CN116845346A - In-situ polymerization double-crosslinking polymer electrolyte and preparation method and application thereof - Google Patents
In-situ polymerization double-crosslinking polymer electrolyte and preparation method and application thereof Download PDFInfo
- Publication number
- CN116845346A CN116845346A CN202310700782.9A CN202310700782A CN116845346A CN 116845346 A CN116845346 A CN 116845346A CN 202310700782 A CN202310700782 A CN 202310700782A CN 116845346 A CN116845346 A CN 116845346A
- Authority
- CN
- China
- Prior art keywords
- polymer electrolyte
- battery
- preparing
- crosslinked polymer
- situ polymerized
- 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
Links
- 239000005518 polymer electrolyte Substances 0.000 title claims abstract description 61
- 238000011065 in-situ storage Methods 0.000 title claims abstract description 38
- 238000006116 polymerization reaction Methods 0.000 title abstract description 21
- 238000002360 preparation method Methods 0.000 title abstract description 18
- 238000004132 cross linking Methods 0.000 title abstract description 16
- 238000000034 method Methods 0.000 claims abstract description 29
- 239000002243 precursor Substances 0.000 claims abstract description 23
- KMTRUDSVKNLOMY-UHFFFAOYSA-N Ethylene carbonate Chemical compound O=C1OCCO1 KMTRUDSVKNLOMY-UHFFFAOYSA-N 0.000 claims abstract description 22
- 239000003431 cross linking reagent Substances 0.000 claims abstract description 20
- 229910052744 lithium Inorganic materials 0.000 claims abstract description 20
- 229910003002 lithium salt Inorganic materials 0.000 claims abstract description 14
- 159000000002 lithium salts Chemical class 0.000 claims abstract description 14
- 238000010438 heat treatment Methods 0.000 claims abstract description 13
- 239000003999 initiator Substances 0.000 claims abstract description 13
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 claims abstract description 7
- 229910001416 lithium ion Inorganic materials 0.000 claims abstract description 7
- 229920000642 polymer Polymers 0.000 claims description 21
- OZAIFHULBGXAKX-UHFFFAOYSA-N 2-(2-cyanopropan-2-yldiazenyl)-2-methylpropanenitrile Chemical compound N#CC(C)(C)N=NC(C)(C)C#N OZAIFHULBGXAKX-UHFFFAOYSA-N 0.000 claims description 18
- 229920006037 cross link polymer Polymers 0.000 claims description 14
- 239000003792 electrolyte Substances 0.000 claims description 12
- 229910003473 lithium bis(trifluoromethanesulfonyl)imide Inorganic materials 0.000 claims description 11
- QSZMZKBZAYQGRS-UHFFFAOYSA-N lithium;bis(trifluoromethylsulfonyl)azanide Chemical group [Li+].FC(F)(F)S(=O)(=O)[N-]S(=O)(=O)C(F)(F)F QSZMZKBZAYQGRS-UHFFFAOYSA-N 0.000 claims description 11
- 150000001408 amides Chemical class 0.000 claims description 10
- 238000002156 mixing Methods 0.000 claims description 4
- ZIUHHBKFKCYYJD-UHFFFAOYSA-N n,n'-methylenebisacrylamide Chemical compound C=CC(=O)NCNC(=O)C=C ZIUHHBKFKCYYJD-UHFFFAOYSA-N 0.000 claims description 4
- 239000007784 solid electrolyte Substances 0.000 claims description 4
- 238000003756 stirring Methods 0.000 claims description 4
- 230000000379 polymerizing effect Effects 0.000 claims description 3
- UVDDHYAAWVNATK-VGKOASNMSA-L (z)-4-[dibutyl-[(z)-4-oxopent-2-en-2-yl]oxystannyl]oxypent-3-en-2-one Chemical compound CC(=O)\C=C(C)/O[Sn](CCCC)(CCCC)O\C(C)=C/C(C)=O UVDDHYAAWVNATK-VGKOASNMSA-L 0.000 claims description 2
- 239000004342 Benzoyl peroxide Substances 0.000 claims description 2
- OMPJBNCRMGITSC-UHFFFAOYSA-N Benzoylperoxide Chemical compound C=1C=CC=CC=1C(=O)OOC(=O)C1=CC=CC=C1 OMPJBNCRMGITSC-UHFFFAOYSA-N 0.000 claims description 2
- 229910015015 LiAsF 6 Inorganic materials 0.000 claims description 2
- 229910013063 LiBF 4 Inorganic materials 0.000 claims description 2
- 229910013870 LiPF 6 Inorganic materials 0.000 claims description 2
- UKLDJPRMSDWDSL-UHFFFAOYSA-L [dibutyl(dodecanoyloxy)stannyl] dodecanoate Chemical compound CCCCCCCCCCCC(=O)O[Sn](CCCC)(CCCC)OC(=O)CCCCCCCCCCC UKLDJPRMSDWDSL-UHFFFAOYSA-L 0.000 claims description 2
- 235000019400 benzoyl peroxide Nutrition 0.000 claims description 2
- 239000012975 dibutyltin dilaurate Substances 0.000 claims description 2
- NVLHKSGUMYMKRR-UHFFFAOYSA-N dodeca-2,10-dienediamide Chemical compound NC(=O)C=CCCCCCCC=CC(N)=O NVLHKSGUMYMKRR-UHFFFAOYSA-N 0.000 claims description 2
- ZQMHJBXHRFJKOT-UHFFFAOYSA-N methyl 2-[(1-methoxy-2-methyl-1-oxopropan-2-yl)diazenyl]-2-methylpropanoate Chemical compound COC(=O)C(C)(C)N=NC(C)(C)C(=O)OC ZQMHJBXHRFJKOT-UHFFFAOYSA-N 0.000 claims description 2
- 229920002554 vinyl polymer Polymers 0.000 claims description 2
- 239000007787 solid Substances 0.000 abstract description 15
- 230000008569 process Effects 0.000 abstract description 10
- 238000011068 loading method Methods 0.000 abstract description 7
- 238000004519 manufacturing process Methods 0.000 abstract description 6
- 239000013543 active substance Substances 0.000 abstract description 2
- 230000000052 comparative effect Effects 0.000 description 15
- 238000012360 testing method Methods 0.000 description 9
- SECXISVLQFMRJM-UHFFFAOYSA-N N-Methylpyrrolidone Chemical compound CN1CCCC1=O SECXISVLQFMRJM-UHFFFAOYSA-N 0.000 description 7
- 239000002131 composite material Substances 0.000 description 7
