WO2019117669A1 - Continuous manufacturing method for lithium secondary battery having passivation film formed on surface of lithium metal electrode and lithium ion battery produced by same manufacturing method - Google Patents

Abstract

The present invention relates to a manufacturing method for a lithium secondary battery and a lithium secondary battery produced by the manufacturing method, the method comprising the steps of: (i) preparing a lithium metal electrode having metal lithium (Li) formed one surface or both surfaces of a current collector; (ii) forming a passivation film, which is a stable coating, by applying, to a surface of the metal lithium, an electrolyte for coating containing at least one lithium salt, at least one non-aqueous-based organic solvent, and at least one additive; (iii) manufacturing an electrode assembly with using the lithium metal electrode as a negative electrode; and (iv) embedding the electrode assembly in a secondary battery case and injecting an electrolyte for injection containing at least one lithium salt, at least one non-aqueous-based organic solvent, and at least one additive, wherein the additive of the electrolyte for coating and the additive of the electrolyte for injection employ particular materials and have different compositions.

Description

2019/117669 1 ^» (: 1 ^ {2018/015931

Title of the Invention

 A continuous method for manufacturing a lithium secondary battery in which a passivation film is formed on the surface of a lithium metal electrode and a lithium secondary battery

 TECHNICAL FIELD

₅ Mutual quotation with related stem (s)

 This application claims the benefit of priority based on Korean Patent Application No. 10-2017-0172275, dated December 14, 2017, and Korean Patent Application No. 10-2018-0161296, dated December 13, 2018, The entire contents of which are incorporated herein by reference.

₁₀ The present invention relates to a continuous production method of ritum secondary battery to form a film passivated on the surface of the lithium metal electrode, specifically, the passivation after forming membrane electrode assembly, and by coating the electrolyte on Lyrium metal electrode prior to assembly of Lyrium secondary battery The present invention relates to a method for producing a lithium secondary battery and a lithium secondary battery manufactured by the method.

_[15] Background Art

 As technology development and demand for mobile devices are increasing, the demand for secondary batteries as energy sources is rapidly increasing. Among such secondary batteries, lithium secondary batteries having high energy density and voltage, long cycle life and low self- It is commercialized and widely used.

_{20 In} general, a lithium secondary battery includes a positive electrode, a separator interposed between the positive electrode and the negative electrode, and a nonaqueous electrolyte solution is injected into the battery case,

 At this time, although the carbonaceous material having high stability is mainly used for the negative electrode, despite the problems caused by the high chemical activity,

_As the demand for the development of high energy density secondary batteries continues to increase as the use of mobile communications and portable electronic devices continue to increase and rapidly develop, the density _{(0.54 g / cm 3)} is low and the standard reduction potential _{(-3.045 V SHE: standard hydrogen electrode)} is the most popular material for cathode materials for high energy density cells due to its very low characteristics.

_{In the} meantime, the manufacturing method of the lithium metal battery is also described in 2019/117669 1 »(1 ^ ¾2018 / 015931

And has been carried out in accordance with a manufacturing method of a lithium ion battery using a carbon-based material that has been killed. However _{, the} two batteries differ from each other in the formation step of the passivation film which has a crucial influence on the long life characteristic due to the difference in the cathode material, and thus a fundamental change in the battery manufacturing technology is required.

요표피 부근의 전위를 나타내는이 전위는전해액용매 및 첨가제의 환원분해 전위보다높기 때문에 전해액 주입만으로는 전해액 용매와 첨가제의 분해에 의한 부동태막이 형성되지 않는다. 따라서, 카본 전극의 경우， 부동태막의 형성은 활성화代_{01111 011}） 공정에서 전위를 인가함에 따라 생성되는데, 이때, 카본 전극의 표면에 전해액이 균일하게 함침되도록상온또는고온（40〜 60方）분위기 하에 24시간 이상 진행되는 에이징 ₁ ） 공정을 거치게 된다. 따라서， 카본 전극을 사용하는 경우， 표면에 균일한 피막 형성이 비교적 잘 이루어지는 편이다. In the case of the conventional carbon electrode,

Since this potential indicating the potential near the epidermis is higher than the decomposition potential of the electrolyte solvent and the additive, a passive film due to the decomposition of the electrolyte solvent and the additive is not formed only by injecting the electrolyte. Accordingly, in the case of carbon electrodes, to form passivation film is under active代_{01111 011)} is generated as the voltage applied in the process, this time, room temperature or high temperature such that the electrolyte is uniformly impregnated into the surface of the carbon electrode (40~ 60方) atmosphere And the aging ₁ ) process is carried out for 24 hours or more. Therefore, when a carbon electrode is used, uniform film formation on the surface is comparatively well performed.

