KR101137139B1 - Non-aqueous electrolyte and secondary battery comprising the same - Google Patents

Abstract

The present invention relates to a secondary battery using a compound containing a sulfonate group and a lactone group as one constituent of an electrolyte solution, thereby forming a more compact and stable SEI film on the surface of a negative electrode, thereby improving capacity storage characteristics and lifetime performance of the battery.

Description

Non-aqueous electrolyte and secondary battery comprising same {NON-AQUEOUS ELECTROLYTE AND SECONDARY BATTERY COMPRISING THE SAME}

The present invention is a non-aqueous electrolyte; And it relates to a secondary battery comprising the same. More specifically, the present invention provides a non-aqueous electrolyte containing a compound capable of improving capacity storage characteristics and lifespan performance of a secondary battery; And it relates to a secondary battery comprising the same.

In recent years, with the trend of miniaturization and weight reduction of electronic devices, miniaturization and weight reduction of batteries serving as power sources are also required. BACKGROUND ART Secondary batteries have been put to practical use as small-sized, light-weight, high-capacitance rechargeable batteries, and are used in portable electronic and communication devices such as small video cameras, mobile phones, and notebook computers.

The secondary battery may be composed of a positive electrode, a negative electrode, a porous separator, and a non-aqueous electrolyte containing an electrolyte salt and an electrolyte solvent.

The non-aqueous electrolyte generally requires the following characteristics with respect to the operation and use of the battery. First, it must be able to sufficiently transfer ions between two electrodes during insertion and desorption of lithium ions from the cathode and anode, and second, it is electrochemically stable at the potential difference between the two electrodes, so that there is little concern about side reactions such as decomposition of electrolyte components. All.

However, the potential difference between a carbon electrode and a lithium metal compound electrode, which is commonly used as a battery negative electrode and a positive electrode, is in the range of 0 to 4.3 V, and a conventional electrolyte solvent such as a carbonate-based organic solvent decomposes at the electrode surface during charge and discharge at the potential difference. May cause side reactions in the battery. In addition, an organic solvent such as propylene carbonate (PC), dimethyl carbonate (DMC), or diethyl carbonate (DEC) may be co-intercalated between graphite layers in the carbon-based negative electrode, thereby disrupting the structure of the negative electrode.

On the other hand, it is known that the problem can be solved by a solid electrolyte interface (SEI) film formed on the surface of the negative electrode by electrical reduction of the carbonate-based organic solvent during the initial charging of the battery. However, when the SEI film is formed, lithium ions in the electrolyte are irreversibly involved, resulting in a decrease in battery capacity. In addition, the SEI film is generally not electrochemically or thermally stable, and may easily be collapsed by increased electrochemical energy and thermal energy as charging and discharging proceeds. Therefore, the battery capacity may be reduced due to the continuous regeneration of the SEI film during charging and discharging of the battery, and the lifespan performance of the battery may be reduced.

In addition, side reactions such as decomposition of the electrolyte may occur on the exposed surface of the negative electrode due to the collapse of the SEI film, and a problem may occur that the battery swells or the internal pressure increases due to the generated gas.

In order to solve the above problems, 1,3-propanesultone (Japanese Patent Application No. 1999-339850), 1,3-propenesultone (1,3-propensultone; Japanese Patent Application No. 2001- 151863) has been presented. However, even in the case of the above method, as the cycle continues, the capacity gradually decreases, and the above problems still exist.

The present invention is to improve the capacity storage characteristics, life performance, and the like of the battery by forming a denser and more stable SEI film on the negative electrode surface by using a compound containing a sulfonate group and a lactone group as one component of the electrolyte.

The present invention provides a secondary battery electrolyte comprising an electrolyte salt and an electrolyte solvent, the electrolyte solution is characterized in that it comprises a compound of formula (1); And it provides a secondary battery having the electrolyte solution.

[Formula 1]

In Formula 1, R ₁ is a C ₄ ~ C ₃₀ lactone group, R ₂ is a C ₁ ~ C ₂₀ hydrocarbon group.

The present invention also provides novel compounds.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail.

The present invention is characterized by forming a more compact and stable solid electrolyte interface (SEI) film on the surface of the negative electrode by using the compound of Formula 1 as one component of the electrolyte. This action can be estimated as follows, but is not limited thereto.

