CN115458811A - Electrolyte based on sulfone-based eutectic solvent, preparation method of electrolyte and lithium ion battery - Google Patents

Electrolyte based on sulfone-based eutectic solvent, preparation method of electrolyte and lithium ion battery Download PDF

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CN115458811A
CN115458811A CN202211071217.2A CN202211071217A CN115458811A CN 115458811 A CN115458811 A CN 115458811A CN 202211071217 A CN202211071217 A CN 202211071217A CN 115458811 A CN115458811 A CN 115458811A
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sulfone
lithium
electrolyte
eutectic solvent
negative electrode
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CN115458811B (en
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张嘉恒
吴万宝
李明雨
王密
喻文
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Shenzhen Graduate School Harbin Institute of Technology
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Shenzhen Graduate School Harbin Institute of Technology
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    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01MPROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00Secondary cells; Manufacture thereof
    • H01M10/05Accumulators with non-aqueous electrolyte
    • H01M10/056Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
    • H01M10/0564Accumulators 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
    • H01M10/0566Liquid materials
    • H01M10/0569Liquid materials characterised by the solvents
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01MPROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00Secondary cells; Manufacture thereof
    • H01M10/05Accumulators with non-aqueous electrolyte
    • H01M10/052Li-accumulators
    • H01M10/0525Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01MPROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00Secondary cells; Manufacture thereof
    • H01M10/05Accumulators with non-aqueous electrolyte
    • H01M10/056Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
    • H01M10/0564Accumulators 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
    • H01M10/0566Liquid materials
    • H01M10/0567Liquid materials characterised by the additives
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01MPROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00Secondary cells; Manufacture thereof
    • H01M10/05Accumulators with non-aqueous electrolyte
    • H01M10/058Construction or manufacture
    • YGENERAL 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
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02EREDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10Energy storage using batteries

Abstract

The invention relates to the field of lithium ion batteries, in particular to an electrolyte based on a sulfone-based eutectic solvent, a preparation method of the electrolyte and a lithium ion battery. The electrolyte based on the sulfone-based eutectic solvent comprises: the eutectic solvent is obtained by blending lithium salt and a solid sulfone compound. The electrolyte has the advantages of incombustibility, high thermal stability, high lithium ion transference number, large electrochemical window and the like, is applied to a lithium ion battery, and can effectively improve the cycle performance and safety of the battery. And the preparation method of the electrolyte is simple, is suitable for large-scale industrial production, and has good application prospect.

