CN115398695A - Electrolyte solution, electrochemical device comprising the same, and electronic device - Google Patents

Electrolyte solution, electrochemical device comprising the same, and electronic device Download PDF

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CN115398695A
CN115398695A CN202180028402.0A CN202180028402A CN115398695A CN 115398695 A CN115398695 A CN 115398695A CN 202180028402 A CN202180028402 A CN 202180028402A CN 115398695 A CN115398695 A CN 115398695A
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electrolyte
substituted
lithium
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彭谢学
唐超
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Dongguan Amperex Technology Ltd
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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
    • H01M10/0566—Liquid materials
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/409—Separators, membranes or diaphragms characterised by the material
    • H01M50/411—Organic material
    • H01M50/414—Synthetic resins, e.g. thermoplastics or thermosetting resins
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M2300/00—Electrolytes
    • H01M2300/0017—Non-aqueous electrolytes
    • H01M2300/0025—Organic electrolyte
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Abstract

The application provides an electrolyte, an electrochemical device containing the electrolyte and an electronic device, wherein the electrolyte comprises a compound shown in a formula (I), and the mass percentage of the compound shown in the formula (I) is 0.05-5% based on the mass of the electrolyte. The compound shown in the formula (I) comprises a nitrogen-containing unsaturated sulfone functional group, so that a stable anode electrolyte interface is formed at a positive electrode, a stable solid electrolyte interface is formed at a negative electrode, the stability of an electrolyte is improved to inhibit the decomposition of the electrolyte, and the cycle performance and the storage performance of an electrochemical device are improved.

Description

Electrolyte solution, electrochemical device comprising the same, and electronic device
Technical Field
The application relates to the technical field of electrochemistry, in particular to electrolyte, an electrochemical device containing the electrolyte and an electronic device.
Background
The lithium ion battery has the advantages of high energy storage density, high open circuit voltage, low self-discharge rate, long cycle life, good safety and the like, and is widely applied to electronic products such as cameras, mobile phones, unmanned aerial vehicles, notebook computers, smart watches and the like as a power source.
With the continuous expansion of the application range of lithium ion batteries, the market puts higher demands on the lithium ion batteries, for example, the lithium ion batteries are required to have longer service life and better cycle performance while having high energy density. However, when the energy density of the lithium ion battery is increased, the decomposition of the electrolyte is often accelerated, so that the service life and the cycle performance of the lithium ion battery are affected. Therefore, in view of the above, the development of a suitable electrolyte solution is a technical problem to be solved by those skilled in the art.
Disclosure of Invention
An object of the present invention is to provide an electrolyte, an electrochemical device and an electronic device including the same, which can improve the cycle performance of the electrochemical device. The specific technical scheme is as follows:
the first aspect of the application provides an electrolyte, which comprises a compound represented by formula (I), wherein the mass percentage of the compound represented by formula (I) is 0.05% to 5% based on the mass of the electrolyte:
Figure BDA0003888819670000011
wherein the content of the first and second substances,
R 1 selected from the group consisting of hydrogen, substituted or unsubstituted C1 to C10 alkyl, substituted or unsubstituted C2 to C10 alkenyl, substituted or unsubstituted C2 to C10 alkynyl, substituted or unsubstituted C6 to C10 aryl, substituted or unsubstituted C2 to C10 heteroaryl, substituted or unsubstituted C3 to C10 alicyclic hydrocarbon, substituted or unsubstituted C1 to C10 heterocyclic, substituted or unsubstituted heteroatom-containing functional group; when substituted, each substituent is independently selected from a halogen atom, a C1 to C3 alkyl group, a C2 to C3 alkenyl group or a C2 to C3 alkynyl group; the hetero atoms in the heteroaryl and heterocyclic radicals are each independently selected from B, N, O, si, P or S, a hetero atom-containing groupThe functional group is at least one of a sulfur-oxygen double bond-containing functional group or a P-O-containing functional group;
R 11 and R 12 Each independently selected from a substituted or unsubstituted C1 to C10 alkylene group, a substituted or unsubstituted C2 to C10 alkenylene group, and when substituted, each independently selected from a halogen atom, a C1 to C3 alkyl group, a C2 to C4 alkenyl group, or a C2 to C4 alkynyl group.
In some embodiments of the present application, the electrolyte includes at least one of the following compounds I-1 to I-15:
Figure BDA0003888819670000021
the compound shown in the formula (I) comprises a nitrogen-containing unsaturated sulfone functional group, so that a stable anode electrolyte interface (CEI) is formed at a positive electrode, a stable Solid Electrolyte Interface (SEI) is formed at a negative electrode, the stability of an electrolyte is improved to inhibit the decomposition of the electrolyte, and the cycle performance of an electrochemical device is improved; it is also advantageous to slow the increase in the impedance of the electrochemical device, thereby improving the memory performance of the electrochemical device.
In some embodiments of the present application, the electrolyte further includes a lithium-containing additive, the lithium-containing additive is included in an amount of 0.01 to 2% by mass based on the mass of the electrolyte, and the lithium-containing additive includes a boron-containing lithium salt and/or a phosphate-based lithium salt. By regulating the mass percentage of the lithium-containing additive within the above range, the boron-containing lithium salt or phosphate lithium salt can form a synergistic effect with the compound shown in formula (I) to improve the stability of the electrolyte, thereby improving the cycle performance of the electrochemical device.
In some embodiments of the present application, the boron-containing lithium salt comprises at least one of lithium tetrafluoroborate, lithium dioxalate borate, or lithium difluorooxalate borate, and the phosphate lithium salt comprises at least one of lithium difluorophosphate, lithium difluorobis-oxalate phosphate, or lithium tetrafluorooxalate phosphate. By selecting the boron-containing lithium salt and/or the phosphate lithium salt, a good synergistic effect can be formed between the lithium-containing additive and the compound shown in the formula (I) on the premise of not influencing the electrochemical performance of the electrochemical device, so that the cycle performance of the electrochemical device is improved.
In some embodiments of the present application, the electrolyte further comprises a sulfur-oxygen double bond containing compound in an amount of 0.01 to 10% by mass based on the mass of the electrolyte, the sulfur-oxygen double bond containing compound comprising at least one of 1,3-propane sultone, 1,4-butane sultone, methylene methanedisulfonate, 1,3-propane disulfonic anhydride, vinyl sulfate, 4-methyl vinyl sulfate, 2,4-butane sultone, 1-methyl-1,3-propane sultone, 1-fluoro-1,3-propane sultone, 2-fluoro-1,3-propane sultone, or 3-fluoro-1,3-propane sultone. By regulating the mass percentage of the compound containing the sulfur-oxygen double bond within the above range, the cycle performance and the dynamic performance of the electrochemical device can be improved. The sulfur-oxygen double bond-containing compound is more favorable for forming a synergistic effect with the compound shown in the formula (I) through selecting the compound so as to improve the cycle performance of the electrochemical device.
