KR102272371B1 - New lithium phosphate derivatives and New lithium borate derivatives, the method of preparing the same and electrolyte solution and lithium secondary battery containing the same - Google Patents

Abstract

The present invention relates to a novel lithium phosphate derivative and a novel lithium borate derivative, a method for preparing the same, an electrolyte solution for a lithium secondary battery and a lithium secondary battery comprising the same, and the novel lithium phosphate and lithium borate derivative according to the present invention and a novel preparation thereof The method provides a new lithium salt material, an electrolyte additive suitable for the performance requirements of lithium secondary batteries that require superior performance compared to existing small lithium secondary batteries such as electric vehicles or energy storage systems (ESS), and is simple and economically dangerous. There is an effect that it is possible to provide a new lithium salt material with high purity and high yield without a process.

Description

New lithium phosphate derivative and new lithium borate derivative, manufacturing method thereof, electrolyte solution for lithium secondary battery and lithium secondary battery containing same, the method of preparing the same and electrolyte solution and lithium secondary battery containing the same}

The present invention relates to a novel lithium phosphate derivative, a novel lithium borate derivative, a method for preparing the same, an electrolyte for a lithium secondary battery and a lithium secondary battery comprising the same, and more particularly, to a novel electrolyte additive or lithium salt for a lithium secondary battery It relates to a lithium phosphate derivative and a novel lithium borate derivative, a manufacturing method capable of manufacturing the same with high purity and high yield without a simple and economically dangerous process, and an electrolyte solution and a secondary battery including the same.

The lithium secondary battery comprising an electrolyte used as an electrolyte additive or lithium salt for a lithium secondary battery of lithium phosphate and lithium borate of the present invention improves the resistance characteristics of the battery and relates to a lithium secondary battery having the advantage of exhibiting high output.

Recently, with the commercialization of various mobile devices, the need for high-performance secondary batteries is increasing, and with the commercialization of electric vehicles and hybrid electric vehicles, and the development of electric storage devices, it is equipped with performance such as high output, high energy density, and high discharge voltage. A secondary battery is needed.

In order to achieve this, the importance of lithium salt in the composition of the electrolyte has been raised, and the need for an electrolyte additive with excellent price competitiveness and better performance required compared to existing products is emerging according to the need for high-efficiency and price-competitive secondary batteries.

_{Materials with simple structures such as lithium hexafluorophosphate (LiPF 6} ) and lithium tetrafluoroborate (LiBF ₄ ) have been used for many years as an additive to the existing electrolyte, but new materials derived from the basic structure have been developed according to the gradually increasing performance requirements. The need for development has increased, and accordingly, it is necessary to research and develop a new lithium salt that exhibits superior performance compared to the existing one.

Korean Patent No. 1535733

An object of the present invention is to overcome the disadvantages of existing commercial products and to further improve performance, lithium phosphate derivatives and lithium borate derivatives, which are novel lithium salts that can be used in electrolytes for lithium secondary batteries, and high purity and high purity and high-purity products without risky processes simply and economically. An object of the present invention is to provide a lithium secondary battery with improved performance by providing a manufacturing method that can be manufactured in a yield.

In order to achieve the above object, the present invention provides a lithium derivative represented by the following formula (1).

[Formula 1]

X is phosphorus (P) or boric acid (B),

n + m is 4 to 6,

L is a sulfone-based ligand compound including any one hydroxy or amino group selected from HO-SO ₂ -OH, HO-SO ₂ R, HN(SO ₂ R) ₂ , or H-NH-SO _{2 R,}

R is C1 to C10 alkyl, C1 to C10 aryl, halide, or C1 to C10 alkyl halide.

The present invention also provides an electrolyte solution for a lithium secondary battery comprising the lithium derivative.

In addition, the present invention comprises the steps of preparing a first mixture by mixing a _{lithium hexafluorophosphate (LiPF 6} ) solution or a lithium tetrafluoroborate (LiBF _{4 ) solution and a solvent;} preparing a second mixture by adding a sulfone-based ligand compound containing a hydroxy or amino group to the first mixture; adding an organic silyl halide mixture to the second mixture and reacting with stirring; and preparing a lithium derivative represented by the following Chemical Formula 1 by heating the reaction product at a temperature, reducing the pressure, and separating by filtration.

[Formula 1]

X is phosphorus (P) or boric acid (B),

n + m is 4 to 6,

L is a sulfone-based ligand compound including any one hydroxy or amino group selected from HO-SO ₂ -OH, HO-SO ₂ R, HN(SO ₂ R) ₂ , or H-NH-SO _{2 R,}

R is C1 to C10 alkyl, C1 to C10 aryl, halide, or C1 to C10 alkyl halide.

In addition, the present invention is the lithium derivative; the electrolyte; a positive electrode in which the electrolyte includes a positive electrode active material capable of intercalating and releasing lithium; an anode in which the electrolyte includes an anode active material capable of occluding and releasing lithium; and a separator; provides a lithium secondary battery comprising.

A novel lithium phosphate and lithium borate derivative and a novel manufacturing method thereof according to the present invention meet the required performance of a lithium secondary battery that requires superior battery performance compared to existing small lithium secondary batteries such as electric vehicles and energy storage systems (ESS). There is an effect of providing a new lithium salt material that is a suitable electrolyte additive, and also providing a new lithium salt material with high purity and high yield without a simple and economically risky process.

Hereinafter, a novel lithium phosphate derivative and a novel lithium borate derivative according to the present invention, a manufacturing method thereof, an electrolyte solution for a lithium secondary battery including the same, and a lithium secondary battery will be described in more detail.

The inventor of the present invention, while researching and developing the secondary battery electrolyte additive, a lithium secondary battery with a sulfone functional group introduced into the _{basic structure of lithium hexafluorophosphate (LiPF 6} ) or lithium tetrafluoroborate (LiBF _{4 )} When applied to the present invention, it was found that the sulfone functional group can exhibit the required performance while maintaining stability, thereby exhibiting various performances and performing without problems in electrochemical conditions such as severe charge/discharge in the lithium secondary battery. completed.

The present invention provides a lithium derivative represented by the following formula (1).

[Formula 1]

X is phosphorus (P) or boric acid (B),

n + m is 4 to 6,

L is a sulfone-based ligand compound including any one hydroxy or amino group selected from HO-SO ₂ -OH, HO-SO ₂ R, HN(SO ₂ R) ₂ , or H-NH-SO _{2 R,}

R is C1 to C10 alkyl, C1 to C10 aryl, halide, or C1 to C10 alkyl halide.

In the lithium derivative, X may be phosphorus (P), and n + m may be 6, but is not limited thereto.

The lithium derivative may be any one selected from compounds represented by the following Chemical Formulas 2 to 9, but is not limited thereto.

[Formula 2]

[Formula 3]

[Formula 4]

[Formula 5]

[Formula 6]

[Formula 7]

[Formula 8]

[Formula 9]

The lithium derivatives represented by Formulas 2 to 9 are lithium phosphate derivatives.

In the lithium derivative, X may be boric acid (B), and n + m may be 4, but is not limited thereto.

