WO2019108031A1 - Composition for gel polymer electrolyte, gel polymer electrolyte prepared by means of same, and lithium secondary battery comprising same - Google Patents

Composition for gel polymer electrolyte, gel polymer electrolyte prepared by means of same, and lithium secondary battery comprising same Download PDF

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Publication number
WO2019108031A1
WO2019108031A1 PCT/KR2018/015122 KR2018015122W WO2019108031A1 WO 2019108031 A1 WO2019108031 A1 WO 2019108031A1 KR 2018015122 W KR2018015122 W KR 2018015122W WO 2019108031 A1 WO2019108031 A1 WO 2019108031A1
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Prior art keywords
group
compound
formula
polymer electrolyte
gel polymer
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PCT/KR2018/015122
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French (fr)
Korean (ko)
Inventor
오정우
안경호
이철행
이정훈
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주식회사 엘지화학
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Priority claimed from KR1020180147637A external-priority patent/KR102287769B1/en
Application filed by 주식회사 엘지화학 filed Critical 주식회사 엘지화학
Priority to PL18883233.1T priority Critical patent/PL3660971T3/en
Priority to US16/638,673 priority patent/US20210194052A1/en
Priority to EP18883233.1A priority patent/EP3660971B1/en
Priority to CN201880053720.0A priority patent/CN111386624B/en
Publication of WO2019108031A1 publication Critical patent/WO2019108031A1/en

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
    • H01M10/0564—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of organic materials only
    • H01M10/0565—Polymeric materials, e.g. gel-type or solid-type
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
    • H01M10/0564—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of organic materials only
    • H01M10/0566—Liquid materials
    • H01M10/0567—Liquid materials characterised by the additives
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M2300/00—Electrolytes
    • H01M2300/0085—Immobilising or gelification of electrolyte
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Definitions

  • the present invention relates to a composition for a gel polymer electrolyte, a gel polymer electrolyte prepared therefrom, and a lithium secondary battery comprising the gel polymer electrolyte. More particularly, the present invention relates to a gel polymer electrolyte composition for improving cell safety by suppressing side reactions by lithium salts, And a lithium secondary battery comprising the gel polymer electrolyte.
  • lithium secondary batteries having high energy density and voltage have been commercialized and widely used.
  • Lithium metal oxide is used as the positive electrode active material of the lithium secondary battery, and lithium metal, lithium alloy, crystalline or amorphous carbon or carbon composite material is used as the negative electrode active material.
  • the active material is coated on the current collector with an appropriate thickness and length, or the active material itself is coated in a film form and wound or laminated together with a separator as an insulator to form an electrode assembly.
  • the electrode assembly is then placed in a container such as a can or a pouch. To prepare a secondary battery.
  • the safety of a battery is improved in the order of a liquid electrolyte ⁇ gel polymer electrolyte ⁇ solid polymer electrolyte, while a cell electrolyte Is known to decrease.
  • a cell electrolyte Is known to decrease.
  • the solid polymer electrolyte is not yet commercialized due to inferior battery performance.
  • non-aqueous organic solvents are used in the electrolyte.
  • Propylene carbonate (EC) is conventionally used as a double non-aqueous organic solvent.
  • EC ethylene carbonate
  • it has a problem that it can cause irreversible decomposition reaction with graphite materials.
  • an ethylene / 3-component nonaqueous organic solvent including ethylene carbonate (EC) has been used.
  • ethylene carbonate has a high melting point, the use temperature is limited, and there is a problem that battery performance may be considerably deteriorated at a low temperature.
  • the performance of the battery may be deteriorated.
  • moisture may be contained in the active material during the manufacturing process, or may be contained in a trace amount in the electrolyte.
  • lithium titanium oxide used as an anode active material has a very low structural change during charging and discharging, is excellent in life characteristics due to a zero-strain material, forms a relatively high voltage band, It is known that it has excellent safety and stability and it has the advantage of having a rapid charging electrode characteristic that can be charged within a few minutes.
  • due to the property of absorbing moisture in the air There is a problem in that when the electrode is manufactured using such a material, water contained therein is decomposed to generate a large amount of gas.
  • the moisture present in the electrolyte can react with the electrolyte due to the potential energy provided in the charging process to generate a gas.
  • the cell may be swollen and the reliability of the battery may deteriorate.
  • LiPF 6 one of the lithium salts, reacts with water to form HF, which is a strong acid, which can react spontaneously with an electrode active material exhibiting weak basicity.
  • the electrode active material component is eluted by the above reaction, the battery performance is deteriorated and lithium fluoride (LiF) is formed on the surface of the positive electrode, resulting in electrical resistance in the electrode, and the lifetime of the battery is lowered. Therefore, it is necessary to inhibit the formation of HF in the electrolytic solution and to prevent HF from causing a side reaction.
  • Patent Document 1 Korean Patent Laid-Open No. 10-2009-0030237
  • an object of the present invention is to provide a gel polymer electrolyte having improved safety while suppressing the generation of HF which is an impurity generated from anions of lithium salts during charging, A gel polymer electrolyte prepared using the same, and a lithium secondary battery.
  • the present invention provides an oligomer comprising: an oligomer represented by Formula 1; additive; A polymerization initiator; Lithium salts; And a non-aqueous solvent,
  • the additive comprises at least one compound selected from the group consisting of an imide compound, a compound having a Si-N bond, a nitrile compound, a phosphate compound and a borate compound, and a composition for a gel polymer electrolyte .
  • Each of A and A ' is independently a unit containing a (meth) acrylate group
  • Each of C and C ' is independently a unit containing an oxyalkylene group
  • D is a unit containing a siloxane group
  • k is an integer of 1 to 100;
  • R 10 and R 10 ' are each independently selected from the group consisting of an alkyl group having 1 to 12 carbon atoms and a cycloalkyl group having 3 to 12 carbon atoms.
  • the compound having the Si-N bond may include a compound represented by the following formula (3).
  • R 11 is hydrogen or a silyl group in which the alkyl group having 1 to 5 carbon atoms is substituted or unsubstituted
  • R 12 and R 13 are each independently selected from the group consisting of hydrogen, a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms
  • the hetero atom is selected from the group consisting of a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms and a substituted or unsubstituted silyl group having an alkyl group having 1 to 5 carbon atoms
  • the hetero atom is selected from the group consisting of oxygen (O), nitrogen (N) (S). ≪ / RTI >
  • the nitrile compound may include at least one compound selected from the group consisting of compounds represented by the following formulas (4-1) and (4-2).
  • R 14 is selected from the group consisting of a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms and a substituted or unsubstituted alkenyl group having 1 to 5 carbon atoms.
  • R 15 is selected from the group consisting of a substituted or unsubstituted alkylene group having 1 to 5 carbon atoms and a substituted or unsubstituted alkenyl group having 1 to 5 carbon atoms.
  • the phosphate-based compound may include at least one compound selected from the group consisting of tris (trimethylsilyl) phosphate and tris (trimethyl) phosphate.
  • the borate compound may include at least one compound selected from the group consisting of lithium tetrafluoroborate and tris (trimethylsilyl) borate.
  • the oligomer of the present invention may include at least one compound selected from the group consisting of compounds represented by 1-1 to 1-5.
  • n, o and p are each independently an integer of 1 to 30, and q is an integer of 1 to 100.
  • the present invention provides a gel polymer electrolyte prepared using the composition for gel polymer electrolyte, and a lithium secondary battery comprising the gel polymer electrolyte.
  • composition for a gel polymer electrolyte By using the composition for a gel polymer electrolyte according to the present invention, formation of HF, which is an impurity generated during formation of an electrolyte, is inhibited and the cathode active material is prevented from being eluted, so that the capacity of the battery can be maintained at a certain level or more.
  • composition for a gel polymer electrolyte according to the present invention comprises an oligomer; additive; A polymerization initiator; Lithium salts; And non-aqueous solvents.
  • the oligomer may be three-dimensionally coupled through a polymerization reaction to form a polymer network, and includes a (meth) acrylate group, an amide group, an oxyalkylene group, and a siloxane group.
  • the lithium secondary battery can be divided into a lithium ion battery using a liquid electrolyte and a lithium polymer battery using a polymer electrolyte depending on the type of electrolyte used.
  • a lithium ion battery using a liquid electrolyte and a lithium polymer battery using a polymer electrolyte depending on the type of electrolyte used.
  • an ion conductive liquid electrolyte in which a lithium salt or the like is dissolved in a liquid electrolyte, particularly, a non-aqueous organic solvent has been mainly used.
  • the safety of a battery is improved in the order of liquid electrolyte ⁇ gel polymer electrolyte ⁇ solid polymer electrolyte, while battery performance is rather reduced.
  • the gel polymer electrolyte is disadvantageous in that the conductivity of the lithium ion is lower than that of the liquid electrolyte composed of the electrolyte solution.
  • the present invention aims to solve these problems by using a gel polymer electrolyte including a polymer network formed by three-dimensionally bonding the oligomer.
  • the degree of freedom of lithium ion is increased by the anion immobilization and stabilization, and the electric resistance is reduced to realize high lithium ion conductivity.