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 description 6
- 239000002033 PVDF binder Substances 0.000 description 6
- GELKBWJHTRAYNV-UHFFFAOYSA-K lithium iron phosphate Chemical compound [Li+].[Fe+2].[O-]P([O-])([O-])=O GELKBWJHTRAYNV-UHFFFAOYSA-K 0.000 description 6
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 6
- 229920002981 polyvinylidene fluoride Polymers 0.000 description 6
- 239000002202 Polyethylene glycol Substances 0.000 description 5
- 125000004386 diacrylate group Chemical group 0.000 description 5
- 239000000178 monomer Substances 0.000 description 5
- 229920001223 polyethylene glycol Polymers 0.000 description 5
- 239000011149 active material Substances 0.000 description 4
- 239000011267 electrode slurry Substances 0.000 description 4
- 229910052739 hydrogen Inorganic materials 0.000 description 4
- 239000001257 hydrogen Substances 0.000 description 4
- 150000002500 ions Chemical class 0.000 description 4
- 229910001220 stainless steel Inorganic materials 0.000 description 4
- 239000010935 stainless steel Substances 0.000 description 4
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 3
- 229910052782 aluminium Inorganic materials 0.000 description 3
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 3
- 229910052799 carbon Inorganic materials 0.000 description 3
- 239000011248 coating agent Substances 0.000 description 3
- 238000000576 coating method Methods 0.000 description 3
- 238000005520 cutting process Methods 0.000 description 3
- 239000011888 foil Substances 0.000 description 3
- 230000014759 maintenance of location Effects 0.000 description 3
- 238000001291 vacuum drying Methods 0.000 description 3
- 230000009286 beneficial effect Effects 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000000977 initiatory effect Effects 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- -1 polyethylene carbonate Polymers 0.000 description 2
- 230000009471 action Effects 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 125000002915 carbonyl group Chemical group [*:2]C([*:1])=O 0.000 description 1
- 230000001351 cycling effect Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000011031 large-scale manufacturing process Methods 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 230000005012 migration Effects 0.000 description 1
- 238000013508 migration Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000011056 performance test Methods 0.000 description 1
- 229920000867 polyelectrolyte Polymers 0.000 description 1
- 229910001251 solid state electrolyte alloy Inorganic materials 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 238000009864 tensile test Methods 0.000 description 1
- 238000010998 test method Methods 0.000 description 1
- 239000002699 waste material Substances 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
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
- H01M10/0564—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of organic materials only
- H01M10/0565—Polymeric materials, e.g. gel-type or solid-type
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F224/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a heterocyclic ring containing oxygen
-
- 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
- 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
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/058—Construction or manufacture
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M2300/00—Electrolytes
- H01M2300/0017—Non-aqueous electrolytes
- H01M2300/0065—Solid electrolytes
- H01M2300/0082—Organic polymers
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M2300/00—Electrolytes
- H01M2300/0085—Immobilising or gelification of electrolyte
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Electrochemistry (AREA)
- Manufacturing & Machinery (AREA)
- General Physics & Mathematics (AREA)
- Inorganic Chemistry (AREA)
- Physics & Mathematics (AREA)
- Dispersion Chemistry (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- Materials Engineering (AREA)
- Health & Medical Sciences (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- Secondary Cells (AREA)
Abstract
The invention belongs to the technical field of polymer electrolytes, and particularly relates to an in-situ polymerization double-crosslinking polymer electrolyte, and a preparation method and application thereof. Ethylene carbonate, lithium salt, a cross-linking agent and an initiator are mixed to form a precursor solution, the precursor solution is injected into a battery, and a polymer electrolyte is generated in situ in the battery after heating. The obtained solid polymer electrolyte has higher ionic conductivity and excellent mechanical property at room temperature, and the solid lithium metal battery prepared by the method has higher capacity exertion and excellent cycle stability at room temperature. At high active substance loadings, high capacities can also be obtained. The invention has simple process and is compatible with the existing lithium ion battery process, can effectively simplify the production and assembly processes of the solid lithium metal battery, and improves the battery performance, thereby having great application prospect.
