CN111116388A - Preparation method of polyether-based ionic liquid, preparation method and application of high-voltage electrolyte - Google Patents
Preparation method of polyether-based ionic liquid, preparation method and application of high-voltage electrolyte Download PDFInfo
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- CN111116388A CN111116388A CN201911287297.3A CN201911287297A CN111116388A CN 111116388 A CN111116388 A CN 111116388A CN 201911287297 A CN201911287297 A CN 201911287297A CN 111116388 A CN111116388 A CN 111116388A
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Abstract
The preparation method of the polyether-based ionic liquid and the preparation method and application of the high-pressure electrolyte are characterized in that tris (2- (2-methoxyethoxy) ethyl) amine and halogenated alkane are mixed and then added into a solvent, the mixture is reacted for 24-48h at 70-90 ℃ under protective gas, washed and dried, then added into ionic water, uniformly stirred, added with lithium salt, stirred for 2-12h and dried, and the polyether-based ionic liquid is obtained. The ionic liquid is used for replacing an organic solvent, so that the electrochemical stability of the electrolyte is obviously improved, and the safety of the battery is greatly improved; simultaneously promote the SEI film of the battery cathodeThe cycle stability of the battery is improved. Application of the electrolyte to LiFePO4In the Li battery, the battery works under the multiplying power of 0.1C, has an obvious charge-discharge platform, has the specific discharge capacity of 150mAh/g, can stably work for 100 cycles, and has the coulombic efficiency close to 100 percent.
Description
Technical Field
The invention belongs to the technical field of ionic liquid, and relates to a preparation method of polyether-based ionic liquid, a preparation method of high-voltage electrolyte and application of the high-voltage electrolyte.
Background
In recent years, people have been intensively researched for clean and sustainable energy sources such as solar energy, wind energy, tidal energy, geothermal energy and the like, and with the continuous and intensive research on new energy sources, related mining, transformation and utilization technologies are also continuously improved. However, these energy sources are either intermittent or severely limited by regions, and therefore, in order to utilize energy more efficiently, energy storage technology is also developed, wherein secondary batteries are increasingly regarded as an important component of the existing energy storage technology. Lithium ion batteries, which are ideal power sources for electric vehicles, face a significant challenge in improving battery energy density and safety performance. The energy density of the battery restricts the endurance mileage of the new energy automobile, and the improvement of the working voltage of the electrolyte is one of effective ways for improving the energy density of the lithium ion battery. The traditional electrolyte comprises an organic solvent and electrolyte lithium salt, and has many limitations, such as small dielectric constant of the organic carbonate solvent in the traditional electrolyte, poor salt dissolving capability, easy oxidative decomposition under high pressure and easy combustion, so that the safety performance of the lithium ion battery is reduced. The maximum limit voltage is 4.35V, and the electrolyte becomes very unstable when the voltage is higher than 4.5V, which accelerates the degradation of cycle performance and safety of the battery.
The ionic liquid is salt substance which is composed of anion and cation and is liquid at room temperature. Compared with the traditional electrolyte system, the ionic liquid has the advantages of low vapor pressure, no ignition point, wide temperature range, high thermal stability, large heat capacity, non-flammability, wide electrochemical window, easy recovery and the like, and can be directly used as the liquid electrolyte component of the lithium battery. Currently, imidazole ionic liquids are widely and deeply studied as electrolytes due to their superior properties. However, the redox stability is not high, and the electrochemical window is not wide, so that the application of the method in high-energy electrochemical devices is limited. The ionic liquid taking saturated alkane quaternary ammonium ions as cations has better oxidation-reduction stability, and theoretically, the theory can be explained that N on the cations of the saturated quaternary ammonium type ionic liquid is enabled to be due to the electron donating property of alkyl+The ionic stability is enhanced. All in oneWhen the ionic liquid is used, a proper alkyl chain is selected and introduced to the nitrogen atom of the cation in the ionic liquid, so that the effect of reducing the melting point of the ionic liquid can be achieved. Related studies have found that ionic liquids containing ether group-containing quaternary ammonium cations have lower melting points than other ionic liquids not containing ether groups, and that the resulting ionic liquids have relatively high conductivities and wider electrochemical windows. It is worth mentioning that the distance between the oxygen atom and the nitrogen atom in the ether group-containing ionic liquid has a great influence on the performance of the ionic liquid as an electrolyte, and the two atoms are too close to each other to increase the electropositivity of the nitrogen atom, but too far away from each other to increase the total carbon number of the ionic liquid too much to increase the ionic volume, thereby affecting the physical, chemical and electrochemical performance of the ionic liquid. Thus, methoxyethyl (CH)3OC2H5-) is one of the ether groups suitably introduced on the cationic nitrogen.