  • the polymer network formed of the oligomer has high heat resistance and high temperature durability, and has low volatility even at a high temperature, resulting in high electrochemical stability. Therefore, even when the lithium secondary battery is used in a high temperature environment or when the temperature inside the battery rises during driving of the battery, it is possible to control the amount of heat generation and suppress the occurrence of ignition, thereby improving the high temperature safety of the battery.
  • the oligomer may be represented by the following general formula (1).
  • D is a unit containing a siloxane group
  • k is an integer of 1 to 100.
  • k is preferably an integer of 1 to 50, more preferably an integer of 1 to 30.
  • the oligomer represented by Formula 1 has an appropriate weight average molecular weight (Mw).
  • the weight average molecular weight in the present specification may mean a value converted to standard polystyrene measured by GPC (Gel Permeation Chromatograph), and unless otherwise specified, the molecular weight may mean a weight average molecular weight.
  • the weight average molecular weight can be measured by Gel Permeation Chromatography (GPC). For example, after a sample of a certain concentration is prepared, the GPC measurement system alliance 4 apparatus is stabilized.
  • the weight average molecular weight (Mw) of the oligomer represented by Formula 1 may be controlled by the number of repeating units, and may be about 1,000 to 20,000, specifically 1,000 to 15,000, more specifically 1,000 to 10,000. When the weight average molecular weight of the oligomer is within the above range, it is possible to effectively improve the mechanical strength of the battery and to improve the processability (moldability) and the cell stability.
  • the units A and A ' are units containing a (meth) acrylate group so that oligomers are combined in a three-dimensional structure to form a polymer network.
  • the units A and A ' may be derived from monomers comprising at least one monofunctional or multifunctional (meth) acrylate or (meth) acrylic acid in the molecular structure.
  • the units A and A ' may each independently include at least one or more units represented by the following formulas (A-1) to (A-5).
  • each of R 1 's may independently be selected from the group consisting of hydrogen and a substituted or unsubstituted alkylene group having 1 to 6 carbon atoms.
  • the ion transfer characteristic is controlled, and the function of controlling mechanical properties and adhesion is given .
  • the performance of the gel polymer electrolyte formed of an oligomer can be improved by stabilizing the anion generated by the side reaction of HF and suppressing the generation of HF.
  • the units B and B ' may each independently include a unit represented by the following formula (B-1).
  • R 2 represents a linear or non-linear alkylene group having 1 to 10 carbon atoms, a substituted or unsubstituted cycloalkylene group having 3 to 10 carbon atoms, a substituted or unsubstituted bicycloalkylene group having 6 to 20 carbon atoms, At least one selected from the group consisting of an unsubstituted aryl group, a unit represented by the following formula: R 2 -1, and a unit represented by the following formula: R 2 -2.
  • the R 2 may include at least one or more units represented by the following general formulas R 2 -3 to R 2 -8.
  • the units C and C ' are each independently an oxyalkylene group-containing unit to increase dissociation of salts in the polymer network and increase affinity with a surface having a high polarity in a battery. More specifically, it is used to control the impregnation ability of the solvent, the electrode affinity and the ion transporting ability.
  • the units C and C ' may each independently include a unit represented by the following formula (C-1).
  • R 3 is a linear or non-linear alkylene group having 1 to 10 carbon atoms substituted or unsubstituted, and 1 is an integer of 1 to 30.
  • R 3 may be -CH 2 CH 2 - or -CHCH 3 CH 2 -.
  • the unit D is a unit containing a siloxane group and is intended to control the mechanical properties and the affinity with the separator. Specifically, a structure for securing flexibility other than the solid structural region due to the amide bond in the polymer network can be formed, and the affinity with the polyolefin separator membrane fabric can be increased by utilizing the low polarity. In particular, when the affinity with the polyolefin-based separator membrane is improved, the effect of reducing the resistance and further improving the ionic conductivity can be realized at the same time. On the other hand, when a siloxane group is contained, stabilization of anions generated by HF and inhibition of the generation of HF can improve the performance of the oligomer-containing gel polymer electrolyte.
  • the unit D may include a unit represented by the formula D-1.
  • R 8 and R 9 are linear or non-linear alkylene groups having 1 to 5 carbon atoms
  • R 4, R 5, R 6 and R 7 are each independently hydrogen, an alkyl group having 1 to 5 carbon atoms, An aryl group having 6 to 12 carbon atoms, and m is an integer of 1 to 500.
  • the above-mentioned m may more preferably be an integer of 10 to 500.
  • the polarity of the oligomer can be lowered, so that the wetting of the battery can be improved and the lithium dendrite (Li dendrite) is formed on the electrode by controlling the chemical reaction with the lithium metal So that the safety of the battery can be improved.
  • the unit D represented by the above formula (D-1) may be a unit represented by the following formula (D-2).
  • R 4, R 5, R 6, and R 7 are each independently hydrogen, an alkyl group having 1 to 5 carbon atoms, or an aryl group having 6 to 12 carbon atoms.
  • the unit D represented by the formula (D-2) may include one of the units represented by the following formulas (D-3) and (D-4).
  • m is an integer of 1 to 500, respectively. And more preferably an integer of 10 to 500.
  • the oligomer may be contained in an amount of 0.5 to 20 parts by weight, preferably 1.0 to 20 parts by weight, more preferably 1.5 to 20 parts by weight based on 100 parts by weight of the composition for a gel polymer electrolyte .
  • the content of the oligomer is less than 0.5 part by weight, a network reaction between oligomers for forming a gel polymer electrolyte is difficult to be formed.
  • the oligomer content exceeds 20 parts by weight, the gel polymer electrolyte has a viscosity exceeding a certain level, Impregnation, wetting degradation and electrochemical stability may be impaired.
  • the additive may include at least one compound selected from the group consisting of an imide compound, a compound having a Si-N bond, a nitrile compound, a phosphate compound and a borate compound.
  • the gel polymer electrolyte composition includes a lithium salt and a non-aqueous solvent in addition to an oligomer.
  • a fluoride-based lithium salt having a high ionic conductivity is widely used as a lithium salt.
  • the anions generated by the chemical reaction of the fluoride-based lithium salts react with a trace amount of water to produce by-products such as HF, and such by-products cause decomposition of the organic solvent and electrode side reactions, have.
  • the high temperature storability of the secondary battery may be deteriorated due to the negative ions and by-products.
  • PF 6 - which is an anion may lose electrons on the cathode side and PF 5 may be generated. At this time, the following chemical reactions can proceed in a cascade.
  • the decomposition of the organic solvent or the side reaction with the electrode may occur due to HF or other by-products generated, and the performance of the battery may be continuously deteriorated.
  • a method of removing water present in the electrolyte a method of suppressing the generation of HF by using an HF scavenger, a method of stabilizing and stabilizing anions generated from a lithium salt, and the like can be used.
  • the imide compound and the compound having the Si-N bond can fix the H 2 O as shown in the following reaction mechanism to remove moisture in the electrode, react with the anion generated from the lithium salt in the electrolyte It is possible to suppress the generation of HF which is an impurity.
  • the oligomer according to the present invention may be used together with an additive to form HF during the formation of the gel polymer electrolyte.
  • the HF may collapse the polymer structure, and the electrolyte may not be properly formed.
  • the gel polymer electrolyte can be easily formed by stabilizing anions generated by HF generation and HF.
  • the imide compound may include a carbodiimide compound represented by the following formula (2).
  • R 10 and R 10 ' are each independently selected from the group consisting of an alkyl group having 1 to 12 carbon atoms and a cycloalkyl group having 3 to 12 carbon atoms.
  • the imide compound is selected from the group consisting of N, N'-dicyclopentylcarbodiimide, N, N'-dicyclohexylcarbodiimide and N, N'-dicycloheptylcarbodiimide But it is not limited thereto.
  • the compound having Si-N bond may include a compound represented by the following general formula (3).
  • R 11 is hydrogen or a substituted or unsubstituted silyl group having 1 to 5 carbon atoms
  • R 12 and R 13 are each independently selected from the group consisting of hydrogen, a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms
  • the hetero atom is selected from the group consisting of a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms and a substituted or unsubstituted silyl group having an alkyl group having 1 to 5 carbon atoms
  • the hetero atom is selected from the group consisting of oxygen (O), nitrogen (N) (S). ≪ / RTI >
  • the compound represented by the general formula (3) is preferably selected from the group consisting of 1,1,1,3,3,3-hexamethyldisilazane, heptamethyldisilazane, N, N-diethylaminotrimethylsilane, O-tris (trimethylsilyl) hydroxyamine, and the like.
  • the compound having the Si-N bond can be 1,1,3,3,3-hexamethyldisilazane, but is not limited thereto.
  • the nitrile compound can stabilize and stabilize the lithium salt anion in the cell through a non-covalent electron pair in the nitrile.
  • the nitrile compound may include at least one compound selected from the group consisting of compounds represented by the following formulas (4-1) and (4-2).
  • R 14 is selected from the group consisting of a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms and a substituted or unsubstituted alkenyl group having 1 to 5 carbon atoms.
  • R 15 is selected from the group consisting of a substituted or unsubstituted alkylene group having 1 to 5 carbon atoms and a substituted or unsubstituted alkenyl group having 1 to 5 carbon atoms.
  • the nitrile compound is at least one compound selected from the group consisting of adiponitrile, succinonitrile, glutaronitrile, pimelonitrile, hept-3-adnitlinyl, And hex-3-enedinitrile.