In some embodiments of the present application, the electrolyte solution further comprises a polynitrile compound in an amount of 0.01 to 10% by mass based on the mass of the electrolyte solution, the polynitrile compound comprising at least one of succinonitrile, adiponitrile, 1,4-dicyano-2-butene, 1,2-bis (2-cyanoethoxy) ethane, 1,3,6-hexanetrinitrile, 1,2,3-tris (2-cyanoethoxy) propane, tris (2-cyanoethyl) phosphine, glutaronitrile, 2-methylglutaronitrile, 2-methyleneglutaronitrile, pimelonitrile, 1,3,5-pentanedinitrile, or 4- (2-cyanoethyl) heptanedinitrile. By regulating the mass percentage of the polynitrile compound within the range, the cycle performance and the dynamic performance of the electrochemical device can be improved. By selecting the polynitrile compound, the polynitrile compound is more favorable for forming a synergistic effect with the compound shown in the formula (I) so as to improve the cycle performance of an electrochemical device.
In some embodiments of the present application, the electrolyte further includes a cyclic carbonate compound represented by formula (III), and the cyclic carbonate compound is contained in an amount of 0.01% to 30% by mass, based on the mass of the electrolyte:
Figure BDA0003888819670000031
wherein R is 3 Selected from substituted or unsubstituted C1 to C6 alkylene, substituted or unsubstituted C2 to C6 alkenylene; when substituted, each substituent is independently selected from a halogen atom, a C1 to C6 alkyl group, or a C2 to C6 alkenyl group.
In some embodiments of the present application, the electrolyte further comprises at least one of the following compounds III-1 to III-8:
Figure BDA0003888819670000032
by regulating the mass percentage of the cyclic carbonate compound shown in the formula (III) to be within the range, the cycle performance and the storage performance of the electrochemical device are improved. By selecting the cyclic carbonate compound, a synergistic effect with the compound shown in the formula (I) is favorably formed, so that the cycle performance and the storage performance of the electrochemical device are improved.
A second aspect of the present application provides an electrochemical device comprising the electrolyte solution of any one of the preceding embodiments. The electrolyte provided by the application has good stability, so that the electrochemical device provided by the application has good cycle performance and storage performance.
In some embodiments of the present application, the electrochemical device further comprises a separator comprising a polyolefin substrate layer and a polymer layer and/or an inorganic layer disposed on the polyolefin substrate layer; the polymer layer comprises at least one of polyvinylidene fluoride, vinylidene fluoride-hexafluoropropylene copolymer, polyacrylonitrile, polyimide, acrylonitrile-butadiene copolymer, acrylonitrile-styrene-butadiene copolymer, polymethyl methacrylate, polymethyl acrylate, polyethyl acrylate, acrylic acid-styrene copolymer, polydimethylsiloxane, sodium polyacrylate or sodium carboxymethylcellulose; the inorganic layer comprises boehmite, mg (OH) 2 、SrTiO 3 、SnO 2 、CeO 2 、MgO、NiO、CaO、ZnO、ZrO 2 、Y 2 O 3 、Al 2 O 3 、TiO 2 Or SiC. The isolation film has good stability, and is beneficial to improving the cycle performance of the electrochemical device.
A third aspect of the present application provides an electronic device comprising the electrochemical device of any one of the preceding embodiments. The electrochemical device provided by the application has good cycle performance and storage performance, so that the electronic device provided by the application has longer service life and good service performance.
The application provides an electrolyte, which comprises a compound shown as a formula (I), wherein the compound shown as the formula (I) accounts for 0.05-5% of the mass of the electrolyte. The compound shown in the formula (I) comprises a nitrogen-containing unsaturated sulfone functional group, so that stable CEI can be formed at a positive electrode, stable SEI can be formed at a negative electrode, the stability of the electrolyte is improved to inhibit the decomposition of the electrolyte, and the cycle performance of an electrochemical device is improved; it is also advantageous to slow the increase in the impedance of the electrochemical device, thereby improving the memory performance of the electrochemical device.
Detailed Description
In order to make the objects, technical solutions and advantages of the present application more apparent, the present application is further described in detail below with reference to examples. It is to be understood that the embodiments described are only a few embodiments of the present application and not all embodiments. All other technical solutions obtained by a person of ordinary skill in the art based on the embodiments in the present application belong to the scope of protection of the present application.
In the embodiments of the present application, the present application will be explained by taking a lithium ion battery as an example of an electrochemical device, but the electrochemical device of the present application is not limited to a lithium ion battery.
The first aspect of the present application provides an electrolyte, which includes a compound represented by formula (I), wherein the mass percentage of the compound represented by formula (I) is 0.05% to 5%, preferably 0.1% to 5%, based on the mass of the electrolyte:
Figure BDA0003888819670000041
wherein the content of the first and second substances,
R 1 selected from the group consisting of hydrogen, substituted or unsubstituted C1 to C10 alkyl, substituted or unsubstituted C2 to C10 alkenyl, substituted or unsubstituted C2 to C10 alkynyl, substituted or unsubstituted C6 to C10 aryl, substituted or unsubstituted C2 to C10 heteroaryl, substituted or unsubstituted C3 to C10 alicyclic hydrocarbon, substituted or unsubstituted C1 to C10 heterocyclic, substituted or unsubstituted heteroatom-containing functional group; when substituted, each substituent is independently selected from a halogen atom, a C1 to C3 alkyl group, a C2 to C3 alkenyl group, or a C2 to C3 alkynyl group; the heteroatoms in the heteroaryl and the heterocyclic radical are respectively and independently selected from B, N, O, si, P or S, and the functional group containing the heteroatoms is at least one of a sulfur-oxygen double bond-containing functional group or a P-O-containing functional group;
R 11 and R 12 Each independently selected from a substituted or unsubstituted C1 to C10 alkylene group, a substituted or unsubstituted C2 to C10 alkenylene group, and when substituted, each independently selected from a halogen atom, a C1 to C3 alkyl group, a C2 to C4 alkenyl group, or a C2 to C4 alkynyl group.
Preferably, the compound represented by the formula (I) may be any one of the following compounds I-1 to I-15. In some embodiments of the present application, the electrolyte includes at least one of the following compounds I-1 to I-15:
Figure BDA0003888819670000051
for example, the compound of formula (I) may be present in an amount of 0.05%, 0.1%, 1%, 2%, 3%, 4%, 5% by mass or any range therebetween. The electrolyte provided by the application comprises a compound shown in a formula (I), wherein the compound shown in the formula (I) comprises a nitrogen-containing unsaturated sulfone functional group, so that stable CEI can be formed at a positive electrode, stable SEI can be formed at a negative electrode, the stability of the electrolyte is improved to inhibit the decomposition of the electrolyte, and the cycle performance of an electrochemical device is improved; it is also advantageous to slow the increase in the impedance of the electrochemical device, thereby improving the memory performance of the electrochemical device. However, when the mass percentage of the compound represented by formula (I) is too low (e.g., less than 0.05%), it is not favorable for forming stable CEI and SEI. When the mass percentage of the compound represented by formula (I) is too high (e.g., more than 5%), the viscosity of the electrolyte increases, and the resistance of the formed CEI and SEI increases, which may affect the dynamic properties (e.g., rate capability) of the electrochemical device. By regulating the mass percentage of the compound shown in the formula (I) within the range, the cycle performance and the storage performance of the electrochemical device are improved, and the electrochemical device has good dynamic performance.