Sulfonates may form [SO ₃ ?] Radicals through electrical reduction, and lactones (cyclic esters) may be ring-opened upon electrical reduction to form [? ORCO? (Where R is a hydrocarbon group)] radical. Since the compound of the present invention is in the form of a sulfonate group and a lactone group connected, it is possible to form a radical including three reactive active sites during electrical reduction.

That is, in the present invention, during the initial charging of the battery, as the compound of Formula 1 is electrically reduced, a radical having excellent reactivity is generated, and various types of polymerization reactions can be actively performed on the surface of the negative electrode, and as a result, the conventional carbonate Compared to the SEI film formed by the organic solvent, a denser and more stable SEI film can be formed on the cathode surface.

In the present invention, any compound having the structure of Chemical Formula 1 may be used without particular limitation.

More specifically, in Formula 1, the C ₄ ~ C ₃₀ lactone group of R ₁ may be represented by the following Formula 2, C ₁ ~ C ₂₀ hydrocarbon group of R ₂ C ₁ ~ C ₂₀ Alkyl group, C ₂ It may be an alkenyl group of ˜C ₂₀ or an aryl group of C ₆ ˜C ₂₀ .

[Formula 2]

In Formula 2, R ₃ and R ₄ are each independently substituted or unsubstituted C ₁ ~ C ₂₀ linear or cyclic alkyl group, C ₂ ~ C ₂₀ alkenyl group, phenyl (phenyl), and benzyl ( benzyl) group, n is 1.

In particular, R ₂ is preferably a C ₃ to C ₃₀ alkenyl group having β, γ-unsaturated carbon. The sulfonate group of the present invention may form [SO ₃ ?] Radicals and [R ₂ ?] Radicals upon electrical reduction, wherein R ₂ is a C ₃ to C ₂₀ alkenyl group having a β, γ-unsaturated carbon (eg, Allyl group), the [R ₂ ?] Radical may have a chemically stable resonance. This may advantageously work for the reduction of sulfonate groups and may improve reactivity in forming the SEI film. In addition, the C ₃ ~ C ₂₀ alkenyl group having the β, γ-unsaturated carbon preferably has a conjugation structure. In this case, the alkenyl group radicals may have a number of resonance structures and thus may be more chemically stable, which may make the reduction of the sulfonate group of the present invention more advantageous.

The alkenyl group of C ₃ to C ₂₀ having the β, γ-unsaturated carbon may be represented by the following Chemical Formula 3.

(3)

In Chemical Formula 3, R ₅ to R ₈ are each independently hydrogen, a C ₁ to C ₁₇ alkyl group or haloalkyl group, a C ₂ to C ₁₇ alkenyl group, a phenyl group, and a benzyl group Is selected from.

Non-limiting examples of the compound of formula 1 used in the present invention, tetrahydro-2-oxo-4,4-dimethyl-3-furanyl allylsulfonate (tetrahydro-2-oxo-4,4-dimethyl -3-furanyl allylsulfonate, tetrahydro-2-oxo-4-methyl-4-ethyl-3-furanyl allylsulfonate (tetrahydro-2-oxo-4-methyl-4-ethyl-3-furanyl allylsulfonate), Tetrahydro-2-oxo-4-methyl-4-propyl-3-furanyl allylsulfonate (tetrahydro-2-oxo-4-methyl-4-propyl-3-furanyl allylsulfonate), tetrahydro-2-oxo- 4-methyl-4-butyl-3-furanyl allylsulfonate (tetrahydro-2-oxo-4-methyl-4-butyl-3-furanyl allylsulfonate), tetrahydro-2-oxo-4,4-diethyl- 3-furanyl allylsulfonate (tetrahydro-2-oxo-4,4-diethyl-3-furanyl allylsulfonate), tetrahydro-2-oxo-4-ethyl-4-propyl-3-furanyl allylsulfonate (tetrahydro -2-oxo-4-ethyl-4-propyl-3-furanyl allylsulfonate), tetrahydro-2-oxo-4-ethyl-4-butyl Tetrahydro-2-oxo-4-ethyl-4-butyl-3-furanyl allylsulfonate, tetrahydro-2-oxo-4,4-dipropyl-3-furanyl allylsulfonate (tetrahydro-2-oxo-4,4-dipropyl-3-furanyl allylsulfonate), tetrahydro-2-oxo-4-propyl-4-butyl-3-furanyl allylsulfonate (tetrahydro-2-oxo-4- propyl-4-butyl-3-furanyl allylsulfonate), tetrahydro-2-oxo-4-methyl-4-cyclopropyl-3-furanyl allylsulfonate (tetrahydro-2-oxo-4-methyl-4-cyclopropyl- 3-furanyl allylsulfonate, tetrahydro-2-oxo-4-methyl-4-vinyl-3-furanyl allylsulfonate, tetrahydro-2-oxo-4-methyl-4-vinyl-3-furanyl allylsulfonate, tetra Tetra-2-oxo-4-methyl-4-allyl-3-furanyl allylsulfonate, tetrahydro-2-oxo-4 Tetrahydro-2-oxo-4-methyl-4-fluoro-3-furanyl allylsulfonate, tetrahigh Tetrahydro-2-oxo-4-methyl-4-trifluoromethyl-3-furanyl allylsulfonate, tetrahydro-2- chloro-2-oxo-4-methyl-4-trifluoromethyl-3-furanyl allylsulfonate Tetrahydro-2-oxo-4-methyl-4-phenyl-3-furanyl allylsulfonate, tetrahydro-2-oxo-4-methyl-4 Benzyl-3-furanyl allylsulfonate (tetrahydro-2-oxo-4-methyl-4-benzyll-3-furanyl allylsulfonate) and the like, which may be used alone or in combination.