Description
Technical field:
the invention belongs to the technical field of polymer electrolytes, and particularly relates to an in-situ polymerization double-crosslinking polymer electrolyte, and a preparation method and application thereof.
The background technology is as follows:
the polyethylene carbonate (PVEC) electrolyte is a polymer electrolyte material obtained by mixing a lithium salt, an initiator, and various additives with ethylene carbonate (VEC) monomers to form a precursor solution, and then initiating polymerization under heating or ultraviolet light. The PVEC electrolyte has higher room temperature ion conductivity, excellent lithium salt dissolution capability and wider electrochemical stability window, can be prepared by directly injecting a precursor solution into a battery in an in-situ polymerization initiation mode, can be matched with the existing lithium battery production process, and is one of ideal materials of high-performance solid-state electrolytes.
The mechanical properties of the polymer electrolyte are important parameters affecting the electrochemical performance of polymer-based solid state lithium batteries. The polymer electrolyte with good mechanical properties can buffer the volume change of the electrode in the charge and discharge process, and the stability of the electrode/electrolyte interface is maintained. However, the existing PVEC-based polymer electrolyte has the problems of poor mechanical properties and the like, and the practical application still faces challenges. The unmodified PVEC electrolyte is a linear polymer and contains more oligomers and has poor mechanical properties, resulting in poor cycling stability of the assembled solid state battery. Researchers copolymerize VEC monomers with other polymerizable monomers or cross-linking agents to obtain block or cross-linked PVEC electrolyte, and the methods improve the mechanical properties of PVEC-based electrolyte to a certain extent, but reduce the movement capability of polymer molecular chains, so that the ionic conductivity is reduced, and good mechanical properties and good ionic conductivity cannot be simultaneously considered, so that the practical application is difficult to meet.
The invention comprises the following steps:
in order to solve the defects in the prior art, the invention aims to provide an in-situ polymerization double-crosslinked polymer electrolyte, a preparation method and application thereof, wherein a polymerizable amide crosslinking agent is introduced into a VEC monomer, and the double-crosslinked polymer electrolyte with combined action of covalent crosslinking and hydrogen bonding crosslinking can be prepared through in-situ polymerization, so that the mechanical property of the polymer electrolyte is improved, and meanwhile, the higher ionic conductivity is maintained. The electrolyte is applied to a solid lithium metal battery, and can exert high capacity and stable circulation at room temperature and high loading.
In order to achieve the above purpose, the technical scheme adopted by the invention is as follows:
a method for preparing an in-situ polymerized double-crosslinked polymer electrolyte, which comprises the following steps:
(1) Mixing ethylene carbonate, lithium salt, amide polymer cross-linking agent and initiator in proportion, and uniformly stirring to obtain a precursor solution;
(2) And (3) taking the precursor solution obtained in the step (1) as electrolyte to assemble the battery, heating and then in-situ polymerizing to generate the solid electrolyte in the battery.
In the preparation method of the in-situ polymerization double-crosslinking polymer electrolyte, the amide polymer crosslinking agent is one or more than two of N, N '-methylene bisacrylamide, N' -vinyl bisacrylamide and hexamethylene bisacrylamide.
