KR20210081303A - Electrolytes and electrochemical devices - Google Patents

Abstract

The present application relates to an electrolytic solution and an electrochemical device and an electronic device including the electrolytic solution. The electrolyte solution includes fluoroethylene carbonate and a silicate compound, and optionally further includes at least one of a cyclic carboxylic acid anhydride compound and a disulfonate compound. The electrolyte may optionally further include at least one of an unsaturated cyclic carbonate, a cyclic sultone, a cyclic sulfate lactone, or a nitrile compound. The electrolyte of the present invention can significantly improve battery cycle life and rate discharge performance.

Description

Electrolytes and electrochemical devices

This application claims priority to the Chinese patent application filed on December 20, 2019 with application number CN201911327801.8, the contents of which are incorporated herein in their entirety.

technical field

The present application relates to the field of energy storage technology, and more particularly, to an electrolyte solution, an electrochemical device including the electrolyte solution, and an electronic device including the electrochemical device.

Lithium-ion battery is a next-generation green eco-friendly battery developed since the 1990s. Due to its high operating voltage, high specific capacity, long cycle life, eco-friendliness, and no memory effect, it is widely used in new energy electric vehicles, information and communication electronic products, portable electronic equipment, It is widely applied in fields such as power tools, energy storage, military industry, and aerospace. However, as the application range of lithium-ion batteries continues to expand and the latest information technology continues to develop, people's requirements for battery energy density and safety performance of lithium-ion batteries have increased.

The development of high-voltage lithium-ion batteries is one of the effective means of improving the energy density of lithium-ion batteries. Under high voltage and high temperature conditions, the oxidation activity of the positive electrode material increases and the stability thereof decreases, so that in the conventional electrolyte, oxidation and decomposition are accelerated on the surface of the positive electrode to generate gas. In addition, transition metal elements (e.g., nickel, cobalt, manganese, etc.) in the positive electrode active material (especially manganese material) may be precipitated on the negative electrode after the charge/discharge process due to accelerated elution, which causes the solid electrolyte membrane (SEI) to be destroyed. As a result, the electrolyte is reduced and decomposed at the negative electrode and the electrochemical performance of the lithium-ion battery may be further deteriorated. It is urgent to find a way to further improve the high-temperature storage and cycling performance of lithium-ion batteries.

The present application provides an electrolyte, an electrochemical device including the electrolyte, and an electronic device including the electrochemical device, wherein the electrolyte includes fluoroethylene carbonate and a silicate compound. The addition of fluoroethylene carbonate and silicate compounds in a certain proportion to the electrolyte is advantageous to form a stable interfacial protective layer on the surfaces of the positive and negative electrodes, so that the cycle life and high temperature storage performance of the lithium ion battery are remarkably improved.

In some embodiments, the present application provides an electrolyte comprising fluoroethylene carbonate and a silicate compound.

In some embodiments, the structure of the silicate compound in the electrolyte is as shown in Formula I.

wherein R ₁ , R ₂ , R ₃ and R ₄ are each independently selected from a substituted or unsubstituted C ₁ to C ₁₀ hydrocarbon group, wherein the substituent when substituted is a halogen, wherein the silicate The mass ratio of the compound and the fluoroethylene carbonate is 1:1 to 1:10.

In some embodiments, the structure of the silicate compound in the electrolyte includes at least one of the following compounds.

,

또는

.

,

or

.

In some embodiments, the content of the silicate compound in the electrolyte is about 0.1 wt% to about 5 wt% of the total weight of the electrolyte.

In some embodiments, the electrolyte solution further comprises a cyclic carboxylic anhydride compound, wherein the cyclic carboxylic acid anhydride compound comprises at least one of the structures of Formula II, Formula III, or Formula IV have

,

,

,

,

wherein R ₅ , R ₆ , R ₇ , R ₈ , R ₉ , R ₁₀ and R ₁₁ are each independently selected from hydrogen, halogen and a substituted or unsubstituted C ₁ to C ₁₀ hydrocarbon group, wherein the substituted When the substituent is halogen.

In some embodiments, the content of the cyclic carboxylic acid anhydride in the electrolyte is about 0.1 wt% to about 5 wt% of the total weight of the electrolyte.

In some embodiments, the cyclic carboxylic acid anhydride in the electrolyte is maleic anhydride, succinic anhydride, 2-methylsuccinic anhydride, 2,3-dimethylsuccinic acid at least one of 2,3-dimethylsuccinic anhydride and glutaric anhydride.

In some embodiments, the electrolyte further comprises a disulfonate compound having the formula (V).

Here, n is an integer from 1 to 4.

In some embodiments, the content of the disulfonate compound in the electrolyte is about 0.1 wt% to about 5 wt% of the total weight of the electrolyte.

In some embodiments, the disulfonate compound is selected from methylene methanedisulfonate.

In some embodiments, the electrolyte solution is LiPO ₂ F ₂ , unsaturated cyclic carbonate (carbonate), cyclic sultone (sultone), cyclic sulfate lactone (sulfate lactone) or at least one additive of a nitrile (nitrile) compound include more The content of the additive is about 0.001 wt% to about 13 wt% of the total weight of the electrolyte.

Here, the _{content of LiPO 2} F ₂ is about 0.001 wt% to about 2 wt% of the total weight of the electrolyte.

The unsaturated cyclic carbonate includes at least one of vinylene carbonate or vinylethylene carbonate, and the content of the unsaturated cyclic carbonate is about 0.001 wt% to about 2 wt% of the total weight of the electrolyte.

The cyclic sultone is 1,3-propane sultone, 1,4-butane sultone, or 1,3-propene sultone. Including at least one of, the content of the cyclic sultone is about 0.01wt% to about 3wt% of the total weight of the electrolyte.

The cyclic sulfate lactone includes at least one of ethylene sulfate, propylene sulfate, and propane 1,2-cyclic sulfate. The content of the cyclic sulfate lactone is 0.01 wt% to 3 wt% of the total weight of the electrolyte solution.

The nitrile compound is succinonitrile (succinonitrile), glutaronitrile (glutaronitrile), adiponitrile (adiponitrile), 2-methylene glutaronitrile (2-methyleneglutaronitrile), 2-propyl malononitrile (2-propylmalononitrile), 1 ,3,6-hexanetricarbonitrile (1,3,6-hexanetricarbonitrile), 1,2,6-hexanetricarbonitrile, 1,3,5-pentanetricarbonitrile (1,3,5-pentanetricarbonitrile) or at least one of 1,2-bis(cyanoethoxy)ethane, wherein the content of the nitrile compound is about 0.5wt% to about 7wt% of the total weight of the electrolyte .