  • the compounds represented by the above formulas (4-1) and (4-2) may be succinonitrile, but are not limited thereto.
  • the phosphate-based compound and the borate-based compound can inhibit the generation of HF as an HF scavenger. More specifically, an anion or a by-product (for example, PF 6 - or PF 5 ) produced from the lithium salt acts as a Lewis base, and the phosphate compound and the borate compound act as a Lewis acid ). At this time, the anion and the by-product may be stabilized by the Lewis acid-base reaction to inhibit the chain reaction.
  • an anion or a by-product for example, PF 6 - or PF 5
  • the phosphate-based compound may include at least one compound selected from the group consisting of tris (trimethylsilyl) phosphate and tris (trimethyl) phosphate.
  • the borate compound may include at least one compound selected from the group consisting of lithium tetrafluoroborate and tris (trimethylsilyl) borate.
  • the additive may be added in an amount of 0.1 to 30 parts by weight, preferably 0.1 to 10 parts by weight based on 100 parts by weight of the composition for a gel polymer electrolyte.
  • the content of the additive is within the above range, the gel polymer structure can be maintained by stabilizing the anion without deteriorating the battery performance.
  • the polymerization initiator is for polymerizing the oligomer of the present invention to form a polymer network bonded in a three-dimensional structure, and conventional polymerization initiators known in the art can be used without limitation.
  • the polymerization initiator may be a photo polymerization initiator or a thermal polymerization initiator depending on the polymerization method.
  • the photopolymerization initiator is exemplified by 2-hydroxy-2-methylpropiophenone (HMPP), 1-hydroxy-cyclohexylphenyl-ketone, benzophenone, 2- Phenyl-acetic acid, 2- [2-oxo-2-phenyl-acetoxy-ethoxy] -ethyl ester, oxy-phenyl-acetic acid 2-benzyl-2- (dimethylamino) -1- [4- (4-morpholinyl) phenyl] (2,4,6-trimethylbenzoyl) -1-butanone, 2-methyl-1- [4- (methylthio) phenyl] -2- (Bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, bis (eta 5-2,4-cyclopentadien-1-yl), bis [2,6-difluoro- Methylphenyl iodonium, hexafluorophosphate, and
  • thermal polymerization initiator examples include benzoyl peroxide, acetyl peroxide, dilauryl peroxide, di-tert-butyl peroxide, t-butyl peroxy-2-ethyl-hexanoate, cumyl hydroperoxide and hydrogen peroxide, 2,2'-dicyclohexylcarbodiimide, Azobis (isobutyronitrile), azobis (2-cyanobutane), 2,2'-azobis (methylbutyronitrile), 2,2'-azobis And at least one compound selected from the group consisting of 2,2'-azobisdimethyl-valeronitrile (AMVN).
  • AMVN 2,2'-azobisdimethyl-valeronitrile
  • the polymerization initiator is decomposed by heat at 30 to 100 ° C in a battery or decomposed by light such as UV at room temperature (5 to 30 ° C) to form radicals, and crosslinking is effected by free radical polymerization So that the oligomer can be polymerized.
  • the polymerization initiator may be used in an amount of 0.01 to 5 parts by weight, preferably 0.05 to 5 parts by weight, more preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the oligomer.
  • the content of the polymerization initiator is used within the above range, the amount of the unreacted polymerization initiator which may adversely affect battery performance can be minimized.
  • gelation can be appropriately performed.
  • the lithium salt is used as an electrolyte salt in a lithium secondary battery and is used as an agent for transferring ions.
  • the lithium salt is selected from the group consisting of LiPF 6 , LiBF 4 , LiSbF 6 , LiAsF 6 , LiClO 4 , LiN (C 2 F 5 SO 2 ) 2 , LiN (CF 3 SO 2 ) 2 , CF 3 SO 3 Li, LiC 3 SO 2 ) 3 , LiC 4 BO 8 , LiTFSI, LiFSI, and LiClO 4 , preferably LiPF 6 , but is not limited thereto .
  • the lithium salt may be contained at 0.5 to 5M, preferably 0.5 to 4M.
  • the content of the lithium salt is less than the above range, the lithium ion concentration in the electrolyte is low, so that the charge and discharge of the battery may not be performed properly. If the content exceeds the above range, the viscosity of the gel polymer electrolyte increases and wetting in the battery decreases So that the battery performance can be deteriorated.
  • the non-aqueous solvent is, for example, ether, ester (Acetate, Propionate), amide, linear carbonate or cyclic carbonate, nitrile (acetonitrile, SN etc.) May be used alone or in combination of two or more.
  • a carbonate-based electrolyte solvent containing a carbonate compound which is typically a cyclic carbonate, a linear carbonate, or a mixture thereof, may be used.
  • cyclic carbonate compound examples include ethylene carbonate (EC), propylene carbonate (PC), 1,2-butylene carbonate, 2,3-butylene carbonate, 1,2-pentylene carbonate, Carbonate, vinylene carbonate, and halides thereof, or a mixture of at least two or more thereof.
  • linear carbonate compound examples include dimethyl carbonate (DMC), diethyl carbonate (DEC), dipropyl carbonate (DPC), ethyl methyl carbonate (EMC), methyl propyl carbonate (MPC) and ethyl propyl carbonate (EPC) , Or a mixture of at least two of these compounds may be used.
  • DMC dimethyl carbonate
  • DEC diethyl carbonate
  • DPC dipropyl carbonate
  • EMC ethyl methyl carbonate
  • MPC methyl propyl carbonate
  • EPC ethyl propyl carbonate
  • EPC ethyl propyl carbonate
  • EPC e
  • propylene carbonate and ethylene carbonate which are cyclic carbonates in the carbonate electrolyte solution, are highly viscous organic solvents having a high dielectric constant and can dissociate the lithium salt in the electrolytic solution well.
  • cyclic carbonates such as ethylmethyl carbonate, diethyl carbonate Or a low viscosity, low dielectric constant linear carbonate such as dimethyl carbonate in an appropriate ratio can be used to more advantageously use an electrolytic solution having a high electrical conductivity.
  • esters in the electrolyte solvent examples include methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate,? -Butyrolactone,? -Valerolactone,? -Caprolactone,? -Valerolactone And? -Caprolactone, or a mixture of at least two of them, but the present invention is not limited thereto.
  • composition for a gel polymer electrolyte according to an embodiment of the present invention may further include other additives capable of realizing such physical properties known in the art in order to increase the efficiency of polymer network formation reaction and reduce resistance of the oligomer, , Inorganic particles, and the like.
  • Examples of the other additives include VC (vinylene carbonate), VEC (vinyl ethylene carbonate), PS (propane sultone), SN (succinonitrile), AdN (adiponitrile), ESa (ethylene sulfate), PRS , TMSPa (3-trimethoxysilanyl-propyl-N-aniline), TMSPi (Tris (trimethylsilyl) Phosphite), LiPO 2 F 2 , LiODFB (Lithium difluorooxalatoborate), LiBOB (Lithium bis- , LiBF 4, and the like.
  • the inorganic particles may be BaTiO 3 , BaTiO 3 , Pb (Zr, Ti) O 3 (PZT), Pb 1 -a La a Zr 1-b Ti b O 3 (PLZT, Pb (Mg 1/3 Nb 2/3 ) O 3 -PbTiO 3 (PMN-PT), hafnia (HfO 2 ), SrTiO 3 , SnO 2 , CeO 2 2 , MgO, NiO, CaO, ZnO, ZrO 2 , Y 2 O 3 , Al 2 O 3 , TiO 2 , SiC and mixtures thereof, or a mixture of at least two or more thereof .
  • inorganic particles having lithium ion transferring ability that is, lithium phosphate (Li 3 PO 4 ), lithium titanium phosphate (Li c Ti d (PO 4 ) 3 , 0 ⁇ d ⁇ 2, 0 ⁇ d ⁇ 3) as phosphate (Li a1 Al b1 Ti c1 ( PO 4) 3, 0 ⁇ a1 ⁇ 2, 0 ⁇ b1 ⁇ 1, 0 ⁇ c1 ⁇ 3), 14Li 2 O-9Al 2 O 3 -38TiO 2 -39P 2 O 5 like (LiAlTiP) a2 O b2 series glass (glass) (0 ⁇ a2 ⁇ 4, 0 ⁇ b2 ⁇ 13), lithium lanthanum titanate (Li a3 La b3 TiO 3, 0 ⁇ a3 ⁇ 2, 0 ⁇ b3 ⁇ 3) (Li a4 Ge b4 P c2 S d , 0 ⁇ a4 ⁇ 4, 0 ⁇ b
  • the gel polymer electrolyte is prepared using the gel polymer electrolyte composition.
  • the gel polymer electrolyte according to the present invention is characterized in that fluorine is a unit A comprising a substituted or unsubstituted alkylene group having 1 to 5 carbon atoms, units B and B 'each independently containing an amide group, By forming a polymer network with oligomers comprising units C and C 'comprising an acrylate group, ionic conductivity and mechanical properties can be improved.
  • the gel polymer electrolyte composition of the present invention contains an additive, when the electrolyte is prepared from the gel polymer electrolyte composition, the formation of HF or the reaction of HF with the electrolyte can be inhibited, .
