KR20130142375A - Electrolyte for lithium secondary battery including additives, and lithium secondary battery - Google Patents

Abstract

The present invention relates to a nonaqueous electrolyte for a lithium secondary battery produced by adding predetermined amount of additives thereto. The present invention is the nonaqueous electrolyte containing organic silica compounds, wherein trialkylsilyl fluoride is used as a nonaqueous electrolyte. According to the present invention, the nonaqueous electrolyte improves low-temperature discharge characteristics and high-temperature storage characteristics of the battery by including fluoridation organic silica compounds.

Description

ELECTROLYTE FOR LITHIUM SECONDARY BATTERY INCLUDING ADDITIVES, AND LITHIUM SECONDARY BATTERY}

The present invention relates to a nonaqueous electrolyte solution for a lithium secondary battery produced by adding a constant additive to the nonaqueous electrolyte solution.

Batteries are devices that convert chemical energy generated during the electrochemical redox reaction of chemical substances into electrical energy.The primary battery that needs to be discarded when all the energy inside the battery is consumed and the rechargeable battery that can be charged many times Can be divided into The dual secondary battery may be charged and discharged many times using reversible mutual conversion of chemical energy and electrical energy.

Conventionally, the structure of a lithium secondary battery is comprised by using lithium metal mixed oxide as a positive electrode active material, metal lithium etc. as a negative electrode active material, and having melt | dissolved the lithium salt compound in the organic solvent suitably in quantity as electrolyte.

Recently, there is an increasing demand for improved battery performance, in particular, excellent charge / discharge performance, and development of a technology for adding a specific compound to an electrolyte in order to satisfy this situation is actively progressing.

Korean Patent Laid-Open Publication No. 10-2011-0036107 (Patent Document 1) discloses a nonaqueous electrolytic solution containing an organosilicon compound and a fluorine-containing alkali metal salt and having a content of a fluorinated organosilicon compound produced by the reaction of the two substances of 0.2 wt% or less. There is a bar. At this time, the fluorinated organosilicon compound is a compound which is produced when a specific organosilicon compound is decomposed in the nonaqueous electrolytic solution. When the content in the nonaqueous electrolytic solution exceeds 0.2% by weight, there is a possibility that the battery characteristics are impaired and its use is limited.

Republic of Korea Patent Publication 10-2011-0036107, pp. 9, line 9 ~ 22

The present invention is to solve the conventional problems, further improves the low-temperature performance, high temperature storage properties, initial capacity and charge and discharge life characteristics of the lithium secondary battery, more specifically, the lithium battery excellent in low-temperature discharge efficiency, high temperature storage efficiency The purpose is to provide a non-aqueous electrolyte solution for secondary batteries.

In order to solve the conventional problems, the present invention provides a non-aqueous electrolyte containing an organosilicon compound, wherein the organosilicon compound is trialkylsilyl fluoride of the formula (1).

 [Formula 1]

(In Formula 1, R ₁ , R ₂ and R ₃ are each independently an alkyl group having ₁ to ₄ carbon atoms.)

The non-aqueous electrolyte solution according to the present invention contains 0.5 to 5% by weight of the trialkylsilyl fluoride.

The non-aqueous electrolyte according to the present invention includes a basic electrolyte containing a non-aqueous organic solvent and a lithium salt compound dissolved in the non-aqueous organic solvent.

The non-aqueous organic solvent contains one or two or more selected from the group consisting of cyclic carbonates and chain carbonates.

At this time, the cyclic carbonate is selected from the group consisting of ethylene carbonate, propylene carbonate, butylene carbonate, vinylene carbonate, vinyl ethylene carbonate and mixtures thereof, the chain carbonate is dimethyl carbonate, diethyl carbonate, dipropyl carbonate, ethyl Methyl carbonate, methyl propyl carbonate, methyl isopropyl carbonate, ethyl propyl carbonate and mixtures thereof.