In the electrolyte solution provided by the present invention, the content of the compound of Chemical Formula 1 may be adjusted according to the goal of improving the performance of the battery, but preferably 0.1 to 20 parts by weight per 100 parts by weight of the electrolyte. If less than 0.1 part by weight, the desired cycle preservation effect is insignificant, and if it exceeds 20 parts by weight, the battery resistance may increase.

Meanwhile, the electrolyte solution of the present invention may include, in addition to the compound, conventional electrolyte components known in the art, such as electrolyte salts and electrolyte solvents.

The electrolyte salt is A ⁺ B ^- A salt of the structure, such as, A ⁺ is Li ^+, Na ^+,, and comprising an alkali metal cation or an ion composed of a combination thereof, such as K ⁺ B ^- is PF ₆ ^-, BF _{^{4 -, Cl -, Br -}} , I -, ClO 4 -, AsF 6 -, CH 3 CO 2 -, CF 3 SO 3 -, N (CF 3 SO 2) 2 -, C (CF 2 SO 2) 3 ^- is a salt containing an anion ion or a combination thereof, such as. In particular, lithium salts such as LiClO ₄ , LiCF ₃ SO ₃ , LiPF ₆ , LiBF ₄ , LiN (C ₂ F ₅ SO ₂ ) ₂ , or Li (CF ₃ SO ₂ ) ₂ are preferred.

In addition, the electrolyte solvent may be used conventional organic solvents known in the art, such as cyclic carbonate and / or linear carbonate. In particular, in order to increase the dissociation and transfer ability of lithium ions of the electrolyte, it is preferable to use a cyclic carbonate having a high polarity, and to mix the cyclic carbonate and linear carbonate in order to prevent a decrease in the lithium ion conductivity due to the viscosity increase of the electrolyte. It is more preferable to improve the lifespan characteristics of the battery. Non-limiting examples of the solvent solvent is propylene carbonate (PC), ethylene carbonate (EC), diethyl carbonate (DEC), dimethyl carbonate (DMC), dipropyl carbonate (DPC), dimethyl sulfoxide, acetonitrile, dimethoxy Ethane, diethoxyethane, tetrahydrofuran, N-methyl-2-pyrrolidone (NMP), ethylmethyl carbonate (EMC), gamma butyrolactone (GBL), fluoroethylene carbonate (FEC), methyl formate, formic acid Ethyl, propyl formate, methyl acetate, ethyl acetate, propyl acetate, pentyl acetate, methyl propionate, ethyl propionate, propyl propionate, butyl propionate or halogen derivatives thereof. These electrolyte solvents may be used alone or in combination of two or more thereof. For example, ethylene carbonate and propylene carbonate may be mixed to solve the problem of lowering the low temperature performance of ethylene carbonate.

In addition, the present invention (a) anode; (b) a cathode; (c) an electrolyte solution containing the compound of Formula 1; And (d) provides a secondary battery having a separator.

Non-limiting examples of the secondary battery includes a lithium metal secondary battery, a lithium ion secondary battery, a lithium polymer secondary battery or a lithium ion polymer secondary battery.