In some embodiments, the present application provides an electrochemical device including any one of the electrolytes.

In some embodiments, the present application provides an electronic device including the electrochemical device.

Additional aspects and advantages of the embodiments of the present application are hereinafter partially described, illustrated, or elucidated through practice of the embodiments of the present application.

Examples of the present application will be described in detail below. The examples of the present application should not be construed as limiting the present application.

As used herein, the terms “approximately,” “substantially,” “substantially,” and “about” are intended to describe and describe small variations. When used in conjunction with an event or circumstance, the term may refer to an example in which the event or circumstance occurs precisely and an example in which the event or circumstance occurs very closely. For example, when used in conjunction with a numerical value, the term may mean a range of variation of ±10% or less of the numerical value, for example, ±5% or less, ±4% or less, ±3% or less, ±2 % or less, ±1% or less, ±0.5% or less, ±0.1% or less, or ±0.05% or less. For example, if the difference between two values is ±10% or less of the mean of the values (e.g., ±5% or less, ±4% or less, ±3% or less, ±2% or less, ±1% or less, ±0.5 % or less, ±0.1% or less, or ±0.05% or less), the two values can be considered "substantially" equal.

Also, quantities, ratios, and other numerical values are sometimes referred to herein in the form of ranges. This range format is for descriptive convenience and brevity, and includes not only numbers limited to the explicitly specified ranges, but also every individual number or subrange within that range, which explicitly states each number and subrange. It should be understood as flexible as specifying.

A list of items linked by the terms “at least one of”, “at least one of”, “at least one kind of” or other similar terms in specific embodiments and claims may mean any combination of the listed items. For example, where items A and B are listed, the phrases "at least one of A and B" and "at least one of A or B" mean A only, B only, or A and B. In another example, where items A, B and C are listed, the phrases "at least one of A, B and C" and "at least one of A, B or C" refer to A only, B only, C only, A and B (excluding C), A and C (excluding B), B and C (excluding A), or all of A, B and C. Item A may contain a single component or multiple components. Item B may contain a single component or multiple components. Item C may contain a single component or multiple components.

As used herein, the term “hydrocarbon group” includes alkyl, alkenyl and alkynyl. For example, a hydrocarbon group is expected to be a straight chain hydrocarbon structure having 1 to 20 carbon atoms. A “hydrocarbon group” is expected to be a branched chain or cyclic hydrocarbon structure having 3 to 10 carbon atoms. When designating a hydrocarbon group having a specific number of carbons, it is expected to include all geometric isomers having that number of carbons. The hydrocarbon group herein may be a hydrocarbon group of 1 to 8 carbon atoms, a hydrocarbon group of 1 to 6 carbon atoms, or a hydrocarbon group of 1 to 4 carbon atoms. The hydrocarbon group may also be optionally substituted. For example, the hydrocarbon group may be substituted with halogen or alkyl including fluorine, chlorine, bromine and iodine.

The term “alkyl” is expected to be a straight chain saturated hydrocarbon structure having from 1 to 10 carbon atoms. "Alkyl" is expected to be a branched chain or cyclic hydrocarbon structure having 3 to 10 carbon atoms. For example, alkyl may be alkyl of 1 to 8 carbon atoms, alkyl of 1 to 6 carbon atoms, alkyl of 1 to 4 carbon atoms. When designating an alkyl having a specific number of carbons, it is expected to include all geometric isomers having that number of carbons. Thus, for example, "butyl" includes n-butyl, sec-butyl, isobutyl, tert-butyl and cyclobutyl, and "propyl" includes n-propyl, isobutyl propyl (isopropyl) and cyclopropyl (cyclopropyl). Examples of alkyl include methyl (methyl), ethyl (ethyl), n-propyl, isopropyl, cyclopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, cyclobutyl, n-pentyl (n -pentyl), isopentyl, neopentyl, cyclopentyl, methylcyclopentyl, ethylcyclopentyl, n-hexyl, isohexyl , cyclohexyl, n-heptyl, octyl, cyclopropyl, cyclobutyl, norbornyl, and the like. Alkyl may also be optionally substituted.

The term "alkenyl" means a monovalent unsaturated hydrocarbon group that is straight or branched and has at least one usually 1, 2 or 3 carbon-carbon double bonds. Unless otherwise defined, the alkenyl typically contains 2 to 10 carbon atoms, for example alkenyl having 6 to 10 carbon atoms, alkenyl having 2 to 8 carbon atoms or alkenyl having 2 to 6 carbon atoms. It could be Neil. Representative alkenyls include (eg) vinyl, n-propenyl, isopropenyl, n-but-2-enyl, but- 3-enyl (but-3-enyl), n-hex-3-enyl (n-hex-3-enyl), and the like. Alkenyl may also be optionally substituted.

The term “alkynyl” means a monovalent unsaturated hydrocarbon group that is straight or branched and has at least one usually 1, 2 or 3 carbon-carbon triple bonds. Unless otherwise defined, said alkynyl typically contains 2 to 10 carbon atoms, for example alkynyl having 6 to 10 carbon atoms, alkynyl having 2 to 8 carbon atoms or 2 to carbon atoms 6 individual alkynyl. Representative alkynyls are (eg) ethynyl, prop-2-ynyl (n-propynyl), n-but-2-ynyl (n- but-2-ynyl), n-hex-3-ynyl, and the like. Also alkynyl may be optionally substituted

As used herein, the term “halogen” may be F, Cl, Br or I.

一. electrolyte

The present application provides an electrolyte, wherein the electrolyte includes fluoroethylene carbonate (FEC) and a silicate compound.

In some embodiments, the structure of the silicate compound is as shown in Formula I.

wherein R ₁ , R ₂ , R ₃ and R ₄ are each independently a substituted or unsubstituted C ₁ -C ₁₀ hydrocarbon group, a substituted or unsubstituted C ₁ -C ₆ hydrocarbon group, or a substituted or unsubstituted C ₁ to C ₄ hydrocarbon groups, wherein the substituent when substituted is halogen. In some embodiments, R ₁ , R ₂ , R _{3 ,} and R ₄ are each independently selected from substituted or unsubstituted C ₁ -C ₄ alkyl, wherein the substituent when substituted is halogen. In some other embodiments, R ₁ , R ₂ , R ₃ and R ₄ are each independently selected from methyl, ethyl, or propyl.

In some embodiments, the silicate compound of Formula I in the electrolyte is selected from at least one of the following compounds 1 to 3.