Description

Electrolyte based on sulfone-based eutectic solvent, preparation method of electrolyte and lithium ion battery
Technical Field
The invention relates to the field of lithium ion batteries, in particular to an electrolyte based on a sulfone-based eutectic solvent, a preparation method of the electrolyte and a lithium ion battery.
Background
The lithium ion battery has the advantages of high energy density, good cycle stability, environmental friendliness and the like, and is widely applied to the fields of portable electronic equipment, electric automobiles, energy storage and the like. With the continuous development of modern science and technology, higher requirements are put forward on the energy density and the safety performance of the lithium ion battery. The traditional organic electrolyte using a carbonate solvent has the characteristics of low flash point and easy volatilization, and is easy to cause safety problems such as combustion, explosion and the like. Meanwhile, in a battery system having a higher energy density, the safety problem of the battery is one of the important reasons that hinder the industrialization thereof.
At present, in order to solve the above-mentioned problems of high energy density and high safety, a flame retardant additive is usually added into a conventional electrolyte, and the flame retardant additive is usually added by more than 20wt%, although a certain flame retardant effect can be achieved, the electrochemical performance of the lithium ion battery is always reduced, especially the cycle life and the rate performance, and the manufacturing cost of the battery is also increased, which is not beneficial to large-scale production.
Therefore, the development of non-flammable electrolyte while ensuring good cycle life is imminent, thereby promoting the development of next-generation high-safety and high-energy density lithium ion batteries.
Disclosure of Invention
In view of the defects of the prior art, the invention aims to provide an electrolyte based on a sulfone-based eutectic solvent, a preparation method thereof and a lithium ion battery, and aims to solve the problem that the cycle life of the battery is shortened even though the existing non-combustible electrolyte can achieve a certain flame retardant effect.
The technical scheme of the invention is as follows:
an electrolyte based on a sulfone-based eutectic solvent, comprising: the eutectic solvent is obtained by blending lithium salt and a solid sulfone compound.
Optionally, the molar ratio of the lithium salt to the sulfone compound is 1-1.
Optionally, the sulfone compound is selected from one or more of dimethyl sulfone, diethyl sulfone, n-butyl sulfone, ethyl methyl sulfone, ethyl phenyl sulfone, diphenyl sulfone, methyl phenyl sulfone, 4-difluoro diphenyl sulfone and 3-sulfolene.
Optionally, the lithium salt is selected from one or more of lithium bistrifluoromethanesulfonylimide, lithium dioxalate borate, lithium hexafluorophosphate and lithium tetrafluoroborate.
Optionally, the additive is selected from at least one of cyclic carbonates, lithium nitrate, and lithium difluorooxalato borate.
Optionally, the cyclic carbonate is one or more of ethylene carbonate, fluoroethylene carbonate, difluoroethylene carbonate and vinylene carbonate.
The invention discloses a preparation method of an electrolyte based on a sulfone-based eutectic solvent, which comprises the following steps:
in an inert atmosphere environment, mixing lithium salt and a solid sulfone compound, heating and stirring to obtain a low co-solvent; and adding an additive into the low eutectic solvent, and stirring to prepare the electrolyte.
Optionally, mixing a lithium salt and a solid sulfone compound, heating and stirring to obtain a low cosolvent; adding an additive into the low eutectic solvent, and then stirring, wherein the method specifically comprises the following steps: mixing lithium salt and solid sulfone compound, and stirring at 50-70 ℃ until the mixture is clear and transparent to obtain a low co-solvent; and (4) after cooling, adding an additive into the low eutectic solvent, and then uniformly stirring.
The lithium ion battery comprises the electrolyte based on the sulfone eutectic solvent.
Optionally, the lithium ion battery further includes: a positive electrode, a negative electrode, a separator;
the material of the positive electrode is one or more of lithium iron phosphate, lithium manganese iron phosphate, lithium manganate, lithium cobaltate, lithium nickel manganate, nickel cobalt manganese ternary material and nickel cobalt aluminum ternary material;
the negative electrode is one or more of a graphite negative electrode, a metal lithium negative electrode, a silicon-carbon negative electrode and a silicon-oxygen negative electrode;
the diaphragm is one or more of a polyethylene diaphragm, a polypropylene diaphragm, a PP/PE/PP three-layer composite film and a glass fiber diaphragm.
Has the advantages that: the invention provides a sulfone-based eutectic solvent electrolyte of a lithium ion battery, which has the advantages of incombustibility, high thermal stability, high lithium ion migration number, large electrochemical window and the like, still has excellent cycle life on the premise of ensuring high safety of the battery, and has good application prospect.
Drawings
FIG. 1 is a linear scanning voltammogram of the electrolyte prepared in example 1 of the present invention.
Fig. 2 is a thermogravimetric diagram of the electrolyte prepared in example 1 of the present invention and the conventional electrolyte of comparative example 1.
FIG. 3 is a graph showing long cycle performance of the electrolyte prepared in example 1 of the present invention.
Detailed Description
The invention provides an electrolyte based on a sulfone-based eutectic solvent, a preparation method thereof and a lithium ion battery, and further details of the invention are provided below in order to make the purpose, technical scheme and effect of the invention clearer and clearer. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
Eutectic solvents have many advantages, such as high thermal stability, low vapor pressure, non-flammability and good salt solubility. Particularly, the low-eutectic solvent is nonflammable, so that the problem of flammability of the conventional commercial carbonate electrolyte can be effectively solved, and the low-eutectic solvent has good safety. Meanwhile, the electrolyte has the advantages of low cost, easy manufacture, no toxicity and biodegradability, and is an ideal choice for battery electrolytes.
Based on this, an embodiment of the present invention provides an electrolyte based on a sulfone-based eutectic solvent, including: the eutectic solvent is obtained by blending lithium salt and a solid sulfone compound.
The embodiment provides an electrolyte based on a sulfone-based eutectic solvent (DES), specifically, the DES is formed by lithium salts and solid sulfone compounds with different molar ratios, and a certain amount of additives are added to form the electrolyte. The electrolyte has the advantages of non-flammability, high thermal stability, high lithium ion transference number, large electrochemical window and the like, and can effectively improve the cycle performance and safety of the battery when being applied to the lithium ion battery. And the preparation method of the electrolyte is simple, is suitable for large-scale industrial production, and has good application prospect.