Disclosure of Invention
Aiming at the problems in the prior art, the invention aims to provide a preparation method of polyether-based ionic liquid, a preparation method of high-voltage electrolyte and application of the high-voltage electrolyte.
In order to achieve the purpose, the invention adopts the following technical scheme:
a polyether-based ionic liquid, the structural formula of which is as follows:
wherein R is CH3Or CH2CH3，Y-Is FSI-Or TFSI-。
The preparation method of the polyether-based ionic liquid comprises the following steps:
(1) mixing tris (2- (2-methoxyethoxy) ethyl) amine and halogenated alkane, adding the mixture into a solvent, reacting for 24-48h at 70-90 ℃ under a protective atmosphere, cleaning, and drying to obtain tris (2- (2-methoxyethoxy) ethyl) -alkyl-ammonium halide;
(2) adding the tri (2- (2-methoxyethoxy) ethyl) -alkyl-ammonium halide into the ionic water, uniformly stirring, then adding the lithium salt, stirring for 2-12h, and drying to obtain the polyether type ionic liquid.
In a further improvement of the invention, in the step (1), the molar ratio of the reactants is tris (2- (2-methoxyethoxy) ethyl) amine to haloalkane is 1: 1.25-1.75.
A further development of the invention consists in that tris (2- (2-methoxyethoxy) ethyl) amine haloalkane is present in a molar ratio of 1: 1.5.
In the further improvement of the invention, in the step (1), the halogenated alkane is bromoethane or methyl iodide; the solvent is acetone or acetonitrile.
In a further development of the invention, in step (1), the ratio of tris (2- (2-methoxyethoxy) ethyl) amine to solvent is 0.1mol per tris (2- (2-methoxyethoxy) ethyl) amine: 100 mL; the protective atmosphere is a nitrogen atmosphere.
The invention is further improved in that in the step (2), the molar ratio of the tri (2- (2-methoxyethoxy) ethyl) -alkyl-ammonium halide to the lithium salt is 1: 1.25-1.75, and the lithium salt is LiTFSI or LiFSI.
A further improvement of the invention is that tris (2- (2-methoxyethoxy) ethyl) -alkyl-ammonium halide lithium salt in a molar ratio of 1: 1.5.
The invention is further improved in that the step (2) further comprises a purification step: adding dichloromethane into the product after stirring for 2-12h to extract an organic phase, collecting the organic phase through liquid separation, repeatedly washing the organic phase with deionized water for many times, removing dichloromethane in the solution through rotary evaporation, and drying to obtain the polyether-based ionic liquid.
A preparation method of electrolyte of polyether-based ionic liquid is characterized in that lithium salt is added into the polyether-based ionic liquid, and the mixture is stirred under protective atmosphere until the lithium salt is dissolved, so that the polyether-based ionic liquid electrolyte is obtained.
The invention further improves that the lithium salt is LiTFSI or LiFSI.
A further development of the invention is that the amount of lithium salt added per gram of polyether-based ionic liquid is from 0.5 to 1.5 mmol.
An application of polyether-based ionic liquid in a high-voltage lithium ion battery.
Compared with the prior art, the invention has the beneficial effects that:
the polyether-based ionic liquid and the ionic liquid electrolyte prepared by the method are simple in preparation method, easy to control the reaction and suitable for large-scale production. The ionic liquid electrolyte has good electrochemical performance, wide electrochemical window, high stability and good safety, and can be applied to the field of high-voltage lithium batteries. The concrete expression is as follows:
the cation of the obtained ionic liquid is alkyl-substituted quaternary ammonium cation, so that the ionic liquid has higher decomposition potential, wide electrochemical window and high electrochemical stability; meanwhile, the ionic liquid has a large number of functional ether bonds due to the alkoxy alkyl carried by the branched chain, so that the dissolving capacity is greatly increased. The electrolyte is prepared into lithium ion battery electrolyte for LiFePO4In the Li battery, the capacity retention rate is high, and the cycle effect is stable.