부근의 전위를나타내며, 이 전위는 전해액 용매 및 첨가제의 환원 분해 전위보다낮기 때문에 전해액의 주액과 거의 동시에, 전해액 용매 및 첨가제의 환원 분해에 의한 부동태막이 리륨 금속과 접촉함에 따라 즉각 생성된다. However, in the case of metal electrodes the Li contrast to the carbon electrode, -3.04 ¥沙after pouring the electrolytic solution _3.

And this potential is lower than the reduction decomposition potential of the electrolyte solvent and the additive so that the passive film due to the reduction decomposition of the electrolyte solvent and the additive is formed immediately upon contact with the lyrium metal almost simultaneously with the electrolyte solution.

Therefore, unlike the impregnated electrolyte injection immediately outside portion passivation film is formed internal cell is the electrolyte impregnation is done after aging _¾) of a certain period of time at the same time, because the passivation film is formed, the battery inside the passivation film in accordance with the time variation between the outer A difference in physical properties such as the composition, thickness, and density is caused.

 The difference in the physical properties of the passivation film causes an unbalance in the current density at the time of charging and discharging, resulting in the local generation and growth of the ritum dendrite, which is the main cause of the deterioration of the lifetime of the metal battery.

As a method for preventing this, introduction of a novel electrolyte solvent and additives has been proposed, but it has not reached a solution method of a fundamental problem. In addition, when a large amount of additive is added as a method for solving the above problem, among the above additives, it is preferable from the viewpoint of formation property of passivation. However, when the remaining amount is left in the electrolyte solution, 2019/117669 1 ^» (: 1 ^ {2018/015931

There is a problem that the performance of the secondary battery is deteriorated due to the existence of a problem such as being present.

Therefore _, there is a great need for a technique capable of preventing the performance degradation of the lithium secondary battery while forming a uniform passivation film on the surface of the lithium metal electrode.

 DETAILED DESCRIPTION OF THE INVENTION

 [Technical Problem]

 SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems of the prior art and the technical problems required from the past.

₁₀ The inventors of the present invention have conducted intensive research and various experiments, and as described later, before the assembling of the electrode assembly and the lithium secondary battery, the electrolytic solution containing the additive favorable to the characteristics of the passivation film is first applied to the lyrium metal electrode, When the electrode assembly and the lithium secondary battery are manufactured using the same, a uniform passivation film ₁₅ can be formed on the surface of the lithium metal electrode, and the performance of the lithium secondary battery is deteriorated And thus the present invention has been completed

 [Technical Solution]

 Accordingly, a method of manufacturing a lithium secondary battery according to the present invention includes:

₍₂₀₎ A process for preparing a lysoch metal electrode having metal lyrium _{(1 )} on one surface or both surfaces of a current collector.

_11. The process of applying the coating solution for the surface including at least _one lithium salt, a non-aqueous organic solvent is at least _one on of the metal _lithium, and _one or more additives to form a stable passivation film coating;

₂₅₎ fabricating an electrode assembly using the lyrium metal electrode formed with the passivation film as a cathode; and

_(), The process of manufacturing the secondary battery by injecting the injected solution for containing the electrode assembly for a secondary battery built in the case, and at least _one Li salt, at least one non-aqueous organic solvent, and _one or more additives to;

₃₀ , 2019/117669 1 »(: 1 ^ {2018/015931

The additive for the coating electrolyte is selected from the group consisting of vinyl ene carbonate (VC), vinyl ethylene carbonate (VEC), fluoro ethylene carbonate (FEC), propane sultone (PS), 1,3-propane sultone (PRS), ethylene sulfate (ESa), succinonitrile (SN), adiponitrile (AN)), hexane tricarbonitrile (HTCN), gamma-butyrolactone (GBL), biphenyl (BP), cyclohexyl benzene (CHB) , And tert-amyl benzene (TAB)),

 The electrolyte solution for a liquid for injection may be at least one selected from the group consisting of pyridine, triethylphosphite, triethanolamine, cyclic ether, ethylenediamine, glyme, nucleophilic triamide, nitrobenzene derivatives, sulfur, quinoneimine dyes, N, N-substituted imidazolidine, ethylene glycol dialkyl ether, ammonium salt, pyrrole, 2-methoxyethanol, trichloroaluminum, carbon tetrachloride, trifluoroethylene, fluoroethylene carbonate (FEC) And propane sultone (PS), and at least one selected from the group consisting of propane sultone (PS)

 The additive composition of the electrolyte for coating is characterized by being different from the additive composition of the electrolyte for injecting liquid.