  • the gel polymer electrolyte according to the present invention is formed by polymerizing a composition for a gel polymer electrolyte according to a conventional method known in the art.
  • gel polymer electrolytes can be prepared by in-situ polymerization or coating polymerization.
  • the in-situ polymerization includes the steps of (a) inserting an electrode assembly comprising a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode into a battery case, and (b) And injecting a composition for a gel polymer electrolyte according to the method of the present invention, followed by polymerization, to prepare a gel polymer electrolyte.
  • the in-situ polymerization in the lithium secondary battery can be performed by E-BEAM, gamma ray, room temperature / high temperature aging process, and may be performed through thermal polymerization or photopolymerization according to one embodiment of the present invention.
  • the polymerization time is about 2 minutes to 12 hours
  • the thermal polymerization temperature may be 30 to 100 ° C
  • the light polymerization temperature may be room temperature (5 to 30 ° C).
  • an in-situ polymerization reaction in a lithium secondary battery is performed by injecting the gel polymer electrolyte composition into a battery cell, and then gelating through a polymerization reaction to form a gel polymer electrolyte.
  • the gel polymer electrolyte composition may be coated on one surface of an electrode and a separator, cured (gelled) using heat such as heat or UV, and then the electrode and / The electrode assembly may be manufactured by inserting the electrode assembly into the battery case and reusing the existing liquid electrolyte.
  • a secondary battery according to another embodiment of the present invention includes a cathode, an anode, a separator interposed between the anode and the cathode, and a gel polymer electrolyte.
  • the gel polymer electrolyte is the same as that described above, so a detailed description thereof will be omitted.
  • the anode may be prepared by coating a cathode mixture slurry containing a cathode active material, a binder, a conductive material, and a solvent on a cathode collector.
  • the positive electrode collector is not particularly limited as long as it has electrical conductivity without causing chemical change in the battery.
  • the positive electrode collector may be formed of a metal such as carbon, stainless steel, aluminum, nickel, titanium, sintered carbon, , Nickel, titanium, silver, or the like may be used.
  • the cathode active material is a compound capable of reversibly intercalating and deintercalating lithium, and may specifically include a lithium composite metal oxide including lithium and at least one metal such as cobalt, manganese, nickel, or aluminum have. More specifically, the lithium composite metal oxide may be at least one selected from the group consisting of lithium-manganese-based oxides (for example, LiMnO 2 and LiMn 2 O 4 ), lithium-cobalt oxides (for example, LiCoO 2 ), lithium- (for example, LiNiO 2 and the like), lithium-nickel-manganese-based oxide (for example, LiNi 1-Y1 Mn Y1 O 2 (here, 0 ⁇ Y1 ⁇ 1), LiMn 2-z1 Ni z1 O 4 ( here, 0 ⁇ Z1 ⁇ 2) and the like), lithium-nickel-cobalt oxide (e.
  • LiMnO 2 and LiMn 2 O 4 lithium-cobalt oxides
  • LiCoO 2 lithium-
  • lithium-manganese-cobalt oxide e. g., LiCo 1-Y3 Mn Y3 O 2 (here, 0 ⁇ Y3 ⁇ 1), LiMn 2-z2 Co z2 O 4 ( here, 0 ⁇ z2 ⁇ 2) and the like
  • the lithium composite metal oxide may be LiCoO 2 , LiMnO 2 , LiNiO 2 , lithium nickel manganese cobalt oxide (for example, Li (Ni 0.6 Mn 0.2 Co 0.2 ) O 2 , Li (Ni 0.5 Mn 0.3 Co 0.2) O 2 or Li (Ni 0.8 Mn 0.1 Co 0.1 ) O 2 ), or lithium nickel cobalt aluminum oxide (e.g., LiNi 0.8 Co 0.15 Al 0.05 O 2 , etc.) or the like Considering the remarkable improvement effect according to the kind and content ratio of constituent elements forming the lithium composite metal oxide, the lithium composite metal oxide is Li (Ni 0.6 Mn 0.2 Co 0.2 ) O 2 , Li (Ni 0.5 Mn 0.3 Co 0.2 ) O 2, Li (Ni 0.7 Mn 0.15 Co 0.15) O 2 or Li (Ni 0.8 Mn 0.1 Co 0.1 ) O 2 and the like, any one or a mixture of two or more may be used of which have.
  • the cathode active material may be contained in the cathode mixture slurry in an amount of 60 to 98% by weight, preferably 70 to 98% by weight, more preferably 80 to 98% by weight, based on the total weight of the solids excluding the solvent have.
  • the binder is a component that assists in bonding of the active material to the conductive material and bonding to the current collector.
  • binders examples include polyvinylidene fluoride, polyvinyl alcohol, carboxymethylcellulose (CMC), starch, hydroxypropylcellulose, regenerated cellulose, polyvinylpyrrolidone, tetrafluoroethylene, polyethylene (PE) , Ethylene-propylene-diene terpolymer (EPDM), sulfonated EPDM, styrene-butadiene rubber, fluorine rubber, various copolymers and the like.
  • CMC carboxymethylcellulose
  • EPDM Ethylene-propylene-diene terpolymer
  • EPDM Ethylene-propylene-diene terpolymer
  • EPDM Ethylene-propylene-diene terpolymer
  • sulfonated EPDM styrene-butadiene rubber
  • fluorine rubber various copolymers and the like.
  • the binder is included in the positive electrode material mixture slurry in an amount of 1% by weight to 20% by weight, preferably 1% by weight to 15% by weight, more preferably 1% by weight to 10% by weight, based on the total weight of the solids excluding the solvent .
  • the conductive material is a component for further improving the conductivity of the cathode active material.
  • the conductive material is not particularly limited as long as it has electrical conductivity without causing chemical changes in the battery, for example, graphite; Carbon-based materials such as carbon black, acetylene black, ketjen black, channel black, furnace black, lamp black, and thermal black; Conductive fibers such as carbon fiber and metal fiber; Metal powders such as carbon fluoride, aluminum, and nickel powder; Conductive whiskey such as zinc oxide and potassium titanate; Conductive metal oxides such as titanium oxide; Conductive materials such as polyphenylene derivatives and the like can be used.
  • Carbon-based materials such as carbon black, acetylene black, ketjen black, channel black, furnace black, lamp black, and thermal black
  • Conductive fibers such as carbon fiber and metal fiber
  • Metal powders such as carbon fluoride, aluminum, and nickel powder
  • Conductive whiskey such as zinc oxide and potassium titanate
  • Conductive metal oxides such as titanium oxide
  • Conductive materials such as polyphenylene derivatives and the like can be used.
  • acetylene black series such as Chevron Chemical Company, Denka Singapore Private Limited, Gulf Oil Company, etc.
  • Ketjenblack EC (Armak Company)
  • Vulcan XC-72 Cabot Company
  • Super P Tucal
  • the conductive material is used in an amount of 1 to 20% by weight, preferably 1 to 15% by weight, more preferably 1 to 10% by weight, based on the total weight of the solid material excluding the solvent, .
  • the solvent may include an organic solvent such as NMP (N-methyl-2-pyrrolidone), and may be used in an amount that makes it desirable to contain the cathode active material, and optionally, a binder and a conductive material .
  • concentration of the solid content including the positive electrode active material, and optionally the binder and the conductive material is 50 wt% to 95 wt%, preferably 70 wt% to 95 wt%, more preferably 70 wt% to 90 wt% %. ≪ / RTI >
  • the negative electrode may be prepared, for example, by coating a negative electrode current collector with a negative electrode mixture slurry containing a negative electrode active material, a binder, a conductive material and a solvent, or a carbon (C) electrode or metal itself as a negative electrode.
  • the negative electrode collector when a negative electrode is manufactured by coating a negative electrode mixture slurry on the negative electrode collector, the negative electrode collector generally has a thickness of 3 to 500 ⁇ m.
  • the negative electrode current collector is not particularly limited as long as it has high conductivity without causing chemical change in the battery.
  • the negative electrode current collector include copper, stainless steel, aluminum, nickel, titanium, sintered carbon, copper or stainless steel Surface-treated with carbon, nickel, titanium, silver or the like, aluminum-cadmium alloy, or the like can be used.
  • fine unevenness can be formed on the surface to enhance the bonding force of the negative electrode active material, and it can be used in various forms such as films, sheets, foils, nets, porous bodies, foams and nonwoven fabrics.
  • Examples of the negative electrode active material include natural graphite, artificial graphite, carbonaceous material; Lithium-containing titanium composite oxide (LTO), metals (Me) with Si, Sn, Li, Zn, Mg, Cd, Ce, Ni or Fe; An alloy composed of the metal (Me); An oxide of the metal (Me) (MeOx); And a composite of the metal (Me) and the carbon (C).
  • LTO Lithium-containing titanium composite oxide
  • Me metals with Si, Sn, Li, Zn, Mg, Cd, Ce, Ni or Fe
  • An alloy composed of the metal (Me) An oxide of the metal (Me) (MeOx)
  • a composite of the metal (Me) and the carbon (C) a composite of the metal (Me) and the carbon (C).
  • the negative electrode active material may include 80 wt% to 99 wt%, preferably 85 wt% to 99 wt%, and more preferably 90 wt% to 98 wt% based on the total weight of the solid material excluding the solvent in the negative electrode material mixture slurry have.