Compared with the traditional organic electrolyte, the polyether-based ionic liquid electrolyte overcomes the defects of poor salt dissolving capacity, easy oxidative decomposition under high pressure, easy combustion, low safety performance and the like. The ionic liquid is used for replacing an organic solvent, so that the electrochemical stability of the electrolyte is obviously improved, and the safety of the battery is greatly improved; meanwhile, the formation of an SEI film of the negative electrode of the battery is promoted, and the cycling stability of the battery is improved. Application of the electrolyte to LiFePO4In the Li battery, the battery works under the multiplying power of 0.1C, has an obvious charge-discharge platform, has the specific discharge capacity of 150mAh/g, can stably work for 100 cycles, and has the coulombic efficiency close to 100 percent.
Drawings
Fig. 1 is a linear voltammogram scan of an ionic liquid electrolyte prepared according to example 1 of the present invention.
Fig. 2 shows the charge-discharge cycle performance and coulombic efficiency of the ionic liquid electrolyte-based lithium ion battery prepared according to example 1 of the present invention.
Detailed Description
In order to make the above objects, performance characteristics and preparation methods of the present invention more comprehensible, the present invention is further described below with reference to examples. The examples are preferred in the experimental process and are only used for more complete illustration of the present invention, but are not to be construed as limiting the scope of the present invention.
In order to make the objects, technical solutions and advantages of the embodiments of the present invention more obvious and easy to understand, the technical solutions in the embodiments of the present invention will be described below clearly with reference to the accompanying drawings in the embodiments of the present invention.
The instruments and drug materials used in the present invention are commercially available.
The invention synthesizes polyether-based ionic liquid which has the following structural formula:
wherein R is CH3Or CH2CH3，Y-Is FSI-Or TFSI-。
The cation of the polyether-based ionic liquid is alkyl-substituted quaternary ammonium cation, so that the ionic liquid has higher decomposition potential, wide electrochemical window and high electrochemical stability; meanwhile, the ionic liquid has a large number of functional ether bonds due to the alkoxy alkyl carried by the branched chain, so that the dissolving capacity is greatly increased. Through performance detection, the ionic liquid has a wider electrochemical window and higher electrochemical stability.
The invention also provides a preparation method of the polyether-based ionic liquid, which comprises the following steps:
s11, mixing tris (2- (2-methoxyethoxy) ethyl) amine and halogenated alkane according to a molar ratio of 1: 1.25-1.75, adding the mixture into an acetone solvent, reacting for 48 hours at 80 ℃ under the protection of nitrogen, washing a product with diethyl ether, and drying to obtain tris (2- (2-methoxyethoxy) ethyl) -alkyl-ammonium halide with the following structure:
wherein R is CH3Or CH2CH3，X-Is Br-Or I-。
Preferably, the molar ratio of tris (2- (2-methoxyethoxy) ethyl) amine to haloalkane is 1: 1.5.
The halogenated alkane is methyl iodide or ethyl bromide.
S12, adding ionic water into tris (2- (2-methoxyethoxy) ethyl) -alkyl-ammonium halide for dissolving, adding lithium salt (LiTFSI or LiFSI) according to the molar ratio of 1: 1.25-1.75, stirring for 2-12h at room temperature until the lithium salt and the LiTFSI are completely mixed, and then drying for 24h under the vacuum condition at 100 ℃ to obtain polyether-based ionic liquid:
preferably, tris (2- (2-methoxyethoxy) ethyl) -alkyl-ammonium halide, lithium salt, is present in a molar ratio of 1: 1.5.
In addition, the preparation method of the polyether-based ionic liquid further comprises the purification steps of: after the tri (2- (2-methoxyethoxy) ethyl) -alkyl-ammonium halide and lithium salt are stirred and react in the deionized water, the obtained ionic liquid is separated and purified; the separation and purification operations are as follows:
adding dichloromethane to extract an organic phase, collecting the organic phase through liquid separation, repeatedly washing the organic phase with deionized water for three times, and checking whether the washing liquid generates precipitates or not by using an AgNO3 solution to judge whether the washing is complete or not. And removing dichloromethane in the solution of the extracted product through rotary evaporation, and fully drying to obtain the polyether-based ionic liquid.