In some embodiments of the present application, the electrolyte further comprises a lithium-containing additive in an amount of 0.01 to 2% by mass, based on the mass of the electrolyte. The lithium-containing additive includes a boron-containing lithium salt and/or a phosphate-based lithium salt, preferably, the boron-containing lithium salt includes lithium tetrafluoroborate (LiBF) 4 ) Lithium bis (oxalato) borate (LiBOB) or lithium difluoro (oxalato) borate (LiDFOB), and the lithium phosphate salt comprises lithium difluoro (LiPO) 2 F 2 ) Lithium difluorobis (oxalato) phosphate (LiDFOP), or lithium tetrafluoro (oxalato) phosphate (LiTFOP). For example, the lithium-containing additive may be present in an amount of 0.01%, 0.05%, 0.1%, 1%, 1.5%, 2% by mass or any range therebetween. The lithium-containing additive comprises boron-containing lithium salt and/or phosphate lithium salt, and the boron-containing lithium salt or the phosphate lithium salt can form a synergistic effect with the compound shown in the formula (I) so as to improve the stability of the electrolyte and further improve the cycle performance of the electrochemical device. However, when the lithium-containing additive is contained in an excessively low amount (for example, less than 0.01%) by mass, the electrochemical performance of the electrochemical device may be affected; when the lithium-containing additive is contained in an excessively high amount by mass (for example, more than 2%), it is not favorable for the formation of a synergistic effect between the lithium-containing additive and the compound represented by formula (I) to improve the cycle performance of the electrochemical device. By selecting the lithium-containing additive and regulating the mass percentage of the lithium-containing additive to be within the range, the lithium-containing additive and the electrochemical device are enabled to have good electrochemical performance without influencing the electrochemical performance of the electrochemical deviceThe compounds shown in the formula (I) can form good synergistic effect so as to improve the cycle performance of an electrochemical device.
In some embodiments of the present application, the electrolyte further comprises a sulfur-oxygen double bond containing compound in an amount of 0.01 to 10% by mass, preferably 0.1 to 8% by mass, based on the mass of the electrolyte, and 0.01 to 10% by mass, the sulfur-oxygen double bond containing compound comprising at least one of 1,3-propane sultone, 1,4-butane sultone, methylene methanedisulfonate, 1,3-propane disulfonic anhydride, vinyl sulfate, 4-methyl vinyl sulfate, 2,4-butane sultone, 1-methyl-1,3-propane sultone, 1-fluoro-1,3-propane sultone, 2-fluoro-1,3-propane sultone, or 3-fluoro-1,3-propane sultone. For example, the content of the compound having a thiooxy double bond may be 0.01%, 0.1%, 1%, 3%, 5%, 8%, 9%, 10% by mass or any range therebetween. The inventor of the application finds that the compound containing the sulfur-oxygen double bond has good oxidation resistance, and can improve the stability of electrolyte so as to improve the cycle performance of an electrochemical device; in addition, when the negative electrode has a lithium precipitation phenomenon, a protective film can be formed on the surface of the precipitated lithium metal, so that the side reaction between the lithium metal and the electrolyte is reduced, and the cycle performance of the electrochemical device is improved. However, when the content by mass of the compound having an oxy-sulfur double bond is too low (for example, less than 0.01%), improvement in the performance of the electrochemical device is not significant; when the content of the sulfur-oxygen double bond-containing compound is too high by mass (for example, more than 10%), viscosity of the electrolyte increases, which may affect dynamic properties of the electrochemical device, such as rate capability. By regulating the mass percentage of the compound containing the sulfur-oxygen double bond within the above range, the cycle performance and the dynamic performance of the electrochemical device can be improved. The sulfur-oxygen double bond containing compound is selected to be more favorable for forming a synergistic effect with the compound shown in the formula (I) so as to improve the cycle performance of an electrochemical device.
In some embodiments of the present application, the electrolyte solution further comprises a polynitrile compound in an amount of 0.01 to 10% by mass, preferably 0.1 to 5% by mass, based on the mass of the electrolyte solution, the polynitrile compound comprising at least one of succinonitrile, adiponitrile, 1,4-dicyano-2-butene, 1,2-bis (2-cyanoethoxy) ethane, 1,3,6-hexanetricarbonitrile, 1,2,3-tris (2-cyanoethoxy) propane, tris (2-cyanoethyl) phosphine, glutaronitrile, 2-methylglutaronitrile, 2-methyleneglutaronitrile, pimelonitrile, 1,3,5-pentanedinitrile, or 4- (2-cyanoethyl) heptanedinitrile. For example, the polynitrile compound may be contained in an amount of 0.01%, 0.1%, 1%, 3%, 5%, 7%, 9%, 10% by mass or in any range therebetween. The inventors of the present invention have found that the polynitrile compound has excellent structural stability and can improve the stability of the electrolyte. And the energy level of lone pair electrons in the cyano group in the polynitrile compound is close to the energy level of a vacant orbit at the outermost layer of transition metal atoms in the anode active material, so that the polynitrile compound can form a complex structure with the anode active material on the surface of the anode, the side reaction between the electrolyte and the anode active material can be reduced, and the cycle performance and the high-temperature storage performance of an electrochemical device can be improved. However, when the mass percentage of the polynitrile compound is too low (for example, less than 0.01%), the performance of the electrochemical device is not significantly improved; when the mass percentage of the polynitrile compound is too high (e.g., more than 10%), the polynitrile compound forms too many complex structures with the positive electrode active material, which affects the transmission of lithium ions, thereby affecting the kinetic properties, such as rate performance, of the electrochemical device. By regulating the mass percentage of the polynitrile compound within the range, the cycle performance and the dynamic performance of the electrochemical device can be improved. By selecting the polynitrile compound, the polynitrile compound is more favorable for forming a synergistic effect with the compound shown in the formula (I) so as to improve the cycle performance of an electrochemical device.
In some embodiments of the present application, the electrolyte further includes a cyclic carbonate compound represented by formula (III), and the content of the cyclic carbonate compound is 0.01% to 30% by mass, preferably 0.01% to 9% by mass, based on the mass of the electrolyte:
Figure BDA0003888819670000071
wherein R is 3 Selected from substituted or unsubstituted C1 to C6 alkylene, substituted or unsubstituted C2 to C6 alkenylene; when substituted, each substituent is independently selected from a halogen atom, a C1 to C6 alkyl group, or a C2 to C6 alkenyl group.
