CN115483505B - Lithium metal battery functional diaphragm and preparation method and application thereof - Google Patents
Lithium metal battery functional diaphragm and preparation method and application thereof Download PDFInfo
- Publication number
- CN115483505B CN115483505B CN202211222270.8A CN202211222270A CN115483505B CN 115483505 B CN115483505 B CN 115483505B CN 202211222270 A CN202211222270 A CN 202211222270A CN 115483505 B CN115483505 B CN 115483505B
- Authority
- CN
- China
- Prior art keywords
- lithium metal
- covalent organic
- drying
- metal battery
- diaphragm
- 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
- 229910052744 lithium Inorganic materials 0.000 title claims abstract description 54
- 238000002360 preparation method Methods 0.000 title claims abstract description 15
- 239000013310 covalent-organic framework Substances 0.000 claims abstract description 40
- ANOBYBYXJXCGBS-UHFFFAOYSA-L stannous fluoride Chemical compound F[Sn]F ANOBYBYXJXCGBS-UHFFFAOYSA-L 0.000 claims abstract description 37
- 229960002799 stannous fluoride Drugs 0.000 claims abstract description 37
- 239000000463 material Substances 0.000 claims abstract description 24
- 239000002033 PVDF binder Substances 0.000 claims abstract description 23
- 229920002981 polyvinylidene fluoride Polymers 0.000 claims abstract description 23
- 238000001035 drying Methods 0.000 claims abstract description 21
- -1 polypropylene Polymers 0.000 claims abstract description 18
- 239000004743 Polypropylene Substances 0.000 claims abstract description 14
- 229920001155 polypropylene Polymers 0.000 claims abstract description 14
- 239000000758 substrate Substances 0.000 claims abstract description 12
- 239000002131 composite material Substances 0.000 claims abstract description 6
- 239000002002 slurry Substances 0.000 claims abstract description 6
- 239000011248 coating agent Substances 0.000 claims abstract description 4
- 238000000576 coating method Methods 0.000 claims abstract description 4
- 238000013329 compounding Methods 0.000 claims abstract description 4
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 claims description 21
- IAZDPXIOMUYVGZ-UHFFFAOYSA-N Dimethylsulphoxide Chemical compound CS(C)=O IAZDPXIOMUYVGZ-UHFFFAOYSA-N 0.000 claims description 14
- IIPYXGDZVMZOAP-UHFFFAOYSA-N lithium nitrate Chemical compound [Li+].[O-][N+]([O-])=O IIPYXGDZVMZOAP-UHFFFAOYSA-N 0.000 claims description 12
- 239000006255 coating slurry Substances 0.000 claims description 10
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 claims description 9
- 239000012528 membrane Substances 0.000 claims description 8
- ZSUXOVNWDZTCFN-UHFFFAOYSA-L tin(ii) bromide Chemical compound Br[Sn]Br ZSUXOVNWDZTCFN-UHFFFAOYSA-L 0.000 claims description 8
- 238000005406 washing Methods 0.000 claims description 7
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 6
- MNBSXKSWDLYJHN-UHFFFAOYSA-N 2,4,6-trimethylbenzene-1,3,5-triol Chemical compound CC1=C(O)C(C)=C(O)C(C)=C1O MNBSXKSWDLYJHN-UHFFFAOYSA-N 0.000 claims description 5
- ZMMJGEGLRURXTF-UHFFFAOYSA-N ethidium bromide Chemical compound [Br-].C12=CC(N)=CC=C2C2=CC=C(N)C=C2[N+](CC)=C1C1=CC=CC=C1 ZMMJGEGLRURXTF-UHFFFAOYSA-N 0.000 claims description 5
- 229960005542 ethidium bromide Drugs 0.000 claims description 5
- DDFHBQSCUXNBSA-UHFFFAOYSA-N 5-(5-carboxythiophen-2-yl)thiophene-2-carboxylic acid Chemical compound S1C(C(=O)O)=CC=C1C1=CC=C(C(O)=O)S1 DDFHBQSCUXNBSA-UHFFFAOYSA-N 0.000 claims description 3
- 239000004698 Polyethylene Substances 0.000 claims description 3
- 238000001914 filtration Methods 0.000 claims description 3
- 229920000573 polyethylene Polymers 0.000 claims description 3
- 239000000047 product Substances 0.000 claims description 3
- 239000003054 catalyst Substances 0.000 claims description 2
- 239000008367 deionised water Substances 0.000 claims description 2
- 229910021641 deionized water Inorganic materials 0.000 claims description 2
- 239000011261 inert gas Substances 0.000 claims description 2
- 239000003960 organic solvent Substances 0.000 claims description 2
- 239000002244 precipitate Substances 0.000 claims description 2