Firstly, tri (2- (2-methoxyethoxy) ethyl) -alkyl-ammonium halide is prepared by reacting tri (2- (2-methoxyethoxy) ethyl) amine with halogenated alkane, then lithium salt containing target anions and tri (2- (2-methoxyethoxy) ethyl) -alkyl-ammonium halide are subjected to ion exchange reaction, and the product obtained after purification and drying is the polyether ionic liquid. The preparation method is simple to operate, the reaction is easy to control, the product yield is high (70-75%), and the prepared polyether-based ionic liquid has good electrochemical performance and is suitable for the field of lithium ion batteries.
In addition, the invention also provides a preparation method of the polyether-based ionic liquid electrolyte.
The electrolyte comprises the following components: polyether-based ionic liquid and lithium salt; wherein the concentration of the lithium salt is 1mmol (lithium salt)/g (ionic liquid). Wherein, the lithium salt is LiTFSI or LiFSI.
Compared with the traditional organic electrolyte, the electrolyte overcomes the defects of poor salt dissolving capacity, easy oxidative decomposition under high pressure, easy combustion, low safety performance and the like. The ionic liquid is used for replacing an organic solvent, so that the electrochemical stability of the electrolyte is obviously improved, and the safety of the battery is greatly improved; meanwhile, the formation of an SEI film of the negative electrode of the battery is promoted, and the cycling stability of the battery is improved.
The preparation method of the ionic liquid electrolyte comprises the following steps:
s21, preparing the polyether ionic liquid.
S22, adding lithium salt into the ionic liquid according to the concentration of 0.5-1mmol (lithium salt)/g (ionic liquid), and fully stirring under a protective atmosphere until the lithium salt is completely dissolved to obtain the ionic liquid electrolyte.
The preparation method of the electrolyte is simple to operate and suitable for large-scale production, and the prepared polyether-based ionic liquid electrolyte has good electrochemical performance and good stability and is suitable for the field of lithium ion batteries.
The present invention will be described in more detail with reference to examples.
Example 1
Weighing 6.47g (0.02mol) of tris (2- (2-methoxyethoxy) ethyl) amine and 3.27g (0.03mol) of bromoethane, mixing the two, adding 20mL of acetone, adding the mixture into a reaction kettle, carrying out hydrothermal reaction at the reaction temperature of 80 ℃, taking out the mixture to cool to room temperature after 48 hours of reaction, obtaining a yellow clear solution, adding ether to wash the solution, obtaining a yellow viscous liquid as a washing product, and drying the washing product in an oven for 24 hours to obtain 7g of tris (2- (2-methoxyethoxy) ethyl) -ethylammonium bromide.
Dissolving tris (2- (2-methoxyethoxy) ethyl) -ethylammonium bromide in water, dropwise adding a lithium salt (LiTFSI) aqueous solution according to the molar ratio of the tris (2- (2-methoxyethoxy) ethyl) -ethylammonium bromide to the lithium salt of 1:1.5, and stirring the obtained mixed solution at room temperature for 2 hours to generate a water-insoluble organic liquid phase. And adding 30mL of dichloromethane into the mixed solution, fully mixing, standing for layering, separating, collecting a dichloromethane organic phase, and repeatedly washing with deionized water for three times until no bromide ion residue in the cleaning solution can be detected by using a silver nitrate solution. Finally, the extracted product is subjected to rotary evaporation to remove dichloromethane in the solution, and then the dichloromethane is placed at the temperature of 100 ℃ for drying for 24 hours, so that brown viscous liquid tris (2- (2-methoxyethoxy) ethyl) -ethylammonium-bis (trifluoromethylsulfonyl) imide is finally obtained.
Under the protection of argon atmosphere, 2mmol of LiTFSI is added into 2g of the obtained tris (2- (2-methoxyethoxy) ethyl) -ethylammonium-bis (trifluoromethylsulfonyl) imide salt, and the mixture is stirred until the lithium salt is completely dissolved, so that the ionic liquid electrolyte is obtained.
Example 2
Weighing 6.47g (0.02mol) of tris (2- (2-methoxyethoxy) ethyl) amine and 3.27g (0.03mol) of bromoethane, mixing the two, adding 20mL of acetone, adding the mixture into a reaction kettle, carrying out hydrothermal reaction at the reaction temperature of 80 ℃, taking out the mixture to cool to room temperature after 48 hours of reaction, obtaining a yellow clear solution, adding ether to wash the solution, obtaining a yellow viscous liquid as a washing product, and drying the washing product in an oven for 24 hours to obtain 7g of tris (2- (2-methoxyethoxy) ethyl) -ethylammonium bromide.