Eutectic solvents are eutectic mixtures consisting of two or more components in a stoichiometric ratio, resulting in a mixture having a melting point significantly lower than the melting point of each individual component due to intermolecular interactions, including hydrogen bonding, lewis acid-base interactions, and van der waals interactions. In the sulfone-based eutectic solvent provided in this embodiment, lithium ions in the lithium salt and the-S = O group in the sulfone compound have a strong coordination effect, and the lithium ions and anions (such as TFSI) are reduced 、BOB Etc.), and the intermolecular interaction of sulfone compounds, thereby lowering the melting point of the mixture and forming the sulfone-based eutectic solvent.
The existing electrolytic liquid is mainly carbonate and ether electrolyte, and carbonate and ether are volatile, inflammable and poor in thermal stability, and have serious potential safety hazard because fire or explosion is easy to occur when the battery is out of control due to heat. The compatibility of carbonates and lithium metal is poor, lithium dendrite is easily formed in the lithium ion deposition process, a diaphragm can be pierced, and the short circuit of the battery is caused; although ether electrolyte has better compatibility with lithium metal, the electrochemical window of the ether electrolyte is narrower, generally less than 4V, and the ether electrolyte cannot be applied to a high-voltage lithium ion battery system.
The inventor finds that after the lithium salt and the solid sulfone compound are heated and mixed in different stoichiometric ratios, the interaction force between the lithium salt and the solid sulfone compound can be utilized to reduce the melting point and form a liquid eutectic solvent, and the eutectic solvent electrolyte has high thermal stability and oxidation resistance (more than 5V), is nonflammable and has high lithium ion migration number. The lithium iron phosphate lithium ion battery is suitable for various anode materials (high nickel ternary, lithium iron phosphate, lithium manganese iron phosphate, lithium cobaltate, lithium manganate and the like) and various cathodes (graphite, lithium metal, silicon carbon, silicon oxygen cathodes) and has excellent cycle performance.
In addition, although a few electrolytes using low-melting-point liquid sulfone compounds (dimethyl sulfoxide, sulfolane and the like) as solvents exist at present, the electrolytes also have good thermal stability and oxidation resistance (more than 5V), but the electrolytes cannot form a stable electrode/electrolyte interface film on a graphite negative electrode, so that the cycle decay of the battery is rapid; but also greatly limits the application of the sulfone compounds with high melting points. The reason is that the existing electrolyte taking the sulfone compound as the solvent is more of SEI films derived from the solvent, and salt anions are less involved in the SEI film forming process, so that unstable SEI films rich in organic matters are formed. In the electrolyte based on the sulfone eutectic solvent, more salt anions are induced to participate in the formation process of the SEI film, and inorganic substances (LiF, li) are formed 3 N, B-O/F, etc.) more stable SEI films, ensuring long cycle stability of the battery.
In one embodiment, the molar ratio of the lithium salt to the sulfone compound is 1-1. The lithium salt and the sulfone compound can better form the eutectic solvent in the proportion range, and the content of the additive can form a more stable SEI interfacial film in the proportion range.
In one embodiment, the solid sulfone compound is selected from one or more of dimethyl sulfone, diethyl sulfone, n-butyl sulfone, ethyl methyl sulfone, ethyl phenyl sulfone, diphenyl sulfone, methyl benzene sulfone, 4-difluoro diphenyl sulfone, 3-sulfolene, etc.
In one embodiment, the lithium salt is selected from lithium bistrifluoromethanesulfonylimide (LiTFSI), lithium bistrifluorosulfonylimide (LiFSI), lithium dioxalate borate (LiBOB), lithium hexafluorophosphate (LiPF) 6 ) And lithium tetrafluoroborate (LiBF) 4 ) And the like.
In aIn an embodiment, the additive is selected from at least one of cyclic carbonates, lithium nitrate, lithium difluoroborate, and the like. The use of these film-forming additives results in the formation of stable SEI interfacial films, including LiF, li formation 3 N, B-O/F compounds.
In one embodiment, the cyclic carbonate is one or more of ethylene carbonate, fluoroethylene carbonate, difluoroethylene carbonate, vinylene carbonate, and the like.
Compared with the prior art, the electrolyte based on the sulfone eutectic solvent has the following advantages and outstanding effects:
(1) the electrolyte is different from the traditional carbonate solvent electrolyte, is non-combustible, has high thermal stability and high safety;
(2) the electrolyte is different from the traditional carbonate solvent electrolyte, and the electrochemical window of the electrolyte is wider and reaches about 5V; the material is suitable for various high-voltage cathode materials and has good electrochemical performance;
(3) compared with the traditional carbonate solvent electrolyte, the electrolyte has higher lithium ion migration number (more than 0.7), and the traditional carbonate solvent electrolyte is only between 0.2 and 0.4, so the electrolyte has more excellent rate performance;
(4) under the electrolyte system, a stable interface SEI film and a stable CEI film can be formed on the surfaces of the anode and cathode materials, so that the stability of the interface film in the long-cycle charge-discharge process is ensured, and the cycle life is effectively prolonged;
(5) the electrolyte has the advantages of simple and convenient synthesis method, easily obtained raw materials, low cost and convenient large-scale application.
The embodiment of the invention provides a preparation method of the electrolyte based on the sulfone eutectic solvent, which comprises the following steps:
in an inert atmosphere environment, mixing lithium salt and a solid sulfone compound, heating and stirring to obtain a low co-solvent; and adding an additive into the low eutectic solvent, and stirring to prepare the electrolyte.
In one embodiment, the lithium salt and the solid sulfone compound are mixed, heated and stirred to obtain the low cosolvent; adding an additive into the low eutectic solvent, and stirring, wherein the method specifically comprises the following steps: mixing lithium salt and solid sulfone compound, and stirring at 50-70 deg.C (such as 60 deg.C) to obtain low cosolvent; and (4) after cooling, adding an additive into the low eutectic solvent, and then uniformly stirring.
In one embodiment, the inert atmosphere may be an argon atmosphere or a helium atmosphere. Furthermore, under the inert atmosphere environment, the water content and the oxygen content are both below 0.2 ppm.
The embodiment of the invention provides a lithium ion battery, which comprises the electrolyte based on the sulfone eutectic solvent.
The electrolyte described in this example is suitable for a lithium ion battery using metallic lithium as a negative electrode. Specifically, the lithium ion battery includes: electrolyte, positive pole, negative pole, diaphragm, wherein, electrolyte be this embodiment the electrolyte, anodal material is one or more in lithium iron phosphate, lithium manganese iron phosphate, lithium manganate, lithium cobaltate, lithium nickel manganese, nickel cobalt manganese ternary material and the nickel cobalt aluminium ternary material, the negative pole is one or more in graphite negative pole, metal lithium negative pole, silicon carbon negative pole and the silica negative pole, the diaphragm is one of Polyethylene (PE) diaphragm, polypropylene (PP) diaphragm, PP PE/PP three-layer composite diaphragm and glass fiber diaphragm.
The invention is further illustrated by the following specific examples.
Comparative example 1