- 238000003756 stirring Methods 0.000 claims description 2
- 239000007784 solid electrolyte Substances 0.000 abstract description 7
- 229910002651 NO3 Inorganic materials 0.000 abstract description 4
- 229910001128 Sn alloy Inorganic materials 0.000 abstract description 4
- UIDWHMKSOZZDAV-UHFFFAOYSA-N lithium tin Chemical compound [Li].[Sn] UIDWHMKSOZZDAV-UHFFFAOYSA-N 0.000 abstract description 4
- IDBFBDSKYCUNPW-UHFFFAOYSA-N lithium nitride Chemical compound [Li]N([Li])[Li] IDBFBDSKYCUNPW-UHFFFAOYSA-N 0.000 abstract 1
- 239000000243 solution Substances 0.000 description 10
- 238000001000 micrograph Methods 0.000 description 8
- 238000012360 testing method Methods 0.000 description 7
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 description 6
- 229960001078 lithium Drugs 0.000 description 6
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical group [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 description 4
- SECXISVLQFMRJM-UHFFFAOYSA-N N-Methylpyrrolidone Chemical compound CN1CCCC1=O SECXISVLQFMRJM-UHFFFAOYSA-N 0.000 description 4
- 230000005540 biological transmission Effects 0.000 description 4
- 210000004027 cell Anatomy 0.000 description 4
- 229910001416 lithium ion Inorganic materials 0.000 description 4
- GELKBWJHTRAYNV-UHFFFAOYSA-K lithium iron phosphate Chemical compound [Li+].[Fe+2].[O-]P([O-])([O-])=O GELKBWJHTRAYNV-UHFFFAOYSA-K 0.000 description 4
- 230000014759 maintenance of location Effects 0.000 description 4
- 238000000034 method Methods 0.000 description 4
- 239000007774 positive electrode material Substances 0.000 description 4
- 239000006185 dispersion Substances 0.000 description 3
- 239000003792 electrolyte Substances 0.000 description 3
- 239000007788 liquid Substances 0.000 description 3
- 150000004767 nitrides Chemical class 0.000 description 3
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 2
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- WYURNTSHIVDZCO-UHFFFAOYSA-N Tetrahydrofuran Chemical compound C1CCOC1 WYURNTSHIVDZCO-UHFFFAOYSA-N 0.000 description 2
- 210000001787 dendrite Anatomy 0.000 description 2
- 238000011068 loading method Methods 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 230000008092 positive effect Effects 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- RYHBNJHYFVUHQT-UHFFFAOYSA-N 1,4-Dioxane Chemical compound C1COCCO1 RYHBNJHYFVUHQT-UHFFFAOYSA-N 0.000 description 1
- LDDQLRUQCUTJBB-UHFFFAOYSA-N ammonium fluoride Chemical compound [NH4+].[F-] LDDQLRUQCUTJBB-UHFFFAOYSA-N 0.000 description 1
- 239000010405 anode material Substances 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000012512 characterization method Methods 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000003153 chemical reaction reagent Substances 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 230000001351 cycling effect Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000004880 explosion Methods 0.000 description 1
- 229910000625 lithium cobalt oxide Inorganic materials 0.000 description 1
- BFZPBUKRYWOWDV-UHFFFAOYSA-N lithium;oxido(oxo)cobalt Chemical compound [Li+].[O-][Co]=O BFZPBUKRYWOWDV-UHFFFAOYSA-N 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- AUHZEENZYGFFBQ-UHFFFAOYSA-N mesitylene Substances CC1=CC(C)=CC(C)=C1 AUHZEENZYGFFBQ-UHFFFAOYSA-N 0.000 description 1
- 125000001827 mesitylenyl group Chemical group [H]C1=C(C(*)=C(C([H])=C1C([H])([H])[H])C([H])([H])[H])C([H])([H])[H] 0.000 description 1
- 239000011268 mixed slurry Substances 0.000 description 1
- 239000011259 mixed solution Substances 0.000 description 1
- 239000002105 nanoparticle Substances 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 239000002243 precursor Substances 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- 239000012047 saturated solution Substances 0.000 description 1
- YLQBMQCUIZJEEH-UHFFFAOYSA-N tetrahydrofuran Natural products C=1C=COC=1 YLQBMQCUIZJEEH-UHFFFAOYSA-N 0.000 description 1
- 238000005303 weighing Methods 0.000 description 1
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
- 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