The lithium derivative may be any one selected from compounds represented by the following Chemical Formulas 10 to 17, but is not limited thereto.

[Formula 10]

[Formula 11]

[Formula 12]

[Formula 13]

[Formula 14]

[Formula 15]

[Formula 16]

[Formula 17]

The lithium derivatives represented by the above Chemical Formulas 10 to 17 are lithium borate derivatives.

The present invention also provides an electrolyte solution for a lithium secondary battery comprising the lithium derivative.

The electrolyte for a lithium secondary battery may be composed of 0.01 to 30% by weight of the lithium derivative and the remaining amount of the solvent, but is not limited thereto.

The electrolyte for the lithium secondary battery is lithium hexafluorophosphate (LiPF ₆ ), lithium tetrafluoroborate (LiBF ₄ ), lithium perchlorate (LiClO ₄ ), lithium trifluoromethanesulfonate (LiCF ₃ SO ₃ ), lithium difluoro rophosphate (LiPO ₂ F 2 ), lithium bis(fluorosulfonyl)imide [LiN(FSO ₂ ) ₂ ], lithium bis(trifluoromethanesulfonyl)imide [LiN(CF ₃ SO ₂ ) ₂ ], and any one or more selected from a non-aqueous solvent, but is not limited thereto.

The non-aqueous solvent is ethylene carbonate, propylene carbonate, butylene carbonate, ethyl methyl carbonate, dimethyl carbonate, diethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, vinylene carbonate, fluoroethylene carbonate, or halogenated thereof. carbonates that are any one selected from the group consisting of carbonates; lactones selected from the group consisting of gamma-butyrolactone, gamma-valerolactone, gamma-caprolactone, delta-valerolactone, and epsilon-caprolactone; Acetates selected from the group consisting of methyl acetate, ethyl acetate, propyl acetate, or methyl propionate, and ethyl propionate; From the group consisting of 3-methoxy glutaronitrile, 3-ethoxy glutaronitrile, 3-dimethylamino glutaronitrile, thiomethoxy succinonitrile, and 2,2,2-trifluoroethoxy glutaronitrile any one selected nitrile; and 1,3-propanesultone, 1,4-butanesultone, 1,3-propensultone, 1,4-butensultone, and 1-methyl-1,3-propensultone It may be any one selected from the group consisting of sultones, but is not limited thereto.

The electrolyte for a lithium secondary battery may include 0.1 M to 2.0 M (mol/l) of lithium hexafluorophosphate (LiPF ₆ ), but is not limited thereto.

The lithium secondary battery electrolyte is 0.01 to 30% by weight of the lithium derivative, lithium hexafluorophosphate (LiPF ₆ ), lithium tetrafluoroborate (LiBF ₄ ), lithium perchlorate (LiClO ₄ ), lithium trifluoromethanesulfonate ( LiCF ₃ SO ₃ ), lithium difluorophosphate (LiPO 2F ₂ ), lithium bis(fluorosulfonyl)imide [LiN(FSO ₂ ) ₂ ], or lithium bis(trifluoromethanesulfonyl)imide [ LiN(CF ₃ SO ₂ ) ₂ ] 0.01 to 20% by weight, and the remaining amount of the solvent, but is not limited thereto.

In addition, the present invention comprises the steps of preparing a first mixture by mixing a _{lithium hexafluorophosphate (LiPF 6} ) solution or a lithium tetrafluoroborate (LiBF _{4 ) solution and a solvent;} preparing a second mixture by adding a sulfone-based ligand compound containing a hydroxy or amino group to the first mixture; adding an organic silyl halide mixture to the second mixture and reacting with stirring; and preparing a lithium derivative represented by the following Chemical Formula 1 by heating the reaction product at a temperature, reducing the pressure, and separating by filtration.

[Formula 1]

X is phosphorus (P) or boric acid (B),

n + m is 4 to 6,

L is a sulfone-based ligand compound including any one hydroxy or amino group selected from HO-SO ₂ -OH, HO-SO ₂ R, HN(SO ₂ R) ₂ , or H-NH-SO _{2 R,}

R is C1 to C10 alkyl, C1 to C10 aryl, halide, or C1 to C10 alkyl halide.

In the lithium derivative represented by Formula 1, X may be phosphoric acid (P), and n + m may be 6, but is not limited thereto.

The lithium derivative may be any one of compounds represented by the following Chemical Formulas 2 to 9, but is not limited thereto.

[Formula 2]

[Formula 3]

[Formula 4]

[Formula 5]

[Formula 6]

[Formula 7]

[Formula 8]

[Formula 9]

The lithium derivatives represented by Formulas 2 to 9 are lithium phosphate derivatives.

As an embodiment of the present invention, lithium tetrafluoro (sulfato) phosphoric acid represented by Chemical Formula 2 may be prepared as shown in Scheme 1 below.

[Scheme 1]

LiPF ₆ + H ₂ SO ₄ + 2 Me ₃ SiCl ----> LiPF ₄ (SO ₄ ) + 2 MeSiF + 2 HCl

Similar to Scheme 1, the lithium phosphate derivatives represented by Formulas 3 to 9 can be prepared by reacting lithium hexafluorophosphate (LiPF ₆ ) with various hydroxy and amino derivatives with an organosilyl halide reagent using lithium hexafluorophosphate (LiPF 6 ) as a starting material. can

In the lithium derivative represented by Formula 1, X may be boric acid (B), and n + m may be 4, but is not limited thereto.

The lithium derivative may be any one of compounds represented by the following Chemical Formulas 10 to 17, but is not limited thereto.

[Formula 10]

[Formula 11]

[Formula 12]

[Formula 13]

[Formula 14]

[Formula 15]

[Formula 16]

[Formula 17]

The lithium derivatives represented by Chemical Formulas 10 to 17 are lithium borate derivatives.

As an embodiment of the present invention, lithium bis(sulfato)boric acid represented by Chemical Formula 10 may be prepared as shown in Scheme 2 below.

[Scheme 2]

LiBF ₄ + 2 H ₂ SO ₄ + 4 Me ₃ SiCl ----> LiB(SO ₄ ) ₂ + 4 MeSiF + 4 HCl

Similar to Scheme 2, the lithium boric acid compounds represented by Formulas 11 to 18 of the present invention are prepared by reacting lithium tetrafluoroborate (LiBF ₄ ) with various hydroxy and amino derivatives with an organosilyl halide reagent using lithium tetrafluoroborate (LiBF 4 ) as a starting material. can do.

The solvent is an ether selected from the group consisting of diethyl ether, diisopropyl ether, and methyl-t-butyl ether; alkoxyethanes of dimethoxyethane and diethoxyethane; esters selected from the group consisting of methyl acetate, ethyl acetate, propyl acetate, and butyl acetate; nitriles selected from the group consisting of acetonitrile, propionitrile, and butyronitrile; hydrocarbons selected from the group consisting of pentane, hexane, and heptane; alcohols selected from the group consisting of methanol, ethanol, propanol, and butanol; ketones selected from the group consisting of acetone, methyl ethyl ketone, and methyl isopropyl ketone; and carbonates which are any one selected from the group consisting of dimethyl carbonate, diethyl carbonate, and methyl ethyl carbonate; may be any one selected from the group consisting of, but is not limited thereto.