,

,

,

,

In some embodiments, the silicate compound of Formula I is tetraethyl orthosilicate (Compound 1).

In some embodiments, the mass ratio of the silicate compound and the fluoroethylene carbonate (FEC) is from about 1:1 to about 1:10. In some embodiments, the mass ratio of the silicate compound to the fluoroethylene carbonate (FEC) is from about 1:2 to about 1:6, and in some embodiments, the silicate compound and the fluoroethylene carbonate (FEC) are The mass ratio is from about 1:3 to about 1:5. In some embodiments, the mass ratio is about 1:2, about 1:3, about 1:4, about 1:5, about 1:6, or about 1:7. When a silicate compound and fluoroethylene carbonate are added to the electrolyte, both can stabilize the electrolyte within the above-mentioned range, and at the same time, a dense protective layer is formed on the surface of the anode to improve the cycle performance and rate capability of the battery. do.

In some embodiments, the content of the silicate compound is about 0.1 wt% to about 5 wt% of the total weight of the electrolyte solution. In some embodiments, the content of the silicate compound is about 0.5 wt% to about 4 wt% of the total weight of the electrolyte solution. In some embodiments, the content of the silicate compound is about 1 wt% to about 3 wt% of the total weight of the electrolyte solution. In some embodiments, the content of the silicate compound is about 1.5 wt% to about 2 wt% of the total weight of the electrolyte solution. In some embodiments, the content of the silicate compound is about 0.5wt%, about 1wt%, about 1.5wt%, about 2wt%, about 2.5wt%, about 3wt%, about 3.5wt% or about the total weight of the electrolyte solution. 4 wt%. If the content is less than 0.1wt%, stability improvement for the electrolyte is limited, and if it exceeds 5wt%, the film of the anode is formed too thickly ^{, affecting Li +} transport, and cell impedance and circulation performance are reduced.

In some embodiments, the electrolyte solution further comprises a cyclic carboxylic acid anhydride compound, wherein the cyclic carboxylic acid anhydride compound has at least one of the following structures: Formula II, Formula III, or Formula IV.

,

,

,

,

wherein R ₅ , R ₆ , R ₇ , R ₈ , R ₉ , R ₁₀ and R ₁₁ are each independently hydrogen, halogen, a substituted or unsubstituted C ₁ to C ₁₀ hydrocarbon group, a substituted or unsubstituted C ₁ -C ₆ hydrocarbon group, or a substituted or unsubstituted C ₁ -C ₄ hydrocarbon group, wherein the substituent when substituted is halogen. In some embodiments, R ₅ , R ₆ , R ₇ , R ₈ , R ₉ , R ₁₀ and R ₁₁ are each independently selected from substituted or unsubstituted C ₁ -C ₄ alkyl, wherein when substituted The substituent is halogen. In some other embodiments, each of R ₅ , R ₆ , R ₇ , R ₈ , R ₉ , R ₁₀ and R ₁₁ is independently selected from hydrogen or methyl.

In some embodiments, the cyclic carboxylic acid anhydride comprises at least one of maleic anhydride, succinic anhydride, 2-methylsuccinic anhydride, 2,3-dimethylsuccinic anhydride, or glutaric anhydride.

In some embodiments, the content of the cyclic carboxylic acid anhydride accounts for about 0.1 wt% to about 5 wt% of the total weight of the electrolyte solution. In some embodiments, the content of the cyclic carboxylic acid anhydride accounts for about 0.5 wt% to about 4 wt% of the total weight of the electrolyte solution. In some embodiments, the content of the cyclic carboxylic acid anhydride accounts for about 1 wt% to about 3 wt% of the total weight of the electrolyte solution. In some embodiments, the content of the cyclic carboxylic acid anhydride accounts for about 1.5 wt% to about 2 wt% of the total weight of the electrolyte solution. In some embodiments, the cyclic carboxylic acid anhydride is about 0.5 wt%, about 1 wt%, about 1.5 wt%, about 2 wt%, about 2.5 wt%, about 3 wt%, about 3.5 wt% of the total weight of the electrolyte solution. or about 4 wt%. When the cyclic carboxylic acid anhydride is added to the electrolyte solution, a dense SEI film is more preferably formed on the cathode by reduction due to the relatively high reduction potential of the cyclic carboxylic acid anhydride, and furthermore, a silicate compound and FEC formed by The SEI is modified to ^{facilitate Li +} transit, further improving battery rate and cycling performance. If the content of the cyclic carboxylic acid anhydride is too low, the negative electrode interface cannot be sufficiently stably protected, and thus the effect of improving circulation performance cannot be realized. In addition, if the content of the cyclic carboxylic acid anhydride is too high, the membrane may become too thick, which may result in a decrease in battery capacity and an increase in battery impedance.

In some embodiments, in the electrolyte, it further comprises a disulfonate compound having the formula (V).

, 여기에서 n은 1 내지 4의 정수이다.

, where n is an integer from 1 to 4.

In some embodiments, the disulfonate compound is selected from methylene methanedisulfonate (MMDS).

In some embodiments, the content of the disulfonate compound accounts for about 0.1 wt% to about 5 wt% of the total weight of the electrolyte solution. In some embodiments, the content of the disulfonate compound accounts for about 0.5 wt% to about 4 wt% of the total weight of the electrolyte solution. In some embodiments, the content of the disulfonate compound accounts for about 1 wt% to about 3 wt% of the total weight of the electrolyte solution. In some embodiments, the content of the disulfonate compound accounts for about 1.5 wt% to about 2 wt% of the total weight of the electrolyte solution. In some embodiments, the disulfonate compound is about 0.5 wt %, about 1 wt %, about 1.5 wt %, about 2 wt %, about 2.5 wt %, about 3 wt %, about 3.5 wt %, or about the total weight of the electrolyte solution. It accounts for 4 wt%. When the disulfonate is added to the electrolyte, an SEI film with excellent stability may be formed on the positive electrode, which further inhibits the elution of transition metals in the positive electrode material and reduces direct contact with the electrolyte, thereby improving the rate performance and circulation performance of the battery. further improve

In some embodiments, the electrolyte solution further includes at least one additive of an unsaturated cyclic carbonate, a cyclic sultone, a cyclic sulfate lactone, a nitrile compound, or LiPO ₂ F _{2 .} In some embodiments, the unsaturated cyclic carbonate comprises at least one of vinylene carbonate (VC) or vinylethylene carbonate (VEC), and the cyclic sultone is 1,3-propane sultone (PS), 1,4 - at least one of butane sultone (BS) or 1,3-propene sultone (PST), wherein the cyclic sulfate lactone is ethylene sulfate (DTD), propylene sulfate or propane 1,2-cyclic sulfone and at least one of the nitrile compounds, wherein the nitrile compound is succinonitrile (SN), glutaronitrile, adiponitrile, 2-methyleneglutaronitrile, 2-propylmalononitrile, 1,3,6-hexanetricarbo at least one of nitrile, 1,2,6-hexanetricarbonitrile, 1,3,5-pentanetricarbonitrile, or 1,2-bis(cyanoethoxy)ethane.