Preferably, the cyclic carbonate compound represented by the formula (III) may be any one of the following compounds III-1 to III-8. In some embodiments herein, the electrolyte further includes at least one of the following compounds III-1 to III-8:
Figure BDA0003888819670000072
for example, the content of the cyclic carbonate compound is 0.01%, 0.1%, 1%, 5%, 10%, 15%, 20%, 25%, 30% by mass or any range therebetween. The inventors of the present application have found that the cyclic carbonate compound represented by formula (III) can improve the stability of SEI, reduce side reactions between a negative electrode active material and an electrolyte, thereby improving the cycle performance of an electrochemical device and slowing the increase of impedance. However, when the content by mass of the cyclic carbonate-based compound represented by the formula (III) is too low (for example, less than 0.01%), improvement in the performance of the electrochemical device is not significant; when the content of the cyclic carbonate compound represented by formula (III) is too high by mass (for example, higher than 30%), too much gas is generated during the oxidation and reduction reactions of the cyclic carbonate compound, which may affect the storage performance of the electrochemical device. By regulating the mass percentage of the cyclic carbonate compound shown in the formula (III) to be within the above range, the cycle performance and the storage performance of the electrochemical device are improved. By selecting the cyclic carbonate compound, a synergistic effect with the compound shown in the formula (I) is favorably formed, so that the cycle performance and the storage performance of the electrochemical device are improved. In addition, when the mass percentage of the cyclic carbonate compound in the electrolyte is greater than or equal to 10% and less than or equal to 30%, the storage performance of the electrochemical device is slightly reduced, at this time, at least one of the lithium-containing additive, the compound containing a sulfur-oxygen double bond or the polynitrile compound can be added into the electrolyte to improve the storage performance of the electrochemical device, so that the electrochemical device has good storage performance and storage performance at the same time.
In the present application, the electrolyte may further include a lithium salt, which is not particularly limited as long as the object of the present application can be achieved, for example, the lithium salt may include, but is not limited to, liPF 6 、LiAsF 6 、LiClO 4 、LiCH 3 SO 3 、LiCF 3 SO 3 、LiN(SO 2 CF 3 ) 2 、LiC(SO 2 CF 3 ) 3 Or LiSiF 6 Preferably, at least one of (1), preferably LiPF 6 。
The electrolyte provided herein may further include other non-aqueous solvents, and the other non-aqueous solvents are not particularly limited as long as the object of the present disclosure can be achieved, and may include, for example, but not limited to, at least one of a carbonate compound, a carboxylate compound, an ether compound, or other organic solvents. The carbonate compound may include, but is not limited to, at least one of a chain carbonate compound, other cyclic carbonate compounds, or a fluoro carbonate compound. The above chain carbonate compound may include, but is not limited to, at least one of dimethyl carbonate (DMC), diethyl carbonate (DEC), dipropyl carbonate (DPC), methyl Propyl Carbonate (MPC), ethyl Propyl Carbonate (EPC), or Methyl Ethyl Carbonate (MEC). The above-mentioned other cyclic carbonates may include, but are not limited to, at least one of ethylene carbonate (also referred to as ethylene carbonate, abbreviated as EC), propylene Carbonate (PC), butylene Carbonate (BC), or Vinyl Ethylene Carbonate (VEC). The fluoro carbonate compound may include, but is not limited to, at least one of fluoroethylene carbonate (also known as fluoroethylene carbonate, abbreviated as FEC), 1,2-difluoroethylene carbonate, 1,1-difluoroethylene carbonate, 1,1,2-trifluoroethylene carbonate, 1,1,2,2-tetrafluoroethylene carbonate, 1-fluoro-2-methylethylene carbonate, 1-fluoro-1-methylethylene carbonate, 1,2-difluoro-1-methylethylene carbonate, 1,1,2-trifluoro-2-methylethylene carbonate, or trifluoromethylethylene carbonate. The above carboxylic acid ester compound may include, but is not limited to, at least one of methyl formate, methyl acetate, ethyl acetate, n-propyl acetate, t-butyl acetate, methyl propionate, ethyl propionate, propyl propionate, γ -butyrolactone, decalactone, valerolactone, mevalonic lactone, or caprolactone. The above ether compound may include, but is not limited to, at least one of ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, dibutyl ether, tetrahydrofuran, 2-methyltetrahydrofuran, 1,3-dioxane, 1,4-dioxane, or 1,3-dioxolane. The other organic solvent may include, but is not limited to, at least one of ethylvinylsulfone, methylisopropylsulfone, isopropyl sec-butylsulfone, sulfolane, 1,3-dimethyl-2-imidazolidinone, N-methyl-2-pyrrolidone, formamide, dimethylformamide, acetonitrile, trimethyl phosphate, triethyl phosphate, trioctyl phosphate, or phosphate. The above-mentioned other nonaqueous solvent is contained in an amount of 5% to 80% by mass, for example, 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80% by mass or any range therebetween, based on the mass of the electrolytic solution.
A second aspect of the present application provides an electrochemical device comprising the electrolyte solution of any one of the preceding embodiments. The electrolyte provided by the application has good stability, so that the electrochemical device provided by the application has good cycle performance and storage performance.
In some embodiments of the present application, the electrochemical device further comprises a separator comprising a polyolefin substrate layer and a polymer layer and/or an inorganic layer disposed on the polyolefin substrate layer; the polymer layer comprises at least one of polyvinylidene fluoride, vinylidene fluoride-hexafluoropropylene copolymer, polyacrylonitrile, polyimide, acrylonitrile-butadiene copolymer, acrylonitrile-styrene-butadiene copolymer, polymethyl methacrylate, polymethyl acrylate, polyethyl acrylate, acrylic acid-styrene copolymer, polydimethylsiloxane, sodium polyacrylate or sodium carboxymethylcellulose; the inorganic layer comprises boehmite, mg (OH) 2 、SrTiO 3 、SnO 2 、CeO 2 、MgO、NiO、CaO、ZnO、ZrO 2 、Y 2 O 3 、Al 2 O 3 、TiO 2 Or SiC. Poly(s) are polymerizedThe arrangement of the compound layer is beneficial to improving the interface performance between the anode and the isolating membrane so as to improve the safety performance and the cycle performance of the electrochemical device; the provision of the inorganic layer can improve the heat shrinkage performance of the separator, thereby contributing to the safety performance of the electrochemical device.
The thickness of the polyolefin base material layer, the polymer layer and the inorganic layer is not particularly limited as long as the object of the present invention can be achieved, and for example, the thickness of the polyolefin base material layer is 3 μm to 30 μm, and the coating weight of the polymer layer is 0.5 mg/(5000 mm) 2 ) To 10 mg/(5000 mm) 2 ) The inorganic layer has a thickness of 2 μm to 15 μm. In the present application, the polyolefin substrate layer may have a porous structure, and the porosity of the polyolefin substrate layer is not particularly limited as long as the object of the present application is achieved, for example, the porosity of the polyolefin substrate layer is 10% to 60%. The material of the polyolefin substrate layer may include, but is not limited to, at least one of polyethylene, polypropylene, or ethylene propylene copolymer.