Dissolving tris (2- (2-methoxyethoxy) ethyl) -ethylammonium bromide in water, dropwise adding a lithium salt (LiFSI) aqueous solution according to a molar ratio of tris (2- (2-methoxyethoxy) ethyl) -ethylammonium bromide to lithium salt of 1:1.5, and stirring the obtained mixed solution at room temperature for 2 hours to generate a water-insoluble organic liquid phase. And adding 30mL of dichloromethane into the mixed solution, fully mixing, standing for layering, separating, collecting a dichloromethane organic phase, and repeatedly washing with deionized water for three times until no bromide ion residue in the cleaning solution can be detected by using a silver nitrate solution. And finally, performing rotary evaporation on the extracted product to remove dichloromethane in the solution, and then putting the solution at 100 ℃ for drying for 24 hours to finally obtain brown viscous liquid tris (2- (2-methoxyethoxy) ethyl) -ethylammonium-bis (fluorosulfonyl) imide.
Under the protection of argon atmosphere, 2mmol LiFSI is added into 2g of the obtained tris (2- (2-methoxyethoxy) ethyl) -ethylammonium-bis (fluorosulfonyl) imide salt, and the mixture is stirred until lithium salt is completely dissolved, so that the ionic liquid electrolyte is obtained.
Example 3
Weighing 6.47g (0.02mol) of tris (2- (2-methoxyethoxy) ethyl) amine and 2.28g (0.03mol) of methyl iodide, mixing the two, adding 20mL of acetone, adding the mixture into a reaction kettle, carrying out hydrothermal reaction at the reaction temperature of 80 ℃, taking out the mixture to cool to room temperature after 48 hours of reaction, obtaining a red brown clear solution, adding diethyl ether for cleaning, cleaning the product to obtain a red brown viscous liquid, and drying the cleaned product in an oven for 24 hours to obtain 8.4g of the product tris (2- (2-methoxyethoxy) ethyl) -methylammonium iodide.
Dissolving tris (2- (2-methoxyethoxy) ethyl) -methylammonium iodide in water, dropwise adding a lithium salt (LiTFSI) aqueous solution into tris (2- (2-methoxyethoxy) ethyl) -methylammonium iodide and lithium salt at a molar ratio of 1:1.5, and stirring the obtained mixed solution at room temperature for 2 hours to generate a water-insoluble organic liquid phase. And adding 30mL of dichloromethane into the mixed solution, fully mixing, standing for layering, separating, collecting a dichloromethane organic phase, and repeatedly washing with deionized water for three times until no bromide ion residue in the cleaning solution can be detected by using a silver nitrate solution. And finally, performing rotary evaporation on the extracted product to remove dichloromethane in the solution, and then placing the solution at 100 ℃ for drying for 24 hours to finally obtain brown viscous liquid tris (2- (2-methoxyethoxy) ethyl) -methylammonium-bis (trifluoromethylsulfonyl) imide.
Under the protection of argon atmosphere, 2mmol of LiTFSI is added into 2g of the obtained tris (2- (2-methoxyethoxy) ethyl) -methylammonium-bis (trifluoromethylsulfonyl) imide salt, and the mixture is stirred until the lithium salt is completely dissolved, so that the ionic liquid electrolyte is obtained.
Example 4
6.47g (0.02mol) of tris (2- (2-methoxyethoxy) ethyl) amine and 2.28g (0.03mol) of methyl iodide were weighed, mixed and added with 20mL of acetone, and added to the reaction vessel for hydrothermal reaction at a reaction temperature of 80 ℃. After 48h of reaction, the mixture is taken out and cooled to room temperature to obtain a reddish brown clear solution, ether is added for cleaning, the cleaning product is a reddish brown viscous liquid, and the cleaning product is dried in an oven for 24h to obtain 8.4g of the product tris (2- (2-methoxyethoxy) ethyl) -methylammonium iodide.