The secondary battery of the present invention may be prepared according to a conventional method known in the art, for example, after assembling a separator between the positive electrode and the negative electrode (介 在), according to the formula 1 according to the present invention It can be prepared by injecting an electrolyte solution containing a compound of.

The electrode to be applied to the secondary battery of the present invention is not particularly limited and may be prepared according to conventional methods known in the art. For example, the electrode may be prepared by mixing and stirring a solvent, a binder, a conductive material, and a dispersant in an electrode active material, if necessary, and then applying the coating (coating) to a current collector, compressing, and drying the electrode.

The electrode active material may be a positive electrode active material or a negative electrode active material.

The positive electrode active material may be a conventional positive electrode active material that can be used for the positive electrode of a conventional secondary battery, non-limiting examples of lithium such as LiM _x O _y (M = Co, Ni, Mn, Co _a Ni _b Mn _c ) Transition metal composite oxides (for example, lithium manganese composite oxides such as LiMn ₂ O ₄ , lithium nickel oxides such as LiNiO ₂ , lithium cobalt oxides such as LiCoO ₂ , and some of the manganese, nickel and cobalt oxides of these oxides And the like, or a vanadium oxide containing lithium) or a chalcogen compound (for example, manganese dioxide, titanium disulfide, molybdenum disulfide, and the like). Preferably LiCoO ₂ , LiNiO ₂ , LiMnO ₂ , LiMn ₂ O ₄ , Li (Ni _a Co _b Mn _c ) O ₂ (0 <a <1, 0 <b <1, 0 <c <1, a + b + c = 1), LiNi _1-Y Co _Y O ₂ , LiCo _1-Y Mn _Y O ₂ , LiNi _1-Y Mn _Y O ₂ (where 0 ≦ Y <1), Li (Ni _a Co _b Mn _c ) O ₄ (0 <a <2, 0 <b <2, 0 <c <2, a + b + c = 2), LiMn _2-z Ni _z O ₄ , LiMn _2-z Co _z O ₄ ( Here, 0 <Z <2), LiCoPO ₄ , LiFePO _4, or a mixture thereof is mentioned. Non-limiting examples of the positive electrode current collector include a foil made of aluminum, nickel, or a combination thereof.

As the negative electrode active material, a conventional negative electrode active material that can be used for a negative electrode of a conventional secondary battery can be used. Non-limiting examples thereof include lithium adsorbents such as lithium metal or lithium alloy carbon, petroleum coke, activated carbon, graphite, graphite, graphitized carbon or other carbons. It is preferable to use graphitized carbon having a crystal surface distance constant d002 of a carbonaceous material measured by X-ray diffraction method up to 0.338 nm and a specific surface area measured by BET method up to 10 m ² / g. Non-limiting examples of cathode current collectors include foils made of copper, gold, nickel or copper alloys or combinations thereof.

The separator is not particularly limited, but a porous separator may be used, for example, a polypropylene-based, polyethylene-based, or polyolefin-based porous separator.

On the other hand, the present invention provides a compound of formula (4).

[Formula 4]

In Formula 4, R ₂₁ is a C ₂ ~ C ₂₀ alkenyl group, R ₃₁ and R ₄₁ are each independently a substituted or unsubstituted C ₁ ~ C ₂₀ linear or cyclic alkyl group, C ₂ ~ C ₂₀ Is selected from the group consisting of an alkenyl group, a phenyl group, and a benzyl group, and n is 1.

The compound of Formula 4 may be prepared by a conventional method in the art according to the following Scheme 1. In this case, X in Scheme 1 is a halogen element (F, Cl, Br, I).

Scheme 1

The electrolytic solution of the present invention can improve the capacity storage characteristics, lifespan performance and the like of the secondary battery by forming a denser and more stable SEI film on the surface of the negative electrode.

Various modifications may be made without departing from the spirit and scope of the invention as set forth in the claims.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. However, the following examples serve to illustrate the present invention, and the scope of the present invention is not limited thereto.

Example  One

Example 1-1. Preparation of Tetrahydro-2-oxo-4,4-dimethyl-3-furanyl allylsulfonate

To 100 mL of acetonitrile (CH ₃ CN), 13 g (0.1 mol) of pantolactone and 15.4 g (0.11 mol) of allylsulfonyl chloride were added with stirring. After lowering the temperature of the reaction vessel to 0 ℃, triethylamine 11.1 g (0.11 mol) was slowly added dropwise, and stirred for 1 hour to proceed with the reaction.