In the present application, the electrochemical device may further include a positive electrode, and the positive electrode generally includes a positive electrode current collector and a positive electrode material layer, and in the present application, the positive electrode current collector is not particularly limited as long as the object of the present application can be achieved, and may include, for example, but not limited to, an aluminum foil, an aluminum alloy foil, a composite current collector, or the like. In the present application, the thickness of the positive electrode current collector is not particularly limited as long as the object of the present application can be achieved, and is, for example, 8 μm to 12 μm. In the present application, the positive electrode material layer may be provided on one surface in the positive electrode current collector thickness direction, and may also be provided on both surfaces in the positive electrode current collector thickness direction. The "surface" herein may be the entire region of the positive electrode current collector or a partial region of the positive electrode current collector, and the present application is not particularly limited as long as the object of the present application can be achieved.
In the present application, the positive electrode active material is included in the positive electrode material layer, and the present application is not particularly limited as long as the object of the present application can be achieved, and may include, for example, at least one of lithium or a complex oxide, sulfide, selenide, or halide of a transition metal element. This applicationThe transition metal element is not particularly limited as long as the object of the present application can be achieved, and may include at least one of nickel, manganese, cobalt, or iron, for example. Specifically, the positive active material may include LiCoO 2 、LiNiO 2 、LiMnO 2 、LiMn 2 O 4 、Li(Ni a1 Co b1 Mn c1 )O 2 (0<a1<1，0<b1<1，0<c1<1，a1+b1+c1＝1)、LiMn 2 O 4 LiNi 1-y1 Co y1 O 2 (0<y1<1)、LiCo l-y2 Mn y2 O 2 (0<y2<1)、LiNi l-y3 Mn y3 O 2 (0<y3<1)、Li(Ni a2 Mn b2 Co c2 )O 4 (0<a2<2，0<b2<2，0<c2<2，a2+b2+c2＝2)、LiMn 2-z1 Ni z1 O 4 (0<z1<2)、LiMn 2- z2 Co z2 O 4 (0<z2<2)、Li(Ni a3 Co b3 Al c3 )O 2 (0<a3<1，0<b3<1，0<c3<1，a3+b3+c3＝1)、LiCoPO 4 Or LiFePO 4 At least one of (1).
Alternatively, the positive electrode active material has a coating layer on the surface, and the compound of the coating layer is not particularly limited as long as the object of the present application can be achieved, and for example, the compound of the coating layer may be amorphous or crystalline, and the compound of the coating layer may include, but is not limited to, at least one of an oxide of the coating element, a hydroxide of the coating element, a oxyhydroxide of the coating element, an oxycarbonate of the coating element, or an oxycarbonate of the coating element. The coating element may include, but is not limited to, at least one of Mg, al, co, K, na, ca, si, ti, V, sn, ge, ga, B, as, or Zr. The method for preparing the coating layer is not particularly limited, and a method known in the art may be used as long as the object of the present application can be achieved, for example, a spraying method or a dipping method.
The positive electrode material layer may further include a positive electrode binder, and the present application has no particular limitation as long as the object of the present application can be achieved, and may include, for example, but not limited to, at least one of polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, diacetyl cellulose, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, ethylene oxide-containing polymer, polyvinyl pyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, styrene-butadiene rubber, acrylated styrene-butadiene rubber, epoxy resin, or nylon.
In the present application, the positive electrode material layer may further include a conductive agent, and the conductive agent is not particularly limited as long as the object of the present application can be achieved, and may include, for example, but not limited to, at least one of natural graphite, artificial graphite, conductive carbon black (Super P), carbon Nanotubes (CNTs), carbon fibers, flake graphite, ketjen black, graphene, a metal material, or a conductive polymer. The carbon nanotubes may include, but are not limited to, single-walled carbon nanotubes and/or multi-walled carbon nanotubes. The carbon fibers may include, but are not limited to, vapor Grown Carbon Fibers (VGCF) and/or carbon nanofibers. The metal material may include, but is not limited to, metal powder and/or metal fiber, and specifically, the metal may include, but is not limited to, at least one of copper, nickel, aluminum, or silver. The above-mentioned conductive polymer may include, but is not limited to, at least one of polyphenylene derivatives, polyaniline, polythiophene, polyacetylene, or polypyrrole.
Optionally, the positive electrode may further include a conductive layer between the positive current collector and the positive material layer. The composition of the conductive layer is not particularly limited in the present application, and may be a conductive layer commonly used in the art, and may include, for example, but not limited to, the above-mentioned conductive agent and the above-mentioned positive electrode binder.
In the present application, the electrochemical device may further include a negative electrode, and the negative electrode generally includes a negative electrode current collector, and the present application does not particularly limit the negative electrode current collector as long as the object of the present application can be achieved, and for example, may include, but is not limited to, a copper foil, a copper alloy foil, a nickel foil, a stainless steel foil, a titanium foil, a nickel foam, a copper foam, a composite current collector, or the like. In the present application, the thickness of the current collector of the negative electrode is not particularly limited as long as the object of the present application can be achieved, and is, for example, 4 to 12 μm. In the present application, the negative electrode material layer may be provided on one surface in the thickness direction of the negative electrode current collector, and may also be provided on both surfaces in the thickness direction of the negative electrode current collector. The "surface" herein may be the entire region of the negative electrode current collector or a partial region of the negative electrode current collector, and the present application is not particularly limited as long as the object of the present application can be achieved.
In the present application, the anode material layer includes an anode active material, wherein the anode active material is not particularly limited as long as the object of the present application can be achieved, and for example, may include, but is not limited to, at least one of a material capable of reversibly intercalating/deintercalating lithium ions, lithium metal, a lithium metal alloy, a material capable of doping/dedoping lithium, or a transition metal oxide.
The material that reversibly intercalates/deintercalates lithium ions may include, but is not limited to, carbon materials including crystalline carbon and/or amorphous carbon. Crystalline carbon may include, but is not limited to, amorphous or platy, platelet-shaped, spherical, or fibrous natural graphite, synthetic graphite, pyrolytic carbon, mesophase pitch-based carbon fibers, mesophase carbon microbeads, mesophase pitch, or high temperature calcined carbon (such as petroleum or coke derived from coal tar pitch). The amorphous carbon may include, but is not limited to, at least one of soft carbon, hard carbon, mesophase pitch carbonization products, or fired coke. The lithium metal alloy includes lithium and at least one metal of Na, K, rb, cs, fr, be, mg, ca, sr, si, sb, pb, in, zn, ba, ra, ge, al, or Sn. Materials capable of doping/dedoping lithium may include, but are not limited to, si, siO x (0<x is less than or equal to 2), si/C compound, si-Q alloy (wherein, Q comprises at least one of alkali metal, alkaline earth metal, 13-16 group element, transition element and rare earth element, but is not Si), sn and SnO 2 Sn — C composite, sn — R (wherein R includes at least one of alkali metals, alkaline earth metals, group 13 to group 16 elements, transition elements, rare earth elements, but is not Sn), and the like. Q and R are each independently selected from the group consisting of Mg, ca, sr, ba, ra, sc, Y Ti, zr, hf, rf, V, nb, ta, db, cr, mo, W Sg, tc, re, bh, fe, pb, ru, os, hs, rh, ir, pd, pt, cu, ag, au, zn, cd, B, al, ga, sn, cu,At least one of In, tl, ge, P, as, sb, bi, S, se, te or Po. The transition metal oxide may include, but is not limited to, vanadium oxide and/or lithium vanadium oxide.