The solvent may be used in a ratio of 0.5 to 100 equivalents compared to a lithium hexafluorophosphate (LiPF ₆ ) solution or a lithium tetrafluoroborate (LiBF _{4 ) solution, but is not limited thereto.}

The order of adding a mixture of a sulfone-based ligand compound containing a hydroxy or amino group and an organic silyl halide to the first mixture is particularly important.

Specifically, a sulfone-based ligand compound containing a hydroxy or amino group was added to a first mixture prepared by mixing a lithium hexafluorophosphate (LiPF ₆ ) solution or a lithium tetrafluoroborate (LiBF _{4 ) solution and a solvent, and then organic} It is preferred to add an organic silyl halide mixture.

When the above procedure is followed, a high-purity lithium phosphate derivative or lithium borate derivative free from impurities can be prepared. If the organosilyl halide is added first, there is a problem in that the Si-F binding energy is relatively large compared to Si-X (X=Cl, Br, I), so that some impurities contaminated with X are generated.

The organosilyl halide mixture may be a compound represented by the following Chemical Formula 18, but is not limited thereto.

[Formula 18]

Wherein n is an integer of 1 to 3,

R is the same as or different from each other and is C1 to C10 straight or branched alkyl, C2 to C10 straight or branched alkenyl, or aryl,

X is the same as or different from each other and is chlorine (Cl), bromine (Br), or iodine (I).

R may be any one selected from the group consisting of methyl, ethyl, propyl, and vinyl, but is not limited thereto. In particular, as the organosilyl halide, trimethylchlorosilane in which R is methyl and X is chlorine (Cl) is used. It is preferable in terms of stability and corrosion.

The organosilyl halide mixture may be used in an equivalent ratio of 0.1 to 6.0 equivalents compared to _{lithium hexafluorophosphate (LiPF 6 ) solution, or 0.1 to 4.0 equivalent ratio compared to lithium tetrafluoroborate (LiBF 4} ) solution, but is not limited thereto.

Specifically, the organosilyl halide mixture represented by Formula 18 is used in the equivalent of a sulfone-based ligand compound containing a hydroxy or amino group bonded to _{lithium hexafluorophosphate (LiPF 6} ) or lithium tetrafluoroborate (LiBF _{4 ).} In proportion to R ₁ R ₂ R ₃ SiX ₁ (ie, R ₃ SiX ₁ ), it can be used in a 1.0 equivalent ratio compared to lithium hexafluorophosphate (LiPF _{6 ) solution, and R 1} R ₂ SiX ₁ X ₂ (ie, R ₂ SiX2) may be used in an equivalent ratio of 0.5, and in the case of R ₁ SiX ₁ X ₂ X ₃ (ie, R ₁ SiX ₃ ), it may be used in an equivalent ratio of 0.3.

The reacting step may be a step of adding an organic silyl halide mixture to the second mixture and then reacting at -10 to 80° C. while stirring at 60 to 80 rpm, but is not limited thereto.

The reaction conditions such as the reaction temperature are not particularly limited, and may be carried out under any conditions suitable for the situation, but the upper limit of the reaction temperature is preferably 80° C., more preferably 60° C. or less, and the lower limit is preferably Preferably it is -10 degreeC, More preferably, it is 0 degreeC or more. When it exceeds 80 °C, _{it is not preferable because decomposition of lithium hexafluorophosphate (LiPF 6} ) occurs, and at a temperature lower than -10 °C, it is not economical because the progress of the reaction is slow.

After the reaction, the temperature of the reactant is raised to 20° C., the generated acid gas is removed under reduced pressure, and it can be used immediately as a solution, and is concentrated and crystallized as necessary to filter out the lithium phosphate or lithium borate produced. The compounds of the present invention can be prepared by drying.

In addition, the present invention is the lithium derivative; the electrolyte; a positive electrode in which the electrolyte includes a positive electrode active material capable of intercalating and releasing lithium; an anode in which the electrolyte includes an anode active material capable of occluding and releasing lithium; and a separator; provides a lithium secondary battery comprising.

Hereinafter, a novel lithium phosphate derivative and a novel lithium borate derivative according to the present invention, a method for preparing the same, an electrolyte solution for a lithium secondary battery and a lithium secondary battery including the same will be described in more detail by the following examples. However, the present invention is not limited by these examples.

<Example 1> Synthesis of lithium tetrafluoro (sulfato) phosphoric acid powder (Formula 2) using trimethylchlorosilane and sulfuric acid as a ligand

_{A first mixture was prepared by putting 90.0 g of lithium hexafluorophosphate (LiPF 6} ) and 210.0 g of dimethyl carbonate at room temperature in a 1000 ml Teflon flask equipped with a stirring device, a condenser and a thermometer under a nitrogen atmosphere.

The first mixture was cooled to 5° C. using an ice bath, and _{58.1 g of concentrated sulfuric acid (H 2} SO ₄ ) was added to prepare a second mixture.

Then, 128.7 g of trimethylchlorosilane was slowly added to the second mixture, and the reaction was carried out at 5° C. while stirring at 60 rpm to obtain a reaction product.

After completion of the reaction, the temperature was gradually raised to 20° C., and the generated hydrochloric acid gas and trimethylfluorosilane were removed under reduced pressure to 60 mmHg, and after concentration, dichloroethane was added to filter the resulting salt with a filter paper and a small amount of dichloroethane. was washed with

The washed salt was recovered and dried at 40° C. to obtain a lithium tetrafluoro(sulfato) phosphoric acid compound represented by the following Chemical Formula 2 as a white powder (yield: 85%).

[Formula 2]

<Example 2> Synthesis of a solution containing a lithium tetrafluoro (sulfato) phosphoric acid (Formula 2) compound using trimethylchlorosilane and sulfuric acid as a ligand

_{A first mixture was prepared by putting 90.0 g of lithium hexafluorophosphate (LiPF 6} ) and 210.0 g of dimethyl carbonate at room temperature in a 1000 ml Teflon flask equipped with a stirring device, a condenser and a thermometer under a nitrogen atmosphere.

The first mixture was cooled to 5° C. using an ice bath, and _{58.1 g of concentrated sulfuric acid (H 2} SO ₄ ) was added to prepare a second mixture.

Then, 128.7 g of trimethylchlorosilane was slowly added to the second mixture, and the reaction was carried out at 5° C. while stirring at 60 rpm to obtain a reaction product.

After completion of the reaction, the solution containing the lithium tetrafluoro (sulfato) phosphoric acid compound represented by the following Chemical Formula 2 was obtained by slowly raising the temperature to 20 ° C and removing the generated hydrochloric acid gas and trimethylfluorosilane under reduced pressure to 60 mmHg. (291.9 g, yield: 87%, purity: 99%).