The reaction mixture was filtered to remove ammonium sulphate (Et ₃ NHCl), diluted with 100 mL of water, and the organic layer was extracted with ethyl acetate (EtOAc). Sodium sulfate (Na ₂ SO ₄ ) was added thereto to remove excess water, and the resultant obtained by concentration using a rotary evaporator was purified by a silica filter.

20 g (85% yield) of tetrahydro-2-oxo-4,4-dimethyl-3-furanyl allylsulfonate was obtained from the above. It was confirmed by NMR and Mass Spectroscopy.

¹ H NMR (500 MHz, CDCl 3): 6.02-5.94 (m, 1H), 5.86-5.51 (dd, 2H), 4.19-4.02 (m, 4H), 1.29 (s, 3H), 1.18 (s, 3H)

MS (EI): calcd for C ₉ H ₁₅ O ₅ S, 234; Found: 234.

Example 1-2. Preparation of Electrolyte

Tetrahydro-2-oxo-4,4-dimethyl-3-furanyl prepared in Example 1-1 to 100 parts by weight of a 1M LiPF ₆ solution of ethylene carbonate, propylene carbonate and diethyl carbonate in a 1: 1: 2 volume ratio. 2 parts by weight of allylsulfonate was added to prepare an electrolyte solution.

Example 1-3. Manufacture of batteries

The negative electrode was mixed with 93 parts by weight of graphitized carbon active material and 7 parts by weight of polyvinylidene difluoride (PVDF) as a solvent, N-methyl-2-pyrrolidone, and mixed in a mixer for 2 hours. It was prepared by coating a copper foil current collector and drying at 130 ° C. The positive electrode was coated with an aluminum foil current collector after mixing for 2 hours in a mixer using N-methyl-2-pyrrolidone as a solvent with 91 parts by weight of LiCoO ₂ , 3 parts by weight of PVDF, and 6 parts by weight of conductive carbon. Dried and prepared. The anode was cut in a circular shape, placed in a coin-shaped can, a separator (celgard 2400) was placed, and the cathode cut in a circular shape was placed. This was sufficiently impregnated with the electrolyte prepared in Example 1-2, and then covered with a coin-type cap and pressed to produce a coin-type battery.

Example 2.

Same as Examples 1-2 and 1-3, except that 0.5 parts by weight of tetrahydro-2-oxo-4,4-dimethyl-3-furanyl allylsulfonate was added instead of 2 parts by weight. An electrolyte solution and a secondary battery were prepared by the method.

Example 3.

Same as Examples 1-2 and 1-3, except that 5.0 parts by weight of tetrahydro-2-oxo-4,4-dimethyl-3-furanyl allylsulfonate was added instead of 2 parts by weight. An electrolyte solution and a secondary battery were prepared by the method.

Example 4.

Same as Examples 1-2 and 1-3, except that 10.0 parts by weight of tetrahydro-2-oxo-4,4-dimethyl-3-furanyl allylsulfonate was added instead of 2 parts by weight. An electrolyte solution and a secondary battery were prepared by the method.

Example 5.

Except for preparing an electrolyte by adding 2 parts by weight of tetrahydro-2-oxo-3-furanyl allylsulfonate instead of tetrahydro-2-oxo-4,4-dimethyl-3-furanyl allylsulfonate. In the same manner as in Examples 1-2 and 1-3, an electrolyte solution and a secondary battery were prepared.

Example 6.

2 parts by weight of tetrahydro-2-oxo-4,4-dimethyl-3-furanyl ethylsulfonate (Formula 5) instead of tetrahydro-2-oxo-4,4-dimethyl-3-furanyl allylsulfonate An electrolyte solution and a secondary battery were prepared in the same manner as in Examples 1-2 and 1-3, except that the electrolyte solution was prepared by addition.

[Chemical Formula 5]

Comparative Example 1.

An electrolyte solution and a secondary battery were prepared in the same manner as in Examples 1-2 and 1-3, except that no compound was added to the LiPF ₆ solution.

Comparative Example 2

Except that tetrahydro-2-oxo-4,4-dimethyl-3-furanyl allylsulfonate was added to 2 parts by weight of ethoxycarbonylmethyl allylsulfonate (formula 6) to prepare an electrolyte solution, Electrolytic solutions and secondary batteries were prepared in the same manner as in Examples 1-2 and 1-3.