 Here, the 'composition of the additive' means one or more of the content and kind, and it is preferable that the kind and / or the content of the additive contained in the electrolyte for coating is different from the kind and / or content of the additive contained in the electrolyte for the liquid for injection In the case where the additive contained in the electrolytic solution for coating and the additive contained in the electrolyte solution for injection differ from each other, the same kind is included, but the content is different, or some kinds of additives are the same, and some are different Is a concept that includes all but the same case where the kinds are the same but the contents of some parts are different.

Therefore, according to the present invention, it is possible to arbitrarily determine the composition of an electrolyte for coating to form a passivation film by applying it to a lyrium metal electrode, in a manner different from that of a liquid electrolyte for a liquid injected into a case in the course of assembling the battery. Exhibits excellent effects in the formation of a passivation film, but the operation of the secondary battery 2019/117669 1 »(: 1 ^ {2018/015931

It is possible to use an additive or the like which causes a problem when a residual amount remains in the electrolytic solution used in the process, and a passive film of excellent quality can be formed. Further, since the electrolyte is not included in the electrolyte solution for the electrolyte solution, the performance of the lithium secondary battery can be prevented from being deteriorated by such a substance.

 As described above, the electrolyte for coating may include an additive that exhibits favorable properties in the formation of a passivation film. For example, the above materials may be used. Specifically, succinonitrile (SN ), Adiponitrile (AN), hexane tricarbonitrile (HTCN), gamma-butyrolactone (GBL), propane sultone (PS) 1,3-propane sultone (PRS), vinylene carbonate (VC), fluoro ethylene carbonate (FEC), and the like. And more specifically VC and FEC.

 The materials of VC, SN, AN, HTGN, PS, PRS, GBL and FEC form a passive film by forming a passive film by forming a passive film at a high electric potential relative to a solvent in forming a passive film. , The effect of forming a dense passivation film while suppressing the decomposition reaction of the solvent can be exhibited. On the other hand, when the electrolyte is contained in the electrolyte solution injected when the lithium secondary battery is assembled, there is a problem that when the FEC remains excessively, swelling is increased due to generation of gas during storage at a high temperature even when a small amount of VC remains.

 Therefore, according to the present invention, these materials can be preferably contained in the electrolytic solution for coating, and thereafter they can be contained in the electrolytic solution for the liquid injection or in a small amount.

 The additive may be added in an amount of 0.1 to 20% by weight, more preferably 0.5 to 10% by weight, based on the total weight of the electrolytic solution for coating,

1 to 5% by weight.

 Outside of the above range, if it is contained too much, it can not form a passive film of good traits, and if too much is contained, it can act as a resistor, which is not preferable.

On the other hand, the application of the coating electrolyte may be performed by dip coating or roll- 2019/117669 1 ^» (: 1 ^ {2018/015931

Or by roll to roll coating.

Here, dip coating is a method of directly immersing a metal electrode in which a metal lithium _(Li) is formed on one surface or both surfaces of a collector, directly in an electrolyte solution for coating.

 At this time, since the lithium metal electrode is continuously produced in a sheet form, it can be performed by designing the lithium metal electrode sheet to pass through the water tank containing the electrolyte for coating in succession to the production process of the lithium metal.

This method is shown in Fig. ₁

_1, the both surfaces on the metal lithium ₁₁₂ is a lithium metal electrode ₁₁₀ that is formed of a copper current collector ₁₁₁ is conveyed by the rolls into a sheet _{(121, 122, 123). 10} time, can be applied to the coated electrolyte _131, for the coating liquid electrolyte lithium metal electrode ₁₁₀ for moving ₍₁₃₁₎ along which immerse the second roll ₁₂₂ in the tank ₁₃₀ is filled for. Alternatively, in the roll-to-roll coating, the lithium metal electrode does not directly pass through the electrolyte but a part of the roll is immersed in the electrolyte for coating, and the lithium metal electrode is brought into contact with the roll in the non- And the electrolyte solution ₁₅ is indirectly applied to the lump metal electrode.