[Formula 2]

<Example 3> Synthesis of lithium difluorobis(sulfato) phosphoric acid powder (Formula 3) using trimethylchlorosilane and sulfuric acid as a ligand

_{A first mixture was prepared by putting 90.0 g of lithium hexafluorophosphate (LiPF 6} ) and 210.0 g of dimethyl carbonate at room temperature in a 1000 ml Teflon flask equipped with a stirring device, a condenser and a thermometer under a nitrogen atmosphere.

The first mixture was cooled to 5° C. using an ice bath, and _{116.2 g of concentrated sulfuric acid (H 2} SO ₄ ) was added to prepare a second mixture.

Then, 257.2 g of trimethylchlorosilane was slowly added to the second mixture, and the reaction proceeded at 5° C. while stirring at 60 rpm to obtain a reaction product.

After completion of the reaction, the temperature was gradually raised to 20° C., and the generated hydrochloric acid gas and trimethylfluorosilane were removed under reduced pressure to 60 mmHg, and after concentration, dichloroethane was added to filter the resulting salt with a filter paper and a small amount of dichloroethane. was washed with

The washed salt was recovered and dried at 40° C. to obtain a lithium difluorobis(sulfato) phosphoric acid compound represented by the following Chemical Formula 3 as a white powder (yield: 84%).

[Formula 3]

<Example 4> Synthesis of a solution containing a lithium difluorobis(sulfato) phosphoric acid (Formula 3) compound using trimethylchlorosilane and sulfuric acid as a ligand

_{A first mixture was prepared by putting 90.0 g of lithium hexafluorophosphate (LiPF 6} ) and 210.0 g of dimethyl carbonate at room temperature in a 1000 ml Teflon flask equipped with a stirring device, a condenser and a thermometer under a nitrogen atmosphere.

The first mixture was cooled to 5° C. using an ice bath, and _{116.2 g of concentrated sulfuric acid (H 2} SO ₄ ) was added to prepare a second mixture.

Then, 257.2 g of trimethylchlorosilane was slowly added to the second mixture, and the reaction proceeded at 5° C. while stirring at 60 rpm to obtain a reaction product.

After completion of the reaction, the solution containing the lithium difluorobis(sulfato) phosphoric acid compound represented by the following Chemical Formula 3 was removed by gradually raising the temperature to 20° C. and then removing the generated hydrochloric acid gas and trimethylfluorosilane under reduced pressure to 60 mmHg. was obtained (324.5 g, yield: 88%, purity: 99%).

[Formula 3]

<Example 5> Synthesis of lithium pentafluoro (methanesulfonyloxy) phosphoric acid powder (Formula 4) using trimethylchlorosilane and methanesulfonic acid (R = Me) as a ligand

_{A first mixture was prepared by putting 90.0 g of lithium hexafluorophosphate (LiPF 6} ) and 210.0 g of dimethyl carbonate at room temperature in a 1000 ml Teflon flask equipped with a stirring device, a condenser and a thermometer under a nitrogen atmosphere.

The first mixture was cooled to 5° C. using an ice bath, and _{56.9 g of methanesulfonic acid (MeSO 3} H) was added to prepare a second mixture.

Then, 64.4 g of trimethylchlorosilane was slowly added to the second mixture, and the reaction was performed at 10° C. while stirring at 80 rpm to obtain a reaction product.

After completion of the reaction, the temperature was gradually raised to 20° C., and the generated hydrochloric acid gas and trimethylfluorosilane were removed under reduced pressure to 60 mmHg, and after concentration, dichloroethane was added to filter the resulting salt with a filter paper and a small amount of dichloroethane. was washed with

The washed salt was recovered and dried at 40° C. to obtain a lithium pentafluoro(methanesulfonyloxy) phosphoric acid compound represented by the following Chemical Formula 4 as a pale yellow powder (yield: 87%).

[Formula 4]

<Example 6> Synthesis of a solution containing a lithium pentafluoro (methanesulfonyloxy) phosphoric acid (Formula 4) compound using trimethylchlorosilane and methanesulfonic acid (R = Me) as a ligand

_{A first mixture was prepared by putting 90.0 g of lithium hexafluorophosphate (LiPF 6} ) and 210.0 g of dimethyl carbonate at room temperature in a 1000 ml Teflon flask equipped with a stirring device, a condenser and a thermometer under a nitrogen atmosphere.

The first mixture was cooled to 5° C. using an ice bath, and _{56.9 g of methanesulfonic acid (MeSO 3} H) was added to prepare a second mixture.

Then, 64.4 g of trimethylchlorosilane was slowly added to the second mixture, and the reaction proceeded at 10° C. while stirring at 80 rpm to obtain a reaction product.

After completion of the reaction, the solution containing the lithium pentafluoro (methanesulfonyloxy) phosphoric acid compound represented by the following formula (4) by removing the hydrochloric acid gas and trimethylfluorosilane under reduced pressure to 60 mmHg after gradually raising the temperature to 20 ° C. was obtained (331.6 g, yield: 90%, purity: 99%).

[Formula 4]

<Example 7> Synthesis of lithium pentafluoro[bis(fluorosulfonyl)imido] phosphoric acid powder (Formula 8) using trimethylchlorosilane and bis(fluorosulfonyl)amine (R=F) as a ligand

_{A first mixture was prepared by putting 90.0 g of lithium hexafluorophosphate (LiPF 6} ) and 210.0 g of dimethyl carbonate at room temperature in a 1000 ml Teflon flask equipped with a stirring device, a condenser and a thermometer under a nitrogen atmosphere.

The first mixture was cooled to 5° C. using an ice bath, and 107.3 g of bis(fluorosulfonyl)amine was added to prepare a second mixture.

Then, 64.4 g of trimethylchlorosilane was slowly added to the second mixture, and the reaction proceeded at 5° C. while stirring at 60 rpm to obtain a reaction product.

After completion of the reaction, the temperature was gradually raised to 20° C., and the generated hydrochloric acid gas and trimethylfluorosilane were removed under reduced pressure to 60 mmHg, and after concentration, dichloroethane was added to filter the resulting salt with a filter paper and a small amount of dichloroethane. was washed with

The washed salt was recovered and dried at 40° C. to obtain a lithium pentafluoro[bis(fluorosulfonyl)imido]phosphoric acid compound represented by the following Chemical Formula 8 as a white powder (yield: 77%).

[Formula 8]

<Example 8> Lithium pentafluoro [bis (fluorosulfonyl) imido] phosphoric acid (Formula 8) compound using trimethylchlorosilane and bis (fluorosulfonyl) amine (R = F) as a ligand synthesis of solutions

_{A first mixture was prepared by putting 90.0 g of lithium hexafluorophosphate (LiPF 6} ) and 210.0 g of dimethyl carbonate at room temperature in a 1000 ml Teflon flask equipped with a stirring device, a condenser and a thermometer under a nitrogen atmosphere.

The first mixture was cooled to 5° C. using an ice bath, and 107.3 g of bis(fluorosulfonyl)amine was added to prepare a second mixture.

Then, 64.4 g of trimethylchlorosilane was slowly added to the second mixture, and the reaction proceeded at 5° C. while stirring at 60 rpm to obtain a reaction product.