The non-aqueous organic solvent further includes one or two or more selected from fluoroethylene carbonate and sultone compounds.

Lithium salt compounds are LiPF ₆ , LiBF ₄ , LiClO ₄ , LiSbF ₆ , LiAsF ₆ , LiN (SO ₂ C ₂ F ₅ ) ₂ , Li (CF ₃ SO ₂ ) ₂ N, LiN (SO ₃ C ₂ F ₅ ) ₂ , LiCF ₃ SO ₃ , LiC ₄ F ₉ SO ₃ , LiC ₆ H ₅ SO ₃ , LiSCN, LiClO ₄ , LiAlO ₂ , LiAlCl ₄ , LiN (C _x F _{2x + 1} SO ₂ ) (C _y F _{2y + 1} SO ₂ ), where x and y are natural numbers, one or two or more selected from the group consisting of LiCl, LiI and LiB (C ₂ O ₄ ) ₂ .

Thus, the lithium secondary battery including the non-aqueous electrolyte solution according to the present invention is included in the scope of the present invention.

The non-aqueous electrolyte according to the present invention further improves low-temperature performance, high-temperature storage, initial capacity, and charge / discharge life characteristics of a lithium secondary battery, and more specifically, contains a trialkylsilyl fluoride, a fluorinated organosilicon compound, to reduce the temperature Improve performance such as discharge characteristics and high temperature storage characteristics.

The present invention provides a non-aqueous electrolyte containing an organosilicon compound, wherein the organosilicon compound is a trialkylsilyl fluoride of the general formula (1).

 [Formula 1]

(In Formula 1, R ₁ , R ₂ and R ₃ are each independently an alkyl group having ₁ to ₄ carbon atoms.)

Specifically, the present invention provides a non-aqueous electrolyte containing 0.5 to 5% by weight of the trialkylsilyl fluoride.

More specifically, the present invention is a basic electrolyte containing a non-aqueous organic solvent and a lithium salt compound dissolved in the non-aqueous organic solvent; And it provides a non-aqueous electrolyte solution containing 0.5 to 5% by weight of trialkylsilyl fluoride of formula (1).

At this time, the non-aqueous organic solvent contains one or two or more selected from the group consisting of cyclic carbonate and chain carbonate.

The cyclic carbonate is selected from the group consisting of ethylene carbonate, propylene carbonate, butylene carbonate, vinylene carbonate, vinyl ethylene carbonate and mixtures thereof, and the linear carbonate is dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, methyl propyl carbonate. , Methyl isopropyl carbonate, ethyl propyl carbonate and mixtures thereof.

In addition, the non-aqueous organic solvent may further include one or two or more selected from fluoroethylene carbonate and sultone compounds.

Lithium salt compounds are LiPF ₆ , LiBF ₄ , LiClO ₄ , LiSbF ₆ , LiAsF ₆ , LiN (SO ₂ C ₂ F ₅ ) ₂ , Li (CF ₃ SO ₂ ) ₂ N, LiN (SO ₃ C ₂ F ₅ ) ₂ , LiCF ₃ SO ₃ , LiC ₄ F ₉ SO ₃ , LiC ₆ H ₅ SO ₃ , LiSCN, LiClO ₄ , LiAlO ₂ , LiAlCl ₄ , LiN (C _x F _{2x + 1} SO ₂ ) (C _y F _{2y + 1} SO ₂ ), where x and y are natural numbers, LiCl, LiI and LiB (C ₂ O ₄ ) ₂ .

Thus, the lithium secondary battery including the non-aqueous electrolyte solution according to the present invention is included in the scope of the present invention. That is, the lithium secondary battery may be manufactured according to a conventional method using the nonaqueous electrolyte according to the present invention, and the lithium secondary battery thus prepared has better low temperature discharge characteristics and high temperature storage characteristics than conventional secondary batteries. .

It will be described in detail with respect to the present invention.