In the present application, the negative electrode material layer may further include a conductive agent, and the conductive agent is not particularly limited as long as the object of the present application can be achieved, and may include, for example, but is not limited to, at least one of the above-described conductive agents.
In the present application, the negative electrode material layer may further include a negative electrode binder, and the present application does not particularly limit the negative electrode binder as long as the object of the present application can be achieved, and for example, at least one of difluoroethylene-hexafluoropropylene copolymer (PVDF-co-HFP), polyvinylidene fluoride, polyacrylonitrile, polymethylmethacrylate, polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, ethylene oxide-containing polymer, polyvinyl pyrrolidone, polyurethane, polytetrafluoroethylene, polyethylene, polypropylene, styrene-butadiene rubber, acrylated styrene-butadiene rubber, epoxy resin, or nylon may be included.
Optionally, the negative electrode may further include a conductive layer between the negative electrode current collector and the negative electrode material layer. The composition of the conductive layer is not particularly limited in the present application and may be a conductive layer commonly used in the art, and the conductive layer may include, but is not limited to, the above-mentioned conductive agent and the above-mentioned negative electrode binder.
The electrochemical device of the present application is not particularly limited, and may include any device in which an electrochemical reaction occurs. In some embodiments, electrochemical devices may include, but are not limited to: a lithium metal secondary battery, a lithium ion secondary battery (lithium ion battery), a lithium polymer secondary battery, a lithium ion polymer secondary battery, or the like.
The preparation process of the electrochemical device is well known to those skilled in the art, and the present application is not particularly limited, and for example, may include, but is not limited to, the following steps: stacking the positive electrode, the isolating membrane and the negative electrode in sequence, winding and folding the positive electrode, the isolating membrane and the negative electrode according to needs to obtain an electrode assembly with a winding structure, putting the electrode assembly into a packaging bag, injecting electrolyte into the packaging bag and sealing the packaging bag to obtain the electrochemical device; or, stacking the positive electrode, the separator and the negative electrode in sequence, fixing four corners of the whole lamination structure with an adhesive tape to obtain an electrode assembly of the lamination structure, placing the electrode assembly in a packaging bag, injecting electrolyte into the packaging bag and sealing the packaging bag to obtain the electrochemical device. In addition, an overcurrent prevention element, a guide plate, or the like may be placed in the packaging bag as necessary to prevent a pressure rise or overcharge/discharge inside the electrochemical device.
A third aspect of the present application provides an electronic device comprising the electrochemical device of any one of the preceding embodiments. The electrochemical device provided by the application has good cycle performance and storage performance, so that the electronic device provided by the application has longer service life and good service performance.
The electronic device of the present application is not particularly limited, and may be any electronic device known in the art. In some embodiments, the electronic device may include, but is not limited to, a notebook computer, a pen-input computer, a mobile computer, an electronic book player, a portable phone, a portable facsimile machine, a portable copier, a portable printer, a headphone, a video recorder, a liquid crystal television, a handheld cleaner, a portable CD player, a mini-disc, a transceiver, an electronic organizer, a calculator, a memory card, a portable recorder, a radio, a backup power source, an electric motor, an automobile, a motorcycle, a power-assisted bicycle, a lighting fixture, a toy, a game machine, a clock, an electric tool, a flashlight, a camera, a large household battery, a lithium ion capacitor, and the like.
Examples
Hereinafter, embodiments of the present application will be described in more detail with reference to examples and comparative examples. Various tests and evaluations were carried out according to the following methods. Unless otherwise specified, "part" and "%" are based on mass.
The test method and the test equipment are as follows:
cycle capacity retention rate test:
the lithium ion battery was charged at 25 ℃ at 1C to 4.25V and at 4.25V to 0.05C at a constant voltage. And then discharging to 2.8V by using 4C current, namely, one cycle, and recording the capacity of the tested lithium ion battery as the first-turn capacity. And then, circularly testing for 800 circles according to the circulating steps, and recording the capacity of the tested lithium ion battery as the capacity after circulation. Cycle capacity retention = first turn capacity/capacity after cycle × 100%.
Thickness expansion rate test:
charging the lithium ion battery to 4.25V at 25 ℃ with a constant current of 0.5C, then charging at a constant voltage until the current is 0.05C, and testing the thickness of the lithium ion battery and recording the thickness as d 0 (ii) a And testing the thickness of the lithium ion battery to be d after the lithium ion battery is placed in an oven at 85 ℃ for 6h, and monitoring the thickness of the lithium ion battery in the oven in real time. Thickness expansion rate of lithium ion battery after 6h storage at 85 = (d-d) 0 )/d 0 X100%. During the test, if the thickness expansion rate of the lithium ion battery exceeds 50%, the test is stopped. The thickness expansion rate of more than 50% in tables 1 and 4 means that the test time does not reach 6h, and the thickness expansion rate of the lithium ion battery exceeds 50%.
Examples 1 to 1
< preparation of Positive electrode >
LiNi serving as a positive electrode active material 0.8 Mn 0.1 Co 0.1 O 2 Mixing acetylene black serving as a conductive agent and polyvinylidene fluoride serving as a binder according to a mass ratio of 96. And uniformly coating the positive electrode slurry on one surface of an aluminum foil of a positive electrode current collector with the thickness of 12 mu m, and drying the aluminum foil at 120 ℃ for 1h to obtain the positive electrode with the single surface coated with the positive electrode material layer. And repeating the steps on the other surface of the aluminum foil to obtain the anode with the anode material layer coated on the two surfaces. Then the anode is dried for 1h under the vacuum condition of 120 ℃ after cold pressing, cutting and cutting, the specification of 74mm multiplied by 867mm is obtained, and the compaction density of the anode is 3.50g/cm 3 。
< preparation of negative electrode >
Graphite as negative active material and binderMixing the benzene rubber and the thickener sodium carboxymethylcellulose according to a mass ratio of 97.4. And uniformly coating the negative electrode slurry on one surface of a copper foil of a negative electrode current collector with the thickness of 12 mu m, and drying the copper foil at 120 ℃ to obtain the negative electrode with the coating thickness of 130 mu m and the single surface coated with the negative electrode material layer. And repeating the steps on the other surface of the aluminum foil to obtain the cathode with the cathode material layer coated on the two surfaces. Then the mixture is dried for 1h under the vacuum condition of 120 ℃ after cold pressing, cutting into pieces and slitting, and the negative electrode with the specification of 78mm multiplied by 875mm is obtained, and the compaction density of the negative electrode is 1.80g/cm 3 。
< preparation of electrolyte solution >
At water content<In a 10ppm argon atmosphere glove box, mixing ethylene carbonate, propylene carbonate and diethyl carbonate according to a mass ratio of 3 6 And a compound I-6 shown in the formula (I) to obtain an electrolyte. Wherein the concentration of the lithium salt is 1mol/L, the mass percentage of the compound shown in the formula (I) is 0.1 percent based on the mass of the electrolyte, and the balance is the lithium salt and the organic solvent.