  • the binder is a component that assists in bonding between the conductive material, the active material, and the current collector.
  • binders include polyvinylidene fluoride (PVDF), polyvinyl alcohol, carboxymethylcellulose (CMC), starch, hydroxypropylcellulose, regenerated cellulose, polyvinylpyrrolidone, tetrafluoroethylene
  • PVDF polyvinylidene fluoride
  • CMC carboxymethylcellulose
  • EPDM ethylene-propylene-diene polymer
  • sulfonated-EPDM styrene-butadiene rubber
  • fluorine rubber various copolymers thereof.
  • the binder is used in an amount of 1 wt% to 20 wt%, preferably 1 wt% to 15 wt%, more preferably 1 wt% to 10 wt% based on the total weight of the solid material excluding the solvent in the negative electrode material mixture slurry .
  • the conductive material is a component for further improving the conductivity of the negative electrode active material.
  • a conductive material is not particularly limited as long as it has electrical conductivity without causing chemical changes in the battery, for example, graphite such as natural graphite or artificial graphite; Carbon black such as acetylene black, ketjen black, channel black, furnace black, lamp black, and thermal black; Conductive fibers such as carbon fiber and metal fiber; Metal powders such as carbon fluoride, aluminum, and nickel powder; Conductive whiskey such as zinc oxide and potassium titanate; Conductive metal oxides such as titanium oxide; Conductive materials such as polyphenylene derivatives and the like can be used.
  • the conductive material may include 1 wt% to 20 wt%, preferably 1 wt% to 15 wt%, and more preferably 1 wt% to 10 wt% based on the total weight of the solid material excluding the solvent in the negative electrode material mixture slurry .
  • the solvent may include water or an organic solvent such as NMP (N-methyl-2-pyrrolidone), and may be used in an amount that is preferred to contain the negative electrode active material, and optionally a binder and a conductive material.
  • concentration of the solid material including the negative electrode active material, and optionally the binder and the conductive material may be 50 wt% to 95 wt%, preferably 70 wt% to 90 wt%.
  • the negative electrode When the metal itself is used as the negative electrode, the negative electrode may be manufactured by a method of physically bonding a metal to the metal thin film itself or the negative electrode collector, followed by rolling or vapor deposition. The deposition may be performed using an electric or chemical vapor deposition method.
  • the metal to be bonded / rolled / deposited on the metal thin film itself or on the negative electrode current collector may include lithium (Li), nickel (Ni), tin (Sn), copper (Cu), and indium Or an alloy of two kinds of metals, and the like.
  • a conventional porous polymer film conventionally used as a separator for example, a polyolefin such as an ethylene homopolymer, a propylene homopolymer, an ethylene / butene copolymer, an ethylene / hexene copolymer, and an ethylene / methacrylate copolymer
  • a porous polymer film made of a high molecular weight polymer may be used alone or in a laminated manner, or a nonwoven fabric made of a conventional porous nonwoven fabric such as a glass fiber having a high melting point, a polyethylene terephthalate fiber or the like may be used. It is not.
  • the external shape of the lithium secondary battery of the present invention is not particularly limited, but may be a cylindrical shape, a square shape, a pouch shape, a coin shape, or the like using a can.
  • a battery module including the lithium secondary battery as a unit cell and a battery pack including the same. Since the battery module and the battery pack include the lithium secondary battery having a high capacity, a high rate-limiting characteristic, and a cycling characteristic, the battery module and the battery pack can be suitably used as a middle- or large- And can be used as a power source of the device.
  • Ethylene carbonate (EC) and ethyl methyl carbonate (EMC) were mixed in a volume ratio of 3: 7, and 0.7 M of LiPF 6 and 0.3 M of LiFSI were added to prepare a mixed solvent. Then, 91.78 g of the mixed solvent 5 g of an oligomer (weight average molecular weight: 5000) of 1 to 5 and 0.2 g of N, N'-dicyclohexylcarbodiimide as an additive, 0.02 g of a polymerization initiator (AIBN), 1.5 g of vinylene carbonate g, 0.5 g of propane sultone (PS) and 1 g of ethylene sulfate (ESa) were added to prepare a gel polymer electrolyte composition.
  • AIBN polymerization initiator
  • PS propane sultone
  • ESa ethylene sulfate
  • a positive electrode active material LiNi 1/3 Co 1/3 Mn 1/3 O 2 ; NCM
  • carbon black 3% by weight
  • PVDF 3% by weight
  • NMP solvent N-methyl -2-pyrrolidone
  • the positive electrode material mixture slurry was applied to an aluminum (Al) thin film as a positive electrode current collector having a thickness of about 20 mu m, dried, and then rolled to produce a positive electrode.
  • the negative electrode mixture slurry was prepared by adding carbon powder as a negative electrode active material, PVDF as a binder and carbon black as a conductive material to 96 wt%, 3 wt% and 1 wt%, respectively, as a solvent.
  • the negative electrode material mixture slurry was applied to a copper (Cu) thin film as an anode current collector having a thickness of 10 mu m, dried, and then rolled to produce a negative electrode.
  • the electrode assembly was manufactured using the separator composed of the anode, the cathode and the three layers of polypropylene / polyethylene / polypropylene (PP / PE / PP). After the composition for the gel polymer electrolyte was injected into the electrode assembly, Followed by heating at 60 DEG C for 24 hours to prepare a lithium secondary battery containing the gel polymer electrolyte.
  • PP / PE / PP polypropylene / polyethylene / polypropylene
  • Example 1 except that 0.5 g of 1,1,3,3,3-hexamethyldisilazane was used instead of 0.2 g of N, N'-dicyclohexylcarbodiimide as an additive, 1, a lithium secondary battery including a gel polymer electrolyte was prepared .
  • Example 1 0.5 g of 1,1,1,3,3,3-hexamethyldisilazane and 2 g of succinonitrile were used instead of 0.2 g of N, N'-dicyclohexylcarbodiimide as an additive. And adiponitrile (2 g) were added to the lithium secondary battery, a lithium secondary battery including a gel polymer electrolyte was prepared.
  • Example 2 In the same manner as in Example 1 except that 2 g of lithium tetrafluoroborate was used instead of 0.2 g of N, N'-dicyclohexylcarbodiimide as an additive in Example 1, lithium containing a gel polymer electrolyte A secondary battery was manufactured.
  • Ethylene carbonate (EC) and ethyl methyl carbonate (EMC) were mixed at a volume ratio of 3: 7, and LiPF 6 and LiFSI 0.3M were added. Then, 1.5 g of Vinylene Carbonate (VC) , 0.5 g of propane sultone (PS) and 1 g of ethylene sulfate (ESa) were added to prepare an electrolytic solution.
  • VC Vinylene Carbonate
  • PS propane sultone
  • ESa ethylene sulfate
  • a positive electrode active material LiNi 1/3 Co 1/3 Mn 1/3 O 2 ; NCM
  • carbon black 3% by weight
  • PVDF 3% by weight
  • NMP solvent N-methyl -2-pyrrolidone
  • the positive electrode material mixture slurry was applied to an aluminum (Al) thin film as a positive electrode current collector having a thickness of about 20 mu m, dried, and then rolled to produce a positive electrode.
  • the negative electrode mixture slurry was prepared by adding carbon powder as a negative electrode active material, PVDF as a binder and carbon black as a conductive material to 96 wt%, 3 wt% and 1 wt%, respectively, as a solvent.
  • the negative electrode material mixture slurry was applied to a copper (Cu) thin film as an anode current collector having a thickness of 10 mu m, dried, and then rolled to produce a negative electrode.
  • the electrode assembly was manufactured using the separator composed of the anode, the cathode and the three layers of polypropylene / polyethylene / polypropylene (PP / PE / PP), and the prepared electrolyte was injected into the electrode assembly to produce a lithium secondary battery .
  • PP / PE / PP polypropylene / polyethylene / polypropylene
  • Example 2 In the same manner as in Example 1 except that 5 g of an oligomer composed of dipentaerythritol pentaacrylate instead of 5 g of the oligomer of the formula (1-5) was used as the oligomer in Example 1, A lithium secondary battery including a polymer electrolyte was prepared.
  • Example 1 a lithium secondary battery including a gel polymer electrolyte was prepared in the same manner as in Example 1, except that an additive was not used.
  • the lithium secondary batteries prepared according to Examples 1 to 5 and Comparative Examples 1 to 3 were set to have a SOC (state of charge) of 50% at 25 ° C., followed by discharging for 10 seconds at 2.5 C rate discharge pulse , And the resistance value for each lithium secondary battery was confirmed through the voltage drop at that time.
  • SOC state of charge
  • the measured resistance values and voltage drop values are shown in Table 1 below.
  • the lithium secondary batteries prepared according to Examples 1 to 5 and Comparative Examples 1 to 3 were allowed to stand for 1 hour under conditions of SOC 50% and 25 ° C, and were then scanned to 1 KHz-1 mHz.
  • the Rct resistance ) Were measured and are shown in Table 2. At this time, the amplitude of the alternating current was 10 mV, and the DC potential of the battery was 3.68 V.
  • the Rct resistance in the battery manufactured by the comparative examples is larger. This indicates that the Rct resistance (interfacial resistance) is larger due to the side reaction induced from the anion of the salt, as compared with the battery produced by the embodiments.