The carbonate based solvent electrolyte of this comparative example was prepared from LiPF 6 Ethylene Carbonate (EC), dimethyl carbonate (DMC) and Ethyl Methyl Carbonate (EMC), wherein LiPF is contained in the electrolyte 6 The concentration of (1) is 1M, and the volume ratio of EC, DMC and EMC is 1. The electrolyte system is used for a full battery test with metal lithium as a cathode and lithium iron phosphate as an anode, and tests show that the coulombic efficiency of the battery reaches 98.0 percent, and the cycle life of the battery is 500 circles.
Comparative example 2
Comparative example of the presentThe carbonate solvent electrolyte is prepared from LiPF 6 Ethylene Carbonate (EC) and diethyl carbonate (DEC), wherein LiPF is present in the electrolyte 6 The concentration of (1) is 1M, and the volume ratio of EC to DEC is 1. The electrolyte system is used for a full battery test with graphite as a negative electrode and nickel-cobalt-manganese 811 as a positive electrode, and tests show that the coulombic efficiency of the battery reaches 99.0% and the cycle life is 400 circles.
Example 1
Mixing lithium bistrifluoromethanesulfonimide and ethyl methyl sulfone according to a molar ratio of 1. The electrolyte system is used for a full battery test with metal lithium as a cathode and lithium iron phosphate as an anode, and tests show that the coulombic efficiency of the battery reaches 99.0 percent, and the cycle life can reach 2000 circles.
Fig. 1 is a linear scanning voltammogram of the electrolyte prepared in example 1 of the present invention, and it can be seen from the graph that the oxidation resistance potential of the electrolyte reaches 5.5V or more, and the electrolyte is suitable for all high voltage cathode materials.
Fig. 2 is a thermogravimetric diagram of the electrolyte prepared in example 1 of the present invention and the conventional electrolyte of comparative example 1, and it can be seen that the weight loss rate of the electrolyte of example 1 is less than 10% at 150 ℃, and the weight loss rate of the conventional carbonate electrolyte reaches more than 90%.
Fig. 3 is a graph showing long cycle performance of the electrolyte prepared in example 1 of the present invention, and it can be seen that the discharge capacity was 140mAh/g and the capacity retention rate was 92% after 2000 cycles at a 1C rate.
Example 2
Mixing the lithium bis (fluorosulfonyl) imide and the phenylmethanesulfone in a molar ratio of 1. The electrolyte system is used for testing a full battery with metallic lithium as a negative electrode and lithium cobaltate as a positive electrode, and tests show that the coulombic efficiency of the battery reaches 99.5 percent, and the cycle life can reach 1000 circles.
Example 3
Mixing lithium bistrifluoromethanesulfonimide and 4, 4-difluorodiphenyl sulfone according to a molar ratio of 1. The electrolyte system is used for testing a full battery with graphite as a negative electrode and lithium iron phosphate as a positive electrode, and tests show that the coulombic efficiency of the battery reaches 99.2%, and the cycle life of the battery can reach 500 circles.
Example 4
Mixing the lithium bis (fluorosulfonyl) imide and dimethyl sulfone in a molar ratio of 1. The electrolyte system is used for testing a full battery with metal lithium as a negative electrode and manganese iron lithium phosphate as a positive electrode, and tests show that the coulombic efficiency of the battery reaches 99.5%, and the cycle life of the battery can reach 1000 circles.
Example 5
Mixing lithium bistrifluoromethanesulfonimide and ethyl methyl sulfone according to a molar ratio of 1. The electrolyte system is used for a full battery test with metal lithium as a negative electrode and nickel-cobalt-manganese 811 as a positive electrode, and tests show that the coulombic efficiency of the battery reaches 99.5%, and the cycle life can reach 800 circles.
Example 6
Mixing lithium tetrafluoroborate and dimethyl sulfone according to a molar ratio of 1. The electrolyte system is used for a full battery test with graphite as a negative electrode and lithium cobaltate as a positive electrode, and tests show that the coulombic efficiency of the battery reaches 99.0 percent, and the cycle life can reach 500 circles.
Example 7
Mixing the lithium bis (fluorosulfonyl) imide and diethyl sulfone according to a molar ratio of 1. The electrolyte system is used for testing a full battery with silicon as a cathode and lithium iron phosphate as an anode, and tests show that the coulombic efficiency of the battery reaches 99.0 percent, and the cycle life of the battery can reach 300 circles.
Example 8
Mixing bis (trifluoromethanesulfonyl) imide lithium and diphenyl sulfone according to a molar ratio of 1. The electrolyte system is used for a full battery test with silicon carbon as a negative electrode and lithium cobaltate as a positive electrode, and tests show that the coulombic efficiency of the battery reaches 99.5 percent, and the cycle life can reach 500 circles.
Example 9
Mixing lithium hexafluorophosphate and methyl phenyl sulfone according to a molar ratio of 1. The electrolyte system is used for a full battery test with graphite as a negative electrode and lithium iron phosphate as a positive electrode, and tests show that the coulombic efficiency of the battery reaches 99.1 percent, and the cycle life can reach 600 circles.
Example 10
Mixing the lithium bis (fluorosulfonyl) imide, the lithium bis (trifluoromethanesulfonyl) imide and the dimethyl sulfone according to a molar ratio of 0.6. The electrolyte system is used for testing a full battery with graphite as a negative electrode and lithium manganate as a positive electrode, and tests show that the coulombic efficiency of the battery reaches 99.0%, and the cycle life can reach 1000 cycles.
Example 11
Mixing the lithium bis (fluorosulfonyl) imide, the lithium hexafluorophosphate and the diethyl sulfone according to a molar ratio of 0.7 to 4, stirring at 60 ℃ until the mixture is clear and transparent, cooling, adding fluoroethylene carbonate accounting for 10% of the mass of the electrolyte, and stirring uniformly to prepare the electrolyte based on the sulfone eutectic solvent. The electrolyte system is used for testing a full battery with metal lithium as a cathode and lithium iron phosphate as an anode, and tests show that the coulombic efficiency of the battery reaches 99.9 percent, and the cycle life of the battery can reach 2000 circles.
Example 12
Mixing lithium bistrifluorosulfonyl imide, lithium dioxalate borate and methyl phenyl sulfone according to a molar ratio of 0.8. The electrolyte system is used for testing a full battery with metallic lithium as a negative electrode and lithium cobaltate as a positive electrode, and tests show that the coulombic efficiency of the battery reaches 99.3 percent, and the cycle life can reach 1000 circles.
In summary, the electrolyte based on the sulfone eutectic solvent, the preparation method thereof and the lithium ion battery provided by the invention are characterized in that lithium salts and sulfone compounds with different molar ratios are blended, and a certain proportion of additives are added to form the electrolyte. The electrolyte has the advantages of non-flammability, high thermal stability, high lithium ion transference number, large electrochemical window and the like, and can effectively improve the cycle performance and safety of the battery when being applied to the lithium ion battery. And the preparation method of the electrolyte is simple, is suitable for large-scale industrial production, and has good application prospect.
It is to be understood that the invention is not limited to the examples described above, but that modifications and variations may be effected thereto by those of ordinary skill in the art in light of the foregoing description, and that all such modifications and variations are intended to be within the scope of the invention as defined by the appended claims.