In some embodiments, the content of the additive accounts for about 0.1 wt% to about 13 wt% of the total weight of the electrolyte solution, and in some embodiments, the content of the additive is about 0.5 wt% to about 10 wt% of the total weight of the electrolyte solution %, and in some embodiments, the content of the additive comprises about 0.5 wt% to about 8 wt% of the total weight of the electrolyte, and in some embodiments, the content of the additive is about 1 wt% of the total weight of the electrolyte to about 7 wt%, and in some embodiments, the content of the additive accounts for about 1.5 wt% to about 6 wt% of the total weight of the electrolyte. In some embodiments, the additive is about 0.5 wt%, about 1 wt%, about 1.5 wt%, about 2 wt%, about 2.5 wt%, about 3 wt%, about 3.5 wt%, about 4 wt%, about 4.5wt%, about 5wt%, about 5.5wt%, about 6wt%, about 6.5wt%, about 7wt%, about 7.5wt%, about 8wt%, about 8.5wt%, about 9wt% or about 9.5wt% occupy

In some embodiments, the _{content of LiPO 2} F ₂ occupies about 0.1 wt% to about 2 wt% of the total weight of the electrolyte, and in some embodiments, the _{content of LiPO 2} F ₂ is about the total weight of the electrolyte. Occupies 0.1wt% to about 1wt%, and in some embodiments, the _{content of LiPO 2} F ₂ accounts for about 0.1wt% to about 0.6wt% of the total weight of the electrolyte.

In some embodiments, the content of the unsaturated cyclic carbonate accounts for about 0.01 wt% to about 2 wt% of the total weight of the electrolyte, and in some embodiments, the content of the unsaturated cyclic carbonate is about the total weight of the electrolyte Occupies 0.01wt% to about 1.5wt%, and in some embodiments, the content of the unsaturated cyclic carbonate accounts for about 0.01wt% to about 1wt% of the total weight of the electrolyte.

In some embodiments, the content of the cyclic sultone accounts for about 0.01 wt % to about 3 wt % of the total weight of the electrolyte, and in some embodiments, the content of the cyclic sultone is about 0.1 wt % of the total weight of the electrolyte % to about 2 wt%, and in some embodiments, the content of the cyclic sultone accounts for about 0.5 wt% to about 1.5 wt% of the total weight of the electrolyte;

In some embodiments, the content of the cyclic sulfate lactone occupies about 0.01 wt% to about 3 wt% of the total weight of the electrolyte, and in some embodiments, the content of the cyclic sulfate lactone is the total weight of the electrolyte accounts for about 0.1 wt% to about 2 wt%, and in some embodiments, the content of the cyclic sulfate lactone accounts for about 0.5 wt% to about 1.5 wt% of the total weight of the electrolyte.

In some embodiments, the content of the nitrile compound is about 0.5wt% to about 7wt% of the total weight of the electrolyte, and in some embodiments, the content of the nitrile compound is about 0.5wt% to about the total weight of the electrolyte 5wt%, and in some embodiments, the content of the nitrile compound is about 0.5wt% to about 3wt% of the total weight of the electrolyte, and in some embodiments, the content of the nitrile compound is about 1wt of the total weight of the electrolyte % to about 2 wt%.

In some embodiments, the electrolyte further includes an organic solvent and a lithium salt.

In some embodiments, the organic solvent comprises a cyclic ester and a chain ester, the mass ratio of the cyclic ester to the chain ester is from about 1:9 to about 7:3, and the cyclic ester is ethylene carbonate ( EC), propylene carbonate (PC), γ-butyrolactone (BL), ethylene carbonate or propylene carbonate substituted with a fluorine-containing group. The chain ester is dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), ethyl acetate (EA), methyl formate (MF), ethyl formate (MA), ethyl propionate ( EP), propyl propionate (PP), methyl butyrate (MB), fluorinated ethyl methyl carbonate, fluorinated ethyl propionate, and the like. In some embodiments, the content of the organic solvent is about 60 wt% to about 95 wt% of the total weight of the electrolyte, and in some embodiments, the content of the organic solvent is about 60 wt% to about 90 wt% of the total weight of the electrolyte solution to be. In some embodiments, the content of the organic solvent is about 70 wt% to about 85 wt% of the total weight of the electrolyte solution.

In some embodiments, the lithium salt is at least one of an organic lithium salt or an inorganic lithium salt. In some embodiments, the lithium salt includes at least one of elemental fluorine, elemental boron, and elemental phosphorus. In some embodiments, the lithium salt is lithium hexafluorophosphate (LiPF ₆ ), lithium difluorophosphate (lithium difluorophosphate), lithium bis (trifluoromethanesulfonyl) imide (lithium bis (trifluoromethanesulphonyl) )imide, LiN(CF ₃ SO ₂ ) ₂ ), lithium bis(fluorosulfonyl)imide, Li(N(SO ₂ F) ₂ ), lithium bis(oxalate)borate ( lithium bis(oxalate)borate), LiB(C ₂ O ₄ ) ₂ ), lithium difluoro(oxalato)borate, LiBF ₂ (C ₂ O ₄ )), lithium hexafluoroar at least one selected from senate (lithium hexafluoroarsenate, LiAsF ₆ ), lithium perchlorate (LiClO ₄ ), and lithium trifluoromethanesulfonate (LiCF ₃ SO _{3 ).} In some embodiments, the lithium salt may be lithium hexafluorophosphate. In some embodiments, the concentration of the lithium salt is about 0.5 mol/L to about 1.8 mol/L. In some embodiments, the concentration of the lithium salt is about 0.8 mol/L to about 1.5 mol/L. In some embodiments, the concentration of the lithium salt is about 0.8 mol/L to about 1 mol/L.