This method is shown in Fig. ₂

₂ , the lithium metal electrode ₂₁₀ having the metal lithium ₂₁₂ formed on both sides of the copper current collector ₂₁₁ is transported to the sheet by the rolls _{221, 222, and 223. At} this time, , the coated electrolyte _{(231, 241)} a tank filled for _{230 and 240,} the rolls for ₂₀ coating for the coating _{(224, 225),} one side is the state that contained the electrolyte _{(231, 241),} the other end Lee And _is in contact with the metal electrode ₂₁₀ .

At this time, the coating rolls _{224 and 225} out dragged with the rotation coating rolls for _{(224, 5)} buried coating liquid electrolyte _{(231, 241)} is a lithium metal electrode ₍₂₁₀ for in for coating the electrolyte _{(231, 241)} for ₎ . ≪ / RTI >

₂₅ Through such a process, an electrolyte for coating can be applied to one side or both sides of the lithium metal electrode, so that the passivation film due to the reduction decomposition of the solvent and the additive of the coating electrolyte for low- Lt; / RTI > Therefore, there is no limit to the number of times of applying the electrolyte, may be performed more than _once, and thus, the passivation film of a multi-layer structure of a desired degree can also be formed ₃₀ 0 2019/117669 1> (1 '/ 1 technique 018/015931

Here, the passivation film may be a solid electrolyte interphase (SEI) film. According to the manufacturing method of the present application, since an electrolytic solution for coating can be set in a condition favorable only for the formation of a film separately from the electrolyte solution for injection, which is injected at the time of assembling the secondary battery, a passive film of excellent quality can be formed, It is possible to manufacture a lithium secondary battery exhibiting high charging / discharging efficiency and excellent lifetime characteristics. In addition, it has been confirmed that the problem of deterioration in secondary battery performance, which may be a problem afterwards, can be solved by injecting a minimum amount of additive into the electrolyte solution.

 As described above, the electrolyte solution for a liquid electrolyte may include one or more lithium salts, one or more nonaqueous electrolytic solutions, and one or more additives, except that the composition of the additive is different from the coating electrolyte solution .

That is _, as described above, the electrolyte for the liquid electrolyte has favorable conditions for forming a passivation film. However, when residual amount remains in the operation process of the secondary battery, the additive that may deteriorate the performance of the secondary battery is not included, It is possible to include additives of a kind that exhibit a beneficial effect in the course of battery operation. For example, the electrolyte for a liquid electrolyte may contain additives for improving charge / discharge characteristics, flame retardancy, and the like. For example, the above materials may be included. Specifically, fluoro ethylene carbonate (FEC )), And propane sultone (PS).

 When the fluoroethylene carbonate (FEC) is contained in an appropriate amount, the cell performance is not deteriorated. Instead, the fluoroethylene carbonate (FEC) is preferable because it has an effect of improving the life characteristic by acting as a film- Sulfone (PS) is preferable because it suppresses side reactions occurring in the anode at high temperature storage and improves high temperature storage characteristics.

However, materials such as as vinylene carbonate (VC) falling from the above-mentioned example of the injected additive does not include the for the high-temperature storage characteristics are poor _bar, injected by the remaining small amount of _electrolyte.

The additive contained in the electrolyte solution for injection may be contained in an amount of 0.1 to 10% by weight, more specifically 0.5 to 7% by weight, 2019/117669 1 »(: 1 ^ {2018/015931

And more specifically 0.5 to 5% by weight.

 If it is contained in an excessive amount beyond the above range, it is not desirable because it may act as a resistor or rather affect the high temperature storage characteristics. If the content is too low, an improved property , For example, lifetime characteristics and high-temperature storage characteristics can not be expected to be improved.

On the other hand, it includes at least one lithium salt and at least one non-aqueous organic solvent contained in the electrolytic solution for coating and the electrolytic solution for the electrolyte solution. The compositions may be the same or different from each other. Can be selected. The Li salt is a material that is readily soluble in the non-aqueous liquid electrolyte, for example, 001, My!,, 01, 0010, _4, my, ₁₁₀ (No. 1 _10, 1 ^ _6,, - ₃ (the ₀₂ , The people,

Lithium aliphatic carboxylate, lithium 4-phenylborate, imide, and the like can be used.

Examples of the non-aqueous organic solvent include: 1-methyl-2-pyrrolidinone, propylene carbonate, ethylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, gamma-lactone, butyl, 1,2-dimethoxy ethane, tetrahydroxy Franc (6 _¾ :), 2-methyl tetrahydrofuran, dimethylsulfoxide, 1,3-dioxolane, formamide, dimethylformamide, But are not limited to, dioxolane, acetonitrile, nitromethane, methyl formate, methyl acetate, triester phosphate, trimethoxymethane, dioxolane derivatives, sulfolane, methylsulfolane, Propylene carbonate derivatives, tetrahydrofuran derivatives, ether, methyl pyrophosphate, ethyl propionate and the like can be used.