- H01M50/411—Organic material
- H01M50/414—Synthetic resins, e.g. thermoplastics or thermosetting resins
- H01M50/417—Polyolefins
-
- 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
- H01M50/431—Inorganic material
-
- 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
- H01M50/457—Separators, membranes or diaphragms characterised by the material having a layered structure comprising three or more layers
-
- 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)
- Inorganic Chemistry (AREA)
- Cell Separators (AREA)
Abstract
The invention discloses a lithium metal battery functional diaphragm, a preparation method and application thereof, wherein the functional diaphragm is formed by compounding a substrate material, a covalent organic framework, polyvinylidene fluoride and stannous fluoride, and the substrate material can be a polypropylene diaphragm. The preparation method of the composite functional diaphragm comprises the steps of preparing covalent organic frameworks and stannous fluoride, uniformly dispersing the prepared covalent organic frameworks and polyvinylidene fluoride to form slurry, coating the slurry on a substrate material, drying at a proper temperature, dripping a proper amount of stannous fluoride solution, and drying to form the composite functional diaphragm. The functional diaphragm has the function of constructing a stable lithium metal interface, namely, the nitrate ions and stannous fluoride in the functional diaphragm form a solid electrolyte interface layer rich in lithium nitride and lithium tin alloy, so that the stability of the lithium metal battery can be effectively improved.
Description
Technical Field
The invention belongs to the field of lithium metal batteries, and particularly relates to a preparation method and application of a composite functional diaphragm.
Background
The lithium metal has the advantages of high energy density (3860 mAh/g), small density (0.53 g/cm 3) and low potential (-3.04V), and can be matched with the current main commercial anode materials such as lithium iron phosphate, lithium cobalt oxide, ternary materials and the like. Therefore, lithium metal batteries are considered as the next generation of high energy density battery systems with the highest development potential.
However, direct contact between the highly reactive lithium metal and the electrolyte may form an unstable solid electrolyte interface layer on the surface of the lithium metal. During cycling, dendritic lithium dendrites are formed due to uneven deposition of lithium ions caused by the unstable interfacial layer. Disordered growth of lithium dendrites can puncture the separator, cause a short circuit, cause thermal runaway of the battery, and thus lead to a safety hazard of combustion or explosion, which greatly raises concerns about the safety of lithium metal batteries in the industry. Therefore, constructing a stable solid electrolyte interfacial layer on the surface of a lithium metal anode is an effective strategy for optimizing the performance of a lithium metal battery.
Disclosure of Invention
The invention aims to overcome the defects in the prior art, provides a functional separator of a lithium metal battery, and aims to construct a stable and effective solid electrolyte interface layer for the lithium metal battery so as to protect lithium metal.
In order to achieve the above purpose, the invention adopts the following technical scheme:
In a first aspect, the invention provides a lithium metal battery functional separator which is formed by compounding a base material, polyvinylidene fluoride, a covalent organic framework and nano stannous fluoride.
The substrate material is selected from one of a polyethylene diaphragm, a polypropylene diaphragm or a polypropylene-polyethylene-polypropylene three-layer composite diaphragm film.
The mass ratio of the substrate material to the polyvinylidene fluoride to the covalent organic framework to the nano stannous fluoride is (30-50): (1-10): (20-40): (1-10).
The mass ratio of the polyvinylidene fluoride to the covalent organic framework is (5-15): (85-95).