[Formula 6]

Experimental Example 1. Performance Evaluation of Lithium Secondary Batteries

The secondary batteries prepared in Examples 1 to 6 and Comparative Examples 1 to 2 were charged at 25 ° C. to 4.2 V at a rate of 0.5 C, and charged at 4.2 V until the current became 0.05 mA or less, and 0.5 C to 3 V. Charge and discharge experiments were performed by discharging at a rate of. The discharge capacity retention rate (%) was expressed as a percentage of the ratio of the discharge capacity to the initial discharge capacity after 100 cycles. The results are shown in Table 1.

[Table 1]

compound Addition amount
(Parts by weight) Electrolyte composition
(Volume ratio) Discharge capacity
Retention rate (%) Example 1-3 Tetrahydro-2-oxo-4,4-dimethyl-3-furanyl allylsulfonate 2.0 1M LiPF ₆
EC: PC: DEC = 1: 1: 2 90.2 Example 2 Tetrahydro-2-oxo-4,4-dimethyl-3-furanyl allylsulfonate 0.5 1M LiPF ₆
EC: PC: DEC = 1: 1: 2 80.6 Example 3 Tetrahydro-2-oxo-4,4-dimethyl-3-furanyl allylsulfonate 5.0 1M LiPF ₆
EC: PC: DEC = 1: 1: 2 88.7 Example 4 Tetrahydro-2-oxo-4,4-dimethyl-3-furanyl allylsulfonate 10 1M LiPF ₆
EC: PC: DEC = 1: 1: 2 86.6 Example 5 Tetrahydro-2-oxo-3-furanyl allylsulfonate 2.0 1M LiPF ₆
EC: PC: DEC = 1: 1: 2 85.2 Example 6 Tetrahydro-2-oxo-4,4-dimethyl-3-furanyl ethylsulfonate 2.0 1M LiPF ₆
EC: PC: DEC = 1: 1: 2 80.2 Comparative Example 1 - - 1M LiPF ₆
EC: PC: DEC = 1: 1: 2 62.5 Comparative Example 2 Ethoxycarbonylmethyl allylsulfonate 2.0 1M LiPF ₆
EC: PC: DEC = 1: 1: 2 74.8

Experimental results showed that the compound of the formula (1) containing a sulfonate group and a lactone group (cyclic ester group) (tetrahydro-2-oxo-4,4-dimethyl-3-furanyl allylsulfonate, tetrahydro-2-oxo- The batteries of Examples 1 to 6 using 3-furanyl allylsulfonate and tetrahydro-2-oxo-4,4-dimethyl-3-furanyl ethylsulfonate) as electrolyte components were used as electrolytes without any compound added thereto. The discharge capacity retention rate was much higher than that of the battery of Comparative Example 1 used. In particular, compared with the battery of Comparative Example 2 using ethoxycarbonylmethyl allylsulfonate containing a sulfonate group and a linear ester group, the increase in discharge capacity retention rate was about 2 times or more.

Further, from the experimental results of Examples 1 to 5 and Example 6, the life of the battery when the sulfonate group is substituted with a C ₃ to C ₃₀ alkenyl group (allyl group) having β, γ-unsaturated carbon in the present invention It was confirmed that the performance improvement effect is better.

From this, it was confirmed that the present invention can improve the capacity storage characteristics and the life performance of the battery.

Claims (10)

An electrolyte solution comprising an electrolyte salt and an electrolyte solvent, wherein the electrolyte solution comprises a compound represented by the following Chemical Formula 1. [Formula 1]

In Formula 1, R ₁ is a C ₄ ~ C ₃₀ lactone group, R ₂ is a C ₁ ~ C ₂₀ hydrocarbon group. The electrolyte of claim 1, wherein the compound of Formula 1 is represented by R ₁ below. [Formula 2]

In Formula 2, R ₃ and R ₄ are each independently substituted or unsubstituted C ₁ ~ C ₂₀ linear or cyclic alkyl group, C ₂ ~ C ₂₀ alkenyl group, phenyl (phenyl), and benzyl ( benzyl) group, n is 1. The method of claim 1 wherein the compound is R ₂ is C ₁ ~ C ₂₀ alkyl group, C ₂ ~ C ₂₀ alkenyl group or a C ₆ ~ C ₂₀ aryl group is characterized by the electrolyte of the general formula (1). The electrolyte of claim 1, wherein the compound of Formula 1 is a C ₃ to C ₃₀ alkenyl group having R ₂ of β, γ-unsaturated carbon. The electrolyte solution according to claim 4, wherein the alkenyl group of C ₃ to C ₃₀ having β, γ-unsaturated carbon has a conjugation structure. The electrolyte according to claim 4, wherein the C ₃ to C ₃₀ alkenyl group having β, γ-unsaturated carbon is represented by the following Chemical Formula 3. (3)