The initiator is one or more than two of dibutyl tin dilaurate, dibutyl tin bis (acetylacetonate), azodiisobutyronitrile, azodiisoheptanenitrile, dimethyl azodiisobutyrate and benzoyl peroxide.
The preparation method of the in-situ polymerization double-crosslinking polymer electrolyte comprises the step of preparing LiTFSI, liFSI, liClO lithium salt 4 、LiPF 6 、LiBF 4 And LiAsF 6 One or two or more of them.
In the preparation method of the in-situ polymerization double-crosslinking polymer electrolyte, in the step (1), the molar ratio of ethylene carbonate to the crosslinking agent is (10-60): 1, the weight of the lithium salt is 10 to 80 percent of the total weight of ethylene carbonate, the lithium salt, the amide polymer cross-linking agent and the initiator.
In the step (1), the weight of the initiator is 0.1-5 wt% of the total weight of ethylene carbonate, lithium salt, amide polymer crosslinking agent and initiator.
In the preparation method of the in-situ polymerization double-crosslinking polymer electrolyte, in the step (1), the stirring time is 0.5-3 hours.
In the preparation method of the in-situ polymerization double-crosslinking polymer electrolyte, in the step (2), the heating temperature is 45-100 ℃, and the heating time is 12-48 hours.
The in-situ polymerization double-crosslinking polymer electrolyte prepared by the method is applied to a lithium ion battery or a lithium metal battery.
The principle of the invention is as follows:
the crosslinking agent can be used for covalent connection between PVEC molecular chains, weak intermolecular forces between original molecular chains can be converted into strong covalent bond effects, and hydrogen bonds in the crosslinking agent can further enhance the structural stability of the obtained electrolyte, so that the cooperative enhancement of covalent crosslinking and hydrogen bond effects is realized. In addition, the hydrogen bond can weaken the strong coordination of carbonyl and lithium ions, and improve the migration capability of lithium ions. By adjusting the proportion of the cross-linking agent to the monomer, good mechanical properties can be realized while good ionic conductivity is maintained. The precursor solution can be directly injected into the battery in the preparation process, the electrode/electrolyte interface is fully wetted by utilizing the good wettability of the precursor solution, and then the solid-state battery is obtained by in-situ initiated polymerization, so that the preparation method can be matched with the existing lithium battery production process. Based on the above, the polymer electrolyte prepared in situ in the battery has good mechanical properties, can be in close contact with the electrode in the battery cycle process, has high ion conductivity, and can realize the polymer-based solid lithium metal battery working at room temperature.
The invention has the advantages and beneficial effects as follows:
1. the polymer used as the solid electrolyte has the characteristics of higher ionic conductivity and better mechanical property, and the preparation process is simple and is matched with the existing lithium ion battery production process.
2. The solid lithium metal battery prepared and assembled by the method provided by the invention has higher capacity exertion and better cycle stability at room temperature and high anode loading.
3. The in-situ polyelectrolyte designed by the invention has simple preparation process and good repeatability, and is easy for large-scale production.
Description of the drawings:
fig. 1 is a schematic view of a polymer electrolyte prepared according to example 1.
Fig. 2 is a schematic view of a polymer electrolyte prepared according to comparative example 2.
Fig. 3 is a stress strain diagram of a polymer electrolyte prepared according to example 1. In the figure, the abscissa Stress is Strain (%), and the ordinate Stress is Stress (MPa).
Fig. 4 is a graph showing the change in ionic conductivity of the polymer electrolyte according to temperature, prepared in example 1. In the figure, temperature (DEG C) is plotted on the abscissa, and log (S cm) is plotted on the ordinate as the logarithm of ion conductivity (S cm) -1 )。
Fig. 5 is a charge and discharge graph of the solid-state battery prepared according to example 2 at room temperature. In the figure, the abscissa Specific capacity represents the specific capacity (mAhg -1 ) The ordinate Voltage is the Voltage (V).
Fig. 6 is a graph of the cycle specific capacity at room temperature of the solid-state battery prepared according to example 2. In the figure, the abscissa Cycle number is the number of cycles, and the left ordinate Discharge capacity is the discharge capacity (mAh g) -1 ) The right ordinate Coulombic efficiency is coulombic efficiency (%).
Fig. 7 is a charge and discharge graph at room temperature of the high-load solid-state battery prepared according to example 3. In the figure, the abscissa Specific capacity is the specific capacity (mAh g -1 ) The ordinate Voltage is the Voltage (V).
Fig. 8 is a graph of the cycle specific capacity at room temperature of the high-load solid-state battery prepared according to example 3. In the figure, the abscissa indicates the number of cycles, and the left ordinate Discharge capacity indicates the number of cyclesDischarge capacity (mAh g) -1 ) The right ordinate Coulombic efficiency is coulombic efficiency (%).