Dissolving tris (2- (2-methoxyethoxy) ethyl) -methylammonium iodide in water, dropwise adding a lithium salt (LiFSI) aqueous solution of tris (2- (2-methoxyethoxy) ethyl) -methylammonium iodide and a lithium salt at a molar ratio of 1:1.5, and stirring the obtained mixed solution at room temperature for 2 hours to generate a water-insoluble organic liquid phase. And adding 30mL of dichloromethane into the mixed solution, fully mixing, standing for layering, separating, collecting a dichloromethane organic phase, and repeatedly washing with deionized water for three times until no bromide ion residue in the cleaning solution can be detected by using a silver nitrate solution. And finally, performing rotary evaporation on the extracted product to remove dichloromethane in the solution, and then putting the solution at 100 ℃ for drying for 24 hours to finally obtain brown viscous liquid tris (2- (2-methoxyethoxy) ethyl) -methylammonium-bis (fluorosulfonyl) imide.
Under the protection of argon atmosphere, 2mmol LiFSI is added into 2g of the obtained tris (2- (2-methoxyethoxy) ethyl) -methylammonium-bis (fluorosulfonyl) imide salt, and the mixture is stirred until lithium salt is completely dissolved, so that the ionic liquid electrolyte is obtained.
Example 5
Weighing 0.1mol of tris (2- (2-methoxyethoxy) ethyl) amine and 0.125mol of methyl iodide, mixing the two, adding 100mL of acetonitrile, adding the mixture into a reaction kettle for hydrothermal reaction at 70 ℃, taking out the mixture after 48 hours of reaction, cooling the mixture to room temperature to obtain a red brown clear solution, adding diethyl ether for cleaning, wherein the cleaning product is red brown viscous liquid, and drying the cleaning product in an oven for 24 hours to obtain 8.4g of the product tris (2- (2-methoxyethoxy) ethyl) -methyl ammonium iodide.
Dissolving tris (2- (2-methoxyethoxy) ethyl) -methylammonium iodide in water, dropwise adding a lithium salt (LiFSI) aqueous solution of tris (2- (2-methoxyethoxy) ethyl) -methylammonium iodide and a lithium salt at a molar ratio of 1:1.75, and stirring the obtained mixed solution at room temperature for 6 hours to generate a water-insoluble organic liquid phase. And adding 30mL of dichloromethane into the mixed solution, fully mixing, standing for layering, separating, collecting a dichloromethane organic phase, and repeatedly washing with deionized water for three times until no bromide ion residue in the cleaning solution can be detected by using a silver nitrate solution. And finally, performing rotary evaporation on the extracted product to remove dichloromethane in the solution, and then putting the solution at 100 ℃ for drying for 24 hours to finally obtain brown viscous liquid tris (2- (2-methoxyethoxy) ethyl) -methylammonium-bis (fluorosulfonyl) imide.
And under the protection of argon atmosphere, adding 0.5mmol of LiFSI into 1g of the obtained tris (2- (2-methoxyethoxy) ethyl) -methylammonium-bis (fluorosulfonyl) imide salt, and stirring until lithium salt is completely dissolved to obtain the ionic liquid electrolyte.
Example 6
Weighing 0.1mol of tris (2- (2-methoxyethoxy) ethyl) amine and 0.175mol of bromoethane, mixing the two, adding 100mL of acetone, adding the mixture into a reaction kettle for hydrothermal reaction at the reaction temperature of 90 ℃, taking out the mixture after 24 hours of reaction, cooling the mixture to room temperature to obtain yellow clear solution, adding diethyl ether for cleaning, wherein the cleaning product is yellow viscous liquid, and drying the cleaning product in an oven for 24 hours to obtain 7g of tris (2- (2-methoxyethoxy) ethyl) -ethylammonium bromide.
Dissolving tris (2- (2-methoxyethoxy) ethyl) -ethylammonium bromide in water, dropwise adding a lithium salt (LiTFSI) aqueous solution according to the molar ratio of the tris (2- (2-methoxyethoxy) ethyl) -ethylammonium bromide to the lithium salt of 1:1.75, and stirring the obtained mixed solution at room temperature for 12 hours to generate a water-insoluble organic liquid phase. And adding 30mL of dichloromethane into the mixed solution, fully mixing, standing for layering, separating, collecting a dichloromethane organic phase, and repeatedly washing with deionized water for three times until no bromide ion residue in the cleaning solution can be detected by using a silver nitrate solution. Finally, the extracted product is subjected to rotary evaporation to remove dichloromethane in the solution, and then the dichloromethane is placed at the temperature of 100 ℃ for drying for 24 hours, so that brown viscous liquid tris (2- (2-methoxyethoxy) ethyl) -ethylammonium-bis (trifluoromethylsulfonyl) imide is finally obtained.