  • Each of the secondary batteries prepared according to Examples 1 to 5 and Comparative Examples 1 to 3 was stored at a high temperature for 10 weeks (10weeks) under a condition of SOC 100% (4.15 V) at a temperature of 60 ° C. Thereafter, the SOC 50% was set at 25 per foot for each week, and the resistance value was measured by discharging for 10 seconds with a discharge pulse at 5C rate. Then, the resistance was measured based on the resistance value measured at the initial (0 week) The rate of change was measured. The results are shown in Table 3 below.

Abstract

The present invention provides a composition for gel polymer electrolyte, gel polymer electrolyte prepared by means of same, and a lithium secondary battery, the composition comprising: an oligomer represented by chemical formula (1); an additive; a polymerization initiator; lithium salts; and a non-aqueous solvent. The additive comprises one or more compounds selected from the group consisting of an imide-based compound, a compound having a Si-N bond, a nitrile-based compound, a phosphate-based compound and a borate-based compound.

Description

젤 폴리머 전해질용 조성물, 이로부터 제조되는 젤 폴리머 전해질 및 이를 포함하는 리튬 이차 전지Compositions for gel polymer electrolytes, gel polymer electrolytes prepared therefrom, and lithium secondary batteries containing the same
관련출원과의 상호인용Mutual citation with related application
본 출원은 2017년 11월 30일자 한국특허출원 제10-2017-0163719호 및 2018년 11월 26일자 한국특허출원 제 10-2018-0147637호에 기초한 우선권의 이익을 주장하며, 해당 한국특허출원의 문헌에 개시된 모든 내용은 본 명세서의 일부로서 포함된다.This application claims the benefit of priority based on Korean Patent Application No. 10-2017-0163719, dated November 30, 2017, and Korean Patent Application No. 10-2018-0147637, dated November 26, 2018, The entire contents of which are incorporated herein by reference.
기술분야Technical field
본 발명은 젤 폴리머 전해질용 조성물, 이로부터 제조되는 젤 폴리머 전해질 및 이를 포함하는 리튬 이차 전지에 관한 것으로, 보다 상세하게는 리튬염에 의한 부반응을 억제시켜 전지 안전성이 향상되는 젤 폴리머 전해질용 조성물, 이로부터 제조되는 젤 폴리머 전해질 및 이를 포함하는 리튬 이차 전지에 관한 것이다.TECHNICAL FIELD The present invention relates to a composition for a gel polymer electrolyte, a gel polymer electrolyte prepared therefrom, and a lithium secondary battery comprising the gel polymer electrolyte. More particularly, the present invention relates to a gel polymer electrolyte composition for improving cell safety by suppressing side reactions by lithium salts, And a lithium secondary battery comprising the gel polymer electrolyte.
모바일 기기에 대한 기술 개발과 수요가 증가함에 따라 에너지원으로서의 이차전지의 수요가 급격히 증가하고 있고, 이러한 이차전지 중 높은 에너지 밀도와 전압을 가지는 리튬 이차전지가 상용화되어 널리 사용되고 있다.As technology development and demand for mobile devices are increasing, the demand for secondary batteries as energy sources is rapidly increasing. Among these secondary batteries, lithium secondary batteries having high energy density and voltage have been commercialized and widely used.
리튬 이차전지의 양극 활물질로는 리튬 금속 산화물이 사용되고, 음극 활물질로는 리튬 금속, 리튬 합금, 결정 질 또는 비정질 탄소 또는 탄소 복합체가 사용되고 있다. 상기 활물질을 적당한 두께와 길이로 집전체에 도포하 거나 또는 활물질 자체를 필름 형상으로 도포하여 절연체인 세퍼레이터와 함께 감거나 적층하여 전극 조립체를 만든 다음, 캔, 파우치와 같은 용기에 넣은 후, 전해질을 주입하여 이차 전지를 제조한다.Lithium metal oxide is used as the positive electrode active material of the lithium secondary battery, and lithium metal, lithium alloy, crystalline or amorphous carbon or carbon composite material is used as the negative electrode active material. The active material is coated on the current collector with an appropriate thickness and length, or the active material itself is coated in a film form and wound or laminated together with a separator as an insulator to form an electrode assembly. The electrode assembly is then placed in a container such as a can or a pouch. To prepare a secondary battery.
리튬 이차 전지에 적용되는 전해질은 크게, 액체 전해질, 젤 폴리머 전해질, 고체 폴리머 전해질 등으로 나뉘는데, 일반적으로, 전지의 안전성은 액체 전해질 < 겔 폴리머 전해질 < 고체 고분자 전해질 순서로 향상되나, 이에 반해 전지 성능은 감소하는 것으로 알려져 있다. 현재 상기 고체 고분자 전해질은 열등한 전지 성능에 의하여, 아직 상업화되지 않은 것으로 알려져 있다.Generally, the safety of a battery is improved in the order of a liquid electrolyte <gel polymer electrolyte <solid polymer electrolyte, while a cell electrolyte Is known to decrease. At present, it is known that the solid polymer electrolyte is not yet commercialized due to inferior battery performance.
전해질에는, 다양한 비수성 유기 용매가 사용되는데, 종래에는 이중 비수성 유기 용매로서 프로필렌 카보네이트(Propylene Carbonate; EC)를 주로 사용하고 있었으나, 이는 흑연 재료와 비가역적인 분해 반응을 일으킬 수 있는 문제점이 있었다. 이를 대체하기 위해 에틸렌 카보네이트(Ethylene Carbonate; EC)를 기본으로 포함하여 이/삼 성분계 비수성 유기 용매가 사용되어 왔다. 그러나, 에틸렌 카보네이트는 녹는점이 높아서 사용 온도가 제한되어 있고, 저온에 있어서 상당한 전지 성능 저하를 가져올 수 있는 문제가 있다.A variety of non-aqueous organic solvents are used in the electrolyte. Propylene carbonate (EC) is conventionally used as a double non-aqueous organic solvent. However, it has a problem that it can cause irreversible decomposition reaction with graphite materials. In order to replace this, an ethylene / 3-component nonaqueous organic solvent including ethylene carbonate (EC) has been used. However, since ethylene carbonate has a high melting point, the use temperature is limited, and there is a problem that battery performance may be considerably deteriorated at a low temperature.
한편, 리튬 이차 전지는 내부에 수분이 포함될 경우, 전지의 성능을 저하시키는 원인이 될 수 있다. 리튬 이차 전지에서 수분은 제조 공정 동안 활물질 내부에 포함되거나, 전해질 중에 미량 존재하는 형태로 포함될 수 있다. 예컨대, 음극 활물질로 사용되는 리튬 티타늄 산화물은 충방전 동안 구조적 변화가 극히 낮아 제로 변형 률(zero-strain) 물질로 수명특성이 매우 우수하고, 상대적으로 높은 전압대를 형성하며, 수지상 결정 (dendrite)의 발생이 없어, 안전성(safety) 및 안정성(stability)이 매우 우수한 물질로 알려져 있으며, 또한, 수분 내에 충전이 가능한 급속 충전용 전극 특성을 가지고 있는 장점이 있으나, 공기 중의 수분을 흡수하는 성질로 인하여 이를 이용하여 전극을 제작하는 경우, 함유된 수분이 분해되어 다량의 기체를 발생시키는 문제가 있다.On the other hand, when moisture is contained in the lithium secondary battery, the performance of the battery may be deteriorated. In the lithium secondary battery, moisture may be contained in the active material during the manufacturing process, or may be contained in a trace amount in the electrolyte. For example, lithium titanium oxide used as an anode active material has a very low structural change during charging and discharging, is excellent in life characteristics due to a zero-strain material, forms a relatively high voltage band, It is known that it has excellent safety and stability and it has the advantage of having a rapid charging electrode characteristic that can be charged within a few minutes. However, due to the property of absorbing moisture in the air There is a problem in that when the electrode is manufactured using such a material, water contained therein is decomposed to generate a large amount of gas.
또한, 전해질 내에 존재하는 수분은, 충전 과정에서 제공되는 전위 에너지에 의해 전해질과 반응하여 가스를 발생시킬 수 있고, 이때, 셀이 부푸는 현상이 일어나는 등, 전지의 신뢰성이 저하될 수 있다. 예컨대 리튬염 중 하나인 LiPF6은 물과 반응하여 강산인 HF를 형성하는데, 이는 약염기성을 나타내는 전극 활물질과 자발적으로 반응할 수 있다. 상기 반응에 의하여 전극 활물질 성분이 용출되면, 전지 성능이 저하되고, 양극 표면에 불화리튬(LiF)을 형성하여 전극 내 전기저항이 되고, 전지의 수명 저하가 초래된다. 따라서, 전해액 중에서의 HF의 형성을 억제하고, HF가 부반응을 일으키는 것을 저지할 필요가 있다. Also, the moisture present in the electrolyte can react with the electrolyte due to the potential energy provided in the charging process to generate a gas. At this time, the cell may be swollen and the reliability of the battery may deteriorate. For example, LiPF 6 , one of the lithium salts, reacts with water to form HF, which is a strong acid, which can react spontaneously with an electrode active material exhibiting weak basicity. When the electrode active material component is eluted by the above reaction, the battery performance is deteriorated and lithium fluoride (LiF) is formed on the surface of the positive electrode, resulting in electrical resistance in the electrode, and the lifetime of the battery is lowered. Therefore, it is necessary to inhibit the formation of HF in the electrolytic solution and to prevent HF from causing a side reaction.