Fig. 9 is a charge-discharge graph at room temperature of the solid-state battery prepared according to comparative example 3. In the figure, the abscissa Specific capacity represents the specific capacity (mAhg -1 ) The ordinate Voltage is the Voltage (V).
Fig. 10 is a graph of the cycle specific capacity at room temperature of the solid-state battery prepared according to comparative example 3. In the figure, the abscissa Cycle number is the number of cycles, and the left ordinate Discharge capacity is the discharge capacity (mAh g) -1 ) The right ordinate Coulombic efficiency is coulombic efficiency (%).
The specific embodiment is as follows:
in a specific implementation process, the invention provides an in-situ polymerization double-crosslinking polymer electrolyte, which is prepared by uniformly mixing ethylene carbonate, lithium salt, a crosslinking agent and an initiator to form a precursor solution, injecting the precursor solution into a battery, and heating and polymerizing the precursor solution after assembling the battery to generate the polymer electrolyte in situ in the battery. Therefore, the polymer electrolyte has the characteristics of higher room temperature ionic conductivity and good mechanical property, and the preparation process is simple. The solid lithium metal battery prepared by the method has higher capacity exertion and excellent cycle stability at room temperature. At high active substance loadings, high capacities can also be obtained.
The present invention will be described below with reference to examples.
Example 1:
in this example, the preparation process of the in situ polymerized double crosslinked polymer electrolyte is as follows:
ethylene carbonate, liTFSI, N' -methylene bisacrylamide and azodiisobutyronitrile are stirred for 0.5h and uniformly mixed to obtain a precursor solution. Wherein, the mol ratio of ethylene carbonate to N, N' -methylene bisacrylamide is 30: the weight of LiTFSI is 30wt% of the total weight of ethylene carbonate and LiTFSI, N '-methylenebisacrylamide and azobisisobutyronitrile, and the weight of azobisisobutyronitrile is 0.5wt% of the total weight of ethylene carbonate and LiTFSI, N' -methylenebisacrylamide and azobisisobutyronitrile. Subsequently, the uniform precursor solution was transferred to an oven, and heated at 70 ℃ for 20 hours and then taken out, thereby obtaining a polymer electrolyte.
As shown in FIG. 1, the polymer electrolyte prepared by the embodiment has certain mechanical properties, can be self-supported, and has the advantages of simple and environment-friendly preparation process and no solvent volatilization waste.
Example 2:
the present example is a stainless steel pair cell prepared for ion conductivity testing by in situ polymerization, the procedure being as follows:
the positive and negative electrodes were each made of a stainless steel sheet with a diameter of 16 mm, and the precursor in example 1 was dropped onto a separator between the positive and negative electrode sheets and put into a 2025 battery case, and a button cell was mounted, then transferred to an oven, and after heating at 70 ℃ for 20 hours, taken out and cooled to room temperature, and then tested.
Example 3:
this example is a high performance polymer based solid state lithium metal battery operated at room temperature prepared by in situ polymerization, the process being as follows:
lithium iron phosphate, polyvinylidene fluoride and conductive carbon black are mixed according to the mass ratio of 80:10:10 in N-methyl pyrrolidone (NMP) to obtain composite positive electrode slurry, and coating the positive electrode slurry on one side of a carbon-coated aluminum foil. Vacuum drying at 80deg.C, removing NMP to obtain composite positive electrode composed of lithium iron phosphate, conductive carbon black and polyvinylidene fluoride, with active material loading of 1.27mg cm -2 。
And cutting the obtained composite positive electrode into a positive electrode plate, wherein a lithium plate is adopted as a negative electrode. The precursor of example 1 was dropped onto a separator between a positive electrode sheet and a negative electrode sheet and put into a 2025 battery case, and a button cell was mounted, then transferred to an oven, and after heating at 70 ℃ for 20 hours, taken out and cooled to room temperature, followed by testing.
Example 4:
this example is a high-load polymer-based solid state lithium metal battery that was prepared by in-situ polymerization at room temperature, the procedure being as follows:
lithium iron phosphate, polyvinylidene fluoride and conductive carbon black are mixed according to the mass ratio of 80:10:10 in NMP, and coating the positive electrode slurry on one side of a carbon-coated aluminum foil. Vacuum drying at 80deg.C, removing NMP to obtain composite positive electrode composed of lithium iron phosphate, conductive carbon black and polyvinylidene fluoride with active material load of 11.9mg cm -2 。
And cutting the obtained composite positive electrode into a positive electrode plate, wherein a lithium plate is adopted as a negative electrode. The precursor of example 1 was dropped onto a separator between a positive electrode sheet and a negative electrode sheet and put into a 2025 battery case, and a button cell was mounted, then transferred to an oven, and after heating at 70 ℃ for 20 hours, taken out and cooled to room temperature, followed by testing.