Under the protection of argon atmosphere, 1.5mmol of LiTFSI is added into 1g of the obtained tris (2- (2-methoxyethoxy) ethyl) -ethylammonium-bis (trifluoromethylsulfonyl) imide salt, and the mixture is stirred until the lithium salt is completely dissolved, so that the ionic liquid electrolyte is obtained.
The following are electrochemical stability tests and performance tests for preparing lithium ion batteries:
the polyether-based ionic liquid electrolyte prepared in example 1 was applied to a Ni/Li battery system, and the electrochemical stability of the ionic liquid electrolyte was tested. The specific implementation steps are as follows:
selecting a glass fiber diaphragm as a battery diaphragm, a lithium sheet as a battery cathode and a nickel sheet as a battery anode; the ionic liquid electrolyte in example 1 was placed between the positive and negative electrodes in an argon-protected glove box, and a button cell was assembled. The assembled cell was subjected to linear voltammetric sweep testing using an electrochemical workstation, the results of which are shown in fig. 1. The current density is 0.1mA/cm2The corresponding voltage is taken as the decomposition voltage, and the decomposition voltage of the ionic liquid electrolyte reaches 4.7V.
The polyether-based ionic liquid electrolyte prepared in example 1 was applied to LiFePO4In the Li lithium ion battery, the charge-discharge curve and the cycle performance of the lithium ion battery are tested. The specific implementation steps are as follows:
the anode material is LiFePO according to the mass ratio4Fully grinding and mixing Super P, namely PVDF (polyvinylidene fluoride) in a ratio of 8:1:1 in an N-methyl pyrrolidone solvent to obtain uniformly dispersed positive electrode slurry; coating the anode slurry on an aluminum foil cleaned by ethanol, and then placing the aluminum foil at the temperature of 110 ℃ for vacuum drying for 24 hours; drying the LiFePO4And cutting the positive electrode into a wafer to be used as the positive electrode of the lithium ion battery. Selecting a glass fiber diaphragm as a lithium ion battery diaphragm, and using a lithium sheet as a lithium ion battery cathode; the ionic liquid electrolyte in example 1 was placed between the positive and negative electrodes in an argon-protected glove box, and a button cell was assembled. The assembled lithium ion battery was subjected to charge and discharge tests at a 0.1C rate, and the test results are shown in fig. 2. The discharge specific capacity of the lithium battery can reach 150mAh/g under the multiplying power of 0.1C, the lithium battery can stably work for 100 cycles, and the coulomb efficiency is close to 100%.
The polyether-based ionic liquid electrolyte has the advantages of high room-temperature ionic conductivity, stable electrochemical performance, good lithium salt dissolving capacity and the like, and the preparation method is simple and can be applied to actual production. And the traditional organic electrolyte is not contained, and the safety performance is high. The ionic liquid electrolyte can be used for assembling a lithium ion battery and has stable cycle performance.
The above embodiments are only embodiments with better effect in the present invention, and should not be construed as limiting the present invention. Variations and modifications or substitutions may be made by those skilled in the art without departing from the spirit and scope of the invention.
Claims (10)
1. A polyether-based ionic liquid, which is characterized in that the structural formula of the ionic liquid is as follows:
wherein R is CH3Or CH2CH3，Y-Is FSI-Or TFSI-。
2. The method of preparing the polyether ionic liquid of claim 1, comprising the steps of:
(1) mixing tris (2- (2-methoxyethoxy) ethyl) amine and halogenated alkane, adding the mixture into a solvent, reacting for 24-48h at 70-90 ℃ under a protective atmosphere, cleaning, and drying to obtain tris (2- (2-methoxyethoxy) ethyl) -alkyl-ammonium halide;
(2) adding the tri (2- (2-methoxyethoxy) ethyl) -alkyl-ammonium halide into the ionic water, uniformly stirring, then adding the lithium salt, stirring for 2-12h, and drying to obtain the polyether type ionic liquid.
