CN111769320B - Solid polymer electrolyte membrane and preparation method thereof - Google Patents
Solid polymer electrolyte membrane and preparation method thereof Download PDFInfo
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- CN111769320B CN111769320B CN201910260154.7A CN201910260154A CN111769320B CN 111769320 B CN111769320 B CN 111769320B CN 201910260154 A CN201910260154 A CN 201910260154A CN 111769320 B CN111769320 B CN 111769320B
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- 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
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- 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
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- 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
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- 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
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- 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
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- 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
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
- Y02P70/50—Manufacturing or production processes characterised by the final manufactured product
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Abstract
The invention discloses a solid polymer electrolyte membrane and a preparation method thereof, wherein the solid polymer electrolyte membrane consists of a polymer and a lithium salt, and the preparation method comprises the following steps: s1: preparing a polyurethane/polyimide solution; s2: preparing a polyurethane/polyimide/lithium salt mixed solution; s3: coating to form a film and drying to obtain the electrolyte film. The polyimide modified polyether polyurethane has the advantages that the molecular chain contains more ether groups, the room-temperature ionic conductivity is favorably improved, and the sulfuryl and fluorine-containing structures are introduced into the molecular chain of the polymer, so that the electrochemical stability of the polymer electrolyte can be effectively improved, the dissociation degree of lithium salt is improved to a certain extent, and the ionic conductivity of the polymer electrolyte is improved; meanwhile, the polyether polyurethane provides toughness of the polymer electrolyte membrane, the polyimide provides rigidity of the polymer electrolyte membrane, and mechanical performance and chemical stability of the polymer electrolyte membrane are improved.
Description
Technical Field
The invention belongs to the technical field of solid lithium ion batteries, and particularly relates to a solid polymer electrolyte membrane and a preparation method thereof.
Background
The lithium ion battery has the advantages of high working voltage, high specific energy, long cycle life, low self-discharge rate, no pollution and the like, and is widely applied to 3C products, new energy electric vehicles, electric bicycles and the like. Currently used commercial lithium ion batteries generally adopt lithium hexafluorophosphate (LiPF)6) The battery contains volatile flammable liquid organic matters, so potential safety hazards such as liquid leakage, ignition, explosion and the like exist, and the potential safety hazards are more likely to appear under the conditions that the battery is subjected to thermal shock, overcharge, overdischarge, short circuit and the like.
In view of this, at present, enterprises and colleges are focusing more on the research of solid-state lithium ion batteries. Compared with the conventional lithium ion battery using a liquid electrolyte, the solid-state lithium ion battery has significant potential advantages in terms of high energy density and safety, and is considered to be a next-generation lithium battery that can be used in the fields of electric vehicles and energy storage. The solid electrolyte material mainly includes three types, namely polymer solid electrolytes, inorganic solid electrolytes and organic-inorganic composite solid electrolytes. The polymer solid electrolyte is composed of organic polymer and lithium salt, but the ionic conductivity and mechanical property are poor, and the application of the polymer solid electrolyte is limited.
In view of the above problems, it is urgently required to provide a new method for producing a solid electrolyte membrane to overcome the above disadvantages.
Disclosure of Invention
The present invention aims at providing a solid polymer electrolyte membrane and a preparation method thereof, and aims at preparing a solid polymer electrolyte membrane and improving the ionic conductivity and mechanical properties of the solid electrolyte.
In order to achieve the purpose, the technical scheme adopted by the invention is as follows:
a solid polymer electrolyte membrane and its preparation method, its solid polymer electrolyte membrane is made up of polymer, lithium salt, its preparation method includes the following steps:
s1: under the protection of nitrogen or inert gas, adding amino-terminated polyimide oligomer and isocyanate-terminated polyurethane prepolymer into an organic solvent, and fully reacting at room temperature to obtain a polyurethane/polyimide solution;
s2: adding lithium salt into the polyurethane/polyimide solution obtained in the step S1, and uniformly stirring to obtain a mixed solution;
s3: the mixed solution in step S2 is uniformly coated on a glass plate, and then dried in a vacuum drying oven for 24 hours.