二. electrochemical device

The electrochemical device of the present application may include any device that causes an electrochemical reaction, and specific examples thereof include all kinds of primary cells, secondary cells, fuel cells, solar cells, or capacitors. In particular, the electrochemical device is a lithium secondary battery, which includes a lithium metal secondary battery, a lithium ion secondary battery, a lithium polymer secondary battery or a lithium ion polymer secondary battery. In some embodiments, the electrochemical device of the present application includes a positive electrode having a positive electrode active material capable of absorbing and emitting metal ions; a negative electrode having an anode active material capable of absorbing and releasing metal ions; a separator positioned between the anode and the cathode; and the electrolyte of the present application.

electrolyte

The electrolyte solution used in the electrochemical device of the present application is any of the above electrolyte solutions of the present application. In addition, the electrolyte used in the electrochemical device of the present application may further include other electrolytes within the scope not departing from the gist of the present application.

anode

The material of the anode used in the electrochemical device of the present application may be prepared using materials, structures, and manufacturing methods known in the art. In some embodiments, the techniques described in US9812739B may be used to manufacture the positive electrode of the present application, which is incorporated herein by reference in its entirety.

In some embodiments, the positive electrode includes a current collector and a positive electrode active material layer disposed on the current collector. The positive electrode active material includes at least one lithiated interlayer compound for reversibly intercalating and deintercalating lithium ions. In some embodiments, the positive active material includes a composite oxide. In some embodiments, the composite oxide includes lithium and at least one element selected from cobalt, manganese and nickel.

In some embodiments, the positive active material is a lithium nickel cobalt manganese (NCM) ternary material, lithium iron phosphate (LiFePO ₄ ), LiCoO ₂ , LiNiO ₂ , LiMn ₂ O ₄ , LiCo _1-y M _y O ₂ , LiNi _{1- y} M _y O ₂ , LiMn _2-y M _y O ₄ , LiNi _x Co _y Mn _z M _1-xyz O ₂ , wherein M is Fe, Co, Ni, Mn, Mg, Cu, Zn, Al , Sn, B, Ga, Cr, Sr, V, Ti selected from one or more, 0≤y≤1, 0≤x≤1, 0≤z≤1, x+y+z≤1 or any thereof It is a combination.

In some embodiments, the positive electrode active material may have a coating layer on its surface, or may be mixed with other compounds having a coating layer. The coating layer may include at least one coating element compound selected from an oxide of a coating element, a hydroxide of a coating element, an oxyhydroxide of a coating element, an oxycarbonate of a coating element, and a hydroxycarbonate of a coating element. . The compound used for the coating layer may be amorphous or crystalline.

In some embodiments, the coating element included in the coating layer is Mg, Al, Co, K, Na, Ca, Si, Ti, V, Sn, Ge, Ga, B, As, Zr, P, or any combination thereof. may include In some embodiments, the coating of the coating layer may be at least one of AlPO ₄ , Mg ₃ (PO ₄ ) ₂ , Co ₃ (PO ₄ ) ₂ , AlF ₃ , MgF ₂ , CoF ₃ , NaF, and B ₂ O ₃ . . In some embodiments, based on the total weight of the positive active material, the content of the coating element in the coating layer is about 0.01 wt% to about 10 wt%. As long as the performance of the positive electrode active material is not adversely affected, the coating layer may be formed by any method. For example, the method may include any coating method known in the art, such as spray coating, dipping, and the like.

The positive electrode active material layer further includes a bonding agent, and optionally includes a conductive material. The bonding agent may improve bonding between the positive active material particles, and may also improve bonding between the positive active material and the current collector.

In some embodiments, the binder includes polyvinyl alcohol, hydroxypropyl cellulose, diacetyl cellulose, polyvinyl chloride, carboxylated poly Polymer containing vinyl chloride, polyvinyl fluoride, ethylene oxide, polyvinylpyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride (poly(vinylidene fluoride)), polyethylene, polypropylene, styrene-butadiene rubber, acrylated styrene-butadiene rubber, epoxy resin , nylon, and the like, but are not limited thereto.

In some embodiments, conductive materials include, but are not limited to, carbon-based materials, metallic materials, conductive polymers, and mixtures thereof. In some embodiments, the carbon-based material is natural graphite, artificial graphite, carbon black, acetylene black, ketjen black, carbon fibers, carbon nanotubes, graphene, or any thereof. selected from combinations. In some embodiments, the metallic material is selected from metallic powder, metallic fiber, copper, nickel, aluminum, silver. In some embodiments, the conductive polymer is a polyphenylene derivative.

In some embodiments, the current collector may be aluminum, but is not limited thereto.

The positive electrode may be manufactured by a manufacturing method known in the art. For example, the positive electrode may be obtained through a method of preparing an active material composition by mixing an active material, a conductive material, and a binder in a solvent, and applying the active material composition on a current collector. In some embodiments, the solvent may include, but is not limited to, N-methylpyrrolidone (NMP) or the like.

In some embodiments, the positive electrode is manufactured by forming a positive electrode material using a positive electrode active material layer including a lithium transition metal-based compound powder and a bonding agent on a current collector.

In some embodiments, the cathode active material layer may be prepared by the following operation. That is, the positive electrode material and the binder (conductive material and thickener used as necessary) are dry mixed to form a sheet, and the obtained sheet is connected to the positive electrode current collector, or this material is dissolved or dispersed in a liquid medium. After making it in the form of a slurry, it is applied on the positive electrode current collector and dried. In some embodiments, the material of the positive active material layer includes any material known in the art to which the present invention pertains.

cathode

The material, configuration, and manufacturing method of the negative electrode used in the electrochemical device of the present application may include any technique disclosed in the prior art. In some embodiments, the negative electrode is the negative electrode described in US patent application US9812739B, the contents of which are incorporated herein by reference in their entirety.

In some embodiments, the negative electrode includes a current collector and an anode active material layer disposed on the current collector. The negative active material includes a material that reversibly inserts/desorbs lithium ions. In some embodiments, the material for reversibly intercalating/deintercalating lithium ions includes a carbon material. In some embodiments, the carbon material may be any carbon-based negative active material commonly used in lithium ion rechargeable batteries. In some embodiments, the carbon material includes, but is not limited to, crystalline carbon, amorphous carbon, or mixtures thereof. Crystalline carbon may be amorphous, plate-like, flake-like, spherical or fibrous natural graphite or artificial graphite. The amorphous carbon may be soft carbon, hard carbon, mesophase pitch carbide, calcined coke, or the like.