< preparation of separator >
Polymer layer slurry: polyvinylidene fluoride and polyacrylate are mixed according to a mass ratio of 96.
Inorganic layer slurry: alumina was mixed with polyvinylidene fluoride in a mass ratio of 90.
A porous polyethylene film (supplied by Celgard corporation) having a thickness of 5 μm and a porosity of 39% was used, and the polymer layer slurry was coated on one surface of the polyethylene film, and after the drying treatment, the inorganic layer slurry was coated on the other surface of the polyethylene film, and the separator was obtained after the drying treatment. Wherein the coating weight of the polymer layer is 2 mg/(5000 mm) 2 ) The thickness of the inorganic layer was 3 μm.
< preparation of lithium ion Battery >
And (3) stacking the prepared positive electrode, the prepared isolating membrane and the prepared negative electrode in sequence, enabling the isolating membrane to be positioned between the positive electrode and the negative electrode to play an isolating role, and winding to obtain the electrode assembly. And (3) placing the electrode assembly in an aluminum-plastic film packaging bag, drying, injecting electrolyte, and performing vacuum packaging, standing, formation, degassing, edge cutting and other processes to obtain the lithium ion battery. The upper limit voltage of the formation is 4.15V, the formation temperature is 70 ℃, and the formation standing time is 2h.
Examples 1-2 to examples 1-9
The procedure was as in example 1-1, except that the relevant production parameters were adjusted as shown in Table 1.
Example 2-1 to example 2-9
The same as in example 1-2 was repeated, except that in < preparation of electrolyte solution >, a compound containing a sulfur-oxygen double bond was further added and the relevant preparation parameters were adjusted in accordance with Table 2.
Example 3-1 to example 3-7
The procedure of example 1-2 was repeated, except that in < preparation of electrolyte solution >, polynitrile compounds were further added and the relevant preparation parameters were adjusted as shown in Table 3.
Example 4-1 to example 4-8
The same procedures as in example 1-2 were repeated, except that in < preparation of electrolyte solution >, the cyclic carbonate-based compound represented by the formula (III) was further added and the relevant preparation parameters were adjusted as shown in Table 4.
Example 5-1 to example 5-9
The procedure of example 1-2 was repeated, except that in < preparation of electrolyte solution >, a lithium-containing additive, a boron-containing lithium salt and/or a phosphate-based lithium salt was further added in accordance with table 5, and the mass percentage thereof was adjusted in accordance with table 5.
Example 6-1 to example 6-10
The procedure was as in example 1-2, except that in < preparation of electrolyte solution >, the relevant preparation parameters were adjusted as shown in Table 6.
Comparative examples 1-1 and comparative examples 1-2
The procedure was as in example 1-1, except that the relevant production parameters were adjusted as shown in Table 1.
The relevant preparation parameters and performance tests for each example and comparative example are shown in tables 1 to 6.
TABLE 1
Figure BDA0003888819670000151
Note: the "/" in table 1 indicates that no corresponding manufacturing parameters or materials are present.
As can be seen from examples 1-1 to 1-9 and comparative example 1-1, when the electrolyte includes the compound represented by formula (I), the obtained lithium ion battery has better cycle performance and storage performance. As can be seen from examples 1-1 to examples 1-6 and comparative examples 1-2, when the mass percentage of the compound represented by formula (I) is within the range of the present application, the cycle performance and the storage performance of the obtained lithium ion battery are better. As can be seen from examples 1-1 to examples 1-9, when the compound represented by formula (I) within the range of the present application is selected, the resulting lithium ion battery has good cycle performance and storage performance.
TABLE 2
Figure BDA0003888819670000152
Figure BDA0003888819670000161
Note: the "/" in table 2 indicates that no corresponding manufacturing parameters or materials are present.
It can be seen from examples 1-2 and 2-1 to 2-9 that when the electrolyte solution includes a compound represented by formula (I) and a compound containing a sulfur-oxygen double bond, the cycle performance and the storage performance of the lithium ion battery can be further improved. From example 2-1 to example 2-9, it can be seen that when the amount of the compound containing a double bond is controlled within the range of the present application, the obtained lithium ion battery has both good cycle performance and good storage performance.
TABLE 3
Figure BDA0003888819670000162
Note: the "/" in table 3 indicates that no corresponding manufacturing parameters or materials are present.
From examples 1-2 and 3-1 to 3-7, it can be seen that when the electrolyte further comprises a polynitrile compound on the basis of the compound shown in the formula (I), the cycle performance and the storage performance of the lithium ion battery can be further improved. From the examples 3-1 to 3-7, it can be seen that when the polynitrile compound in the range of the application is selected and the mass percentage of the polynitrile compound is regulated to be within the range of the application, the obtained lithium ion battery has good cycle performance and storage performance.
TABLE 4
Figure BDA0003888819670000171
Note: the "/" in table 4 indicates that no corresponding manufacturing parameters or materials are present.
It can be seen from examples 1-2 and 4-1 to 4-8 that when the electrolyte includes the compound of formula (I) and the cyclic carbonate compound of formula (III), the cycle performance and the storage performance of the lithium ion battery can be further improved. From examples 4-1 to 4-8, it can be seen that when the cyclic carbonate compound represented by formula (III) is selected and the mass percentage of the cyclic carbonate compound represented by formula (III) is adjusted to be within the range of the present application, the obtained lithium ion battery has both good cycle performance and good storage performance.
TABLE 5
Figure BDA0003888819670000172
Note: the "/" in table 5 indicates that no corresponding production parameters or materials are present.
It can be seen from examples 1-2 and 5-1 to 5 that when the electrolyte further includes a boron-containing lithium salt as a lithium-containing additive in addition to the compound of formula (I), the cycle performance and the storage performance of the lithium ion battery can be further improved. It can be seen from examples 5-1 to 5-5 that when the boron-containing lithium salt is selected and the mass percentage of the boron-containing lithium salt is controlled within the range of the present application, the obtained lithium ion battery has both good cycle performance and good storage performance. It can be seen from examples 1-2 and 5-6 to 5-8 that when the electrolyte includes a lithium-containing additive, namely a phosphate lithium salt, on the basis of the compound of formula (I), the cycle performance and the storage performance of the lithium ion battery can be further improved. From examples 5-6 to 5-8, it can be seen that when the phosphate lithium salt in the range of the present application is selected and the mass percentage of the phosphate lithium salt is controlled to be in the range of the present application, the obtained lithium ion battery has good cycle performance and storage performance. From examples 5 to 9, it can be seen that the boron-containing lithium salt and the phosphate lithium salt have good superposability, and the obtained lithium ion battery has good cycle performance and storage performance.