(특허문헌 1) 대한민국 공개특허공보 제10-2009-0030237호(Patent Document 1) Korean Patent Laid-Open No. 10-2009-0030237
본 발명은 상기와 같은 문제점을 해결하기 위한 것으로, 충전시 리튬염의 음이온으로부터 유발되는 불순물인 HF 생성을 억제하고, 부반응을 저감시켜 리튬 이차 전지의 성능이 일정하게 유지되면서도, 안전성이 향상된 젤 폴리머 전해질용 조성물, 이를 이용하여 제조되는 젤 폴리머 전해질 및 리튬 이차 전지를 제공하기 위한 것이다.Disclosure of Invention Technical Problem [8] Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a gel polymer electrolyte having improved safety while suppressing the generation of HF which is an impurity generated from anions of lithium salts during charging, A gel polymer electrolyte prepared using the same, and a lithium secondary battery.
일 측면에서, 본 발명은 하기 화학식 1로 표시되는 올리고머; 첨가제; 중합개시제; 리튬염; 및 비수계 용매를 포함하고,In one aspect, the present invention provides an oligomer comprising: an oligomer represented by Formula 1; additive; A polymerization initiator; Lithium salts; And a non-aqueous solvent,
상기 첨가제는 이미드계 화합물, Si-N계 결합을 갖는 화합물, 나이트릴계 화합물, 포스페이트계 화합물 및 보레이트계 화합물로 이루어진 군에서 선택되는 적어도 하나 이상의 화합물을 포함하는 것인 젤 폴리머 전해질용 조성물을 제공한다.Wherein the additive comprises at least one compound selected from the group consisting of an imide compound, a compound having a Si-N bond, a nitrile compound, a phosphate compound and a borate compound, and a composition for a gel polymer electrolyte .
[화학식 1][Chemical Formula 1]
Figure PCTKR2018015122-appb-I000001
Figure PCTKR2018015122-appb-I000001
상기 화학식 1에서,In Formula 1,
상기 A 및 A'는 각각 독립적으로 (메타)아크릴레이트기를 포함하는 단위이고,Each of A and A 'is independently a unit containing a (meth) acrylate group,
상기 B 및 B'는 각각 독립적으로 아마이드기를 포함하는 단위이며,B and B 'each independently represent an amide group-containing unit,
상기 C 및 C'는 각각 독립적으로 옥시알킬렌기를 포함하는 단위이고,Each of C and C 'is independently a unit containing an oxyalkylene group,
상기 D는 실록산기를 포함하는 단위이며,D is a unit containing a siloxane group,
k는 1 내지 100의 정수이다. k is an integer of 1 to 100;
한편, 상기 이미드계 화합물은,On the other hand, the imide-
하기 화학식 2로 표시되는 카보디이미드계 화합물을 포함하는 것일 수 있다.And a carbodiimide compound represented by the following formula (2).
[화학식 2](2)
Figure PCTKR2018015122-appb-I000002
Figure PCTKR2018015122-appb-I000002
상기 화학식 2에서, R10 및 R10'은 각각 독립적으로, 탄소수 1 내지 12의 알킬기 및 탄소수 3 내지 12의 사이클로알킬기로 이루어진 군에서 선택되는 것이다.In Formula 2, R 10 and R 10 'are each independently selected from the group consisting of an alkyl group having 1 to 12 carbon atoms and a cycloalkyl group having 3 to 12 carbon atoms.
상기 Si-N계 결합을 갖는 화합물은, 하기 화학식 3으로 표시되는 화합물을 포함하는 것일 수 있다.The compound having the Si-N bond may include a compound represented by the following formula (3).
[화학식 3](3)
Figure PCTKR2018015122-appb-I000003
Figure PCTKR2018015122-appb-I000003
상기 화학식 3에서, R11 는 수소 또는 탄소수 1 내지 5의 알킬기가 치환 또는 비치환된 실릴기이고, R12 및 R13은 각각 독립적으로, 수소, 치환 또는 비치환된 탄소수 1 내지 5의 알킬기, 헤테로 원자가 치환 또는 비치환된 탄소수 1 내지 5의 알킬기 및 탄소수 1 내지 5의 알킬기가 치환 또는 비치환된 실릴기로 이루어진 군에서 선택되는 것이며, 상기 헤테로 원자는 산소(O), 질소(N) 및 황(S)으로 이루어진 군에서 선택되는 어느 하나 이상의 원자일 수 있다.In Formula 3, R 11 is hydrogen or a silyl group in which the alkyl group having 1 to 5 carbon atoms is substituted or unsubstituted, R 12 and R 13 are each independently selected from the group consisting of hydrogen, a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms, Wherein the hetero atom is selected from the group consisting of a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms and a substituted or unsubstituted silyl group having an alkyl group having 1 to 5 carbon atoms and the hetero atom is selected from the group consisting of oxygen (O), nitrogen (N) (S). &Lt; / RTI &gt;
또한, 상기 나이트릴계 화합물은, 하기 화학식 4-1 및 4-2로 표시되는 화합물로 이루어진 군에서 선택되는 적어도 하나 이상의 화합물을 포함하는 것일 수 있다.The nitrile compound may include at least one compound selected from the group consisting of compounds represented by the following formulas (4-1) and (4-2).
[화학식 4-1][Formula 4-1]
Figure PCTKR2018015122-appb-I000004
Figure PCTKR2018015122-appb-I000004
상기 화학식 4-1에서, R14는 치환 또는 비치환된 탄소수 1 내지 5의 알킬기 및 치환 또는 비치환된 탄소수 1 내지 5의 알케닐기로 이루어진 군에서 선택되는 것이다.In Formula 4-1, R 14 is selected from the group consisting of a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms and a substituted or unsubstituted alkenyl group having 1 to 5 carbon atoms.
[화학식 4-2] [Formula 4-2]
Figure PCTKR2018015122-appb-I000005
Figure PCTKR2018015122-appb-I000005
상기 화학식 4-2에서, R15는 치환 또는 비치환된 탄소수 1 내지 5의 알킬렌기 및 치환 또는 비치환된 탄소수 1 내지 5의 알케닐기로 이루어진 군에서 선택되는 것이다.In Formula 4-2, R 15 is selected from the group consisting of a substituted or unsubstituted alkylene group having 1 to 5 carbon atoms and a substituted or unsubstituted alkenyl group having 1 to 5 carbon atoms.
또한, 상기 포스페이트계 화합물은 트리스(트리메틸실릴)포스페이트 및 트리스(트리메틸)포스페이트로 이루어진 군에서 선택되는 적어도 하나 이상의 화합물을 포함하는 것일 수 있다.In addition, the phosphate-based compound may include at least one compound selected from the group consisting of tris (trimethylsilyl) phosphate and tris (trimethyl) phosphate.
한편, 상기 보레이트계 화합물은 리튬테트라플루오로보레이트 및 트리스(트리메틸실릴)보레이트로 이루어진 군에서 선택되는 적어도 하나 이상의 화합물을 포함할 수 있다.Meanwhile, the borate compound may include at least one compound selected from the group consisting of lithium tetrafluoroborate and tris (trimethylsilyl) borate.
또한, 본 발명의 상기 올리고머는 1-1 내지 1-5로 표시되는 화합물로 이루어진 군에서 선택되는 적어도 하나 이상의 화합물을 포함하는 것일 수 있다.In addition, the oligomer of the present invention may include at least one compound selected from the group consisting of compounds represented by 1-1 to 1-5.
[화학식 1-1][Formula 1-1]
Figure PCTKR2018015122-appb-I000006
Figure PCTKR2018015122-appb-I000006
[화학식 1-2][Formula 1-2]
Figure PCTKR2018015122-appb-I000007
Figure PCTKR2018015122-appb-I000007
[화학식 1-3][Formula 1-3]
Figure PCTKR2018015122-appb-I000008
Figure PCTKR2018015122-appb-I000008
[화학식 1-4][Formula 1-4]
Figure PCTKR2018015122-appb-I000009
Figure PCTKR2018015122-appb-I000009
[화학식 1-5][Formula 1-5]
Figure PCTKR2018015122-appb-I000010
Figure PCTKR2018015122-appb-I000010
상기 화학식 1-1 내지 1-5에서, n, o, p는 각각 독립적으로 1 내지 30의 정수이고, q는 1 내지 100의 정수이다.In the above formulas 1-1 to 1-5, n, o and p are each independently an integer of 1 to 30, and q is an integer of 1 to 100.
다른 측면에서, 본 발명은 상기와 같은 젤 폴리머 전해질용 조성물을 이용하여 제조되는 젤 폴리머 전해질 및 이를 포함하는 리튬 이차 전지를 제공한다.In another aspect, the present invention provides a gel polymer electrolyte prepared using the composition for gel polymer electrolyte, and a lithium secondary battery comprising the gel polymer electrolyte.