As a result of adding a certain amount of trialkylsilyl fluoride to the non-aqueous electrolyte, the present inventors have found that the low-temperature discharge characteristics and the high-temperature storage characteristics of the battery are excellent, thus completing the present invention.

The present invention provides a nonaqueous electrolytic solution containing an organosilicon compound, wherein the organosilicon compound is trialkylsilyl fluoride of formula (1).

 [Formula 1]

(In Formula 1, R ₁ , R ₂ and R ₃ are each independently an alkyl group having ₁ to ₄ carbon atoms.)

More specifically, the present invention provides a non-aqueous electrolyte solution containing a trialkylsilyl fluoride of Formula 1, a non-aqueous organic solvent and a lithium salt compound dissolved in the non-aqueous organic solvent.

The kind of trialkylsilyl fluoride is not particularly limited as long as it satisfies Formula 1, but trimethylsilyl fluoride and triethylsilyl fluoride may be used, and most preferably trimethylsilyl fluoride may be used.

The inventors have found that the non-aqueous electrolyte solution exhibits a low temperature discharge efficiency and a high temperature storage efficiency of 85% or more when the trialkylsilyl fluoride of Formula 1 is included, and thus the low temperature discharge and high temperature storage of the trialkylsilyl fluoride is excellent. The present invention was completed by confirming that it possesses characteristics.

At this time, the content of the trialkylsilyl fluoride is preferably in the range of 0.5 to 5% by weight of the non-aqueous electrolyte, more preferably 1 to 5% by weight. If less than 0.5%, the improvement of low-temperature discharge characteristics and high-temperature storage characteristics of the battery, which is the object of the present invention, is insignificant, and if it is more than 5%, the film on the electrode surface is formed too thick, resulting in a high resistance of the battery.

In the prior art, it is known for the non-aqueous electrolyte solution containing trialkylsilyl fluoride as a product. When the content exceeds 0.2% by weight, the initial battery resistance of the lithium secondary battery is high and its content is limited. In other words, trialkylsilyl fluoride is a compound produced when a specific organosilicon compound is decomposed in a nonaqueous electrolytic solution, and if its content exceeds 0.2%, there is a risk of damaging battery characteristics. However, the present invention has been completed to know that even if the trialkylsilyl fluoride exceeds 0.2% by weight can retain excellent lithium secondary battery characteristics. That is, the present invention can be characterized by using trialkylsilyl fluoride as an organosilicon compound so that there is no side reaction by other additives. Accordingly, the present invention has been completed by studying a non-aqueous electrolyte solution having a simple and efficient composition and improving the low temperature discharge characteristics and the high temperature storage characteristics of a lithium secondary battery.

Next, the non-aqueous organic solvent will be described in detail. The non-aqueous organic solvent serves as a medium through which lithium ions can move.

The non-aqueous organic solvent according to the present invention may first be selected from the group consisting of cyclic carbonates and chain carbonates.

The cyclic carbonate is selected from the group consisting of ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC), vinylene carbonate (VC), vinyl ethylene carbonate (VEC) and mixtures thereof. Carbonates include dimethyl carbonate (DMC), diethyl carbonate (DEC), dipropyl carbonate (DPC), ethyl methyl carbonate (EMC), methyl propyl carbonate (MPC), methyl isopropyl carbonate, ethyl propyl carbonate (EPC) and their It may be selected from the group consisting of a mixture.

More specifically, the non-aqueous organic solvent is a combination of the cyclic carbonate and the linear carbonate, specifically, a combination of ethylene carbonate and dimethyl carbonate, a combination of ethylene carbonate and ethyl methyl carbonate, an ethylene carbonate and diethyl carbonate, , Propylene carbonate and dimethyl carbonate, propylene carbonate and methyl ethyl carbonate, propylene carbonate and diethyl carbonate, ethylene carbonate and propylene carbonate and dimethyl carbonate, ethylene carbonate and propylene carbonate Combination of methyl ethyl carbonate, combination of ethylene carbonate, propylene carbonate and diethyl carbonate, combination of ethylene carbonate, dimethyl carbonate and methyl ethyl carbonate, with ethylene carbonate A combination of dimethyl carbonate and diethyl carbonate, a combination of ethylene carbonate, propylene carbonate, dimethyl carbonate and methyl ethyl carbonate, and a combination of ethylene carbonate, propylene carbonate, dimethyl carbonate and diethyl carbonate.