Comparative example 1:
in this comparative example, the polymer electrolyte was prepared as follows:
ethylene carbonate, liTFSI and azodiisobutyronitrile are stirred for 0.5h and uniformly mixed to obtain a precursor solution. Wherein the weight of LiTFSI is 30wt% of the total weight of ethylene carbonate and LiTFSI and azodiisobutyronitrile, and the weight of azodiisobutyronitrile is 0.5wt% of the total weight of ethylene carbonate and LiTFSI and azodiisobutyronitrile. Subsequently, the uniform precursor solution was transferred to an oven, and heated at 70 ℃ for 20 hours and then taken out, thereby obtaining a polymer electrolyte.
The polymer electrolyte has extremely poor mechanical properties and cannot be self-supported, and the reason is that: because the crosslinking agent is not adopted, the high molecular chains have weak intermolecular acting force, and good mechanical properties cannot be provided.
Comparative example 2:
in this comparative example, the polymer electrolyte was prepared as follows:
ethylene carbonate, liTFSI, polyethylene glycol diacrylate and azodiisobutyronitrile are stirred for 0.5h and uniformly mixed to obtain a precursor solution. Wherein, the mol ratio of ethylene carbonate to polyethylene glycol diacrylate is 30: the weight of LiTFSI is 30 percent of the total weight of ethylene carbonate and LiTFSI, polyethylene glycol diacrylate and azodiisobutyronitrile, and the weight of azodiisobutyronitrile is 0.5 percent of the total weight of ethylene carbonate and LiTFSI, polyethylene glycol diacrylate and azodiisobutyronitrile. Subsequently, the uniform precursor solution was transferred to an oven, and heated at 70 ℃ for 20 hours and then taken out, thereby obtaining a polymer electrolyte.
As shown in fig. 2, the polymer electrolyte prepared in this comparative example has poor mechanical properties because: the amide polymer cross-linking agent is replaced by polyethylene glycol diacrylate, and the cross-linking agent only provides single covalent cross-linking and cannot provide better mechanical properties.
Comparative example 3:
this comparative example is a polymer-based solid state lithium metal battery prepared by in situ polymerization, the procedure being as follows:
lithium iron phosphate, polyvinylidene fluoride and conductive carbon black are mixed according to the mass ratio of 80:10:10 in NMP, and coating the positive electrode slurry on one side of a carbon-coated aluminum foil. Vacuum drying at 80deg.C, removing NMP to obtain composite positive electrode composed of lithium iron phosphate, conductive carbon black and polyvinylidene fluoride, with active material loading of 1.27mg cm -2 。
And cutting the obtained composite positive electrode into a positive electrode plate, wherein a lithium plate is adopted as a negative electrode. The precursor of comparative example 2 was dropped on a separator between the positive electrode sheet and the negative electrode sheet and put into a 2025 battery case, and a coin cell was mounted, then transferred to an oven, and after heating at 70 ℃ for 20 hours, taken out and cooled to room temperature, followed by testing.
The following are performance tests on samples prepared in each example:
1. mechanical property test:
the polymer electrolyte prepared in example 1 was subjected to a tensile test at room temperature. As shown in fig. 3, a stress strain diagram of a polymer electrolyte was prepared according to example 1. As is clear from FIG. 3, the polymer electrolyte had a tensile strength of 1.395MPa and an elongation of 81.77%. Thus, the polymer electrolyte has good mechanical properties.
The polymer electrolytes prepared in comparative examples 1 and 2 were not able to perform such a test due to too poor mechanical properties, as shown in fig. 2.
2. Conductivity test:
the stainless steel of example 2 was tested on batteries by the following specific test methods: the stainless steel was subjected to electrochemical impedance testing of the cell at a frequency range of 0.1Hz to 1MHz (electrochemical workstation). The cell was then disassembled and tested to give the polymer electrolyte membrane thickness. Finally, according to parameters such as electrochemical impedance, thickness of the sample, area of the electrode and the like, calculating to obtain the ionic conductivity of the sample. As shown in fig. 4, the polymer electrolyte of example 1 has a curve of ionic conductivity as a function of temperature. As can be seen from fig. 4, as the temperature increases, the ionic conductivity of the polymer electrolyte increases, and the ionic conductivity is greater than 10 at room temperature and above -4 S/cm. Thus, the polymer electrolyte has a high ionic conductivity over a wide temperature range.