In Formula 3, R ₅ to R ₈ are each independently hydrogen, a C ₁ ~ C ₁₇ alkyl group or haloalkyl group, C ₂ ~ C ₁₇ alkenyl group, phenyl (phenyl) group, benzyl group Is selected from. The method of claim 1, wherein the compound of Formula 1 is tetrahydro-2-oxo-4,4-dimethyl-3-furanyl allylsulfonate (tetrahydro-2-oxo-4,4-dimethyl-3-furanyl allylsulfonate Tetrahydro-2-oxo-4-methyl-4-ethyl-3-furanyl allylsulfonate, tetrahydro-2- Tetrahydro-2-oxo-4-methyl-4-propyl-3-furanyl allylsulfonate, tetrahydro-2-oxo-4-methyl-4 -Butyl-3-furanyl allylsulfonate (tetrahydro-2-oxo-4-methyl-4-butyl-3-furanyl allylsulfonate), tetrahydro-2-oxo-4,4-diethyl-3-furanyl allyl Sulfonate (tetrahydro-2-oxo-4,4-diethyl-3-furanyl allylsulfonate), tetrahydro-2-oxo-4-ethyl-4-propyl-3-furanyl allylsulfonate (tetrahydro-2-oxo- 4-ethyl-4-propyl-3-furanyl allylsulfonate), tetrahydro-2-oxo-4-ethyl-4-butyl-3-furanyl allylsulfonane (tetrahydro-2-oxo-4-ethyl-4-butyl-3-furanyl allylsulfonate), tetrahydro-2-oxo-4,4-dipropyl-3-furanyl allylsulfonate (tetrahydro-2-oxo-4 , 4-dipropyl-3-furanyl allylsulfonate), tetrahydro-2-oxo-4-propyl-4-butyl-3-furanyl allylsulfonate (tetrahydro-2-oxo-4-propyl-4-butyl-3- furanyl allylsulfonate), tetrahydro-2-oxo-4-methyl-4-cyclopropyl-3-furanyl allylsulfonate, tetrahydro-2-oxo-4-methyl-4-cyclopropyl-3-furanyl allylsulfonate, tetrahydro Tetrahydro-2-oxo-4-methyl-4-vinyl-3-furanyl allylsulfonate, tetrahydro-2-oxo-4 Tetrahydro-2-oxo-4-methyl-4-allyl-3-furanyl allylsulfonate, tetrahydro-2-oxo-4-methyl-4-fluoro 3-furanyl allylsulfonate (tetrahydro-2-oxo-4-methyl-4-fluoro-3-furanyl allylsulfonate), tetrahydro-2-oxo-4-methyl-4-tri Roromethyl-3-furanyl allylsulfonate (tetrahydro-2-oxo-4-methyl-4-trifluoromethyl-3-furanyl allylsulfonate), tetrahydro-2-oxo-4-methyl-4-phenyl-3-furanyl Allylsulfonate (tetrahydro-2-oxo-4-methyl-4-phenyl-3-furanyl allylsulfonate), and tetrahydro-2-oxo-4-methyl-4-benzyl-3-furanyl allylsulfonate (tetrahydro- 2-oxo-4-methyl-4-benzyll-3-furanyl allylsulfonate). The method of claim 1, wherein the content of the compound of formula 1 is characterized in that the electrolyte solution is 0.1 to 20 parts by weight per 100 parts by weight of the electrolyte. In a secondary battery comprising a positive electrode, a negative electrode and an electrolyte solution, The secondary battery is characterized in that the electrolyte solution of any one of claims 1 to 8. A compound having the structure of formula [Formula 4]

In Formula 4, R ₂₁ is a C ₂ ~ C ₂₀ alkenyl group, R ₃₁ and R ₄₁ are each independently a substituted or unsubstituted C ₁ ~ C ₂₀ linear or cyclic alkyl group, C ₂ ~ C ₂₀ Is selected from the group consisting of an alkenyl group, a phenyl group, and a benzyl group, and n is 1.