江西省通瑞新能源科技发展有限公司 A kind of Organic-inorganic composite power lithium battery diaphragm
WO2020155001A1 (en) * 2019-01-31 2020-08-06 青岛蓝科途膜材料有限公司 Lithium ion battery separator having high temperature-resistant coating and preparation method therefor
CN112531290A (en) * 2019-09-18 2021-03-19 珠海冠宇电池股份有限公司 Ceramic microsphere, diaphragm containing ceramic microsphere and lithium ion battery containing diaphragm

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
姚汪兵等: "陶瓷涂层隔膜对锂离子电池性能影响", 《电池工业》 *

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114497899A (en) * 2022-02-11 2022-05-13 北京宇程科技有限公司 High-temperature-resistant polymer microsphere coated modified composite diaphragm and preparation method thereof
CN114614199A (en) * 2022-03-28 2022-06-10 惠州亿纬动力电池有限公司 Diaphragm and preparation method and application thereof
CN115491737A (en) * 2022-09-14 2022-12-20 暨南大学 Method for dispersing ceramic particles in metal ceramic composite plating solution
CN115491737B (en) * 2022-09-14 2023-09-29 暨南大学 Method for dispersing ceramic particles in metal ceramic composite plating solution

Similar Documents

Publication Publication Date Title
CN113611983A (en) Composite diaphragm slurry, preparation method thereof and battery diaphragm
CN112795184B (en) Polymer particle, separator containing polymer particle and lithium ion battery
CN109509857B (en) Porous lithium ion battery diaphragm with interpenetrating network structure and application thereof
CN111653717B (en) Preparation method of composite diaphragm, composite diaphragm and lithium ion battery
CN111509173A (en) Functional coating diaphragm for lithium ion battery and preparation method thereof
Yu et al. A newly-developed heat-resistance polyimide microsphere coating to enhance the thermal stability of commercial polyolefin separators for advanced lithium-ion battery
WO2016161920A1 (en) Composite separator and preparation method therefor, and lithium-ion battery
CN111370625A (en) Aramid fiber phase-transition coating lithium ion battery diaphragm and preparation method thereof
CN108735953A (en) A kind of SiO2- PS nucleocapsid ceramic-coated separators and its preparation method and application
CN111916622A (en) Multifunctional double-sided heterogeneous Janus diaphragm for lithium ion battery and preparation method thereof
CN112216928A (en) Modified composite heat-resistant lithium ion battery diaphragm and preparation method thereof
CN114725616A (en) Inorganic hybrid aramid nanofiber membrane, preparation method and application of inorganic hybrid aramid nanofiber membrane in lithium battery
CN112038549A (en) PMMA crosslinked spherical micro powder coating diaphragm and preparation method thereof and application of PMMA crosslinked spherical micro powder coating diaphragm in lithium ion battery
CN104752660B (en) A kind of battery diaphragm and preparation method thereof
CN105161660A (en) Aluminum oxide and barium sulfate composite membrane for lithium ion battery and preparation method thereof
CN112038546A (en) Functional diaphragm of lithium-sulfur battery, preparation method and application thereof, and lithium-sulfur battery
CN111293256B (en) Ceramic particle, diaphragm comprising ceramic particle and battery
CN114122619A (en) Lithium battery diaphragm and preparation method thereof
CN110556496B (en) High-safety composite diaphragm with high-temperature self-closing function and preparation method thereof
CN111509176A (en) Cross-linked polyimide/ceramic composite diaphragm and preparation method thereof
CN112072047A (en) Sol coating diaphragm and preparation method thereof
CN114335535B (en) Explosion-proof lithium battery slurry and preparation method thereof
CN213026385U (en) Lithium ion battery is with multi-functional two-sided heterogeneous Janus diaphragm
CN114883746A (en) Novel polyimide microsphere slurry and coating diaphragm thereof
CN113745761A (en) Polyimide/silicon nitride whisker composite lithium ion battery diaphragm and preparation 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
RJ01 Rejection of invention patent application after publication

Application publication date: 20211105

RJ01 Rejection of invention patent application after publication