3. And (3) charge and discharge testing:
the solid-state battery prepared in example 3 was tested at room temperature (25 ℃). The charge cutoff voltage was 4.2V and the discharge cutoff voltage was 2.5V. The charge-discharge current was set to 0.5C. As shown in fig. 5, the solid-state battery prepared according to example 3 has a charge-discharge curve at room temperature. As can be seen from fig. 5, the solid-state battery containing the polymer electrolyte has a discharge specific capacity of up to 144.4mAh/g at room temperature. As shown in fig. 6, a cycle specific capacity chart at room temperature of the solid-state battery prepared according to example 3. As can be seen from fig. 6, the prepared solid-state battery was stable over 300 cycles, with a capacity retention of 94.2%. Thus, such polymer solid-state batteries also have a high charge-discharge capability at room temperature.
The high-load solid-state battery prepared in example 4 was tested at room temperature (25 ℃). The charge cutoff voltage was 4.2V and the discharge cutoff voltage was 2.5V. The charge-discharge current was set to 0.1C. As shown in fig. 7, the charge-discharge curve of the solid-state battery of the high-load positive electrode prepared according to example 4 at room temperature. As can be seen from fig. 7, the solid-state battery containing the polymer electrolyte has a discharge specific capacity of up to 134mAh/g at room temperature. As shown in fig. 8, a cycle specific capacity chart at room temperature of the high-load solid-state battery prepared according to example 4. As can be seen from fig. 8, the prepared solid-state battery was stable in 40 cycles, and the capacity retention was 97.0%. Thus, such polymer solid-state batteries also have higher charge and discharge capabilities at room temperature with high-load positive electrodes.
The solid-state battery prepared in comparative example 3 was tested at room temperature (25 ℃). The charge cutoff voltage was 4.2V and the discharge cutoff voltage was 2.5V. The charge-discharge current was set to 0.5C. As shown in fig. 9, the polymer solid-state battery prepared according to comparative example 3 has a charge-discharge curve at room temperature. As can be seen from fig. 9, the solid-state battery containing the polymer electrolyte has a specific discharge capacity of only 121.6mAh/g. As shown in fig. 10, the solid-state battery prepared according to comparative example 3 has a cycle specific capacity at room temperature. As can be seen from fig. 10, the prepared solid-state battery had an initial capacity of which capacity decayed rapidly in 300 cycles and a capacity retention rate of only 41.9%.
Therefore, based on the above expression, the invention provides an in-situ polymerization double-crosslinking electrolyte and a preparation method thereof, which can effectively improve the mechanical properties of the solid electrolyte under the condition of keeping higher room temperature ionic conductivity. The polymer solid lithium metal battery assembled by the method has higher capacity exertion and more stable circulation under the conditions of room temperature and higher active material loading. The invention has simple process and is compatible with the existing lithium ion battery process, can effectively simplify the production and assembly processes of the solid lithium metal battery, improves the battery performance, is beneficial to the wide production and application of the solid lithium metal battery, and has great practical application prospect.
The foregoing description of the preferred embodiments of the invention has been presented for purposes of illustration only, and is not to be construed as limiting the invention, as various improvements and modifications can be made without departing from the principles of the invention, which are also intended to be considered within the scope of the invention.
Claims (10)
1. A method for preparing an in-situ polymerized double-crosslinked polymer electrolyte, which is characterized by comprising the following steps:
(1) Mixing ethylene carbonate, lithium salt, amide polymer cross-linking agent and initiator in proportion, and uniformly stirring to obtain a precursor solution;
(2) And (3) taking the precursor solution obtained in the step (1) as electrolyte to assemble the battery, heating and then in-situ polymerizing to generate the solid electrolyte in the battery.
2. The method for preparing an in-situ polymerized double-crosslinked polymer electrolyte according to claim 1, wherein the amide polymer crosslinking agent is one or more of N, N '-methylenebisacrylamide, N' -vinyl bisacrylamide and hexamethylenebisacrylamide.
3. The method for preparing an in-situ polymerized double crosslinked polymer electrolyte according to claim 1, wherein the initiator is one or more of dibutyl tin dilaurate, dibutyl tin bis (acetylacetonate), azobisisobutyronitrile, azobisisoheptonitrile, dimethyl azobisisobutyrate, and benzoyl peroxide.
4. The method for preparing an in-situ polymerized double crosslinked polymer electrolyte according to claim 1, wherein the lithium salt is LiTFSI, liFSI, liClO 4 、LiPF 6 、LiBF 4 And LiAsF 6 One or two or more of them.