 Hereinafter, other components will be described.

 The lithium metal electrode can be manufactured by depositing a lithium metal on one side or both sides of a planar current collector, or rolling a lyrium foil. At this time, the current collector may be copper foil in detail.

 The copper foil may be generally formed to a thickness of 3 to 50 micrometers, and the metal lithium formed on the copper foil may be formed to a thickness of, for example, 1 to 300 micrometers.

The electrode assembly includes a cathode, a lithium metal electrode on which the passivation film is formed, _{2019/117669 1 »} (: ₁ ^ _{2018/015931

An anode, and a separator interposed between the cathode and the anode

 In this case, the electrode assembly is not limited in its structure, but may be a laminated electrode assembly in which a positive electrode and a separator negative electrode are laminated by a unit electrode, a positive electrode 5 sheet, a separator, and a negative electrode sheet, , Or a stacked and folded electrode assembly in which the unit electrodes are arranged and wound on a sheet-like separation film.

 The anode may include both the conventional anode manufacturing method and components

With ₁₀ Specifically, the positive electrode is, for example, after applying the mixture of the positive electrode active material, conductive material and a binder on a positive electrode current collector, if necessary, and drying is made by, a filler may be further added to the mixture.

The cathode current collector is generally ₃ to make a _{500-micrometer-thick} cathode current collector and an extended current collector is, so long as having a high conductivity without ₁₅ causing chemical changes in the fabricated battery is not particularly limited, for For example, the surface of stainless steel aluminum, nickel, titanium-fired carbon, or aluminum or stainless steel surface-treated with carbon, nickel, titanium, silver, etc. may be used. And the adhesive force of the cathode active material can be increased. Various forms such as ₂₀ film, sheet foil net porous body foam, and nonwoven fabric are possible.

The positive electrode active material is Lyrium cobalt oxide (0> _02), Lyrium nickel oxide (0 chassis _02), a layered compound or a 1 or a compound more transition substituted with metal and the like; formula I ₊ ^ -, where is from 0 to 0.33 ), 1 _{/ [1103, 01} ^ _{11203, 1} "t _[1102 including Lyrium manganese oxides; lithium garden cargo如₂ air 0 _{2); 0¼0 8, 1 ¾04, \ 0} 5, 12 \ 0 7 2 vanadium oxide, such as _{5: 2} formula ^ ₁₁ ^ 0 _(here, M = ₀ 0, _¾411, Shin, (¾ Mg, 3

Manganese composite oxide LiMn _{204 in} which a part of the formula is substituted with an alkaline earth metal ion _; 3 ₀ disulfide compound; ₂ (? ₀₀₄ ^) _3, the formula you ^{_{1¾ \ 1% (¾1> 0}} 4 ( where, _X,父_2³0, 2019/117669 1 »(: 1 ^ {2018/015931

And the lithium metal phosphate compound represented by the following formula (1) + (+ +)), but the present invention is not limited thereto.

 The conductive material is usually added in an amount of 1 to 30% by weight based on the total weight of the mixture including the cathode active material. Such a conductive material is not particularly limited as long as it has electrical conductivity without causing any chemical change in the battery, for example, graphite such as natural graphite or artificial graphite; Carbon black, carbon black, acetylene black, ketjen black, channel black, furnace black, lamp black, summer black, and carbon black; conductive fibers such as carbon fiber and metal fiber; metal powders such as carbon fluoride, aluminum, and nickel powder; Conductive whiskey such as potassium titanate; conductive metal oxides such as titanium oxide; Conductive materials such as polyphenylene derivatives and the like can be used.

술폰화 EPDM, 스티렌 브티렌 고무, 불소 고무, 다양한 공중합체등을들수있다. The binder is a component which assists in bonding of the active material and the conductive material and bonding to the current collector, and is usually added in an amount of 1 to 30% by weight based on the total weight of the mixture containing the cathode active material. Examples of such binders include polyvinylidene fluoride, polyvinyl alcohol, carboxymethylcellulose (CMC), starch, hydroxypropylcellulose, regenerated cellulose, polyvinylpyrrolidone, tetrafluoroethylene, polyethylene , Polypropylene, ethylene-propylene-diene ter

Sulfonated EPDM, styrene butylene rubber, fluorine rubber, various copolymers, and the like.