In some embodiments, the anode active material layer includes an anode active material. In some embodiments, the negative active material is lithium metal, structured lithium metal, natural graphite, artificial graphite, meso carbon micro beads (MCMB), hard carbon, soft carbon, silicon, silicon-carbon composite, Li -Sn alloy, Li-Sn-O alloy, Sn, SnO, SnO ₂ , spinel structured lithiated TiO ₂ -Li ₄ Ti ₅ O ₁₂ , Li-Al alloy, or any combination thereof .

When a silicon carbon compound is included in the negative electrode, silicon:carbon = about 1:10 to 10:1 based on the total weight of the negative active material, and the median particle diameter (D50) of the silicon carbon compound is about 0.1 μm to 20 μm. When the anode contains an alloy material, the anode active material layer may be formed using a method such as deposition, sputtering, plating, or the like. When lithium metal is included in the negative electrode, the active material layer is formed using, for example, a spherical strand-shaped conductive skeleton and metal particles dispersed in the conductive skeleton. In some embodiments, the conductive scaffold in the shape of a spherical strand may have a porosity of about 5% to about 85%. In some embodiments, a protective layer may be further installed on the lithium metal anode active material layer.

In some embodiments, the anode active material layer may include a bonding agent, and optionally a conductive material. The bonding agent improves the bonding between the negative active material particles and the bonding between the negative active material and the current collector. In some embodiments, the binder includes polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, diacetyl cellulose, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride , polymer containing ethylene oxide, polyvinylpyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, styrene-butadiene rubber, acrylated styrene-butadiene rubber, epoxy resin , nylon, and the like, but are not limited thereto.

In some embodiments, conductive materials include, but are not limited to, carbon-based materials, metallic materials, conductive polymers, or mixtures thereof. In some embodiments, the carbon-based material is selected from natural graphite, synthetic graphite, carbon black, acetylene black, Ketjen black, carbon fiber, or any combination thereof. In some embodiments, the metallic material is selected from metallic powder, metallic fiber, copper, nickel, aluminum, silver. In some embodiments, the conductive polymer is a polyphenylene derivative.

In some embodiments, current collectors include, but are not limited to, copper foil, nickel foil, stainless steel foil, titanium foil, nickel foam, copper foam, a polymer substrate covered with a conductive metal, and any combination thereof.

The negative electrode may be manufactured by a manufacturing method known in the art to which the present invention pertains. For example, the negative electrode may be obtained through a method of preparing an active material composition by mixing an active material, a conductive material, and a binder in a solvent, and applying the active material composition on a current collector. In some embodiments, the solvent may include, but is not limited to, water and the like.

separator

In some embodiments, in the electrochemical device of the present application, a separator is installed between the anode and the cathode to prevent a short circuit. The material and shape of the separator used in the electrochemical device of the present application is not particularly limited, and may be any technique disclosed in the prior art. In some embodiments, the separator includes a polymer or inorganic material formed of a material stable in the electrolyte of the present application.

For example, the separator may include a base layer and a surface treatment layer. The base layer is a nonwoven fabric, a film, or a composite film having a porous structure, and the material of the base layer is selected from at least one of polyethylene, polypropylene, polyethylene terephthalate, and polyimide. . Specifically, a polypropylene porous film, a polyethylene porous film, a polypropylene nonwoven fabric, a polyethylene nonwoven fabric, or a polypropylene-polyethylene-polypropylene porous composite film may be selected. The base layer may be one or more layers, and when the base layer is multilayer, the polymers of different base layers may have the same or different compositions, and the weight average molecular weights of the polymers of the different base layers are not completely the same. When the substrate layer is multi-layered, the closed cell temperatures of the polymers of the different substrate layers are different.

In some embodiments, a surface treatment layer is formed on at least one surface of the base layer, and the surface treatment layer may be a polymer layer or an inorganic material layer, or a layer formed by mixing a polymer and an inorganic material.

The inorganic material layer includes inorganic particles and a binder, and the inorganic particles include aluminum oxide, silicon oxide, magnesium oxide, titanium oxide, hafnium dioxide, tin oxide, cerium dioxide, nickel oxide, zinc oxide, calcium oxide, zirconium oxide, and yttrium oxide. , silicon carbide, boehmite, aluminum hydroxide, magnesium hydroxide, calcium hydroxide, and a combination of one or more of barium sulfate. The binder is polyvinylidene fluoride, a copolymer of vinylidene fluoride-hexafluoro propylene, polyamide, polyacrylonitrile, polyacrylate ( polyacrylate, polyacrylic acid, polyacrylate, polyvinylpyrrolidone, polyvinyl ether, polymethyl methacrylate, polytetrafluoroethylene ( polytetrafluoroethylene) and polyhexafluoropropylene (polyhexafluoropropylene). The polymer layer comprises a polymer, and the material of the polymer is polyamide, polyacrylonitrile, acrylate polymer, polyacrylic acid, polyacrylate, polyvinylpyrrolidone, polyvinylether polyvinylidene fluoride or poly(vinylidene). fluoride-hexafluoro propylene).

three. Applications

The electrolyte solution according to the present application can improve high-temperature storage and circulation performance of an electrochemical device, and the electrochemical device manufactured therefrom is suitable for electronic equipment in various fields.

The use of the electrochemical device of the present application is not particularly limited, and may be used for any purpose known in the prior art. In one embodiment, the electrochemical device of the present application is a notebook computer, a pen input type computer, a mobile computer, an e-book player, a mobile phone, a portable fax machine, a portable copier, a portable printer, a headset type stereo headphone, a video recorder, an LCD TV, portable cleaner, portable cd player, minidisc, transceiver, electronic notebook, calculator, memory card, portable recorder, radio, backup power supply, motor, automobile, motorcycle, power assisted bicycle, bicycle, light fixture, toys, game console, watch , power tools, flashlights, cameras, large household batteries and lithium-ion capacitors.

4. Example

Hereinafter, the present application will be described in more detail through Examples and Comparative Examples, but the present application is not limited to these Examples unless departing from the gist of the present application.

1. Manufacture of lithium-ion batteries

(1) Anode manufacturing

Lithium manganese oxide (LiMn ₂ O ₄ ), a conductive agent (Super P® conductive carbon) and polyvinylidene fluoride (PVDF) were mixed in a weight ratio of 96:2:2, and N-methylpyrrolidone (NMP) was It was added and stirred uniformly under the action of a vacuum stirrer to obtain a positive electrode slurry, wherein the positive electrode slurry had a solid content of 72 wt%. The positive electrode slurry is uniformly applied to a 13 μm thick aluminum foil, and the aluminum foil is dried at 85 ° C., followed by cold pressing, cutting, and slitting, followed by drying under a vacuum condition of 85 ° C. for 4 hours to obtain a positive electrode.