5. The method for preparing an in-situ polymerized double crosslinked polymer electrolyte according to claim 1, wherein in the step (1), the molar ratio of ethylene carbonate to the crosslinking agent is (10-60): 1, the weight of the lithium salt is 10 to 80 percent of the total weight of ethylene carbonate, the lithium salt, the amide polymer cross-linking agent and the initiator.
6. The method for preparing an in-situ polymerized double crosslinked polymer electrolyte according to claim 1, wherein in the step (1), the weight of the initiator is 0.1-5 wt% of the total weight of ethylene carbonate, lithium salt, amide polymer crosslinking agent and initiator.
7. The method for preparing an in-situ polymerized double crosslinked polymer electrolyte according to claim 1, wherein in the step (1), the stirring time is 0.5 to 3 hours.
8. The method for preparing an in-situ polymerized double crosslinked polymer electrolyte according to claim 1, wherein in the step (2), the heating temperature is 45-100 ℃ and the heating time is 12-48 hours.
9. An in situ polymerized bi-crosslinked polymer electrolyte prepared by the method of any one of claims 1 to 8.
10. Use of the in situ polymerized double cross-linked polymer electrolyte of claim 9 in a lithium ion battery or a lithium metal battery.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310700782.9A CN116845346A (en) | 2023-06-13 | 2023-06-13 | In-situ polymerization double-crosslinking polymer electrolyte and preparation method and application thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310700782.9A CN116845346A (en) | 2023-06-13 | 2023-06-13 | In-situ polymerization double-crosslinking polymer electrolyte and preparation method and application thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN116845346A true CN116845346A (en) | 2023-10-03 |
Family
ID=88164442
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310700782.9A Pending CN116845346A (en) | 2023-06-13 | 2023-06-13 | In-situ polymerization double-crosslinking polymer electrolyte and preparation method and application thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116845346A (en) |
-
2023
- 2023-06-13 CN CN202310700782.9A patent/CN116845346A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110808409A (en) | Polymer lithium secondary battery and in-situ preparation method thereof | |
| CN111533851A (en) | Preparation method of polymer electrolyte and application of polymer electrolyte in all-solid-state battery | |
| KR100613800B1 (en) | Solid Electrolytic Secondary Battery | |
| CN113839096B (en) | Preparation method of electrolyte, lithium ion battery and preparation method of lithium ion battery | |
| CN110911739A (en) | Solid polymer electrolyte, preparation method thereof and lithium battery | |
| CN114014965B (en) | Polymer film, electrolyte, all-solid-state battery, and preparation method and application thereof | |
| CN111725559A (en) | Solid electrolyte, method for preparing the same, and lithium secondary solid battery | |
| CN114976263A (en) | Solid-state battery with integrated positive electrode and electrolyte and preparation method thereof | |
| CN111934020A (en) | High-pressure-resistant all-solid-state lithium battery interface layer and in-situ preparation method and application thereof | |
| CN113611545B (en) | Stretchable, compressible and anti-freezing organic hydrogel electrolyte-based supercapacitor and preparation method thereof | |
| CN113299982A (en) | In-situ polymerization electrolyte, method for preparing in-situ all-solid-state battery by adopting same and in-situ all-solid-state battery | |
| CN110611120A (en) | Single-ion conductor polymer all-solid-state electrolyte and lithium secondary battery comprising same | |
| CN114512708A (en) | Preparation method and application of lithium ion composite solid electrolyte | |
| CN111799508B (en) | All-solid-state polymer electrolyte diaphragm, preparation method and all-solid-state lithium ion battery | |
| CN114335705A (en) | Integrated all-solid-state battery and preparation method thereof | |
| JP2003331838A (en) | Lithium secondary battery | |
| CN117004353A (en) | Modified binder and preparation method and application thereof | |
| CN115714200B (en) | Method for preparing solid-state battery by selective solidification | |
| CN116632334A (en) | Solid electrolyte and preparation method thereof, and solid lithium battery and preparation method thereof | |
| CN115000499A (en) | Fluoride composite solid electrolyte membrane, preparation method thereof and solid sodium battery using fluoride composite solid electrolyte membrane | |
| CN113394376B (en) | High-voltage-resistant solid-state battery composite positive electrode and preparation method thereof | |
| US20220356280A1 (en) | Copolymerized pvdf resin for lithium ion battery binders and its preparation method | |
| CN113363573B (en) | Preparation method of solid electrolyte, solid electrolyte and all-solid-state battery | |
| CN116845346A (en) | In-situ polymerization double-crosslinking polymer electrolyte and preparation method and application thereof | |
| CN115594803A (en) | Application of polymerized monomer, in-situ polymerization electrolyte and method for preparing all-solid-state secondary battery by using in-situ polymerization electrolyte |
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 |