After completion of the reaction, lithium pentafluoro[bis(fluorosulfonyl)imido]phosphoric acid represented by the following formula 8 by removing the hydrochloric acid gas and trimethylfluorosilane under reduced pressure to 60 mmHg after gradually raising the temperature to 20 ° C. A solution containing the compound was obtained (344.2 g, yield: 80%, purity: 98%).

[Formula 8]

<Example 9> Synthesis of lithium difluoro (sulfato) boric acid powder (Formula 10) using trimethylchlorosilane and sulfuric acid as a ligand

_{A first mixture was prepared by putting 60.0 g of lithium tetrafluoroborate (LiBF 4} ) and 340.0 g of dimethyl carbonate at room temperature in a 1000 ml Teflon flask equipped with a stirring device, a condenser and a thermometer under a nitrogen atmosphere.

The first mixture was cooled to 5° C. using an ice bath, and _{62.8 g of concentrated sulfuric acid (H 2} SO ₄ ) was added to prepare a second mixture.

Then, 139.1 g of trimethylchlorosilane was slowly added to the second mixture, and the reaction proceeded at 5° C. while stirring at 60 rpm to obtain a reaction product.

After completion of the reaction, the temperature was gradually raised to 20° C., and the generated hydrochloric acid gas and trimethylfluorosilane were removed under reduced pressure to 60 mmHg, and after concentration, dichloroethane was added to filter the resulting salt with a filter paper and a small amount of dichloroethane. was washed with

The washed salt was recovered and dried at 40° C. to obtain a lithium difluoro(sulfato) boric acid compound represented by the following Chemical Formula 10 as a white powder (yield: 80%).

[Formula 10]

<Example 10> Synthesis of a solution containing a compound of lithium difluoro (sulfato) boric acid (Formula 10) using trimethylchlorosilane and sulfuric acid as a ligand

_{A first mixture was prepared by putting 60.0 g of lithium tetrafluoroborate (LiBF 4} ) and 340.0 g of dimethyl carbonate at room temperature in a 1000 ml Teflon flask equipped with a stirring device, a condenser and a thermometer under a nitrogen atmosphere.

The first mixture was cooled to 5° C. using an ice bath, and _{62.8 g of concentrated sulfuric acid (H 2} SO ₄ ) was added to prepare a second mixture.

Then, 139.1 g of trimethylchlorosilane was slowly added to the second mixture, and the reaction proceeded at 5° C. while stirring at 60 rpm to obtain a reaction product.

After completion of the reaction, the solution containing the lithium difluoro (sulfato) boric acid compound represented by the following formula (10) was obtained by slowly raising the temperature to 20 °C and then removing the generated hydrochloric acid gas and trimethylfluorosilane under reduced pressure to 60 mmHg. (422.6 g, yield: 85%, purity: 99%).

[Formula 10]

<Example 11> Synthesis of lithium trifluoro(methanesulfonyloxy) boric acid powder (Formula 12) using trimethylchlorosilane and methanesulfonic acid (R=Me) as a ligand

_{A first mixture was prepared by putting 60.0 g of lithium tetrafluoroborate (LiBF 4} ) and 340.0 g of dimethyl carbonate at room temperature in a 1000 ml Teflon flask equipped with a stirring device, a condenser and a thermometer under a nitrogen atmosphere.

The first mixture was cooled to 5° C. using an ice bath, and _{61.5 g of methanesulfonic acid (MeSO 3} H) was added to prepare a second mixture.

Then, 69.5 g of trimethylchlorosilane was slowly added to the second mixture, and the reaction was carried out at 10° C. while stirring at 80 rpm to obtain a reaction product.

After completion of the reaction, the temperature was gradually raised to 20° C., and the generated hydrochloric acid gas and trimethylfluorosilane were removed under reduced pressure to 60 mmHg, and after concentration, dichloroethane was added to filter the resulting salt with a filter paper and a small amount of dichloroethane. was washed with

The washed salt was recovered and dried at 40° C. to obtain a lithium trifluoro(methanesulfonyloxy) boric acid compound represented by the following Chemical Formula 12 as a white powder (yield: 84%).

[Formula 12]

<Example 12> Synthesis of a solution containing lithium trifluoro (methanesulfonyloxy) boric acid (Formula 12) compound using trimethylchlorosilane and methanesulfonic acid (R = Me) as a ligand

_{A first mixture was prepared by putting 60.0 g of lithium tetrafluoroborate (LiBF 4} ) and 340.0 g of dimethyl carbonate at room temperature in a 1000 ml Teflon flask equipped with a stirring device, a condenser and a thermometer under a nitrogen atmosphere.

The first mixture was cooled to 5° C. using an ice bath, and _{61.5 g of methanesulfonic acid (MeSO 3} H) was added to prepare a second mixture.

Subsequently, 69.5 g of trimethylchlorosilane was slowly added to the second mixture, and the reaction was carried out at 10° C. while stirring at 60 rpm to obtain a reaction product.

After completion of the reaction, a solution containing a lithium trifluoro(methanesulfonyloxy) boric acid compound represented by the following formula 12 by slowly raising the temperature to 20° C. and removing the generated hydrochloric acid gas and trimethylfluorosilane under reduced pressure to 60 mmHg. was obtained (432.4 g, yield: 85%, purity: 98%).

[Formula 12]

<Example 13> Synthesis of lithium trifluoro[bis(fluorosulfonyl)imido] boric acid powder (Formula 16) using trimethylchlorosilane and bis(fluorosulfonyl)amine (R=F) as a ligand

_{A first mixture was prepared by putting 60.0 g of lithium tetrafluoroborate (LiBF 4} ) and 340.0 g of dimethyl carbonate at room temperature in a 1000 ml Teflon flask equipped with a stirring device, a condenser and a thermometer under a nitrogen atmosphere.

The first mixture was cooled to 5° C. using an ice bath, and 115.9 g of bis(fluorosulfonyl)amine was added to prepare a second mixture.

Subsequently, 69.5 g of trimethylchlorosilane was slowly added to the second mixture, and the reaction proceeded at 5° C. while stirring to obtain a reaction product.

After completion of the reaction, the temperature was gradually raised to 20° C., and the generated hydrochloric acid gas and trimethylfluorosilane were removed under reduced pressure to 60 mmHg, and after concentration, dichloroethane was added to filter the resulting salt with a filter paper and a small amount of dichloroethane. was washed with

The filtered salt was recovered and dried at 40° C. to obtain a lithium trifluoro[bis(fluorosulfonyl)imido]boric acid compound represented by the following Chemical Formula 16 as a white powder (yield: 70%).

[Formula 16]

<Example 14> Lithium trifluoro [bis (fluorosulfonyl) imido] boric acid (Formula 16) compound using trimethylchlorosilane and bis (fluorosulfonyl) amine (R = F) as a ligand synthesis of solutions

_{A first mixture was prepared by putting 60.0 g of lithium tetrafluoroborate (LiBF 4} ) and 340.0 g of dimethyl carbonate at room temperature in a 1000 ml Teflon flask equipped with a stirring device, a condenser and a thermometer under a nitrogen atmosphere.