(2) Preparation of negative electrode

Artificial graphite, conductive agent (Super P® conductive carbon), sodium carboxymethylcellulose (CMC), and styrene-butadiene rubber (SBR) are mixed in a weight ratio of 96.4:1.5:0.5:1.6 and deionized water is added. , to obtain a negative electrode slurry under the action of a vacuum stirrer, wherein the solid content of the negative electrode slurry is 54 wt%. The negative electrode slurry was uniformly applied on the negative electrode current collector copper foil, the copper foil was dried at 85° C., cold pressed, cut and slitted, and dried under vacuum conditions at 120° C. for 12 hours to obtain a negative electrode.

(3) Preparation of electrolyte solution

In a dry argon glove box, ethylene carbonate (EC), ethyl methyl carbonate (EMC) and diethyl carbonate (DEC) are mixed according to a weight ratio of EC:EMC:DEC=3:5:2, followed by specific amounts and types of additives After dissolving and stirring sufficiently, lithium salt LiPF ₆ was added and uniformly mixed to obtain an electrolyte solution. Here, _{the concentration of LiPF 6} is 1 mol/L. Specific types and amounts of additives used in the electrolyte are shown in the table below, and the content of the additives is a mass percentage calculated based on the total mass of the electrolyte.

(4) Preparation of separation membrane

A polyethylene (PE) separator with a thickness of 12 μm is used.

(5) Manufacturing of lithium-ion batteries

After the positive electrode, the separator and the negative electrode are sequentially stacked so that the separator causes a separation action between the positive electrode and the negative electrode, an electrode assembly is obtained after tab winding and welding, and the electrode assembly is placed in a packaging bag and dried, Lithium-ion battery was obtained by injecting the electrolyte prepared in , vacuum packaging, stationary, chemical formation (charged to 3.3V with 0.02C constant current and then charged to 3.6V with 0.1C constant current), shaping, and capacity testing. do.

2. Li-ion battery performance test

(1) Rate test of lithium-ion batteries at 25℃

Place the lithium-ion battery in a 25°C incubator and let stand for 30 minutes to allow the lithium-ion battery to reach a constant temperature. After charging a lithium-ion battery that has reached constant temperature to a voltage of 4.2V with a constant current of 0.5C, it is charged up to a current of 0.05C with a constant voltage of 4.2V, and discharged to 3.0V at a rate of 0.5C/1C/2C/5C, respectively. The discharge capacity under different rates is recorded, and the 5C discharge capacity retention rate is calculated by taking the 0.5C discharge capacity as 100%.

(2) Cycling performance of lithium-ion batteries at 25℃

Place the lithium-ion battery in a 25°C incubator and let stand for 30 minutes to allow the lithium-ion battery to reach a constant temperature. After the lithium-ion battery that has reached constant temperature is charged to a voltage of 4.2V with a constant current of 0.5C, it is charged up to a current of 0.05C with a constant voltage of 4.2V, and then discharged to a voltage of 3.0V at a constant current of 1C, which is one charge/discharge. do it in circulation. After repeating the charge/discharge cycle 500 times with the capacity of the initial discharge set to 100%, the test is stopped and the cycle capacity maintenance rate is recorded and used as an index to evaluate the cycle performance of the lithium-ion battery.

The circulating capacity retention rate is a value multiplied by 100% by dividing the capacity at the time of circulation up to a specific cycle by the capacity at the time of initial discharge.

(2) Cycling performance of lithium-ion batteries at 45℃

Place the lithium-ion battery in a 45°C incubator and allow it to stand for 30 minutes to allow the lithium-ion battery to reach a constant temperature. After the lithium-ion battery that has reached constant temperature is charged to a voltage of 4.2V with a constant current of 0.5C, it is charged up to a current of 0.05C with a constant voltage of 4.2V, and then discharged to a voltage of 3.0V at a constant current of 1C, which is one charge/discharge. do it in circulation. After repeating the charge/discharge cycle 300 times with the capacity of the initial discharge set to 100%, the test is stopped and the cycle capacity maintenance rate is recorded and used as an index to evaluate the cycle performance of the lithium-ion battery.

(4) Thickness expansion rate of the battery

The thickness of the battery is measured and the thickness expansion rate of the battery is calculated according to the following equation.

Thickness expansion rate = (thickness of battery after cycle - thickness of battery before cycle)/thickness of battery before cycleХ100%

A. The electrolytes and lithium ion batteries of Examples 1 to 13 and Comparative Examples 1 to 7 were prepared according to the above method. The lithium-ion battery is tested for 25°C rate discharge performance, 25°C cycle retention rate, 45°C cycle retention ratio, and thickness expansion ratio, and the test results are shown in Table 1.

Table 1

Here, "/" indicates that the above substance has not been added.

From the test results of Comparative Examples 1 to 6, when a silicate compound having a specific structure and fluoroethylene carbonate (FEC) are not added to the electrolyte or only one of the two is added, the rate discharge performance and circulation performance of the battery are relatively poor, and the thickness It can be seen that the expansion rate is high.

From the data of Examples 1 to 13 and Comparative Examples 1 to 7, the addition of a silicate compound and fluoroethylene carbonate (FEC) in a specific ratio effectively improves the rate discharge performance and cycle capacity retention rate of the battery, while at the same time increasing the battery thickness increase rate during the cycle can be seen to be improved. Without wishing to be bound by any theory, the performance improvement may be due to the silicate compound adsorbing trace amounts of water and HF in the electrolyte solution, which is beneficial to increase the stability of the electrolyte solution. In addition, it is easy to oxidize and forms a dense protective film on the anode to reduce damage to the anode of the electrolyte, and the reduction potential of fluoroethylene carbonate (FEC) is relatively high, so it is preferentially reduced at the cathode during initial charging and discharging, forming a film and forming a film The formation is dense and the electrolyte is suppressed from causing a decomposition reaction at the cathode. When the ratio of tetraethyl orthosilicate and FEC added to the electrolyte solution is within a certain range, the electrolyte solution can be more effectively stabilized, and better interfacial protection can be formed at the positive electrode and the negative electrode. If the ratio of tetraethyl orthosilicate to FEC is too high, the film-forming impedance is relatively large, increasing the battery impedance and affecting the battery performance. On the other hand, if the ratio is too low, it is not enough to form a good interfacial protection, so the effect of improving battery cycle performance cannot be realized.