3. The method for preparing the polyether-type ionic liquid according to claim 2, wherein in the step (1), the molar ratio of the reactants is tris (2- (2-methoxyethoxy) ethyl) amine to haloalkane is 1: 1.25-1.75.
4. The method for preparing the polyether-based ionic liquid according to claim 2, wherein in the step (1), the halogenated alkane is ethyl bromide or methyl iodide; the solvent is acetone or acetonitrile.
5. The method for preparing a polyether ionic liquid according to claim 2, wherein in the step (1), the ratio of each tris (2- (2-methoxyethoxy) ethyl) amine to the solvent is 0.1 mol: 100 mL; the protective atmosphere is a nitrogen atmosphere.
6. The method for preparing the polyether-based ionic liquid according to claim 2, wherein in the step (1) and in the step (2), the molar ratio of the tris (2- (2-methoxyethoxy) ethyl) -alkyl-ammonium halide to the lithium salt is 1: 1.25-1.75, and the lithium salt is LiTFSI or LiFSI.
7. The method for preparing a polyether ionic liquid according to claim 2, wherein the step (2) further comprises a purification step of: adding dichloromethane into the product after stirring for 2-12h to extract an organic phase, collecting the organic phase through liquid separation, repeatedly washing the organic phase with deionized water for many times, removing dichloromethane in the solution through rotary evaporation, and drying to obtain the polyether-based ionic liquid.
8. A method for preparing an electrolyte of a polyether-based ionic liquid prepared by the method of any one of claims 2 to 7, wherein a lithium salt is added to the polyether-based ionic liquid, and the mixture is stirred under a protective atmosphere until the lithium salt is dissolved, thereby obtaining the polyether-based ionic liquid electrolyte.
9. A method for preparing an electrolyte of a polyether based ionic liquid according to claim 8, wherein the amount of the substance of lithium salt added per gram of the polyether based ionic liquid is 0.5 to 1.5 mmol; the lithium salt is LiTFSI or LiFSI.
10. Use of the polyether-based ionic liquid prepared according to the method of claim 8 in a high voltage lithium ion battery.
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Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20030013021A1 (en) * | 2000-12-22 | 2003-01-16 | Fuji Photo Film Co., Ltd. | Electrolyte composition and non-aqueous electrolyte secondary cell |
| WO2017075299A1 (en) * | 2015-10-28 | 2017-05-04 | The Procter & Gamble Company | Fragrance compositions comprising ionic liquids |
| CN107925055A (en) * | 2015-05-20 | 2018-04-17 | 迪肯大学 | Electro-chemical cell |
-
2019
- 2019-12-14 CN CN201911287297.3A patent/CN111116388A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20030013021A1 (en) * | 2000-12-22 | 2003-01-16 | Fuji Photo Film Co., Ltd. | Electrolyte composition and non-aqueous electrolyte secondary cell |
| CN107925055A (en) * | 2015-05-20 | 2018-04-17 | 迪肯大学 | Electro-chemical cell |
| WO2017075299A1 (en) * | 2015-10-28 | 2017-05-04 | The Procter & Gamble Company | Fragrance compositions comprising ionic liquids |
Non-Patent Citations (3)
| Title |
|---|
| HILDER, MATTHIAS ETAL: "Effect of mixed anions on the physicochemical properties of a sodium containing alkoxyammonium ionic liquid electrolyte", 《PHYSICAL CHEMISTRY CHEMICAL PHYSICS》 * |
| HILDER, MATTHIAS ETAL: "Stable cycling of NaFePO4 cathodes in high salt concentration ionic liquid electrolytes", 《JOURNAL OF POWER SOURCES》 * |
| MEGA KAR ETAL: "Ionic liquid electrolytes for reversible magnesium electrochemistry", 《CHEMICAL COMMUNICATIONS (CAMBRIDGE, UNITED KINGDOM) 》 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115947752A (en) * | 2022-12-22 | 2023-04-11 | 烟台先进材料与绿色制造山东省实验室 | Phosphate proton type ionic liquid, preparation method thereof and application of phosphate proton type ionic liquid as basic lubricating liquid additive |
| CN115947752B (en) * | 2022-12-22 | 2024-03-08 | 烟台先进材料与绿色制造山东省实验室 | Phosphate ionic liquid, preparation method thereof and application of phosphate ionic liquid as basic lubricating liquid additive |
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