The first mixture was cooled to 5° C. using an ice bath, and 115.9 g of bis(fluorosulfonyl)amine was added to prepare a second mixture.

Subsequently, 69.5 g of trimethylchlorosilane was slowly added to the second mixture, and the reaction proceeded at 5° C. while stirring to obtain a reaction product.

After completion of the reaction, lithium trifluoro[bis(fluorosulfonyl)imido] boric acid represented by the following formula 16 by removing the hydrochloric acid gas and trimethylfluorosilane under reduced pressure to 60 mmHg after gradually raising the temperature to 20 ° C. A solution containing the compound was obtained (467.2 g, yield: 78%, purity: 98%).

[Formula 16]

<Battery characteristics evaluation method>

In order to compare the lithium derivative synthesized according to the above example and lithium difluorophosphate (LiPO ₂ F ₂ ), a commercial product showing the best performance in the related art, the battery characteristics of each item were compared.

Specifically, the lithium derivative synthesized according to the above example and the comparative sample, a commercial product, lithium difluorophosphate (LiPO ₂ F ₂ ), each contained 1.0% by weight, vinylene carbonate (VC), respectively, 1.5% by weight, and 1.15M of lithium hexafluorophosphate (LiPF ₆ ) of ethylene carbonate (EC) / ethyl methyl carbonate (EMC) / dimethyl carbonate (DMC) = 2: 4: Basic composition of the remaining electrolyte solution in a volume ratio of 4: 4 (hereinafter referred to as ‘standard composition’) ') was added, and battery performance was evaluated according to Experimental Examples 1 to 6 below.

<Experimental Example 1> Formation (formation) capacity (mAh) comparison

Item by sample FMC
(mAh) STD
(mAh) No.1 Standard composition (without additives) 915.1 946.3 No.2 Standard composition + 1.5% VC + 1.0% LiPO ₂ F ₂ 957.2 939.8 No.3 Standard composition + 1.5% VC + 1.0% Formula 3 956.5 935.7 No.4 Standard composition + 1.5% VC + 1.0% Formula 4 943.3 934.8 No.5 Standard composition + 1.5% VC + 1.0% Formula 5 938.5 938.7 No.6 Standard composition + 1.5% VC + 1.0% Formula 9 912.8 928.5 No.7 Standard composition + 1.5% VC + 1.0% Formula 11 922.5 923.7 No.8 Standard composition + 1.5% VC + 1.0% Chemical formula 13 927.1 935.3 No.9 Standard composition + 1.5% VC + 1.0% Formula 17 931.8 937.2

Table 1 shows an electrolyte solution having only a standard composition (No. 1), an electrolyte solution containing commercially available lithium difluorophosphate (LiPO ₂ F ₂ ) (No. 2), and phosphoric acid synthesized according to an embodiment of the present invention This is a comparison of the formation capacity using electrolytes (No.3 to No.9) containing lithium derivatives and lithium borate derivatives.

Specifically, when using the electrolyte solution (No. 3 to No. 9) to which the lithium phosphate derivative and the lithium borate derivative synthesized according to the embodiment of the present invention were added at the same concentration, the commercial product lithium difluorophosphate ( LiPO ₂ F ₂ ) showed a similar level of formation capacity as when added.

<Experimental Example 2> Comparison of cell thickness change before and after high temperature (70°C) storage

Item by sample thickness before storage
(mm) thickness after storage
(mm) No.1 Standard composition (without additives) 5.6 8.2 (+2.6) No.2 Standard composition + 1.5% VC + 1.0% LiPO ₂ F ₂ 5.6 6.8 (+1.2) No.3 Standard composition + 1.5% VC + 1.0% Formula 3 5.6 6.8 (+1.2) No.4 Standard composition + 1.5% VC + 1.0% Formula 4 5.6 6.5 (+0.9) No.5 Standard composition + 1.5% VC + 1.0% Formula 5 5.6 6.9 (+1.3) No.6 Standard composition + 1.5% VC + 1.0% Formula 9 5.6 6.9 (+1.3) No.7 Standard composition + 1.5% VC + 1.0% Formula 11 5.6 7.2 (+1.6) No.8 Standard composition + 1.5% VC + 1.0% Chemical formula 13 5.6 6.8 (+1.2) No.9 Standard composition + 1.5% VC + 1.0% Formula 17 5.6 7.0 (+1.4)

Table 2 shows an electrolyte solution (No. 1) having only a standard composition, an electrolyte solution (No. _{2 ) to which commercial product lithium difluorophosphate (LiPO 2} F 2 ) is added, and phosphoric acid synthesized according to an embodiment of the present invention Cells were fabricated using electrolytes containing lithium derivatives and lithium borate derivatives (No.3 to No.9), maintained at 70° C. for 1 week, and the thickness of the fabricated cells is shown.

Specifically, when using the electrolyte solution (No. 3 to No. 9) to which the lithium phosphate derivative and the lithium borate derivative synthesized according to the embodiment of the present invention were added at the same concentration, the commercial product lithium difluorophosphate ( LiPO ₂ F ₂ ) showed a similar level of thickness change as when added. It can be seen that the high-temperature stability is excellent because the thickness increase rate is smaller than when no additives are added, and among them, No.3, No.4, and No.8 in particular showed excellent results.

<Experimental Example 3> Comparison of changes in open circuit voltage (hereinafter 'OCV') before and after storage at high temperature (70°C)

Item by sample Voltage difference before storage
(V) Voltage difference after storage
(V) No.1 Standard composition (without additives) 4.18 4.06 No.2 Standard composition + 1.5% VC + 1.0% LiPO ₂ F ₂ 4.19 4.10 No.3 Standard composition + 1.5% VC + 1.0% Formula 3 4.20 4.10 No.4 Standard composition + 1.5% VC + 1.0% Formula 4 4.18 4.10 No.5 Standard composition + 1.5% VC + 1.0% Formula 5 4.19 4.10 No.6 Standard composition + 1.5% VC + 1.0% Formula 9 4.20 4.10 No.7 Standard composition + 1.5% VC + 1.0% Formula 11 4.20 4.09 No.8 Standard composition + 1.5% VC + 1.0% Chemical formula 13 4.19 4.09 No.9 Standard composition + 1.5% VC + 1.0% Formula 17 4.19 4.10

Table 3 shows an electrolyte solution (No. 1) having only a standard composition, an electrolyte solution (No. _{2 ) to which commercial product lithium difluorophosphate (LiPO 2} F 2 ) is added, and phosphoric acid synthesized according to an embodiment of the present invention It is a diagram showing the difference in OCV of cells manufactured by using electrolytes (No.3 to No.9) to which lithium derivatives and lithium borate derivatives are added, and then maintained at 70° C. for 1 week.

Specifically, when using the electrolyte solution (No. 3 to No. 9) to which the lithium phosphate derivative and the lithium borate derivative synthesized according to the embodiment of the present invention were added at the same concentration, the commercial product lithium difluorophosphate ( LiPO ₂ F ₂ ) showed a similar level of difference in OCV as when added. It can be seen that this maintains a higher voltage difference than when no additives are added and has excellent high-temperature stability.