B. The electrolytes and lithium ion batteries of Examples 14 to 24 and Comparative Examples 8 to 9 were prepared according to the above method. Lithium-ion batteries are tested for 25°C rate-discharge performance, 25°C cycle retention and 45°C cycle retention and thickness expansion. See Table 2 for test results.

Table 2

Here, "/" indicates that the above substance has not been added.

Based on Examples 6 and 14 to 23, as can be seen from the comparison of Examples and Comparative Examples 8 to 9, a disulfonate compound (eg, methylene methanedisulfonate) in an electrolyte containing tetraethyl orthosilicate (MMDS)) or cyclic carboxylic acid anhydrides (e.g. maleic anhydride, glutaric anhydride and succinic anhydride, etc.) can further improve the cycling performance, gas generation state and rate discharge performance of the battery. can

C. Prepare the electrolyte solutions and lithium ion batteries of Examples 25 to 34 according to the above method. Lithium-ion batteries are tested for 25°C rate-discharge performance, 25°C cycle retention and 45°C cycle retention and thickness expansion. See Table 3 for test results.

Table 3

Here, "/" indicates that the above substance has not been added.

As can be seen in Examples 27-33 and 19, 0.1% to about 13% of other additives (e.g. 1,3-propane sultone (PS) in an electrolyte containing tetraethyl orthosilicate and FEC and maleic anhydride) ), vinylene carbonate (VC), LiPO ₂ F ₂ or at least one of 1,3,6-hexanetricarbonitrile) can further improve battery cycleability, gas generation state and rate discharge performance. Also, as can be seen from the comparison of Example 6 with Examples 25 and 26 or the comparison of Example 7 with Example 34, an electrolyte containing a specific amount of tetraethyl orthosilicate and FEC with a specific amount of another additive (e.g. , 1,3-propane sultone (PS), vinylene carbonate (VC), LiPO ₂ F ₂ , 1,3,6-hexanetricarbonitrile or at least one of succinonitrile (SN)) is added to cycle the battery at room temperature and high temperature circulation performance can be further improved. The above experimental results indicate that the combined use of these additives helps to further improve battery performance by enhancing the protection of the battery positive and negative interface.

The meaning indicated by citation of “some embodiments”, “partial embodiments”, “one embodiment”, “another example”, “one example”, “specific example” or “partial example” throughout the specification is, in this application, that at least one embodiment or example includes a particular feature, structure, material, or characteristic described in the embodiment or example. Thus, in the description in each part throughout the specification, for example, "in some embodiments," "in an embodiment," "in one embodiment," "in another example," "in an example," , “in a particular example” or “in an example” are not necessarily referring to the same embodiment or example in the present application. Also, certain features, structures, materials, or properties herein may be combined in any suitable manner in one or more embodiments or examples.

Although illustrative embodiments have been shown and described, those of ordinary skill in the art to which the present invention pertains should not interpret the embodiments as limiting the present application, but do not deviate from the spirit, principle and scope of the present application. It should be understood that changes, substitutions and modifications may be made to the

Claims (10)

In the electrolyte,
fluoroethylene carbonate and
a silicate compound of structure I;

wherein R ₁ , R ₂ , R ₃ and R ₄ are each independently selected from a substituted or unsubstituted C ₁ to C ₁₀ hydrocarbon group, wherein when substituted, the substituent is halogen,
wherein the mass ratio of the silicate compound and the fluoroethylene carbonate is 1:1 to 1:10. According to claim 1,
The silicate compound is an electrolyte solution comprising at least one of the following compounds.

,

or

According to claim 1,
The content of the silicate compound is 0.1wt% to 5wt% of the total weight of the electrolyte solution. According to claim 1,
further comprising a cyclic carboxylic acid anhydride compound, wherein the cyclic carboxylic acid anhydride compound comprises at least one of a structural compound of Formula II, a structural compound of Formula III, or a structural compound of Formula IV;

,

,

wherein R ₅ , R ₆ , R ₇ , R ₈ , R ₉ , R ₁₀ and R ₁₁ are each independently selected from hydrogen, halogen and a substituted or unsubstituted C ₁ to C ₁₀ hydrocarbon group, wherein the substituted When the substituent is a halogen electrolyte. 5. The method of claim 4,
The cyclic carboxylic acid anhydride includes at least one of maleic anhydride, succinic anhydride, 2-methylsuccinic anhydride, 2,3-dimethylsuccinic anhydride, or glutaric anhydride, and the content of the cyclic carboxylic acid anhydride is An electrolyte of 0.1 wt% to 5 wt% of the total weight of the electrolyte. According to claim 1,
Further comprising a disulfonate compound having the formula (V),

wherein n is an integer of 1 to 4, and the content of the disulfonate compound is 0.1 wt% to 5 wt% of the total weight of the electrolyte solution. 7. The method according to any one of claims 1 to 6,
LiPO ₂ F ₂ , unsaturated cyclic carbonate, cyclic sultone, cyclic sulfate lactone, or further comprises at least one additive of a nitrile compound, wherein the content of the additive is 0.1wt% to 13wt% of the total weight of the electrolyte solution phosphorus electrolyte. 8. The method of claim 7,
The _{content of LiPO 2} F ₂ is 0.001wt% to 2wt% of the total weight of the electrolyte,
The unsaturated cyclic carbonate includes at least one of vinylene carbonate or vinylethylene carbonate, and the content of the unsaturated cyclic carbonate is 0.001 wt% to 2 wt% of the total weight of the electrolyte,
The cyclic sultone includes at least one of 1,3-propane sultone, 1,4-butane sultone, or 1,3-propene sultone, and the content of the cyclic sultone is 0.01 wt% to 3 wt% of the total weight of the electrolyte solution. %ego,
The cyclic sulfate lactone includes at least one of ethylene sulfate, propylene sulfate, or propane 1,2-cyclic sulfate, and the content of the cyclic sulfate lactone is 0.01 wt% to 3 wt% of the total weight of the electrolyte solution %ego,
The nitrile compound is succinonitrile, glutaronitrile, adiponitrile, 2-methylene glutaronitrile, 2-propylmalononitrile, 1,3,6-hexanetricarbonitrile, 1,2,6-hexanetricarbo At least one of nitrile, 1,3,5-pentanetricarbonitrile, or 1,2-bis(cyanoethoxy)ethane, wherein the content of the nitrile compound is 0.5 wt% to 7 wt% of the total weight of the electrolyte electrolyte. An electrochemical device comprising the electrolyte according to any one of claims 1 to 8. An electronic device comprising the electrochemical device according to claim 9 .