The molar ratio of the amino-terminated polyimide oligomer to the isocyanate-terminated polyurethane prepolymer in the step S1 is 5-20%. Preferably, the molar ratio of the amino-terminated polyimide oligomer to the isocyanate-terminated polyurethane prepolymer is 10-15%.
Preferably, the amino-terminated polyimide oligomer in step S1 has the formula:
the isocyanate-terminated polyurethane prepolymer is polyether polyurethane prepolymer.
The lithium salt is selected from one or more of lithium bis (trifluoromethylsulfonyl) imide, lithium difluoromethylsulfonyl imide and lithium perchlorate. Preferably, the lithium salt in S1 is selected from one or more of lithium bis (trifluoromethylsulfonyl) imide and lithium difluoromethylsulfonyl imide.
In the step S2, the lithium salt accounts for 5-50% of the weight of the polymer. Preferably, the lithium salt in S2 is added in an amount of 10-30 wt% based on the weight of the polymer.
The organic solvent is selected from one or more of N-methyl pyrrolidone, N-dimethylformamide and N, N-dimethylacetamide. Preferably, the organic solvent is selected from one or more of N-methyl pyrrolidone and N, N-dimethylformamide.
The thickness of the solid polymer electrolyte membrane is 50-200 mu m.
According to another aspect of the present invention, there is provided a polymer solid electrolyte prepared by the preparation method.
The invention has the beneficial effects that: the polyimide modified polyether polyurethane has the advantages that the molecular chain contains more ether groups (-O-), so that the room-temperature ionic conductivity is improved, and the sulfone group and the fluorine-containing structure are introduced into the polymer molecular chain, so that the electrochemical stability of the polymer electrolyte can be effectively improved, the dissociation degree of lithium salt is improved to a certain extent, and the ionic conductivity of the polymer electrolyte is improved; meanwhile, the polyether polyurethane provides toughness of the polymer electrolyte membrane, the polyimide provides rigidity of the polymer electrolyte membrane, and mechanical performance and chemical stability of the polymer electrolyte membrane are improved.
Detailed Description
The present invention is described in detail below with reference to specific embodiments, and the description in this section is only exemplary and explanatory and should not be construed as limiting the scope of the present invention in any way.
Example 1:
a solid polymer electrolyte membrane and its preparation method, its solid polymer electrolyte membrane is made up of polymer, lithium salt, its preparation method includes the following steps:
s1: under the protection of nitrogen or inert gas, adding 10% of amino-terminated polyimide oligomer and isocyanate-terminated polyurethane prepolymer into N-methyl pyrrolidone, and fully reacting at room temperature to obtain a polyurethane/polyimide solution;
s2: adding 10wt% of lithium bis (trifluoromethylsulfonyl) imide into the S1 polyurethane/polyimide solution, and uniformly stirring to obtain a mixed solution;
s3: the mixed solution in S2 was uniformly coated on a glass plate, and then dried in a vacuum oven for 24 hours.
Example 2:
a solid polymer electrolyte membrane and its preparation method, its solid polymer electrolyte membrane is made up of polymer, lithium salt, its preparation method includes the following steps:
s1: under the protection of nitrogen or inert gas, adding 10% of amino-terminated polyimide oligomer and isocyanate-terminated polyurethane prepolymer into N-methyl pyrrolidone, and fully reacting at room temperature to obtain a polyurethane/polyimide solution;
s2: adding 20wt% of lithium bis (trifluoromethylsulfonyl) imide into the S1 polyurethane/polyimide solution, and uniformly stirring to obtain a mixed solution;
s3: the mixed solution in S2 was uniformly coated on a glass plate, and then dried in a vacuum oven for 24 hours.