The framework material of the covalent organic framework is prepared from 2,4, 6-trimethyl phloroglucinol, ethidium bromide and lithium nitrate.
The functional diaphragm provided by the invention is characterized in that a coating slurry of covalent organic frameworks and polyvinylidene fluoride is coated on a substrate material, then stannous fluoride solution is dripped on the surface, and a stable solid electrolyte interface layer rich in nitride and lithium tin alloy is formed through nitrate ions and stannous fluoride in the covalent organic frameworks.
In a second aspect, the present invention provides a method for preparing a functional separator, comprising the steps of:
step S1: preparing a base material;
step S2: preparing a coating slurry containing a covalent organic framework and stannous fluoride, coating the coating slurry on the surface of a base material, and drying;
Step S3: and after drying, dropwise adding stannous fluoride solution to the surface of the functional membrane coated with the slurry, and then drying to obtain the lithium metal battery functional membrane.
The substrate material is selected from one of a polyethylene diaphragm, a polypropylene diaphragm or a polypropylene-polyethylene-polypropylene three-layer composite diaphragm film.
The coating slurry is obtained by dispersing covalent organic frameworks and polyvinylidene fluoride in N-methyl pyrrolidone, wherein the mass ratio of the polyvinylidene fluoride to the covalent organic frameworks is (5-15): (85-95);
the stannous fluoride solution is prepared by dissolving stannous fluoride in dimethyl sulfoxide.
In the step S2, the drying temperature is 60-80 ℃ and the drying time is 6-24h; and S3, drying at 60-80 ℃ for 6-24 hours.
The preparation method of the covalent organic framework comprises the following steps:
Dissolving 2,4, 6-trimethyl phloroglucinol and ethidium bromide in an organic solvent, adding acetic acid, reacting at 100-130 ℃ under the atmosphere of inert gas to obtain dark red precipitate, washing, drying, placing into saturated lithium nitrate solution of methanol and deionized water, stirring for 24-48h, washing, filtering, repeating for 3-5 times, washing with water, and drying to obtain the product;
The preparation method of the stannous fluoride solution comprises the following steps:
Stannous bromide and ammonia fluoride molar ratio 1:2 is dissolved in methanol, mixed at 5-10 ℃ and reacted for 3-7 hours, washed and dried, and then dissolved in dimethyl sulfoxide to obtain the catalyst.
In a third aspect, the present invention provides the above lithium metal battery functional separator or an application of the lithium metal battery functional separator prepared by the above lithium metal battery functional separator preparation method in lithium metal batteries, especially in improving cycle performance of lithium metal batteries.
The functional separator was assembled and tested. In the lithium metal full battery test process, the cycle life of the battery is greatly prolonged, and the functional diaphragm can be proved to be applied to the lithium metal battery.
Compared with the prior art, the invention has the following advantages:
(1) The inventor creatively coats the mixed slurry of covalent organic frameworks and polyvinylidene fluoride on a matrix material in a functional membrane of a lithium battery, and then drops stannous fluoride dispersion liquid, and forms a stable solid electrolyte interface layer rich in nitride and lithium tin alloy through nitrate ions and stannous fluoride in the covalent organic frameworks, thereby playing a technical role in protecting the lithium battery and improving the cycle performance of the lithium battery.
(2) The inventors creatively found that the addition of a covalent organic framework to a lithium battery functional separator can optimize lithium ion conduction and provide lithium nitrate to form a stable interfacial layer; the addition of polyvinylidene fluoride can bring good chemical stability and temperature characteristics, excellent mechanical properties and processability, has positive effect on improving the bonding property, and finally improves the cycle performance of the battery together.
Drawings
FIG. 1 is a scanning electron microscope image of the covalent organic framework prepared in example 1;
FIG. 2 is a transmission electron microscope image of the covalent organic framework prepared in example 1;
FIG. 3 is a scanning electron microscope image of stannous fluoride prepared in example 1;
FIG. 4 is a transmission electron microscope image of stannous fluoride prepared in example 1;
FIG. 5 is a graph of the cycle performance of example 2;
FIG. 6 is a graph of the cycle performance of example 3;
Detailed Description
In order that the invention may be understood more fully, a more particular description of the invention will be rendered by reference to specific embodiments thereof which are illustrated in the appended claims. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. These embodiments are provided so that this disclosure will be thorough and complete. It should be understood that the experimental methods in the following examples, in which specific conditions are not noted, are generally performed under conventional conditions or under conditions suggested by the manufacturer. The various reagents commonly used in the examples are all commercially available products.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and/or" as used herein includes any and all combinations of one or more of the associated listed items.