Claims (10)

1. The electrolyte based on the sulfone-based eutectic solvent is characterized by comprising the following components in percentage by weight: the eutectic solvent is obtained by blending lithium salt and a solid sulfone compound.
2. The electrolyte based on the sulfone-based eutectic solvent as claimed in claim 1, wherein the molar ratio of the lithium salt to the sulfone compound is 1-1.
3. The electrolyte solution based on the sulfone-based eutectic solvent as claimed in claim 1, wherein the sulfone compound is selected from one or more of dimethyl sulfone, diethyl sulfone, n-butyl sulfone, ethyl methyl sulfone, ethyl phenyl sulfone, diphenyl sulfone, methyl phenyl sulfone, 4-difluoro diphenyl sulfone, and 3-sulfolene.
4. The electrolyte solution based on the sulfone-based eutectic solvent as claimed in claim 1, wherein the lithium salt is selected from one or more of lithium bistrifluoromethanesulfonylimide, lithium difluorosulfonylimide, lithium dioxalate borate, lithium hexafluorophosphate and lithium tetrafluoroborate.
5. The electrolyte solution based on the sulfone-based eutectic solvent as claimed in claim 1, wherein the additive is selected from at least one of cyclic carbonates, lithium nitrate and lithium difluorooxalato borate.
6. The electrolyte based on the sulfone-based eutectic solvent as claimed in claim 5, wherein the cyclic carbonates are one or more of ethylene carbonate, fluoroethylene carbonate, difluoroethylene carbonate and vinylene carbonate.
7. The preparation method of the electrolyte based on the sulfone-based eutectic solvent as set forth in any one of claims 1 to 6, comprising the steps of:
in an inert atmosphere environment, mixing lithium salt and a solid sulfone compound, heating and stirring to obtain a low co-solvent; and adding an additive into the low eutectic solvent, and stirring to prepare the electrolyte.
8. The preparation method of the electrolyte based on the sulfone-based eutectic solvent as claimed in claim 7, wherein the low-eutectic solvent is obtained by mixing a lithium salt and a solid sulfone compound, heating and stirring; adding an additive into the low eutectic solvent, and stirring, wherein the method specifically comprises the following steps: mixing lithium salt and solid sulfone compound, and stirring at 50-70 ℃ until the mixture is clear and transparent to obtain a low co-solvent; and (4) after cooling, adding an additive into the low eutectic solvent, and then uniformly stirring.
9. A lithium ion battery comprising an electrolyte based on a sulfone-based eutectic solvent according to any one of claims 1 to 6.
10. The lithium-ion battery of claim 9, further comprising: a positive electrode, a negative electrode, a separator;
the material of the positive electrode is one or more of lithium iron phosphate, lithium manganese iron phosphate, lithium manganate, lithium cobaltate, lithium nickel manganate, nickel cobalt manganese ternary material and nickel cobalt aluminum ternary material;
the negative electrode is one or more of a graphite negative electrode, a metal lithium negative electrode, a silicon-carbon negative electrode and a silicon-oxygen negative electrode;
the diaphragm is one or more of a polyethylene diaphragm, a polypropylene diaphragm, a PP/PE/PP three-layer composite film and a glass fiber diaphragm.
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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116666761A (en) * 2023-07-03 2023-08-29 常州千沐新能源有限公司 Phosphate-based deep eutectic flame-retardant electrolyte, preparation method and lithium ion battery thereof
CN117154224A (en) * 2023-09-15 2023-12-01 常州千沐新能源有限公司 Deep eutectic electrolyte additive capable of solubilizing lithium salt, electrolyte and lithium battery