Example 3:
a solid polymer electrolyte membrane and its preparation method, its solid polymer electrolyte membrane is made up of polymer, lithium salt, its preparation method includes the following steps:
s1: under the protection of nitrogen or inert gas, adding 10% of amino-terminated polyimide oligomer and isocyanate-terminated polyurethane prepolymer into N-methyl pyrrolidone, and fully reacting at room temperature to obtain a polyurethane/polyimide solution;
s2: adding 30wt% of lithium bis (trifluoromethylsulfonyl) imide into the S1 polyurethane/polyimide solution, and uniformly stirring to obtain a mixed solution;
s3: the mixed solution in S2 was uniformly coated on a glass plate, and then dried in a vacuum oven for 24 hours.
Example 4:
a solid polymer electrolyte membrane and its preparation method, its solid polymer electrolyte membrane is made up of polymer, lithium salt, its preparation method includes the following steps:
s1: under the protection of nitrogen or inert gas, adding 15% of amino-terminated polyimide oligomer and isocyanate-terminated polyurethane prepolymer into N-methyl pyrrolidone, and fully reacting at room temperature to obtain a polyurethane/polyimide solution;
s2: adding 20wt% of lithium bis (trifluoromethylsulfonyl) imide into the S1 polyurethane/polyimide solution, and uniformly stirring to obtain a mixed solution;
s3: the mixed solution in S2 was uniformly coated on a glass plate, and then dried in a vacuum oven for 24 hours.
The invention provides a polymer solid electrolyte membrane and a preparation method thereof, and the polymer solid electrolyte membrane is prepared, and the ionic conductivity, the mechanical property and the chemical stability of the solid electrolyte are improved.
The above description is only a preferred embodiment of the present invention, and is not intended to limit the technical scope of the present invention, so that any minor modifications, equivalent changes and modifications made to the above embodiment according to the technical spirit of the present invention are within the technical scope of the present invention.
Claims (7)
1. A method for preparing a solid polymer electrolyte membrane is characterized in that the solid polymer electrolyte membrane consists of a polymer and a lithium salt, and the preparation method comprises the following steps:
s1: under the protection of nitrogen or inert gas, adding amino-terminated polyimide oligomer and isocyanate-terminated polyurethane prepolymer into an organic solvent, and fully reacting at room temperature to obtain a polyurethane/polyimide solution; wherein the isocyanate-terminated polyurethane prepolymer is polyether polyurethane prepolymer;
s2: adding lithium salt into the polyurethane/polyimide solution obtained in the step S1, and uniformly stirring to obtain a mixed solution;
s3: the mixed solution in step S2 is uniformly coated on a glass plate, and then dried in a vacuum drying oven for 24 hours.
2. The method of claim 1, wherein the molar ratio of the amino-terminated polyimide oligomer to the isocyanate-terminated polyurethane prepolymer in step S1 is 5% to 20%.
3. The method of claim 1, wherein the amino-terminated polyimide oligomer in the step S1 has a structural formula of:
4. the method of claim 1, wherein the lithium salt is one or more selected from the group consisting of lithium bis (trifluoromethylsulfonyl) imide, lithium difluoromethylsulfonyl imide, and lithium perchlorate.
5. The method of claim 1, wherein the lithium salt is 5-50% by weight of the polymer in step S2.
6. The method for preparing a solid polymer electrolyte membrane according to claim 1, wherein the organic solvent is one or more selected from the group consisting of N-methylpyrrolidone, N-dimethylformamide, and N, N-dimethylacetamide.
7. The method for manufacturing a solid polymer electrolyte membrane according to claim 1, wherein the thickness of the solid polymer electrolyte membrane is 50 to 200 μm.