<Experimental Example 4> Comparison of changes in internal resistance (hereinafter 'IR') before and after storage at high temperature (70°C)

Item by sample resistance before storage
(mΩ) resistance after storage
(mΩ) No.1 Standard composition (without additives) 10.4 46.2 No.2 Standard composition + 1.5% VC + 1.0% LiPO ₂ F ₂ 9.9 30.9 No.3 Standard composition + 1.5% VC + 1.0% Formula 3 8.7 26.3 No.4 Standard composition + 1.5% VC + 1.0% Formula 4 10.0 28.4 No.5 Standard composition + 1.5% VC + 1.0% Formula 5 10.3 27.3 No.6 Standard composition + 1.5% VC + 1.0% Formula 9 11.6 28.7 No.7 Standard composition + 1.5% VC + 1.0% Formula 11 11.1 28.9 No.8 Standard composition + 1.5% VC + 1.0% Chemical formula 13 10.9 31.3 No.9 Standard composition + 1.5% VC + 1.0% Formula 17 11.0 28.7

Table 4 shows an electrolyte solution (No. 1) having only a standard composition, an electrolyte solution (No. _{2 ) containing lithium difluorophosphate (LiPO 2} F 2 ), a commercial product, and phosphoric acid synthesized according to an embodiment of the present invention It is a diagram showing the IR of the cell manufactured by using the electrolyte solution (No.3 to No.9) to which the lithium derivative and the lithium borate derivative were added, and then maintained at 70° C. for 1 week.

Specifically, when using the electrolyte solution (No. 3 to No. 9) to which the lithium phosphate derivative and the lithium borate derivative synthesized according to the embodiment of the present invention were added at the same concentration, the commercial product lithium difluorophosphate ( LiPO ₂ F ₂ ) It can be seen that after storage at a higher temperature than when added, the IR value is particularly low, indicating relatively excellent battery characteristics.

<Experimental Example 5> Comparison of changes in DC resistance (hereinafter 'DC-IR') before and after storage at high temperature (70°C)

Item by sample resistance before storage
(mΩ) resistance after storage
(mΩ) No.1 Standard composition (without additives) 34.0 147.8 No.2 Standard composition + 1.5% VC + 1.0% LiPO ₂ F ₂ 29.7 73.4 No.3 Standard composition + 1.5% VC + 1.0% Formula 3 29.2 69.9 No.4 Standard composition + 1.5% VC + 1.0% Formula 4 29.5 71.6 No.5 Standard composition + 1.5% VC + 1.0% Formula 5 29.9 74.9 No.6 Standard composition + 1.5% VC + 1.0% Formula 9 31.9 77.9 No.7 Standard composition + 1.5% VC + 1.0% Formula 11 30.1 74.0 No.8 Standard composition + 1.5% VC + 1.0% Chemical formula 13 29.8 73.5 No.9 Standard composition + 1.5% VC + 1.0% Formula 17 30.5 73.6

Table 5 shows an electrolyte (No. 1) having only a standard composition, an electrolyte (No. _{2 ) containing lithium difluorophosphate (LiPO 2} F 2 ), a commercial product, and phosphoric acid synthesized according to an embodiment of the present invention It is a diagram showing the DC-IR of the cell manufactured by using the electrolyte solution (No.3 to No.9) to which the lithium derivative and the lithium borate derivative were added, and then maintained at 70° C. for 1 week.

Specifically, when the same concentration is added, when the electrolyte solution (No. 3 to No. 9) containing the lithium phosphate derivative and the lithium borate derivative synthesized according to the embodiment of the present invention is used, lower than the case where the additive is not added DC-IR value was exhibited, and it can be seen that the commercial product lithium difluorophosphate (LiPO ₂ F ₂ ) exhibited lower room temperature and high temperature DC-IR values than when added, indicating relatively excellent battery characteristics.

<Experimental Example 6> Comparison of changes in pulse power (hereinafter 'PP') before and after storage at high temperature (70°C)

Item by sample output before storage
(W) Output after storage
(W) No.1 Standard composition (without additives) 83.3 13.8 No.2 Standard composition + 1.5% VC + 1.0% LiPO ₂ F ₂ 95.4 38.0 No.3 Standard composition + 1.5% VC + 1.0% Formula 3 97.0 40.0 No.4 Standard composition + 1.5% VC + 1.0% Formula 4 95.4 39.4 No.5 Standard composition + 1.5% VC + 1.0% Formula 5 94.7 38.4 No.6 Standard composition + 1.5% VC + 1.0% Formula 9 89.7 35.5 No.7 Standard composition + 1.5% VC + 1.0% Formula 11 88.9 36.0 No.8 Standard composition + 1.5% VC + 1.0% Chemical formula 13 84.6 38.1 No.9 Standard composition + 1.5% VC + 1.0% Formula 17 87.2 37.9

Table 6 shows an electrolyte solution having only a standard composition (No. 1), an electrolyte solution containing a commercial product lithium difluorophosphate (LiPO ₂ F ₂ ) (No. 2), and phosphoric acid synthesized according to an embodiment of the present invention It is a diagram showing the PP of the cell manufactured by using the electrolyte solution (No. 3 to No. 9) to which a lithium derivative and a lithium borate derivative are added, and then maintained at 70° C. for 1 week.

Specifically, when the same concentration was added, when the electrolyte solution (No. 3 to No. 9) added with the lithium phosphate derivative and the lithium borate derivative synthesized according to the embodiment of the present invention was used, it was higher than when no additives were added. It can be seen that a PP value was exhibited, and a commercial product, lithium difluorophosphate (LiPO ₂ F ₂ ), was added, resulting in higher room temperature and high temperature PP values, indicating relatively excellent battery characteristics.

As described above, although the present invention has been described with reference to limited embodiments and drawings, the present invention is not limited thereto, and the technical spirit of the present invention and the following by those of ordinary skill in the art to which the present invention pertains. Of course, various modifications and variations are possible within the equivalent scope of the claims to be described.