In a first aspect, the present embodiment provides a functional separator for a lithium metal battery, where the functional separator is formed by compounding a base material, polyvinylidene fluoride, a covalent organic framework and stannous fluoride, and the base material is a polypropylene separator.
The functional membrane provided by the embodiment is formed by coating covalent organic frameworks and polyvinylidene fluoride coating slurry on a polypropylene membrane, then dropwise adding stannous fluoride dispersion liquid, and forming a stable solid electrolyte interface layer rich in nitride and lithium tin alloy through nitrate ions and stannous fluoride in the covalent organic frameworks.
Further, the coating slurry is prepared by dispersing polyvinylidene fluoride and a covalent organic framework in N-methyl pyrrolidone, and the mass ratio of the polyvinylidene fluoride to the covalent organic framework is (5-15): (85-95). Wherein the covalent organic framework is used to optimize lithium ion conduction and provide lithium nitrate to form a stable interfacial layer; the polyvinylidene fluoride has good chemical stability and temperature characteristics, excellent mechanical properties and processability, and has positive effect on improving the bonding performance. Too many covalent organic frameworks provide poor slurry adhesion and too little do not facilitate the formation of stable interfaces. The mass ratio of polyvinylidene fluoride to covalent organic framework is controlled to be (5-15): (85-95) a more suitable coating slurry can be formed.
Further, stannous fluoride dispersion liquid is also dripped on the surface of the functional diaphragm, and the stannous fluoride solution is prepared by dissolving stannous fluoride in dimethyl sulfoxide.
In a second aspect, the embodiment of the invention also provides a preparation method of the lithium metal battery functional diaphragm, which is prepared by the preparation method.
The preparation method of the functional membrane of the embodiment preferably comprises the following steps:
step S1 prepares a base material, wherein the base material is a polypropylene separator.
Step S2, uniformly dispersing the prepared covalent organic framework and polyvinylidene fluoride into N-methyl pyrrolidone to form slurry, wherein the mass ratio of the polyvinylidene fluoride to the covalent organic framework is (5-15): (85-95) and coated on a polypropylene separator.
And S3, after drying, dropwise adding a stannous fluoride solution onto the surface of the diaphragm, wherein the stannous fluoride solution is prepared by dissolving stannous fluoride in dimethyl sulfoxide, and finally drying at 60 ℃.
In a third aspect, the present embodiment provides an application of the lithium metal battery functional separator according to the first aspect in a lithium metal battery, and the functional separator according to the first aspect is subjected to battery assembly and testing, so that the result shows that the performance of the lithium metal full battery is effectively improved, and the functional separator can be proved to be applied to the lithium metal battery.
Alternatively, the lithium ion battery prepared by the battery separator as described above may be a button battery or a pouch battery.
The invention has been tested several times in succession, and the invention will now be described in further detail with reference to a few test results, which are described in detail below in connection with specific examples.
Example 1
Preparation of covalent organic frameworks:
2,4, 6-trimethyl phloroglucinol and ethidium bromide (molar ratio 2:3) are weighed and dispersed in a mixed solution of 1,4 dioxane and mesitylene (volume ratio 1:1). Acetic acid of a proper concentration was added and reacted at 120℃for 72 hours under the protection of nitrogen. After washing with acetone and tetrahydrofuran, the mixture was dried at 85℃for 12 hours. Then, 1.5g of the obtained precursor was taken and dispersed in 15mL of a saturated solution of lithium nitrate in water and methanol (volume ratio 1:1) and stirred continuously for 24 hours, and after filtration, the reaction was repeated 3 times, and finally washed three times with water and dried under vacuum at 120℃for 12 hours.