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20110117422A1 (en) * 2008-07-25 2011-05-19 Lg Chem, Ltd. Electrolyte comprising eutectic mixture and electrochemical device equipped with same
CN107959050A (en) * 2017-11-07 2018-04-24 华南师范大学 A kind of high-energy-density highly secure lithium ion battery sulfone-based electrolyte and preparation method thereof
CN112242561A (en) * 2020-10-14 2021-01-19 哈尔滨工业大学(深圳) Eutectic solvent electrolyte, preparation method thereof and lithium metal battery
US20210104772A1 (en) * 2019-10-02 2021-04-08 Phased Technologies, Inc. Deep eutectic solvent based electrolytes and related electrochemical device
CN113594559A (en) * 2021-07-30 2021-11-02 上海交通大学 Electrolyte, preparation method thereof and aluminum ion battery
CN113707938A (en) * 2021-07-23 2021-11-26 哈尔滨工业大学(深圳) Electrolyte based on ternary eutectic solvent, preparation method thereof and lithium metal battery
CN113964376A (en) * 2021-10-18 2022-01-21 南京大学 Preparation and application of novel low eutectic agent
CN114914536A (en) * 2021-02-08 2022-08-16 中国科学院物理研究所 Electrolyte for lithium battery, and method for improving performance of high-temperature lithium battery