Claims (19)

An electrolyte for a lithium secondary battery comprising a lithium derivative represented by the following formula (1),
The electrolyte for the lithium secondary battery is 0.01 to 30% by weight of the lithium derivative; Lithium hexafluorophosphate (LiPF ₆ ), lithium tetrafluoroborate (LiBF ₄ ), lithium perchlorate (LiClO ₄ ), lithium trifluoromethanesulfonate (LiCF ₃ SO ₃ ), lithium difluorophosphate (LiPO ₂ F) ₂ ), lithium bis(fluorosulfonyl) _{imide [LiN(FSO 2 ) 2} ], or lithium bis(trifluoromethanesulfonyl)imide [LiN(CF ₃ SO ₂ ) ₂ ] 0.01 to 20 weight %; And the remaining amount of the solvent; Lithium secondary battery electrolyte solution consisting of:
[Formula 1]

X is phosphorus (P) or boric acid (B),
n + m is 4 to 6,
L is a sulfone-based ligand compound including any one hydroxy or amino group selected from HO-SO ₂ -OH, HO-SO ₂ R, HN(SO ₂ R) ₂ , or H-NH-SO _{2 R,}
R is C1 to C10 alkyl, C1 to C10 aryl, halide, or C1 to C10 alkyl halide. The method according to claim 1,
The lithium derivative is
X is phosphorus (P),
n + m is an electrolyte for a lithium secondary battery, characterized in that 6. 3. The method according to claim 2,
The lithium derivative is
Electrolyte for a lithium secondary battery, characterized in that any one selected from the compounds represented by the following Chemical Formulas 2 to 9:
[Formula 2]

[Formula 3]

[Formula 4]

[Formula 5]

[Formula 6]

[Formula 7]

[Formula 8]

[Formula 9]

The method according to claim 1,
The lithium derivative is
X is boric acid (B),
n + m is an electrolyte for a lithium secondary battery, characterized in that 4. 5. The method according to claim 4,
The lithium derivative is
An electrolyte for a lithium secondary battery, characterized in that it is any one selected from the compounds represented by the following Chemical Formulas 10 to 17:
[Formula 10]

[Formula 11]

[Formula 12]

[Formula 13]

[Formula 14]

[Formula 15]

[Formula 16]

[Formula 17]

The method according to claim 1,
The electrolyte solution for a lithium secondary battery,
An electrolyte for a lithium secondary battery, comprising 0.01 to 30% by weight of the lithium derivative according to claim 1 and the remaining amount of the solvent. The method according to claim 1,
The solvent is ethylene carbonate, propylene carbonate, butylene carbonate, ethyl methyl carbonate, dimethyl carbonate, diethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, vinylene carbonate, fluoroethylene carbonate, or halogenated carbonates thereof. Any one selected from the group consisting of carbonates; lactones selected from the group consisting of gamma-butyrolactone, gamma-valerolactone, gamma-caprolactone, delta-valerolactone, and epsilon-caprolactone; Acetates selected from the group consisting of methyl acetate, ethyl acetate, propyl acetate, or methyl propionate, and ethyl propionate; From the group consisting of 3-methoxy glutaronitrile, 3-ethoxy glutaronitrile, 3-dimethylamino glutaronitrile, thiomethoxy succinonitrile, and 2,2,2-trifluoroethoxy glutaronitrile any one selected nitrile; and 1,3-propanesultone, 1,4-butanesultone, 1,3-propensultone, 1,4-butensultone, and 1-methyl-1,3-propensultone An electrolyte for a lithium secondary battery, comprising any one selected from the group consisting of sultones. The method according to claim 1,
The electrolyte solution for a lithium secondary battery,
0.1 M to 2.0 M (mol / ℓ) of lithium hexafluorophosphate (LiPF ₆ ), characterized in that it comprises an electrolyte for a lithium secondary battery. preparing a first mixture by mixing a lithium hexafluorophosphate (LiPF ₆ ) solution or a lithium tetrafluoroborate (LiBF _{4 ) solution and a solvent;}
preparing a second mixture by adding a sulfone-based ligand compound containing a hydroxy or amino group to the first mixture;
adding an organic silyl halide mixture to the second mixture and reacting with stirring; and
preparing a lithium derivative represented by the following Chemical Formula 1 by increasing the temperature of the reaction product and separating it by filtration after reducing the pressure;
A method for preparing a lithium derivative comprising:
[Formula 1]

X is phosphorus (P) or boric acid (B),
n + m is 4 to 6,
L is a sulfone-based ligand compound including any one hydroxy or amino group selected from HO-SO ₂ -OH, HO-SO ₂ R, HN(SO ₂ R) ₂ , or H-NH-SO _{2 R,}
R is C1 to C10 alkyl, C1 to C10 aryl, halide, or C1 to C10 alkyl halide. 10. The method of claim 9,
The solvent is
ethers selected from the group consisting of diethyl ether, diisopropyl ether, and methyl-t-butyl ether; alkoxyethanes of dimethoxyethane and diethoxyethane; esters selected from the group consisting of methyl acetate, ethyl acetate, propyl acetate, and butyl acetate; nitriles selected from the group consisting of acetonitrile, propionitrile, and butyronitrile; hydrocarbons selected from the group consisting of pentane, hexane, and heptane; alcohols selected from the group consisting of methanol, ethanol, propanol, and butanol; ketones selected from the group consisting of acetone, methyl ethyl ketone, and methyl isopropyl ketone; And dimethyl carbonate, diethyl carbonate, and any one carbonate selected from the group consisting of methyl ethyl carbonate; characterized in that any one selected from the group consisting of, a lithium derivative manufacturing method. 10. The method of claim 9,
The organosilyl halide mixture is
A method for preparing a lithium derivative, characterized in that it is a compound represented by the following formula (18):
[Formula 18]

Wherein n is an integer of 1 to 3,
R is the same as or different from each other and is C1 to C10 straight or branched alkyl, C2 to C10 straight or branched alkenyl, or aryl,
X is the same as or different from each other and is chlorine (Cl), bromine (Br), or iodine (I). 12. The method of claim 11,
wherein R is,
A method for producing a lithium derivative, characterized in that any one selected from the group consisting of methyl, ethyl, propyl, and vinyl. 10. The method of claim 9,
The organosilyl halide mixture is
Lithium hexafluorophosphate (LiPF ₆ ) solution compared to 0.1 to 6.0 equivalent ratio, or lithium tetrafluoroborate (LiBF ₄ ) solution compared to 0.1 to 4.0 equivalent ratio, characterized in that used in a lithium derivative production method. A lithium derivative represented by the following formula (1):
[Formula 1]

X is phosphorus (P) or boric acid (B),
n + m is 4 to 6,
L is HO-SO ₂ R, HN(SO ₂ R) ₂ , or H-NH-SO ₂ R is a sulfone-based ligand compound containing any one hydroxy or amino group selected from,
R is C1 to C10 alkyl, C1 to C10 aryl, halide, or C1 to C10 alkyl halide. 15. The method of claim 14,
The lithium derivative is
X is phosphorus (P),
Lithium derivative, characterized in that n + m is 6. 16. The method of claim 15,
The lithium derivative is
A lithium derivative, characterized in that it is any one selected from the compounds represented by the following Chemical Formulas 4 to 9:
[Formula 4]

[Formula 5]

[Formula 6]

[Formula 7]

[Formula 8]

[Formula 9]

15. The method of claim 14,
The lithium derivative is
X is boric acid (B),
Lithium derivative, characterized in that n + m is 4. 18. The method of claim 17,
The lithium derivative is
A lithium derivative, characterized in that it is any one selected from the compounds represented by the following formulas 12 to 17:
[Formula 12]

[Formula 13]

[Formula 14]

[Formula 15]

[Formula 16]

[Formula 17]

The electrolyte according to any one of claims 1 to 8;
a positive electrode in which the electrolyte includes a positive electrode active material capable of intercalating and releasing lithium;
an anode in which the electrolyte includes an anode active material capable of occluding and releasing lithium; and
separator;
comprising, a lithium secondary battery.