TABLE 6
Figure BDA0003888819670000181
Note: the "/" in table 6 indicates that no corresponding production parameters or materials are present.
As can be seen from examples 1-2 and 6-1 to 6-10, when the electrolyte solution includes at least two of a compound having a double sulfur-oxygen bond, a polynitrile compound, a cyclic carbonate compound represented by formula (III), a boron-containing lithium salt, and a phosphate lithium salt in addition to the compound represented by formula (I), the cycle performance and the storage performance of the lithium ion battery can be further improved. It can be seen from examples 6-1 to 6-10 that the compound represented by formula (I) has good compatibility and superposability with the compound containing a double bond of sulfur and oxygen, the polynitrile compound, the cyclic carbonate compound represented by formula (III), the boron-containing lithium salt, and the phosphate lithium salt, and the lithium ion battery obtained by using the compound in combination has good cycle performance and storage performance.
The above description is only exemplary of the present application and should not be taken as limiting the present application, as any modification, equivalent replacement, or improvement made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims (11)

1. An electrolyte comprising a compound represented by the formula (I) in an amount of 0.05 to 5% by mass, based on the mass of the electrolyte:
Figure FDA0003888819660000011
wherein, the first and the second end of the pipe are connected with each other,
R 1 selected from the group consisting of hydrogen, substituted or unsubstituted C1 to C10 alkyl, substituted or unsubstituted C2 to C10 alkenyl, substituted or unsubstituted C2 to C10 alkynyl, substituted or unsubstituted C6 to C10 aryl, substituted or unsubstituted C2 to C10 heteroaryl, substituted or unsubstituted C3 to C10 alicyclic hydrocarbon, substituted or unsubstituted C1 to C10 heterocyclic, substituted or unsubstituted heteroatom-containing functional group; when substituted, each substituent is independently selected from a halogen atom, a C1 to C3 alkyl group, a C2 to C3 alkenyl group or a C2 to C3 alkynyl group; the heteroatoms in the heteroaryl and the heterocyclic radical are respectively and independently selected from B, N, O, si, P or S, and the functional group containing the heteroatoms is selected from at least one of a sulfur-oxygen double bond-containing functional group or a P-O-containing functional group;
R 11 and R 12 Each independently selected from a substituted or unsubstituted C1 to C10 alkylene group, a substituted or unsubstituted C2 to C10 alkenylene group, and when substituted, each independently selected from a halogen atom, a C1 to C3 alkyl group, a C2 to C4 alkenyl group, or a C2 to C4 alkynyl group.
2. The electrolyte of claim 1, comprising at least one of the following compounds I-1 to I-15:
Figure FDA0003888819660000012
3. the electrolyte of claim 1, further comprising a lithium-containing additive in an amount of 0.01 to 2% by mass based on the mass of the electrolyte, the lithium-containing additive comprising a boron-containing lithium salt and/or a phosphate-based lithium salt.
4. The electrolyte of claim 3, wherein the boron-containing lithium salt comprises at least one of lithium tetrafluoroborate, lithium dioxalate borate, or lithium difluorooxalate borate, and the phosphate lithium salt comprises at least one of lithium difluorophosphate, lithium difluorobis-oxalate phosphate, or lithium tetrafluorooxalate phosphate.
5. The electrolyte of claim 1, further comprising an oxysulfide double bond-containing compound in an amount of 0.01 to 10% by mass based on the mass of the electrolyte, the oxysulfide double bond-containing compound comprising at least one of 1,3-propanesultone, 1,4-butanesultone, methylene methanedisulfonate, 1,3-propanedisulfonic anhydride, vinyl sulfate, 4-methyl vinyl sulfate, 2,4-butanesultone, 1-methyl-1,3-propanesultone, 2-fluoro-1,3-propanesultone, or 3-fluoro-1,3-propanesultone.
6. The electrolyte of claim 1, further comprising a polynitrile compound in an amount of 0.01 to 10% by mass based on the mass of the electrolyte, the polynitrile compound comprising at least one of succinonitrile, adiponitrile, 1,4-dicyano-2-butene, 1,2-bis (2-cyanoethoxy) ethane, 1,3,6-hexanetrinitrile, 1,2,3-tris (2-cyanoethoxy) propane, tris (2-cyanoethyl) phosphine, glutaronitrile, 2-methylglutaronitrile, 2-methyleneglutaronitrile, pimelonitrile, 1,3,5-pentanedinitrile, or 4- (2-cyanoethyl) heptanedinitrile.
7. The electrolyte according to claim 1, further comprising a cyclic carbonate compound represented by formula (III) in an amount of 0.01 to 30% by mass, based on the mass of the electrolyte:
Figure FDA0003888819660000021
wherein R is 3 Selected from substituted or unsubstituted C1 to C6 alkylene, substituted or unsubstituted C2 to C6 alkenylene; when substituted, each substituent is independently selected from a halogen atom, a C1 to C6 alkyl group, or a C2 to C6 alkenyl group.
8. The electrolyte of claim 7, further comprising at least one of the following compounds III-1 to III-8:
Figure FDA0003888819660000022
9. an electrochemical device comprising the electrolyte of any one of claims 1 to 8.
10. The electrochemical device of claim 9, further comprising a separator comprising a polyolefin substrate layer and a polymer layer and/or an inorganic layer disposed on the polyolefin substrate layer;
the polymer layer comprises at least one of polyvinylidene fluoride, vinylidene fluoride-hexafluoropropylene copolymer, polyacrylonitrile, polyimide, acrylonitrile-butadiene copolymer, acrylonitrile-styrene-butadiene copolymer, polymethyl methacrylate, polymethyl acrylate, polyethyl acrylate, acrylic acid-styrene copolymer, polydimethylsiloxane, sodium polyacrylate or sodium carboxymethylcellulose;
the inorganic layer comprises boehmite, mg (OH) 2 、SrTiO 3 、SnO 2 、CeO 2 、MgO、NiO、CaO、ZnO、ZrO 2 、Y 2 O 3 、Al 2 O 3 、TiO 2 Or SiC.
11. An electronic device comprising the electrochemical device of claim 9 or 10.
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Cited By (1)

* Cited by examiner, † Cited by third party
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Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001015156A (en) * 1999-06-30 2001-01-19 Sony Corp Nonaqueous electrolyte battery
JP2012018860A (en) * 2010-07-09 2012-01-26 Konica Minolta Holdings Inc Electrolyte composition, secondary battery and method for manufacturing secondary battery
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CN112349961B (en) * 2020-11-12 2021-09-24 宁德新能源科技有限公司 Electrolyte solution, electrochemical device and electronic apparatus including the same

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115954547A (en) * 2023-03-14 2023-04-11 宁德新能源科技有限公司 Electrolyte, electrochemical device and electronic device

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