KR102179846B1 - Additives composition for electrolyte of lithium secondary battery and manufacturing method thereof - Google Patents

Abstract

The present invention relates to an electrolyte additive composition for a lithium secondary battery and a preparation method therefor. According to the present invention, the electrolyte additive composition for a lithium secondary battery comprises the following chemical formula 3 or chemical formula 4. According to the above-described configuration, the present invention can provide a novel electrolyte additive which is added to an electrolyte for a lithium secondary battery to improve performance of the lithium secondary battery.

Description

Electrolyte additive composition for lithium secondary battery and its manufacturing method {ADDITIVES COMPOSITION FOR ELECTROLYTE OF LITHIUM SECONDARY BATTERY AND MANUFACTURING METHOD THEREOF}

The present invention relates to an electrolyte additive composition for a lithium secondary battery and a method for manufacturing the same, and more particularly, for a lithium secondary battery that can provide a novel electrolyte additive that can improve the performance of a lithium secondary battery by being added to an electrolyte for a lithium secondary battery. It relates to an electrolyte additive composition and a method of manufacturing the same.

In general, batteries are used as a driving power source for portable electronic devices such as video cameras, mobile phones, and notebook computers. The rechargeable lithium secondary battery has more than three times the energy density per unit weight and can be charged at a high speed compared to conventional lead storage batteries, nickel-cadmium batteries, nickel hydride batteries, and nickel zinc batteries.

The demand for such a lithium secondary battery is rapidly increasing, and accordingly, many studies have been conducted on a lithium secondary battery having a high energy density and a discharge voltage, and have been commercialized and widely used.

Compared to other batteries, the lithium secondary battery has advantages such as light weight, small volume, high operating voltage, high energy density, high output power, high charging efficiency, no memory effect, and long lifespan. For this reason, it is widely applied in the field of digital products such as mobile phones and laptop computers, and is considered one of the best choices for electric vehicles and large energy storage devices.

Recently, as the development of medium and large-sized lithium secondary batteries such as electric vehicles progresses, various studies are being conducted to implement high voltage and high capacity lithium secondary batteries.In particular, development of positive electrode active materials and suitable additives to realize high voltage and high capacity Is a necessary situation.

(Prior technical literature)

(Patent Document 01) Domestic registered patent No. 10-1813330 (registered on December 21, 2017)

(Patent Document 02) Korean Patent Publication No. 10-2016-0024414 (published on March 07, 2016)

(Patent Document 03) Korean Patent Publication No. 10-2018-0106972 (published on October 1, 2018)

The present invention is to provide an electrolyte additive composition for a lithium secondary battery and a method of manufacturing the same, which can provide a novel electrolyte additive capable of improving the performance of a lithium secondary battery by being added to an electrolyte for a lithium secondary battery.

In addition, the present invention relates to a sulfur compound including a functional group of imidazole and a triple bond, and to provide an electrolyte additive composition for a lithium secondary battery capable of improving the performance of a lithium secondary battery.

In addition, the present invention is to provide an electrolyte additive composition for a lithium secondary battery capable of having excellent charge and discharge characteristics by forming an electrolyte including a novel additive.

Various problems to be solved by the present invention are not limited to the problems mentioned above, and other problems that are not mentioned will be clearly understood by those skilled in the art from the following description.

The electrolyte additive composition for a lithium secondary battery according to the present invention includes a substituent represented by the following [Chemical Formula 1] or [Chemical Formula 2].

[Formula 1]

[Formula 2]

It may be represented by [Chemical Formula 3] or [Chemical Formula 4] including the functional groups of [Chemical Formula 1] and [Chemical Formula 2].

[Formula 3]

[Formula 4]

An electrolyte additive composition represented by the [Chemical Formula 3] or [Chemical Formula 4]; And an electrolyte solution for a lithium secondary battery including a lithium salt mixture is prepared, the lithium salt mixture is LiPF ₆ , LiClO ₄ , LiAsF ₆ , LiBF ₄ , LiSbF ₆ , LiAlO ₄ , LiAlCl ₄ , LiCF ₃ SO ₃ , LiC ₄ F ₉ SO ₃ , LiN(C ₂ F ₅ SO ₃ ) ₂ , LiN(C ₂ F ₅ SO ₂ ) ₂ , LiN(CF ₃ SO ₂ ) ₂ . LiN(C _x F _{2x +1} SO ₂ )(C _y F _{2y +1} SO ₂ ) (however, x, y are 0 or natural numbers), LiCl, LiI, LiSCN, LiB(C ₂ O ₄ ) ₂ , LiF ₂ At least any one or more lithium salt mixtures selected from the group consisting of BC ₂ O ₄ , LiPF ₄ (C ₂ O ₄ ), LiPF ₂ (C ₂ O ₄ ) ₂ and LiP(C ₂ O ₄ ) ₃ may be used.