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| CN112382787B (en) * | 2020-10-28 | 2024-10-01 | 银隆新能源股份有限公司 | Composition for forming composite solid electrolyte, composite solid electrolyte membrane, and battery comprising same |
| CN113745655A (en) * | 2021-08-31 | 2021-12-03 | 国网湖北省电力有限公司黄冈供电公司 | Preparation method of composite polymer all-solid-state electrolyte based on crosslinked polyurethane |
| CN114015007B (en) * | 2021-11-23 | 2023-06-13 | 哈尔滨工业大学 | Fluorine-containing polyurethane single-ion polymer electrolyte membrane and preparation method and application thereof |
| CN116444760A (en) * | 2023-03-13 | 2023-07-18 | 南京大学 | Solid state polymer electrolyte of perfluoropolyether block, preparation method and application thereof |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2202826A1 (en) * | 2008-12-23 | 2010-06-30 | SMR PATENTS S.à.r.l. | Polymer Electrolytes and Devices containing them |
| CN105612637A (en) * | 2013-10-07 | 2016-05-25 | 日产自动车株式会社 | Electrode material for non-aqueous electrolyte secondary battery, and non-aqueous electrolyte secondary battery electrode and non-aqueous electrolyte secondary battery using same |
| CN105762403A (en) * | 2016-04-12 | 2016-07-13 | 中国科学院大学 | All-solid-state lithium-ion battery based on topological-structured polymer electrolyte |
| CN106410269A (en) * | 2016-04-12 | 2017-02-15 | 中国科学院大学 | All-solid-state composite polymer electrolyte and preparation method thereof |
| EP3389128A1 (en) * | 2015-12-11 | 2018-10-17 | FUJIFILM Corporation | Solid-state electrolyte composition, sheet for all-solid-state secondary battery, electrode sheet for all-solid-state second battery and manufacturing method therefor, and all-solid-state secondary battery and manufacturing method therefor |
| CN109075384A (en) * | 2016-06-14 | 2018-12-21 | 三星Sdi株式会社 | For the composite electrolyte of lithium metal battery, preparation method and including the lithium metal battery of the composite electrolyte |
| CN109286038A (en) * | 2018-09-28 | 2019-01-29 | 苏州清陶新能源科技有限公司 | A kind of New Solid electrolyte and preparation method thereof |
-
2019
- 2019-04-02 CN CN201910260154.7A patent/CN111769320B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2202826A1 (en) * | 2008-12-23 | 2010-06-30 | SMR PATENTS S.à.r.l. | Polymer Electrolytes and Devices containing them |
| CN105612637A (en) * | 2013-10-07 | 2016-05-25 | 日产自动车株式会社 | Electrode material for non-aqueous electrolyte secondary battery, and non-aqueous electrolyte secondary battery electrode and non-aqueous electrolyte secondary battery using same |
| EP3389128A1 (en) * | 2015-12-11 | 2018-10-17 | FUJIFILM Corporation | Solid-state electrolyte composition, sheet for all-solid-state secondary battery, electrode sheet for all-solid-state second battery and manufacturing method therefor, and all-solid-state secondary battery and manufacturing method therefor |
| CN105762403A (en) * | 2016-04-12 | 2016-07-13 | 中国科学院大学 | All-solid-state lithium-ion battery based on topological-structured polymer electrolyte |
| CN106410269A (en) * | 2016-04-12 | 2017-02-15 | 中国科学院大学 | All-solid-state composite polymer electrolyte and preparation method thereof |
| CN109075384A (en) * | 2016-06-14 | 2018-12-21 | 三星Sdi株式会社 | For the composite electrolyte of lithium metal battery, preparation method and including the lithium metal battery of the composite electrolyte |
| CN109286038A (en) * | 2018-09-28 | 2019-01-29 | 苏州清陶新能源科技有限公司 | A kind of New Solid electrolyte and preparation method thereof |
Non-Patent Citations (1)
| Title |
|---|
| 锂电池用全固态聚合物电解质的研究进展;杜奥冰等;《储能科学与技术》;20160901;第5卷(第5期);第627-648页 * |
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Effective date of registration: 20221024 Address after: 523000 Building 9, Dasheng Industrial City, No. 1438, Provincial Road S358, Shangsha Community, Chang'an Town, Dongguan City, Guangdong Province Patentee after: Dongguan Grind Energy Co.,Ltd. Address before: 518105 4th Floor, Building A2, Liyuan Bay Industrial Park, 168 Honghu Road, Yanchuan, Songgang, Baoan District, Shenzhen City, Guangdong Province Patentee before: SHENZHEN GRAND POWERSOURCE Co.,Ltd. |