Characterization of the covalent organic frameworks:
Fig. 1 shows a scanning electron microscope image of a covalent organic framework, and fig. 2 shows a transmission electron microscope image of a covalent organic framework, showing that the covalent organic frameworks prepared are arranged in layers.
Preparing stannous fluoride:
Weighing ammonium fluoride and stannous bromide, respectively dissolving in methanol (molar ratio of 1:2), dropwise adding the ammonium fluoride solution into the stannous bromide solution at 10 ℃, reacting for 12 hours, centrifuging the methanol for 5 times, and drying at 80 ℃ for 12 hours.
Fig. 3 shows a scanning electron microscope image of stannous fluoride, and fig. 4 shows a transmission electron microscope image of stannous fluoride, showing that the prepared stannous fluoride is nano-particle.
Preparing a functional diaphragm:
Step S1: preparing a substrate material polypropylene diaphragm;
Step S2: 10% polyvinylidene fluoride and 90% covalent organic frameworks are weighed and dispersed in N-methyl pyrrolidone, and the mixture is continuously stirred to form coating slurry, coated on a substrate material and dried at 60 ℃ for 12 hours.
Step S3: stannous fluoride is taken to be dissolved in dimethyl sulfoxide, then is dripped on the surface of the dried diaphragm, and finally is dried for 12 hours at 60 ℃.
Example 2 application of lithium metal battery functional separator: lithium metal full cell with NCM811 as positive electrode material
The lithium metal functional separator prepared in example 1 was used as a separator for a lithium metal battery, and was assembled into a full battery using NCM811 as a positive electrode material.
After the functional separator was assembled into a full cell, a charge and discharge test was performed, and fig. 5 is a graph showing the cycle performance of the NCM811 full cell (positive electrode load: about 4mg/cm 2; negative electrode load: about 4mAh; electrolyte amount 15 μl), the test temperature was 30 ℃, and the full cell was cycled between 3 and 4.4V at a rate of 0.3C (1c=180 mAh/g) for 3 cycles, and then cycled at a rate of 1C. As can be seen from the graph, after 120 cycles, the battery capacity of the polypropylene separator is reduced from 187.9mAh/g to 67mAh/g, and the capacity retention rate is only 35.7%; while the capacity of the battery using the functional separator was slowly decayed from 187.9mAh/g to 175.3mAh/g after 200 cycles, the capacity retention was 93.3%. The method can effectively improve the cycle performance of the lithium metal battery.
Example 3 application of lithium metal battery functional separator: lithium metal full battery using lithium iron phosphate as positive electrode material
The lithium metal functional separator prepared in example 1 was used as a separator for a lithium metal battery, and a full battery was fabricated using lithium iron phosphate as a positive electrode material.
After the functional separator was assembled into a full battery, charge and discharge tests were performed, and fig. 6 is a graph showing the cycle performance of a lithium iron phosphate full battery (positive electrode loading: about 12mg/cm 2; negative electrode loading: about 4mAh; electrolyte consumption: 15 μl), at a test temperature of 30 ℃, the full battery was cycled between 2.2-4.1V 3 times at a rate of 0.2C (1c=170 mAh/g), and then cycled at a rate of 1C. As can be seen from the graph, after 120 cycles, the battery capacity of the polypropylene separator is reduced from 140.9mAh/g to 23.1mAh/g, and the capacity retention rate is only 16.4%; while the battery using the functional separator slowly decays from 141.3mAh/g to 133.9mAh/g after 200 cycles, still maintaining a high capacity retention of 94.8%. The method can effectively improve the cycle performance of the lithium metal battery.
The technical features of the above embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.
The foregoing examples illustrate only a few embodiments of the invention and are described in detail herein without thereby limiting the scope of the invention. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the invention, which are all within the scope of the invention. Therefore, the scope of the present invention should be determined only by the preferred embodiments of the present invention described above with reference to the appended claims, and not by way of limitation, but all modifications, equivalents, and improvements within the spirit and principles of the present invention are intended to be included in the scope of the present invention.