The mixing ratio of the cyclic carbonate and at least one of the linear carbonates is 0: 100 to 100: 0, preferably 5:95 to 80:20, more preferably 10:90 to 70:30, particularly preferably in weight ratio. For example, 15: 85-55: 45. By setting it as such a ratio, since the viscosity rise of a nonaqueous electrolyte solution can be suppressed more and the degree of dissociation of electrolyte can be improved more, the conductivity of the electrolyte solution related to the charge-discharge characteristic of a lithium secondary battery can be raised more.

In addition, the non-aqueous organic solvent may further include one or two or more selected from fluoroethylene carbonate and sultone compounds. Propanesultone (PS) etc. are mentioned as an example of the said sultone type compound. The content is not particularly limited, but is preferably 0.1 to 5% by weight.

In addition, the non-aqueous organic solvent according to the present invention can also be used ester solvents, ether solvents, ketone solvents, alcohol solvents and aprotic solvents.

The ester solvents include methyl acetate, ethyl acetate, n-propyl acetate, dimethyl acetate, methyl propionate, ethyl propionate, γ-butyrolactone, decanolide, valerolactone, and mevalolono. Lactone, caprolactone and the like can be used. Examples of the ether solvent include dibutyl ether, tetraglyme, diglyme, 1,2-dimethoxy ethane, 1,2-diethoxy ethane, ethoxymethoxy ethane, 2-methyltetrahydrofuran, tetrahydrofuran and the like. It may be used, cyclohexanone and the like may be used as the ketone solvent.

In addition, ethyl alcohol, isopropyl alcohol, etc. may be used as the alcohol solvent, and as the aprotic solvent, R-CN (R is a linear, branched or cyclic hydrocarbon group having 2 to 20 carbon atoms, Nitrile solvents such as double bonds, aromatic rings or ether bonds), amide solvents such as dimethylformamide, dioxolane solvents such as 1,3-dioxolane, and sulfolane solvents. And the like can be used.

Next, the lithium salt compound will be described in detail.

The lithium salt compound is dissolved in the non-aqueous organic solvent, acts as a source of lithium ions in the battery to enable the operation of the basic lithium secondary battery, and serves to promote the movement of lithium ions between the positive electrode and the negative electrode It is a substance.

Representative examples of such lithium salt compounds are LiPF ₆ , LiBF ₄ , LiClO ₄ , LiSbF ₆ , LiAsF ₆ , LiN (SO ₂ C ₂ F ₅ ) ₂ , Li (CF ₃ SO ₂ ) ₂ N, LiN (SO ₃ C ₂ F ₅ ) ₂ , LiCF ₃ SO ₃ , LiC ₄ F ₉ SO ₃ , LiC ₆ H ₅ SO ₃ , LiSCN, LiClO ₄ , LiAlO ₂ , LiAlCl ₄ , LiN (C _x F _{2x + 1} SO ₂ ) (C _y F _{2y + 1} SO ₂ ), where x and y are natural numbers, one or more selected from the group consisting of LiCl, LiI and LiB (C ₂ O ₄ ) ₂ as supporting electrolyte salts.

The concentration of the lithium salt compound is preferably used within the range of 0.1 to 2.0 M. When the concentration of the lithium salt compound is included in the above range, since the electrolyte has an appropriate conductivity and viscosity, it can exhibit excellent electrolyte performance, and lithium ions can move effectively.