 The filler is not particularly limited as long as it is a fibrous material which is used selectively as a component for suppressing the expansion of the anode and does not cause chemical change in the battery. Examples of the filler include olefin polymers such as polyethylene and polypropylene; Fibrous materials such as fibers and carbon fibers are used.

The separation membrane is interposed between the anode and the cathode, and an insulating thin film having high ion permeability and mechanical strength is used. The pore diameter of the membrane is generally 0.01 to 10 micrometers, and the thickness is generally 5 to 300 micrometers. Such separation membranes include, for example, olefinic polymers such as polypropylene, which are chemically resistant and hydrophobic; A sheet or a nonwoven fabric made of glass fiber, polyethylene or the like is used, and a separation membrane in which a ceramic, a binder or a mixed layer of a ceramic and a binder is coated on the surface of the separation membrane using the above- 2019/117669 1 »(: 1 ^ {2018/015931

Can be used. When a solid electrolyte such as a polymer is used as an electrolyte, the solid electrolyte may also serve as a separation membrane.

 The electrode assembly thus manufactured is housed in a secondary battery case, wherein the secondary battery case may be a pouch-shaped battery case made of an aluminum laminate sheet, or a rectangular or cylindrical battery case made of a metal can. After the electrode assembly is housed in the secondary battery case, the electrolyte solution may be injected through the main liquid port.

 The present invention provides a lithium secondary battery produced by such a method. Specifically, the lithium secondary battery according to the above method is characterized in that the surface of an electrode on which metal lithium is formed on one surface or both surfaces of the current collector is coated with an electrolyte solution And a lyrium metal electrode having a uniformly formed passivation film with a composition according to decomposition.

BRIEF DESCRIPTION OF THE DRAWINGS

 1 is a schematic view of a coating method of an electrolyte solution for coating according to one embodiment of the present invention;

 2 is a schematic view of a coating method of an electrolyte solution for coating according to another embodiment of the present invention.

 DETAILED DESCRIPTION OF THE INVENTION

In the following description, explained with reference to embodiments according to the _invention, which are for a more easy understanding of the invention, the scope of the present invention is not intended to be limited by it.

≪ Example 1 -

A lyrium metal cathode sheet was produced by rolling metallic lyrium (thickness: 20 ~) on a current collector (thickness: 10) made of copper _. The lithium metal negative electrode sheet was immersed in an electrolyte solution for coating in the same manner as in FIG. 1 to form a passivation film on the surface. At this time, the composition of the electrolytic solution for coating was 1: 2: 1 in a mixture of ethylene carbonate, dimethylene carbonate, and diethyl carbonate

As the additive, a liquid electrolyte containing 10% by weight and 2% by weight of each of the following materials was used.

The lithium metal negative electrode was sputtered to form a negative electrode. 2019/117669 1 ^» (: 1 ^ {2018/015931

A conductive material in the weight ratio _95: junhu mix well in _NMP so that the _2.5, applied to the foil during the ₁₂ _ _{thickness: 2.5} (loading quantity: 4 _{111 11} ^2), 130 ᄋ (after drying at, the electrode porosity is _30% To prepare a positive electrode.

The positive electrode and the negative electrode were coated with a polyethylene film ((thickness of _{12 m} ), ethylene carbonate carbonate and diethyl carbonate in a ratio of _{1: 2: 1}

_{% By} weight was used as an electrolyte solution for a dummy solution and housed in a pouch-type case to prepare secondary batteries

≪ Example 2 >

_2:: to an ethylene carbonate, dimethylene carbonate and diethyl carbonate is _one degree was formed in the same manner as ₂ Lyrium film passivated on the metal cathode sheet, a composition of the coating solution for the _first平₁ in a mixed solvent of _{1 \ 1}

A lithium secondary battery was produced in the same manner as in Example ₁ , except that the electrolyte solution was used.