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20110117422A1 (en) * 2008-07-25 2011-05-19 Lg Chem, Ltd. Electrolyte comprising eutectic mixture and electrochemical device equipped with same
CN107959050A (en) * 2017-11-07 2018-04-24 华南师范大学 A kind of high-energy-density highly secure lithium ion battery sulfone-based electrolyte and preparation method thereof
US20210104772A1 (en) * 2019-10-02 2021-04-08 Phased Technologies, Inc. Deep eutectic solvent based electrolytes and related electrochemical device
CN112242561A (en) * 2020-10-14 2021-01-19 哈尔滨工业大学(深圳) Eutectic solvent electrolyte, preparation method thereof and lithium metal battery
CN114914536A (en) * 2021-02-08 2022-08-16 中国科学院物理研究所 Electrolyte for lithium battery, and method for improving performance of high-temperature lithium battery
CN113707938A (en) * 2021-07-23 2021-11-26 哈尔滨工业大学(深圳) Electrolyte based on ternary eutectic solvent, preparation method thereof and lithium metal battery
CN113594559A (en) * 2021-07-30 2021-11-02 上海交通大学 Electrolyte, preparation method thereof and aluminum ion battery
CN113964376A (en) * 2021-10-18 2022-01-21 南京大学 Preparation and application of novel low eutectic agent

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
彭波;周伟瑛;殷月辉;吕豪杰;: "锂电池宽温度范围电解液研究现状" *
李萌;邱景义;余仲宝;廖红英;李冰川;: "高功率锂离子电池电解液中导电锂盐的新应用" *
陈人杰;何舟影;吴锋;: "有机硼酸锂盐及亚硫酸酯类功能电解质材料" *

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116666761A (en) * 2023-07-03 2023-08-29 常州千沐新能源有限公司 Phosphate-based deep eutectic flame-retardant electrolyte, preparation method and lithium ion battery thereof
CN116666761B (en) * 2023-07-03 2024-02-06 常州千沐新能源有限公司 Phosphate-based deep eutectic flame-retardant electrolyte, preparation method and lithium ion battery thereof
CN117154224A (en) * 2023-09-15 2023-12-01 常州千沐新能源有限公司 Deep eutectic electrolyte additive capable of solubilizing lithium salt, electrolyte and lithium battery

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