In addition, in the method for preparing the electrolyte additive composition for a lithium secondary battery according to the present invention, the compound of the following [Formula 3] is 1,1'-sulfinylbis(1H-imidazole) (1,1'-sulfinylbis(1H) in a flask. -imidazole)), and methylene chloride as a solvent, followed by stirring, a solution of propagyl alcohol diluted with methylene chloride is added dropwise, and when the dropping is complete, the reaction proceeds and water is added to the reaction solution. When the dropping of water is complete, the aqueous layer and the methylene chloride layer are separated in the reaction solution, the methylene chloride layer is washed with the same amount of water, the water of the methylene chloride layer is removed with magnesium sulfate and concentrated in vacuo, Diethyl ether is added to the concentrated residue and crystallized in an ice bath to prepare crystals, and the crystals are vacuum-dried.

[Formula 3]

In addition, in the method for preparing an electrolyte additive composition for a lithium secondary battery according to the present invention, the compound of the following [Formula 4] is 1,1'-sulfonylbis(1H-imidazole) (1,1'-sulfonylbis(1H) in a flask. -imidazole)), and methylene chloride as a solvent, followed by stirring, and a solution obtained by diluting propargyl alcohol with methylene chloride is added dropwise, and when the dropping is complete, the reaction proceeds and water is added to the reaction solution. And the water dropping is complete, the aqueous layer and the methylene chloride layer in the reaction solution are separated, the methylene chloride layer is washed with the same amount of water, the water of the methylene chloride layer is removed with magnesium sulfate, and concentrated in vacuo, Diethyl ether is added to the concentrated residue and crystallized in an ice bath to prepare crystals, and the crystals are vacuum-dried.

[Formula 4]

Details of other embodiments are included in the detailed description.

The present invention provides a novel electrolyte additive capable of improving the performance of a lithium secondary battery by being added to an electrolyte for a lithium secondary battery.

In addition, the present invention is an additive of a sulfur compound including a functional group of imidazole and a triple bond, so that the performance of a lithium secondary battery can be improved.

In addition, according to the present invention, a lithium secondary battery having excellent charging and discharging characteristics can be manufactured by forming an electrolyte including a novel additive.

It will be fully understood that the embodiments of the technical idea of the present invention can provide various effects not specifically mentioned.

Advantages and features of the present invention, and a method of achieving them will become apparent with reference to embodiments described below in detail. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided so that the disclosed content may be thorough and complete, and the spirit of the present invention may be sufficiently conveyed to those skilled in the art.

The terms used in the present application are used only to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise.

Unless otherwise defined, all terms including technical or scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs. Terms such as those defined in a commonly used dictionary should be interpreted as having a meaning consistent with the meaning of the related technology, and should not be interpreted as an ideal or excessively formal meaning unless explicitly defined in this application. Does not.

Hereinafter, a preferred embodiment will be described in detail with respect to the electrolyte additive composition for a lithium secondary battery according to the present invention.

The electrolyte additive composition for a lithium secondary battery according to the present invention includes a substituent represented by the following [Chemical Formula 1] or [Chemical Formula 2].

[Formula 1]

[Formula 2]

In addition, the electrolyte additive composition for a lithium secondary battery according to the present invention may include any one of the compounds represented by the following [Chemical Formula 3] or [Chemical Formula 4].

[Formula 3]

[Formula 4]

The compounds of [Chemical Formula 3] or [Chemical Formula 4] containing substituents of [Chemical Formula 1] and [Chemical Formula 2] included in the electrolyte additive composition for a lithium secondary battery according to the present invention are each of the following [Chemical Formula 5] and [Chemical Formula 6].

[Formula 5]

[Formula 6]

The compound of [Chemical Formula 3] or [Chemical Formula 4] according to the present invention may be prepared by performing a reaction in the following steps.

That is, the compound of [Chemical Formula 3] or [Chemical Formula 4] is a step of reacting the [Chemical Formula 5] or [Chemical Formula 6] compound with the [Chemical Formula 2] compound in an organic solvent, and the imidazole generated after completion of the reaction It may be prepared including the step of removing, and concentrating and recrystallizing the compound [Chemical Formula 3] or [Chemical Formula 4] dissolved in an organic solvent.

In addition, in the present invention, after the step of preparing the reactant, the step of filtering the reactant to obtain a filtrate, and the step of obtaining the filtrate dried under vacuum may be further performed.