The lithium secondary battery including the non-aqueous electrolyte solution thus prepared is included in the scope of the present invention. The lithium secondary battery may be manufactured according to a conventional method using the nonaqueous electrolyte according to the present invention, and the lithium secondary battery thus prepared has better low temperature discharge characteristics and high temperature storage characteristics than conventional secondary batteries.

The lithium secondary battery according to the present invention includes a positive electrode and a negative electrode.

The positive electrode includes a positive electrode active material capable of occluding and detaching lithium ions, and the positive electrode active material is preferably at least one selected from cobalt, manganese, nickel, and a composite metal oxide with lithium. In addition to these metals, the employment rate of the metals may be varied. In addition to these metals, Mg, Al, Co, K, Na, Ca, Si, Ti, Sn, V, Ge, Ga, B, As, Zr, Mn, Sr, V, and a rare earth element.

The negative electrode includes a negative electrode active material capable of occluding and desorbing lithium ions, and the negative electrode active material includes carbon materials such as crystalline carbon, amorphous carbon, carbon composite, carbon fiber, lithium metal, alloy of lithium and other elements, and the like. Can be used. Examples of the amorphous carbon include hard carbon, coke, mesocarbon microbead (MCMB) calcined at 1500 ° C. or lower, and mesophase pitch-based carbon fiber (MPCF). The crystalline carbon is a graphite-based material, specifically natural graphite, graphitized coke, graphitized MCMB, and graphitized MPCF. The carbonaceous material is preferably a material having an d002 interplanar distance of 3.35 to 3.38 kPa and an Lc (crystallite size) of at least 20 nm by X-ray diffraction. Other elements constituting the alloy with lithium may be aluminum, zinc, bismuth, cadmium, antimony, silicon, lead, tin, gallium or indium.

The positive electrode or the negative electrode may be prepared by dispersing an electrode active material, a binder and a conductive material, if necessary, a thickener in a solvent to prepare an electrode slurry composition, and applying the slurry composition to an electrode current collector. As the positive electrode current collector, aluminum or an aluminum alloy may be commonly used, and copper or a copper alloy may be used as the negative electrode current collector. The anode current collector and the anode current collector may be in the form of a foil or a mesh.

The binder is a material that plays a role of pasting the active material, mutual adhesion of the active material, adhesion with the current collector, buffering effect on the expansion and contraction of the active material, and the like, for example, polyvinylidene fluoride (PVdF), polyhexafluoro Copolymer of propylene-polyvinylidene fluoride (PVdF / HFP)), poly (vinylacetate), polyvinyl alcohol, polyethylene oxide, polyvinylpyrrolidone, alkylated polyethylene oxide, polyvinyl ether, poly (methylmeth) Acrylate), poly (ethyl acrylate), polytetrafluoroethylene, polyvinylchloride, polyacrylonitrile, polyvinylpyridine, styrene-butadiene rubber, acrylonitrile-butadiene rubber, and the like. The content of the binder is 0.1 to 30% by weight, preferably 1 to 10% by weight, based on the electrode active material. If the content of the binder is too small, the adhesive force between the electrode active material and the current collector is insufficient. If the content of the binder is too large, the adhesive force is improved but the content of the electrode active material is reduced accordingly.

The conductive agent may be a material for improving electronic conductivity, and at least one selected from the group consisting of a graphite-based conductive agent, a carbon black-based conductive agent, and a metal or metal compound-based conductive agent may be used. Examples of the graphite conductive agent include artificial graphite and natural graphite, and examples of the carbon black conductive agent include acetylene black, ketjen black, denka black, thermal black, and channel black. (channel black), and examples of the metal-based or metal compound-based conductive agent include tin, tin oxide, tin phosphate (SnPO ₄ ), titanium oxide, potassium titanate, LaSrCoO ₃ , and perovskite such as LaSrMnO ₃ . There is a substance. However, it is not limited to the conductive agents listed above.

The content of the conductive agent is preferably 0.1 to 10% by weight based on the electrode active material. When the content of the conductive agent is less than 0.1% by weight, the electrochemical properties are lowered, and when the content of the conductive agent is greater than 10% by weight, the energy density per weight decreases.

The thickener is not particularly limited as long as it can play a role of controlling the viscosity of the active material slurry. For example, carboxymethyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, or the like may be used.

A nonaqueous solvent or an aqueous solvent is used as a solvent in which an electrode active material, a binder, a conductive agent, etc. are disperse | distributed. Examples of the non-aqueous solvent include N-methyl-2-pyrrolidone (NMP), dimethylformamide, dimethylacetamide, N, N-dimethylaminopropylamine, ethylene oxide and tetrahydrofuran.

The lithium secondary battery may include a separator that prevents a short circuit between the positive electrode and the negative electrode and provides a passage for lithium ions, and such separators include polypropylene, polyethylene, polyethylene / polypropylene, polyethylene / polypropylene / polyethylene, poly Polyolefin polymer membranes, such as propylene / polyethylene / polypropylene, or a multilayer of these, a microporous film, a woven fabric, and a nonwoven fabric can be used. Further, a film coated with a resin having excellent stability may be used for the porous polyolefin film.

Hereinafter, although an Example demonstrates this invention further more concretely, this invention is not limited to a following example.

EC: Ethylene Carbonate

EMC: Ethyl methyl carbonate

TMSF: Trimethylsilylfluoride

VC: vinylene carbonate

FEC: fluoroethylene carbonate

PS: propane sultine

VEC: vinyl ethylene carbonate

≪ Example 1 >

To a basic electrolyte solution of 1M (mol / L) lithium salt compound (LiPF ₆ ) dissolved in a non-aqueous organic solvent mixed EC and EMC in the content ratio of EC: EMC = 3: 7 according to the content of Table 1 It was. A non-aqueous electrolyte was prepared by adding trimethylsilyl fluoride to 1 wt% of the base electrolyte.

A 25Ah class battery for EV to which the nonaqueous electrolyte was applied was prepared as follows.

LiNiCoMnO ₂ and LiMn ₂ O ₄ as a positive electrode active material were mixed at a weight ratio of 1: 1, polyvinylidene fluoride (PVdF) as a binder and carbon as a binder were mixed at a weight ratio of 92: 4: 4, and then N- A positive electrode slurry was prepared by dispersing in methyl-2-pyrrolidone. This slurry was coated on an aluminum foil having a thickness of 20 mu m, followed by drying and rolling to prepare a positive electrode. Styrene-butadiene rubber as a binder and carboxymethylcellulose as a thickener were mixed in a weight ratio of 96: 2: 2 and then dispersed in water to prepare a negative electrode active material slurry. This slurry was coated on a copper foil having a thickness of 15 mu m, followed by drying and rolling to prepare a negative electrode.

A cell separator was constructed using a pouch having a thickness of 8 mm and a width of 270 mm and a length of 185 mm by stacking a film separator made of polyethylene (PE) having a thickness of 20 μm between the electrodes. The non-aqueous electrolyte was injected into an electrolyte to prepare a 25Ah lithium secondary battery for EV.

The performance of the 25Ah class battery for the electric vehicle (EV) thus prepared was evaluated as follows. Evaluation items are as follows.

[Evaluation item]

1. -20 ℃ 1C Discharge: After charging for 3 hours at 12.5A, 4.2V CC-CV at room temperature, and leaving it for 4 hours at -20 ℃, it is discharged to CC at 25A, and then discharged to CC up to 2.7V. The usable capacity (%) relative to the dose was measured.

2. Capacity recovery rate after 30 days at 60 ℃ (high temperature storage efficiency): After charging for 3 hours at 4.2V and 12.5A CC-CV at room temperature, and leaving it at 60 ℃ for 30 days in a sealed thermostat, with current of 25A, 2.7V Usable capacity (%) compared to initial capacity after discharge to CC until was measured.

[Table 1] Evaluation of electrolyte composition and battery performance

 <Example 2>

A nonaqueous electrolyte was prepared by adding 1 wt% of trimethylsilyl fluoride and 1 wt% of vinylene carbonate to the basic electrolyte solution of Example 1 with reference to Table 1 above.

The prepared electrolyte solution was prepared and evaluated in the battery by the method of Example 1. The results are shown in Table 1.

<Examples 3 to 5>

A non-aqueous electrolyte was prepared by referring to the corresponding composition according to each example of Table 1, and the battery was prepared and evaluated by the method of Example 1. The results are shown in Table 1.

&Lt; Comparative Example 1 &

The battery was produced and evaluated using the basic electrolyte solution of Example 1 as a non-aqueous electrolyte solution. The results are shown in Table 1.

Comparative Example 2

A non-aqueous electrolyte was prepared by referring to the composition corresponding to Comparative Example 2 of Table 1, and a battery was prepared and evaluated by the method of Example 1. The results are shown in Table 1.

As described above, the lithium secondary battery including the non-aqueous electrolyte according to the present invention showed a low temperature discharge efficiency of 85% or more and a high temperature storage efficiency of 85% or more. On the other hand, the charge and discharge characteristics of the non-aqueous electrolytes of Comparative Examples 1 to 2 that do not contain trialkylsilyl fluoride showed a marked difference from the examples. As a result, the non-aqueous electrolyte according to the present invention is expected to contribute greatly to the performance improvement of the lithium secondary battery.

Claims (8)

A non-aqueous electrolyte containing an organosilicon compound, wherein the organosilicon compound is a trialkylsilyl fluoride of the general formula (1).
[Chemical Formula 1]

(In Formula 1, R ₁ , R ₂ and R ₃ are each independently an alkyl group having ₁ to ₄ carbon atoms.) The method of claim 1,
The non-aqueous electrolyte solution is 0.5 to 5% by weight of the trialkylsilyl fluoride. The method of claim 3, wherein
The non-aqueous organic solvent further comprises one or two or more selected from fluoroethylene carbonate and sultone-based compound. The method of claim 1,
The non-aqueous electrolyte solution comprises a non-aqueous organic solvent and a basic electrolyte containing a lithium salt compound dissolved in the non-aqueous organic solvent. 3. The method of claim 2,
The non-aqueous organic solvent is a non-aqueous electrolyte containing one or two or more selected from the group consisting of cyclic carbonate and chain carbonate. 6. The method of claim 5,
The cyclic carbonate is selected from the group consisting of ethylene carbonate, propylene carbonate, butylene carbonate, vinylene carbonate, vinyl ethylene carbonate and mixtures thereof, and the linear carbonate is dimethyl carbonate, diethyl carbonate, dipropyl carbonate, ethyl methyl Non-aqueous electrolyte solution selected from the group consisting of carbonate, methylpropyl carbonate, methyl isopropyl carbonate, ethyl propyl carbonate and mixtures thereof. 5. The method of claim 4,
The lithium salt compound is LiPF ₆ , LiBF ₄ , LiClO ₄ , LiSbF ₆ , LiAsF ₆ , LiN (SO ₂ C ₂ F ₅ ) ₂ , Li (CF ₃ SO ₂ ) ₂ N, LiN (SO ₃ C ₂ F ₅ ) ₂ , LiCF ₃ SO ₃ , LiC ₄ F ₉ SO ₃ , LiC ₆ H ₅ SO ₃ , LiSCN, LiClO ₄ , LiAlO ₂ , LiAlCl ₄ , LiN (C _x F _{2x + 1} SO ₂ ) (C _y F _{2y + 1} SO ₂ ) (where x and y are natural water), LiCl, LiI and LiB (C ₂ O ₄ ) ₂ One or two or more non-aqueous electrolytes selected from the group consisting of. A lithium secondary battery comprising any one non-aqueous electrolyte solution selected from claim 1.