<Comparative Example 1

A lithium secondary battery was prepared in the same manner as in Example ₁ , except that a lithium metal sheet not having a passivation film was plated to form a negative electrode. &Lt; Comparative Example 2 &

As the composition of the electrolyte solution for the liquid for injection, ethylene carbonate,

A lithium secondary battery was prepared in the same manner as in Example ₁ except that a liquid electrolyte 2019/117669 1 &quot; (: 1 ^ {2018/015931 Comparative Example 3 &gt;

포함하는액체 전해액을 사용한것을제외하고는실시예 1과동일하게 리튬이차전지를제조하였다. A lithium metal sheet not forming a passivation film was punched out to form a negative electrode. As a liquid electrolyte for a liquid electrolyte, 0 6 was dissolved in IVOL in a solvent in which ethylene carbonate, dimethyl carbonate and diethyl carbonate were mixed at a ratio of 1: 2: 1, as

The lithium secondary battery was prepared in the same manner as in Example 1, except that the liquid electrolyte was used.

&Lt; Comparative Example 4 &

2 중량%으로 포함하는 액체 전해액을 사용한 것을 제외하고는실시예 1과동일하게 리륨이차전지를제조하였다. As for the composition of the injected electrolyte solution, ethylene carbonate, dimethylene carbonate and diethyl carbonate is 1: 2 in a mixed solvent of 1 ^ 1平₆ is dissolved in 1, and as an additive

A lithium secondary battery was prepared in the same manner as in Example 1, except that a liquid electrolyte containing 2% by weight was used.

_{<Experiment 1} ñ

 The secondary batteries prepared according to Examples 1 and 2 and Comparative Example 1 were charged and discharged twice at 0.2 to 4.3 V intervals to measure initial discharge capacity and discharge efficiency and the results are shown in Table 1 Then, after performing 0.10 charge and 0.50 discharge 100 times, the discharge capacity and the retention rate were calculated 100 times with respect to one discharge capacity, and the results are shown in Table 1 below.

 [Table 1]

Referring to Table 1, the lithium secondary battery manufactured by forming a passivation film on a lyrium metal electrode according to the present invention suppresses non-uniform generation and growth of the lithium diolite and improves the charging / discharging efficiency, A lithium secondary battery in which a passivation film is not formed in advance, or a lithium secondary battery in which a passivation film is formed, 2019/117669 1 »(: 1 ^ {2018/015931

, It can be confirmed that the life characteristic is remarkably lowered.

Experimental Example 2 -

충방전을실시하여 용량 확인 후 0.2（：로 4.3 \자지 재충전하여 60ᄋ（：의 온도에서 21일 방치 후두께 및 스웰링 비율을측정하여 그결과를하기 표 2에 나타내었다. The secondary battery produced according to Examples 1 and 2 and Comparative Examples 2 to 4 was subjected to a voltage of 0.2

After the charge and discharge were performed and the capacity was checked, the thickness and the swelling ratio were measured after being left for 21 days at a temperature of 0.2 (: 4.3), and the results are shown in Table 2 below.

 [Table 2]

우수한 성질의 부동태막을 형성하기 위한 첨가제를 주액용 전해액에 포함시킨 비교예 3 및 4의 경우, 잔량의 첨가제에 기인한 가스 발생으로 인해 고온 저장 중 스웰링 문제가 심각한것을확인할수있다. 본 발명이 속한 분야에서 통상의 지식을 가진 자라면, 상기 내용을 바탕을 본 발명의 범주 내에서 다양한 응용 및 변형을 행하는 것이 가능할 것이다. In the case of an embodiment in which a passivation film is first formed using an additive that improves the properties of the passivation film and then is not included in the electrolyte solution for the liquid electrolyte, While the ring problem can be solved,

In the case of Comparative Examples 3 and 4 in which an additive for forming a passive film having excellent properties was included in the electrolyte solution for injecting solution, the problem of swelling during storage at a high temperature due to the generation of gas due to the residual additive was confirmed to be serious. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

 [Industrial applicability]

As described above, the method for manufacturing a lithium secondary battery according to the present invention is characterized in that, prior to assembly of the electrode assembly and the re-tumbling secondary battery, an electrolyte for coating containing an additive, which is advantageous for the properties of the passivation film, And an electrode assembly and a lithium secondary battery are manufactured by using the electrode assembly and the lithium secondary battery. Thus, a uniform passivation film can be formed on the surface of the lithium metal electrode, 2019/117669 1 ^» (: 1 ^ {2018/015931

The non-uniform generation and growth of lithium dendrites in the produced lithium secondary battery is suppressed, thereby improving the charging / discharging efficiency, thereby contributing to an improvement in the lifetime of the battery.

Furthermore, by not including the additive, which may be a problem during the operation of the lithium secondary battery, in the electrolytic solution for the _five- liquid electrolyte, it is possible to prevent deterioration of the performance of the lithium secondary battery.