Claims (5)
1. The functional diaphragm of the lithium metal battery is characterized by being formed by compounding a base material, polyvinylidene fluoride, a covalent organic framework and nano stannous fluoride; the substrate material is selected from one of a polyethylene diaphragm, a polypropylene diaphragm or a polypropylene-polyethylene-polypropylene three-layer composite diaphragm; the mass ratio of the substrate material to the polyvinylidene fluoride to the covalent organic framework to the nano stannous fluoride is (30-50): (1-10): (20-40): (1-10), the mass ratio of polyvinylidene fluoride to covalent organic framework is (5-15): (85-95);
The framework material of the covalent organic framework is prepared from 2,4, 6-trimethyl phloroglucinol, ethidium bromide and lithium nitrate; the preparation method of the functional diaphragm comprises the following steps:
step S1: preparing a base material;
Step S2: preparing a coating slurry containing a covalent organic framework and polyvinylidene fluoride, coating the coating slurry on the surface of a substrate material, and drying;
Step S3: and after drying, dropwise adding stannous fluoride solution to the surface of the functional membrane coated with the slurry, and then drying to obtain the lithium metal battery functional membrane.
2. The lithium metal battery functional separator according to claim 1, wherein the stannous fluoride solution is prepared by dissolving stannous fluoride in dimethyl sulfoxide.
3. The lithium metal battery functional separator according to claim 1, wherein the drying temperature in step S2 is 60 ℃ to 80 ℃ and the drying time is 6 to 24 h; and S3, drying at 60-80 ℃ for 6-24 h.
4. The lithium metal battery functional separator according to claim 1, wherein the preparation method of the covalent organic framework comprises the following steps:
Dissolving 2,4, 6-trimethyl phloroglucinol and ethidium bromide in an organic solvent, adding acetic acid, reacting at 100-130 ℃ under the atmosphere of inert gas to obtain dark red precipitate, washing, drying, placing into saturated lithium nitrate solution of methanol and deionized water, stirring for 24-48 h times, washing, filtering, repeating for 3-5 times, washing with water, and drying to obtain the product;
The preparation method of the stannous fluoride solution comprises the following steps:
Stannous bromide and ammonium fluoride molar ratio 2:1 are dissolved in methanol, mixed at 5-10 ℃, reacted for 3-7 h ℃, washed and dried, and then dissolved in dimethyl sulfoxide to obtain the catalyst.
5. The lithium metal battery functional separator of claim 1 for use in a lithium metal battery.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211222270.8A CN115483505B (en) | 2022-10-08 | 2022-10-08 | Lithium metal battery functional diaphragm and preparation method and application thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211222270.8A CN115483505B (en) | 2022-10-08 | 2022-10-08 | Lithium metal battery functional diaphragm and preparation method and application thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115483505A CN115483505A (en) | 2022-12-16 |
| CN115483505B true CN115483505B (en) | 2024-05-31 |
Family
ID=84393560
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211222270.8A Active CN115483505B (en) | 2022-10-08 | 2022-10-08 | Lithium metal battery functional diaphragm and preparation method and application thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115483505B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN118763281A (en) * | 2024-05-07 | 2024-10-11 | 深圳欣界能源科技有限公司 | Electrolyte and battery |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104393220A (en) * | 2014-12-03 | 2015-03-04 | 中南大学 | Preparation method of composite diaphragm of lithium-sulphur battery |
| CN109728249A (en) * | 2017-10-30 | 2019-05-07 | 中国科学院宁波材料技术与工程研究所 | A kind of interface protection structure, preparation method and the battery comprising the structure |
| CN109904519A (en) * | 2019-01-18 | 2019-06-18 | 北京理工大学 | A kind of all solid state electrolyte material and its preparation method and application |
| CN110739427A (en) * | 2019-10-18 | 2020-01-31 | 华南师范大学 | Battery diaphragm material and preparation method and application thereof |
| CN112886134A (en) * | 2021-01-18 | 2021-06-01 | 福建师范大学 | Preparation method of diaphragm modification material for lithium-sulfur battery |
| CN114188669A (en) * | 2021-12-21 | 2022-03-15 | 云南大学 | Functional diaphragm and preparation method and application thereof |