In the present invention, the [Chemical Formula 3] and [Chemical Formula 4] compounds can be synthesized in the same manner as in the following reaction formula.

[Scheme 1]

[Scheme 2]

The compounds of [Chemical Formula 3] and [Chemical Formula 4] according to the present invention may be prepared according to [Scheme 1] and [Scheme 2], respectively.

The starting materials for the reaction are 1,1'-sulfinylbis(1H-imidazole) (1,1'-Sulfinylbis(1H-imidazole)), 1,1'-sulfonylbis(1H-imidazole) ( 1,1'-Sulfonylbis (1H-imidazole)) is reacted with propargyl alcohol, and the solvent used in the reaction step is methylene chloride, dichloroethane, diethyl ether, diisopropyl ether, and tetra At least one or more solvents selected from the group consisting of hydrofuran are used, and other than water-immiscible lipophilic organic solvents can be used for synthesis, and solvents not mentioned in the present invention can also be used.

The moisture of the reaction solvent may be 10 to 1000 ppm, preferably 10 to 700 ppm, more preferably 10 to 300 ppm of a solvent.

The propargyl alcohol can be used both for reagents and for industrial use, and the lower the moisture is, the better, but 100 to 2000 ppm, preferably 100 to 1000 ppm, more preferably 100 to 300 ppm can be used to remove moisture.

The reaction temperature may be -5 to 100, preferably -5 to 80, more preferably -5 to 50.

When the moisture is high, the starting materials 1,1'-sulfinylbis(1H-imidazole)(1,1'-Sulfinylbis(1H-imidazole)), 1,1'-sulfonylbis(1H-imidazole) (1,1'-Sulfonylbis(1H-imidazole)) is decomposed by moisture to form impurities.

It is preferable that the reaction proceeds under a nitrogen atmosphere.

The reaction was 1,1'-sulfinylbis(1H-imidazole)(1,1'-Sulfinylbis(1H-imidazole)), 1,1'-sulfonylbis( 1H-imidazole) (1,1'-Sulfonylbis (1H-imidazole)) Each 1 to 4 equivalents are used, preferably 1 to 3 equivalents may be used, and more preferably 1 to 2 equivalents are used. The reaction can proceed.

In addition, the present invention can prepare an electrolyte for a lithium secondary battery including an electrolyte additive composition represented by [Chemical Formula 3] or [Chemical Formula 4], and a lithium salt mixture, wherein the lithium salt mixture is LiPF ₆ , LiClO ₄ , LiAsF ₆ , LiBF ₄ , LiSbF ₆ , LiAlO ₄ , LiAlCl ₄ , LiCF ₃ SO ₃ , LiC ₄ F ₉ SO ₃ , LiN(C ₂ F ₅ SO ₃ ) ₂ , LiN(C ₂ F ₅ SO ₂ ) ₂ , LiN (CF ₃ SO ₂ ) ₂ . LiN(C _x F _2x+1 SO ₂ )(C _y F _2y+1 SO ₂ ) (however, x and y are 0 or a natural number), LiCl, LiI, LiSCN, LiB(C ₂ O ₄ ) ₂ , LiF ₂ At least any one or more lithium salt mixtures selected from the group consisting of BC ₂ O ₄ , LiPF ₄ (C ₂ O ₄ ), LiPF ₂ (C ₂ O ₄ ) ₂ and LiP(C ₂ O ₄ ) ₃ may be used.

< Example 1>

[Formula 3] prop-2- yn -One- yl 1H- imidazole -One- sulfinate Produce

First, a magnetic bar and thermometer are installed in a 250 mL flask, and 20 g of 1,1'-sulfinylbis (1H-imidazole) (1,1'-sulfinylbis (1H-imidazole)) is added. After adding 50 g of methylene chloride having a moisture content of 100 ppm or less as a solvent, the mixture is stirred, and a solution obtained by diluting 3 g of propargyl alcohol with 30 g of methylene chloride is gradually added dropwise. When the dropping is completed, the reaction proceeds for 1 hour, and 50 mL of water is gradually added dropwise to the reaction solution. When the water dropping is complete, the aqueous layer and the methylene chloride layer in the reaction solution are separated, the methylene chloride layer is washed once more with the same amount of water, and the methylene chloride layer is dried with magnesium sulfate and concentrated in vacuo. 10 g of diethyl ether is added to the concentrated residue and crystallized in an ice bath of 0-5 to prepare crystals.

Next, the crystals were vacuum-dried to obtain 5 g of the target product (ie, [Chemical Formula 3]), where the yield is about 55%.

< Example 2>

[Formula 4] prop-2- yn -One- yl 1H- imidazole -One- sulfonate Produce

First, a magnetic bar and a thermometer are installed in a 250 mL flask, and 21.2 g of 1,1'-sulfonylbis (1H-imidazole) (1,1'-sulfonylbis (1H-imidazole)) is added. After adding 50 g of methylene chloride having a moisture content of 100 ppm or less as a solvent, the mixture is stirred, and a solution obtained by diluting 3 g of propargyl alcohol with 30 g of methylene chloride is gradually added dropwise. When the dropping is complete, the reaction proceeds for 1 hour, and 50 mL of water is gradually added dropwise to the reaction solution. When the water dropping is complete, the aqueous layer and the methylene chloride layer in the reaction solution are separated, the methylene chloride layer is washed once more with the same amount of water, and the methylene chloride layer is dried with magnesium sulfate and concentrated in vacuo. 10 g of diethyl ether is added to the concentrated residue and crystallized in an ice bath of 0-5 to prepare crystals.

Next, the crystal was vacuum-dried to obtain 4.2 g of the target material (ie, [Chemical Formula 4]), and the yield was about 43%.

In the above, a preferred embodiment of the present invention has been described, but those of ordinary skill in the art to which the present invention pertains will understand that the present invention can be implemented in other specific forms without changing the technical spirit or essential features. I will be able to. Therefore, it should be understood that the exemplary embodiment described above is illustrative in all respects and is not limiting.

Claims (5)

Including a substituent represented by the following [Formula 1] or [Formula 2],
An electrolyte additive composition for a lithium secondary battery, characterized in that represented by [Chemical Formula 3] or [Chemical Formula 4] including the functional groups of [Chemical Formula 1] and [Chemical Formula 2].
[Formula 1]

[Formula 2]

[Formula 3]

[Formula 4]

delete The method according to claim 1,
An electrolyte additive composition represented by the [Chemical Formula 3] or [Chemical Formula 4]; And
An electrolyte solution for a lithium secondary battery is prepared including a lithium salt mixture,
The lithium salt mixture is LiPF ₆ , LiClO ₄ , LiAsF ₆ , LiBF ₄ , LiSbF ₆ , LiAlO ₄ , LiAlCl ₄ , LiCF ₃ SO ₃ , LiC ₄ F ₉ SO ₃ , LiN(C ₂ F ₅ SO ₃ ) ₂ , LiN (C ₂ F ₅ SO ₂ ) ₂ , LiN(CF ₃ SO ₂ ) ₂ . LiN(C _x F _2x+1 SO ₂ )(C _y F _2y+1 SO ₂ ) (however, x and y are 0 or a natural number), LiCl, LiI, LiSCN, LiB(C ₂ O ₄ ) ₂ , LiF ₂ BC ₂ O ₄ , LiPF ₄ (C ₂ O ₄ ), LiPF ₂ (C ₂ O ₄ ) ₂ and LiP (C ₂ O ₄ ) ₃ characterized by using at least one or more lithium salt mixture selected from the group consisting of An electrolyte additive composition for a lithium secondary battery.
For the compound of the following [Formula 3], 1,1'-sulfinylbis(1H-imidazole) (1,1'-sulfinylbis(1H-imidazole)) was added to the flask, and methylene chloride was added as a solvent. After stirring, a solution obtained by diluting propargyl alcohol with methylene chloride is added dropwise, and when the dropping is complete, the reaction proceeds and water is added dropwise to the reaction solution.When the dropping of water is completed, the aqueous layer and methylene in the reaction solution The chloride layer was separated, the methylene chloride layer was washed with an equal amount of water, the water of the methylene chloride layer was removed with magnesium sulfate and concentrated in vacuo, and diethyl ether was added to the concentrated residue, followed by crystallization in an ice bath. And, the method for producing an electrolyte additive composition for a lithium secondary battery, characterized in that produced by vacuum drying the crystal.
[Formula 3]

For the compound of the following [Formula 4], 1,1'-sulfonylbis (1H-imidazole) (1,1'-sulfonylbis (1H-imidazole)) was added to the flask, and methylene chloride was added as a solvent. After stirring, a solution obtained by diluting propargyl alcohol with methylene chloride is added dropwise, and when the dropping is complete, the reaction proceeds and water is added dropwise to the reaction solution.When the dropping of water is completed, the aqueous layer and methylene in the reaction solution The chloride layer was separated, the methylene chloride layer was washed with an equal amount of water, the water of the methylene chloride layer was removed with magnesium sulfate and concentrated in vacuo, and diethyl ether was added to the concentrated residue, followed by crystallization in an ice bath. And, the method for producing an electrolyte additive composition for a lithium secondary battery, characterized in that produced by vacuum drying the crystal.
[Formula 4]