Claims

2019/117669 1 »(: 1 ^ 1 {2018/015931 Claims)  [Claim 1]  (i) preparing a lithium metal electrode having metal lithium (Li) formed on one surface or both surfaces of the current collector; (ii) applying a coating electrolytic solution containing at least one kind of lithium salt, at least one non-aqueous organic solvent _, and _one or more additives to the surface of the metallic lyrium to form a stable passivation film;  (iii) fabricating an electrode assembly using the lithium metal electrode having the passivation film formed thereon as a cathode; and  (iv) the electrode assembly is housed in a secondary battery case, and one or more lithium salts, A step of preparing a secondary battery by injecting an electrolyte solution for injection solution containing at least one kind of non-aqueous organic solvent and at least one additive;  / RTI &gt;  The additive for the coating electrolyte is selected from the group consisting of vinylene carbonate (VC), vinyl ethylene carbonate (VEC), fluoroethylene carbonate (FEC), propane sultone PS), 1,3-propane sultone (PRS), ethylene sulfate (ESa), succinonitrile (SN), adiponitrile AN), hexane tricarbonitrile (HTCN), gamma-butyrolactone (GBL), biphenyl (BP), cyclohexyl benzene (CHB) And tert-amyl benzene (TAB)),  The electrolyte solution for a liquid for injection may be at least one selected from the group consisting of pyridine, triethylphosphite, triethanolamine, cyclic ether, ethylenediamine, glyme, nucleophilic triamide, nitrobenzene derivatives, sulfur, quinoneimine dyes, N, N-substituted imidazolidine, ethylene glycol dialkyl ether, ammonium salt, pyrrole, 2-methoxyethanol, trichloroaluminum, carbon tetrachloride, ethylene fluoride, fluoroethylene carbonate (FEC) And propane sultone (PS), and at least one selected from the group consisting of propane sultone (PS) The additive composition of the electrolytic solution for coating is determined by the additive composition of the electrolyte solution 2019/117669 1 »(: 1 ^ {2018/015931 Lt; RTI ID = 0.0 &gt; Li &lt; / RTI &gt; [Claim 2]  The method for producing a lithium secondary battery according to claim 1, wherein the composition is at least one of a content and a kind. [3]  The method of manufacturing a lithium secondary battery according to claim 1, wherein the current collector is a copper foil. [4]  The method of manufacturing a lithium secondary battery according to claim 1, wherein the metal lithium is formed on one side or both sides of the current collector by vapor deposition or rolling. [Claim 5]  The method according to claim 1, wherein the additive contained in the coating electrolyte is at least one selected from the group consisting of vinyl ene carbonate (VC), and fluoro ethylene carbonate (FEC) A method of manufacturing a secondary battery. [Claim 6]  The method for producing a lithium secondary battery according to claim 1, wherein the additive contained in the coating electrolyte is contained in an amount of 0.1 to 20% by weight based on the total weight of the coating electrolyte. 7. The method of manufacturing a lithium secondary battery according to claim 1, wherein the application of the coating electrolyte is performed by dip coating or roll-to-roll coating. 2019/117669 1 ^» (: 1 ^ {2018/015931 _8. The method of manufacturing a lithium secondary battery according to claim ₁ , wherein the application of the electrolytic solution is performed at least once. ₅ [Claim ₉ ] The method of manufacturing a lithium secondary battery according to claim ₁ , wherein the passivation film is a _{SEI (solid electrolyte interphase)} film. Claim _{10 10.} The method according to claim ₁ , wherein the electrode assembly includes a cathode, an anode, and a separator interposed between the cathode and the anode, the cathode being a luminescent metal electrode having the passivation film formed thereon. Claim _{11 15.} The electrolyte solution according to claim ₁ , wherein the additive contained in the electrolyte solution is at least _one selected from the group consisting of _{fluoro-ethylene carbonate (FEC),} and _{propane sultone (PS)} A method of manufacturing a lithium secondary battery. ₂₀ [Claim ₁₂ ] The method for producing a lithium secondary battery according to claim ₁ , wherein the additive contained in the electrolyte solution for injection is contained in an amount of _0.1 to _{10 %} by weight based on the total weight of the electrolyte solution for a liquid electrolyte ₂₅ [Claim ₁₃ ] A lithium secondary battery produced by the manufacturing method according to claim ₁ Wherein a passivation film having a composition according to decomposition of an electrolyte solution for coating is uniformly formed on a surface of a lyrium metal electrode having metal lithium _(Li) formed on one surface or both surfaces of the current collector.  30