| CN114204208A (en) * | 2020-08-26 | 2022-03-18 | 中南大学 | Preparation method of PVDF-CTFE-based lithium-sulfur battery composite diaphragm |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP3136475B1 (en) * | 2015-08-31 | 2021-09-22 | Samsung Electronics Co., Ltd. | Lithium metal battery |
-
2022
- 2022-10-08 CN CN202211222270.8A patent/CN115483505B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104393220A (en) * | 2014-12-03 | 2015-03-04 | 中南大学 | Preparation method of composite diaphragm of lithium-sulphur battery |
| CN109728249A (en) * | 2017-10-30 | 2019-05-07 | 中国科学院宁波材料技术与工程研究所 | A kind of interface protection structure, preparation method and the battery comprising the structure |
| CN109904519A (en) * | 2019-01-18 | 2019-06-18 | 北京理工大学 | A kind of all solid state electrolyte material and its preparation method and application |
| CN110739427A (en) * | 2019-10-18 | 2020-01-31 | 华南师范大学 | Battery diaphragm material and preparation method and application thereof |
| CN114204208A (en) * | 2020-08-26 | 2022-03-18 | 中南大学 | Preparation method of PVDF-CTFE-based lithium-sulfur battery composite diaphragm |
| CN112886134A (en) * | 2021-01-18 | 2021-06-01 | 福建师范大学 | Preparation method of diaphragm modification material for lithium-sulfur battery |
| CN114188669A (en) * | 2021-12-21 | 2022-03-15 | 云南大学 | Functional diaphragm and preparation method and application thereof |
Non-Patent Citations (1)
| Title |
|---|
| 锂硫电池最新研究进展;万文博;蒲薇华;艾德生;;《化学进展》;第25卷(第11期);第1830-1841页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115483505A (en) | 2022-12-16 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104733708B (en) | Preparation method of lithium nickel cobalt manganese oxide composite material with surface coated with lithium iron phosphate | |
| CN101436677B (en) | Method for preparing battery | |
| CN114944478A (en) | Sodium ion battery positive electrode material and preparation method and application thereof | |
| CN107611439B (en) | Preparation method of metal complex lithium ion battery electrode material | |
| CN111785949B (en) | Modified conductive polymer coated silicon-based negative electrode material, and preparation method and application thereof | |
| CN111916693A (en) | Method for preparing organic matter coated high-nickel cathode material | |
| CN115483505B (en) | Lithium metal battery functional diaphragm and preparation method and application thereof | |
| CN112768840A (en) | Multifunctional diaphragm of lithium-sulfur battery and preparation method thereof | |
| CN113937262A (en) | Metal oxide modified positive electrode material for sodium ion battery and preparation method and application thereof | |
| CN117832447A (en) | Nitrogen-lithium doped porous carbon and silicon-carbon composite material as well as preparation method and application thereof | |
| CN109728278B (en) | Positive active material, preparation method thereof and lithium ion battery | |
| CN118419892A (en) | Metal doped porous carbon, silicon carbon material and preparation method thereof | |
| CN117080541A (en) | Solid electrolyte, preparation method thereof, solid lithium ion battery and electric equipment | |
| CN106920961B (en) | Modification method of ternary material for lithium ion battery | |
| CN108539168B (en) | Method for improving ageing resistance of lithium battery positive electrode material | |
| CN114220957A (en) | Lithium battery negative active material and preparation method and application thereof | |
| CN113346087A (en) | Hybrid phosphate open framework material composite high-nickel positive electrode material and preparation method thereof | |
| CN112271293A (en) | Preparation method of high-conductivity lithium iron phosphate cathode material | |
| CN110611088A (en) | Lithium ion battery cathode based on organic electrode material and preparation method thereof | |
| CN112652774A (en) | Copper foil composite material and preparation method thereof, negative pole piece and lithium ion battery | |
| CN116454541B (en) | Lithium battery composite diaphragm and preparation method and application thereof | |
| CN108565425B (en) | Surface chemical modification lithium battery positive electrode material and application thereof | |
| WO2024021273A1 (en) | High-voltage ternary positive electrode material and preparation method therefor | |
| CN116177612B (en) | Lithium ion battery positive electrode material and preparation method thereof, and lithium ion battery and preparation method thereof | |
| CN115810736A (en) | Lithium manganese iron phosphate cathode material 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 | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |