KR20210028940A - Electrolyte composition technology for high charge rate of lithium ion battery - Google Patents

Abstract

The present invention relates to a functional electrolyte composition for a lithium ion battery capable of suppressing gas generation due to volatilization of an electrolyte in the battery and to a lithium ion battery comprising the same. According to one aspect of the present invention, the functional electrolyte composition for a lithium ion battery comprises: lithium salt; an organic solvent including a carbonate-based solvent and an ester-based solvent; and an additive.

Description

Electrolyte composition technology for high-speed charging of high-energy-density lithium secondary batteries {ELECTROLYTE COMPOSITION TECHNOLOGY FOR HIGH CHARGE RATE OF LITHIUM ION BATTERY}

The present invention relates to a functional electrolyte composition for a lithium ion battery and a lithium ion battery comprising the same.

A lithium-ion battery (Li-ion battery) is a type of secondary battery, in which lithium ions move from the negative electrode to the positive electrode during a discharge process, and lithium ions move from the positive electrode to the negative electrode during charging.

Lithium-ion batteries are widely used in portable electronic devices on the market because of their high energy density, no memory effect, and a small degree of self-discharge even when not in use.

Lithium-ion batteries have not only achieved commercial success as a power source for portable electronic products, but have also successfully entered the power tool market, and are pursuing full-scale expansion into the electric vehicle and power storage markets in the future.

In this trend, in order to continuously expand the market of lithium-ion batteries, it is necessary to secure high energy density, high power discharge, and safety at the same time, while securing fast charging characteristics.

Accordingly, studies are being conducted to develop rapid charging performance of lithium ion batteries around the world, but most of the studies are being conducted focusing on the development of electrode materials, and studies in terms of electrolyte are hardly performed.

The current battery system is using the electrode by increasing the thickness and density of the electrode to increase the energy density. When using an existing commercially available electrolyte for an electrode with a high thickness and density, there are areas where the electrolyte is not impregnated between the electrode particles. There arises a problem of increasing the resistance of the.

In addition, when rapid charging is performed using an existing commercially available electrolyte, a film that can easily move lithium ions is not formed on the surface of the electrode, so that the charge transfer resistance at the electrode interface increases, resulting in a problem that the performance of the battery is degraded. Occurs.

In addition, in the case of a low-viscosity, high-ionic-conductivity electrolyte that is effective in rapid charging characteristics in a commercially available electrolyte, the high volatility causes gas generation in the battery, and the generation of such gas is a factor that directly affects the stability problem of the battery.

Accordingly, there is a need to develop an electrolyte solution to solve problems such as a decrease in impregnation of the electrolyte solution during rapid charging, a decrease in lithium ion migration, and volatilization of the electrolyte solution in a battery.

The present invention is to solve the above-described problems, and an object of the present invention is to improve impregnation between electrode particles and lithium ion mobility at the electrode interface during rapid charging, and to generate gas due to volatilization of the electrolyte in the battery. It is to provide a functional electrolyte composition for a lithium ion battery capable of suppressing.

However, the problem to be solved by the present invention is 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.

One aspect of the present invention, lithium salt; An organic solvent including a carbonate-based solvent and an ester-based solvent; And it provides a functional electrolyte composition for a lithium ion battery containing;

According to an embodiment, the organic solvent may include a carbonate-based solvent including a compound represented by the following formula (1) and an ester-based solvent including a compound represented by the following formula (2).

[Formula 1]

,

,

[Formula 2]

According to an embodiment, the additive may include a compound represented by Formula 3 below.

[Formula 3]

According to an embodiment, the concentration of the lithium salt may be 0.1 M to 3 M.

According to an embodiment, the organic solvent may be from 10 vol% to 30 vol% of the organic solvent, and the ester solvent may be from 70 vol% to 90 vol%.

According to an embodiment, the content of the additive may be in the range of 0.1% by weight to 10% by weight.

According to an embodiment, the lithium salt is, LiPF ₆ , LiClO ₄ , LiBF ₄ , LiFSI, LiTFSI, LiSO ₃ CF ₃ , LiBOB, LiFOB, LiDFBP, LiTFOP, LiPO ₂ F ₂ , LiCl, LiBr, LiI, LiB _{10 Cl 10, LiCF 3 SO 3,} LiCF 3 CO 2, LiAsF 6, LiSbF 6, LiAlCl 4, CH 3 SO 3 Li, CF 3 SO 3 Li, LiSCN and LiC (CF ₃ SO ₂₎ is selected from the group consisting of ₃ It may include at least any one.

According to an embodiment, the carbonate-based solvent is ethylene carbonate, propylene carbonate, vinylene carbonate, vinyl ethylene carbonate, dimethyl carbonate, It may include at least one selected from the group consisting of ethylmethyl carbonate and diethyl carbonate.

According to an embodiment, the ester-based solvent is methyl propionate, propyl propionate, butyl propionate, methyl butyrate, ethyl butyrate. butyrate), propyl butyrate, butyl butyrate, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, butyrolactone ), decanolide, valerolactone, mevalonolactone, and caprolactone.

According to one embodiment, the additive includes at least one selected from the group consisting of tris (trimethylsilyl) phosphate, fluoroethylene carbonate, and vinylene carbonate. It can be.

According to an embodiment, the organic solvent may be one to form a cathode film.

According to an embodiment, the additive may be one _{to remove HF and stabilize PF 5.}

Another aspect of the invention, the anode; cathode; An ion-permeable separator formed between the anode and the cathode; And it provides a lithium ion battery containing; and a functional electrolyte prepared from the functional electrolyte composition for a lithium ion battery of any one of claims 1 to 12.

The electrolyte composition for a lithium ion battery according to the present invention includes an organic solvent including a carbonate-based solvent and an ester-based solvent, and a functional additive, thereby improving fast charging characteristics and stability of a lithium-ion battery.

Specifically, the electrolyte composition for a lithium ion battery according to the present invention improves the stability of the negative electrode interface by forming a negative electrode film, and prevents damage to the positive electrode and negative electrode interfaces by controlling side reactions, thereby improving the fast charge life characteristics. have.

In addition, according to the low viscosity characteristics, impregnation characteristics into the pores of the high alloy electrode are improved, lithium ion mobility is increased, overvoltage is reduced during high-speed charging, and gas generation in the battery is suppressed due to a decrease in volatility.

1 is a result of evaluation of life characteristics according to a fast charging rate of a full cell composed of NCM811/SIC.
2 is a SEM image and EDS analysis results of the interface of the SIC cathode after 150 cycles.
3 is an SEM image of the interface of the SIC cathode after 150 cycles.
4 is a voltage profile of a first cycle of 2C charge/1C discharge of a full cell using the electrolyte compositions of Example 1 and Comparative Example 1. FIG.
5 is a graph showing the results of comparing the volatility of the electrolyte compositions of Example 1 and Comparative Example 2.
^{6 is a 19} F NMR analysis result of the electrolyte composition of Comparative Example 1.
^{7 shows the results of 19} F NMR analysis of the electrolyte composition in Example 1. FIG.

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. However, since various changes may be made to the embodiments, the scope of the patent application is not limited or limited by these embodiments. It is to be understood that all changes, equivalents, or substitutes to the embodiments are included in the scope of the rights.

The terms used in the examples are used for illustrative purposes only and should not be construed as limiting. Singular expressions include plural expressions unless the context clearly indicates otherwise. In the present specification, terms such as "comprise" or "have" are intended to designate the presence of features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, but one or more other features. It is to be understood that the presence or addition of elements or numbers, steps, actions, components, parts, or combinations thereof does not preclude in advance.

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

In addition, when it is determined that a detailed description of a related known technology may unnecessarily obscure the subject matter of the embodiment in describing the embodiment, the detailed description thereof will be omitted.

Hereinafter, a functional electrolyte composition for a lithium ion battery of the present invention will be described in detail with reference to Examples and drawings. However, the present invention is not limited to these examples and drawings.

One aspect of the present invention, lithium salt; An organic solvent including a carbonate-based solvent and an ester-based solvent; And it provides a functional electrolyte composition for a lithium ion battery containing;

The functional electrolyte composition for a lithium ion battery according to the present invention improves the electrochemical performance of a high energy, high density lithium ion battery, and in particular, has an effect of improving fast charging characteristics.

According to an embodiment, the organic solvent may include a carbonate-based solvent including a compound represented by the following formula (1) and an ester-based solvent including a compound represented by the following formula (2).

[Formula 1]

,

,

[Formula 2]

According to an embodiment, the compound represented by Formula 1 is a fluorinated cyclic carbonate-based compound, and may act as a'cathode coating agent solvent'.

Specifically, the solvent containing the compound represented by Chemical Formula 1 may increase the LiF component in the negative electrode of the lithium ion battery to form a negative electrode film, thereby increasing the stability of the negative electrode interface (SEI), resulting in high-speed charging performance. Can improve.

That is, the formed negative electrode film is stably maintained even after a fast charging cycle, suppressing formation of lithium dendrites at the negative electrode interface and effectively suppressing decomposition of salts, thereby improving fast charging life characteristics.

According to one embodiment, the electrolyte composition for a lithium ion battery may have a characteristic of containing a large amount of the compound represented by Formula 1 as a solvent beyond the range of additives.

Effective factors that determine the high-speed charging performance of a lithium ion battery include viscosity and interfacial properties, and in particular, interfacial properties dominate.

The lithium ion electrolyte composition according to the present invention contains the compound represented by Formula 1 as an organic solvent to secure the stability of the negative electrode interface through the formation of the negative electrode film, thereby improving long-term stability of the electrode and high-speed charging performance.

According to an embodiment, the compound represented by Formula 2 is an ester compound and serves to reduce the volatility of the electrolyte.

Specifically, the compound represented by Formula 2 has a relatively high boiling point compared to dimethyl carbonate (DMC), which is a component of a commercially available electrolyte, so that the volatility of the electrolyte can be reduced. You can reduce the pressure.

In addition, since it has a relatively low viscosity, it is possible to increase the mobility of lithium ions in the electrolyte solution, improve the impregnation characteristics into the pores inside the electrode, and increase the dissociation degree of lithium salt from the solvent at the negative electrode interface because it has a relatively high dielectric constant. By doing so, the mobility of lithium ions can be increased.

In particular, during high-speed charging of lithium ions, non-uniform distribution of lithium ions in the electrolyte solution occurs, and the concentration of lithium ions at the anode interface increases rapidly.Therefore, it is necessary to increase the mobility of lithium ions in the electrolyte in order to improve the fast charging characteristics. There is.

The lithium ion electrolyte composition according to the present invention contains the compound represented by Formula 2 as an organic solvent, so that the mobility of lithium ions in the electrolyte may be increased, and the reversible capacity is reduced by reducing the overvoltage inside the battery during high-speed charging. It can be improved, and the stability of the battery can be improved by reducing gas generation in the battery.

According to an embodiment, the additive may include a compound represented by Formula 3 below.

[Formula 3]

The compound represented by Chemical Formula 3 decomposes hydrogen fluoride (HF) _{and stabilizes PF 5} by a pair of unshared electrons of nitrogen atoms, thereby suppressing the hydrolysis reaction cycle of the salt in the electrolyte.

Specifically, HF is decomposed to prevent decomposition of the electrode film structure due to this, and by _{stabilizing PF 5,} the hydrolysis cycle of the lithium salt can be suppressed, thereby preventing the generation of additional hydrogen fluoride.

In addition, through this, discoloration and changes in physical properties of the electrolyte composition are minimized, so that long-term storage of the electrolyte composition can be secured.

According to an embodiment, the concentration of the lithium salt may be 0.1 M to 3 M.

If the concentration of the lithium salt is less than 0.1 M, the conductivity of the electrolyte composition may be lowered, resulting in poor electrolyte performance, and if it exceeds 3 M, the viscosity of the electrolyte composition increases, resulting in decreased mobility of lithium ions, and overvoltage occurs from the beginning of the cycle. Can occur.

According to an embodiment, the organic solvent may be from 10 vol% to 30 vol% of the organic solvent, and the ester solvent may be from 70 vol% to 90 vol%.

Specifically, among the organic solvents, if the carbonate-based solvent is less than 10% by volume, the negative electrode film is not sufficiently formed, so that the stability of the negative electrode interface may be deteriorated, and if it exceeds 30% by volume, the viscosity of the electrolyte composition may be increased. .

In addition, among the organic solvents, when the ester-based solvent is less than 70% by volume, the mobility of lithium ions may decrease and volatility may increase. When it exceeds 90% by volume, the negative electrode due to the relative decrease of the carbonate-based solvent The stability of the interface may be deteriorated.

The electrolyte composition according to the present invention contains a carbonate-based solvent and an ester-based solvent in an organic solvent in a specific volume ratio, thereby effectively controlling viscosity and interfacial properties for improving fast charging performance.

According to an embodiment, the content of the additive may be in the range of 0.1% by weight to 10% by weight.

If the content of the additive is less than 0.1% by weight of the total weight of the electrolyte composition, the HF in the electrolyte is not removed, so LiOCO ₂ R, Li ₂ CO _{3 present on the anode surface} LIF may be formed on the surface of the positive electrode by reaction with the like, so that the interface resistance may increase, damage may occur at the interface of the positive electrode and the negative electrode due to not removing HF, and a change in physical properties of the electrolyte composition may occur. In addition, when the content of the additive exceeds 10% by weight of the total weight of the electrolyte composition, the viscosity of the electrolyte composition may increase.

According to an embodiment, the lithium salt is, LiPF ₆ , LiClO ₄ , LiBF ₄ , LiFSI, LiTFSI, LiSO ₃ CF ₃ , LiBOB, LiFOB, LiDFBP, LiTFOP, LiPO ₂ F ₂ , LiCl, LiBr, LiI, LiB _{10 Cl 10, LiCF 3 SO 3,} LiCF 3 CO 2, LiAsF 6, LiSbF 6, LiAlCl 4, CH 3 SO 3 Li, CF 3 SO 3 Li, LiSCN and LiC (CF ₃ SO ₂₎ is selected from the group consisting of ₃ It may include at least any one.

The lithium salt may have high compatibility with materials such as aluminum and copper that can be used as a positive electrode current collector or a negative electrode current collector, and in this case, certain lithium salts have low resistance to oxidation in the negative electrode and risk of corroding the positive electrode. There may be a problem with this problem, but this problem can be solved by appropriately mixing two or more substances in the above-described lithium salt substance group.

According to an embodiment, the carbonate-based solvent is ethylene carbonate, propylene carbonate, vinylene carbonate, vinyl ethylene carbonate, dimethyl carbonate, It may include at least one selected from the group consisting of ethylmethyl carbonate and diethyl carbonate.

The compounds contained in the carbonate-based solvents listed above may be included alone or in combination of two or more, and may be included in a mixture with the compound represented by Formula 1 above.

According to an embodiment, the ester-based solvent is methyl propionate, propyl propionate, butyl propionate, methyl butyrate, ethyl butyrate. butyrate), propyl butyrate, butyl butyrate, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, butyrolactone ), decanolide, valerolactone, mevalonolactone, and caprolactone.

The compounds contained in the ester-based solvents listed above may be included alone or in combination of two or more, and may be included by mixing with the compound represented by Formula 2 above.

According to one embodiment, the additive includes at least one selected from the group consisting of tris (trimethylsilyl) phosphate, fluoroethylene carbonate, and vinylene carbonate. It can be.

The compounds included in the above-listed additives may be included alone or in combination of two or more compounds, and may be included by mixing with the compound represented by Formula 3 above.

According to an embodiment, the organic solvent may be one to form a cathode film.

According to an embodiment, the negative electrode film may mean a film formed on a solid electrolyte interface (SEI) formed by reacting an electrolyte solution and a negative electrode.

The negative electrode film prevents the interface of the negative electrode solid electrolyte from being damaged by hydrogen fluoride, thereby improving fast charge life characteristics and increasing the stability of the battery.

According to an embodiment, the additive may be one _{to remove HF and stabilize PF 5.}

The additive not only prevents damage to the electrode interface through HF removal, but also suppresses the generation of additional HF by inhibiting the hydrolysis cycle of the lithium salt through stabilization of _{PF 5.}

Through this, it is possible to improve the electrochemical properties and life performance of a high-energy, high-density lithium-ion battery composed of a silicon-carbon-based negative electrode and a layered positive electrode.

Another aspect of the invention, the anode; cathode; An ion-permeable separator formed between the anode and the cathode; And it provides a lithium ion battery containing; and a functional electrolyte prepared from the functional electrolyte composition for a lithium ion battery of any one of claims 1 to 12.

According to one embodiment, the negative electrode is not particularly limited as long as it is a negative electrode active material capable of adsorbing and releasing lithium ions.

According to an embodiment, the lithium ion battery may further include a solid electrolyte interface (SEI) layer formed on the surface of the negative electrode.

According to an embodiment, various materials may be used as the positive electrode active material for the positive electrode, and components thereof are not particularly limited.

According to an embodiment, the separator is interposed between the anode and the cathode, and is not particularly limited as long as it can be used as an insulating thin film having high ion permeability and mechanical strength.

Hereinafter, the present invention will be described in more detail by examples and comparative examples.

However, the following examples are for illustrative purposes only, and the contents of the present invention are not limited to the following examples.

< Example 1>

_{A lithium salt (LiPF 6)} was added at a concentration of 1.15 M to an organic solvent containing fluoroethylene carbonate (FEC) and ethyl propionate (EP) in a 3: 7 volume ratio, An electrolyte composition was prepared by adding trimethylsilyl isocyanate (TMSNCS) in an amount of 0.1% by weight.

< Comparative example 1>

_{Lithium salt (LiPF 6)} was added at a concentration of 1.15 M to an organic solvent containing ethyl propionate (EP), ethyl methyl carbonate (EMC), and diethyl carbonate (DEC) in a volume ratio of 3: 6: 1, and fluoro An electrolyte composition was prepared by adding 1% by weight of ethylene carbonate (FEC) and 1% by weight of vinylene carbonate (VC).

< Comparative example 2>

_{A lithium salt (LiPF 6)} was added at a concentration of 1.15 M to an organic solvent containing fluoroethylene carbonate (FEC) and dimethyl carbonate (DMC) in a 3: 7 volume ratio, An electrolyte composition was prepared by adding trimethylsilyl isocyanate (TMSNCS) in an amount of 0.1% by weight.

< Experimental example 1> Fast charging life characteristics evaluation

Using the electrolyte compositions of Example 1 and Comparative Example 1, the fast charge life characteristics in full cells were evaluated, and the evaluation results are shown in FIGS. 1 and 1.

At the time of evaluation, the experimental conditions were as follows, and the same was applied to the subsequent experiments.

Cell type: LiNi _{0 . 8} Co _{0 . 1} Mn _{0 . 1} O ₂ /Silicon-Graphite composite coin type full cell

Positive/negative loading: 22.82 mg/cm ² / 9.92 mg/cm ²

1 is a result of evaluation of life characteristics according to a fast charging rate of a full cell composed of NCM811/SIC.

Referring to Figure 1, in the full cell using the Example 1 electrolyte composition (EP, FEC), compared to the full cell using the Comparative Example 1 electrolyte composition (EP, EMC, DEC), charging high rate of 2 C or more It can be seen that the charging characteristics at are greatly improved.

This can be formed by the reaction of _{LiOCO 2} R, Li ₂ CO ₃ and HF present in the anode surface by increasing the stability of the cathode film interface by the FEC of Example 1, and the additive effectively suppressing HF in the electrolyte solution. This is a result of suppressing the formation of LiF.

Here, the formation mechanism of LiF is as follows.

LiOCO ₂ R + HF → LiF + ROH + CO ₂

Li ₂ CO ₃ + 2HF →2LiF + CO ₂ + H ₂ O

Table 1 shows the capacity retention rate after ^{1 st} , 150 ^th capacity and 150 life cycles in a full cell using the electrolyte composition of Example 1 and Comparative Example 1.

1 ^st capacity
(mAh/g) 150 ^th capacity
(mAh/g) Capacity retention
(%) Comparative Example 1 143.9 48.9 34.0 Example 1 145.0 94.6 65.2

As shown in Table 1, it can be seen that the capacity retention rate is about twice as high after 150 lifetimes in the full cell using the Example 1 electrolyte composition.

< Experimental example 2> Analysis of cathode surface after fast charging cycle

Using the electrolyte compositions of Example 1 and Comparative Example 1, after evaluating the fast charge life characteristics in a full cell, surface analysis was performed using a scanning electron microscope (SEM) and an energy dispersive spectroscopy (EDS).

2 is a SEM image and EDS analysis results of the interface of the SIC cathode after 150 cycles.

Referring to FIG. 2, it can be seen that the formation of lithium dendrites on the surface of the negative electrode was suppressed in the case of using the electrolyte composition of Example 1, compared to the case of using the electrolyte composition of Comparative Example 1. Through this, it can be seen that the negative electrode interface film formed by FEC is safely maintained even after the fast charging cycle.

In addition, when the electrolyte composition in Comparative Example 1 was used, phosphorus (P) and fluorine (F) elements were detected in large amounts due to the decomposition of the salt along with the formation of lithium dendrites on the surface, but when the electrolyte composition in Example 1 was used, phosphorus (P) It was confirmed that the number of elements was significantly reduced, and through this, it was found that the negative electrode interface film formed by FEC effectively inhibited lithium salt decomposition as well.

3 is an SEM image of the interface of the SIC cathode after 150 cycles.

Referring to FIG. 3, when the electrolyte composition of Example 1 is used, the shape of the silicon particles on the surface of the negative electrode is maintained even after the cycle, but when the electrolyte composition of Comparative Example 1 is used, it can be seen that the shape of the silicon particles on the surface of the negative electrode is collapsed after the cycle.

< Experimental example 3> Comparison of overvoltage inside the battery during fast charging

In full cells using the electrolyte compositions of Example 1 and Comparative Example 1, voltage profiles were observed during charging and discharging.

4 is a voltage profile of a first cycle of 2C charge/1C discharge of a full cell using the electrolyte compositions of Example 1 and Comparative Example 1. FIG.

Referring to FIG. 4, when using the electrolyte composition of Example 1, the use of ethyl propionate (EP), which is an ultra-low viscosity solvent, lowers the viscosity of the electrolyte composition, so that the overvoltage inside the cell is reduced during high-speed charging. Can, which means that the reversible capacity is improved.

< Experimental example 4> Comparison of volatility of electrolyte composition

The volatility of the electrolyte compositions of Example 1 and Comparative Example 2 was compared.

5 is a graph showing the results of comparing the volatility of the electrolyte compositions of Example 1 and Comparative Example 2.

Referring to FIG. 5, it can be seen that the electrolyte composition of Example 1 has reduced volatility than that of the electrolyte composition of Comparative Example 1.

This is a result shown because the boiling point of ethyl propionate (EP) included in Example 1 is relatively high. When using the electrolyte composition of Example 1, an effect of reducing the pressure inside the cell through suppression of gas generation can be expected.

< Experimental example 5> ¹⁹ HF inhibition and PF of additives through F NMR analysis ₅ Checking the stabilization effect

After adding 1% by weight of water to the electrolyte compositions of Example 1 and Comparative Example 1, storage was performed at room temperature for 24 hours, and a hydrolysis side reaction product of _{LiPF 6} ^{salt was analyzed through 19} F NMR analysis.

^{6 is a 19} F NMR analysis result of the electrolyte composition of Comparative Example 1.

^{7 shows the results of 19} F NMR analysis of the electrolyte composition in Example 1. FIG.

6 and 7, it can be seen _{that HF and PO 3} F ^{2 -} were not found in the electrolyte composition of Example 1, compared with the electrolyte composition of Comparative Example 1.

That is, it can be seen that the use of a small amount of the TMSNCS additive of Example 1 reduces the decomposition reaction of the salt due _{to HF removal and stabilization of PF 5.}

As described above, although the embodiments have been described by the limited drawings, a person of ordinary skill in the art can apply various technical modifications and variations based on the above. For example, even if the described techniques are performed in a different order from the described method, and/or the described components are combined or combined in a form different from the described method, or are replaced or substituted by other components or equivalents. Appropriate results can be achieved. Therefore, other implementations, other embodiments, and claims and equivalents fall within the scope of the following claims.

Claims (13)

Lithium salt;
An organic solvent including a carbonate-based solvent and an ester-based solvent; And
Containing an additive;
Functional electrolyte composition for lithium ion batteries.
The method of claim 1,
The organic solvent,
It includes a carbonate-based solvent containing a compound represented by the following formula (1) and an ester-based solvent containing a compound represented by the following formula (2),
Functional electrolyte composition for lithium ion batteries:
[Formula 1]

,
[Formula 2]

. The method of claim 1,
The additive,
It includes a compound represented by the following formula (3),
Functional electrolyte composition for lithium ion batteries:
[Formula 3]

.
The method of claim 1,
The concentration of the lithium salt is 0.1 M to 3 M,
Functional electrolyte composition for lithium ion batteries.
The method of claim 1,
The organic solvent,
Among the organic solvents, the carbonate-based solvent is 10% to 30% by volume, and the ester-based solvent is 70% to 90% by volume,
Functional electrolyte composition for lithium ion batteries.
The method of claim 1,
The content of the additive is 0.1% to 10% by weight,
Functional electrolyte composition for lithium ion batteries.
The method of claim 1,
The lithium salt,
LiPF ₆ , LiClO ₄ , LiBF ₄ , LiFSI, LiTFSI, LiSO ₃ CF ₃ , LiBOB, LiFOB, LiDFBP, LiTFOP, LiPO ₂ F ₂ , LiCl, LiBr, LiI, LiB ₁₀ Cl ₁₀ , LiCF ₃ SO ₃ , LiCF ₃ CO _2, the _{LiAsF 6, LiSbF 6, LiAlCl 4} , CH 3 SO 3 Li, CF 3 SO 3 Li, to include at least one that LiSCN and LiC (CF ₃ SO ₂₎ selected from the group consisting of _3,
Functional electrolyte composition for lithium ion batteries.

The method of claim 1,
The carbonate-based solvent,
Ethylene carbonate, propylene carbonate, vinylene carbonate, vinyl ethylene carbonate, dimethyl carbonate, ethylmethyl carbonate, and diethyl carbonate ( Diethyl carbonate) containing at least one selected from the group consisting of,
Functional electrolyte composition for lithium ion batteries.
The method of claim 1,
The ester solvent,
Methyl propionate, propyl propionate, butyl propionate, methyl butyrate, ethyl butyrate, propyl butyrate, butyl butyrate (butylbutyrate), methyl acetate, ethyl acetate, propyl acetate, butyl acetate, butyrolactone, decanolide, valerolactone ( Valerolactone), mevalonolactone (Mevalonolactone) and caprolactone (Caprolactone) that comprises at least any one selected from the group consisting of,
Functional electrolyte composition for lithium ion batteries.
The method of claim 1,
The additive,
Tris (trimethylsilyl) phosphate (Tris (trimethylsilyl) phosphate), fluoroethylene carbonate (Fluoroethylene carbonate) and vinylene carbonate (Vinylene carbonate) to contain at least one selected from the group consisting of,
Functional electrolyte composition for lithium ion batteries.
The method of claim 1,
The organic solvent is to form a cathode film,
Functional electrolyte composition for lithium ion batteries.
The method of claim 1,
The additive is to remove HF and stabilize _{PF 5,}
Functional electrolyte composition for lithium ion batteries.
anode;
cathode;
An ion-permeable separator formed between the anode and the cathode; And
Including; a functional electrolyte prepared from the functional electrolyte composition for a lithium ion battery of any one of claims 1 to 12
Lithium ion battery.

Images