본 발명에 따른 젤 폴리머 전해질용 조성물을 사용하여 전해질을 형성하는 도중 발생하게 되는 불순물인 HF의 형성을 억제하여 양극 활물질이 용출되는 것을 방지하여 전지의 용량을 일정 수준 이상으로 유지시킬 수 있다.By using the composition for a gel polymer electrolyte according to the present invention, formation of HF, which is an impurity generated during formation of an electrolyte, is inhibited and the cathode active material is prevented from being eluted, so that the capacity of the battery can be maintained at a certain level or more.
또한, 상기 HF와 전해질이 반응하여 전해질을 구성하는 비수계 용매가 분해되거나, 전극과의 부반응이 발생하는 것을 억제시켜 전지의 성능 및 안전성이 향상된 전지를 구현할 수 있다.Also, it is possible to realize a battery in which the performance and safety of the battery are improved by suppressing the decomposition of the non-aqueous solvent constituting the electrolyte due to the reaction of the HF with the electrolyte or the side reaction with the electrode.
이하, 본 발명에 대한 이해를 돕기 위해 본 발명을 더욱 상세하게 설명한다.Hereinafter, the present invention will be described in detail in order to facilitate understanding of the present invention.
본 명세서 및 청구범위에 사용된 용어나 단어는 통상적이거나 사전적인 의미로 한정해서 해석되어서는 아니 되며, 발명자는 그 자신의 발명을 가장 최선의 방법으로 설명하기 위해 용어의 개념을 적절하게 정의할 수 있다는 원칙에 입각하여 본 발명의 기술적 사상에 부합하는 의미와 개념으로 해석되어야만 한다.The terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary terms and the inventor may appropriately define the concept of the term in order to best describe its invention It should be construed as meaning and concept consistent with the technical idea of the present invention.
본 명세서에서 사용되는 용어는 단지 예시적인 구현예들을 설명하기 위해 사용된 것으로, 본 발명을 한정하려는 의도는 아니다. 단수의 표현은 문맥상 명백하게 다르게 뜻하지 않는 한, 복수의 표현을 포함한다.The terminology used herein is for the purpose of describing example implementations only and is not intended to be limiting of the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise.
본 명세서에서, "포함하다", "구비하다" 또는 "가지다" 등의 용어는 실시된 특징, 숫자, 단계, 구성 요소 또는 이들을 조합한 것이 존재함을 지정하려는 것이지, 하나 또는 그 이상의 다른 특징들이나 숫자, 단계, 구성 요소, 또는 이들을 조합한 것들의 존재 또는 부가 가능성을 미리 배제하지 않는 것으로 이해되어야 한다.In this specification, the terms "comprising," "comprising," or "having ", and the like are intended to specify the presence of stated features, But do not preclude the presence or addition of one or more other features, integers, steps, components, or combinations thereof.
한편, 본 발명에서 특별한 언급이 없는 한 " * "는 동일하거나, 상이한 원자 또는 화학식의 말단부 간의 연결된 부분을 의미한다.In the meantime, unless otherwise specified in the present invention, " * " means the same or different atom or a connected part between the terminals of the formula.
<젤 폴리머 전해질용 조성물>&Lt; Gel polymer electrolyte composition >
본 발명에 따른 젤 폴리머 전해질용 조성물은 올리고머; 첨가제; 중합개시제; 리튬염; 및 비수계 용매를 포함한다.The composition for a gel polymer electrolyte according to the present invention comprises an oligomer; additive; A polymerization initiator; Lithium salts; And non-aqueous solvents.
올리고머Oligomer
먼저, 상기 올리고머에 대하여 설명한다. 상기 올리고머는 중합 반응을 통하여 3차원 결합되어 폴리머 네트워크를 형성할 수 있으며, (메타)아크릴레이트기, 아마이드기, 옥시알킬렌기 및 실록산기를 포함한다.First, the oligomer will be described. The oligomer may be three-dimensionally coupled through a polymerization reaction to form a polymer network, and includes a (meth) acrylate group, an amide group, an oxyalkylene group, and a siloxane group.
리튬 이차 전지는 사용되는 전해질의 종류에 따라 액체 전해질을 사용하는 리튬 이온 전지, 폴리머 전해질을 사용하는 리튬 폴리머 전지로 나눌 수 있다. 종래에는 액체 상태의 전해질, 특히 비수계 유기 용매에 리튬염 등을 용해한 이온 전도성 액체 전해질이 주로 사용되어 왔다.The lithium secondary battery can be divided into a lithium ion battery using a liquid electrolyte and a lithium polymer battery using a polymer electrolyte depending on the type of electrolyte used. Conventionally, an ion conductive liquid electrolyte in which a lithium salt or the like is dissolved in a liquid electrolyte, particularly, a non-aqueous organic solvent has been mainly used.
그러나 에너지 저장 기술에 대한 관심이 갈수록 높아지면서, 소형 경량화 및 고용량으로 충방전이 가능할 뿐만 아니라, 고온 고전압 안전성을 가지는 이차전지의 개발을 요구되고 있다. 이에 따라, 최근 액체 전해질보다 젤 폴리머로 이루어진 젤 폴리머 전해질을 이용한 전지 개발이 주목받고 있다.However, as the interest in energy storage technology becomes higher and higher, it is required to develop secondary batteries having high temperature and high voltage safety as well as being capable of charging and discharging at a small size and high capacity. Accordingly, development of a battery using a gel polymer electrolyte composed of a gel polymer rather than a liquid electrolyte has recently been attracting attention.
일반적으로, 전지의 안전성은 액체 전해질 < 젤 폴리머 전해질 < 고체 고분자 전해질 순서로 향상되는 반면에, 전지 성능은 오히려 감소하는 것으로 알려져 있다. In general, the safety of a battery is improved in the order of liquid electrolyte < gel polymer electrolyte < solid polymer electrolyte, while battery performance is rather reduced.
즉, 상기 젤 폴리머 전해질은 전해액으로만 이루어진 액체 전해질에 비해, 리튬 이온의 전도성이 낮다는 단점이 있다.That is, the gel polymer electrolyte is disadvantageous in that the conductivity of the lithium ion is lower than that of the liquid electrolyte composed of the electrolyte solution.
따라서 본 발명에서는, 상기 올리고머를 3차원 결합하여 형성되는 폴리머 네트워크를 포함하는 젤 폴리머 전해질을 사용하여 이러한 문제들을 해결하고자 하였다. 상기 올리고머를 결합하여 형성되는 젤 폴리머 전해질의 경우, 음이온 고정화 및 안정화에 의하여 리튬 이온의 자유도가 증가하여 전기저항이 감소하는 효과를 구현하여 높은 리튬 이온전도도를 구현할 수 있다. 또한, 상기 올리고머로 형성되는 폴리머 네트워크의 내열성 및 고온 내구성이 높아, 고온에서도 휘발성이 낮아 전기화학적으로 안정성이 높다. 따라서, 고온의 환경에서 리튬 이차 전지를 사용하는 경우, 또는 전지 구동 중 전지 내부의 온도가 상승하는 경우에도 발열량을 제어하고, 발화로 이어지는 것을 억제할 수 있어 전지의 고온 안전성을 향상시킬 수 있다.Accordingly, the present invention aims to solve these problems by using a gel polymer electrolyte including a polymer network formed by three-dimensionally bonding the oligomer. In the case of the gel polymer electrolyte formed by bonding the oligomer, the degree of freedom of lithium ion is increased by the anion immobilization and stabilization, and the electric resistance is reduced to realize high lithium ion conductivity. In addition, the polymer network formed of the oligomer has high heat resistance and high temperature durability, and has low volatility even at a high temperature, resulting in high electrochemical stability. Therefore, even when the lithium secondary battery is used in a high temperature environment or when the temperature inside the battery rises during driving of the battery, it is possible to control the amount of heat generation and suppress the occurrence of ignition, thereby improving the high temperature safety of the battery.
상기 올리고머는, 하기 화학식 1로 표시되는 것일 수 있다.The oligomer may be represented by the following general formula (1).
[화학식 1][Chemical Formula 1]
Figure PCTKR2018015122-appb-I000011
Figure PCTKR2018015122-appb-I000011
상기 화학식 1에서,In Formula 1,
상기 A 및 A'는 각각 독립적으로 (메타)아크릴레이트기를 포함하는 단위이고, 상기 B 및 B'는 각각 독립적으로 아마이드 기를 포함하는 단위이며, 상기 C 및 C'는 각각 독립적으로 옥시알킬렌 기를 포함하는 단위이고, 상기 D는 실록산 기를 포함하는 단위이며, k는 1 내지 100의 정수이다.Wherein A and A 'each independently represent a unit containing a (meth) acrylate group, B and B' each independently represent an amide group-containing unit, and C and C 'each independently represents an oxyalkylene group D is a unit containing a siloxane group, and k is an integer of 1 to 100. [
한편, 상기 k는 바람직하게는 1 내지 50의 정수, 보다 바람직하게는, 1 내지 30의 정수 일 수 있다. 상기 k가 상기 범위 내인 경우, 상기 화학식 1로 표시되는 올리고머가 적절한 중량평균분자량(Mw)을 갖는다.On the other hand, k is preferably an integer of 1 to 50, more preferably an integer of 1 to 30. When k is within the above range, the oligomer represented by Formula 1 has an appropriate weight average molecular weight (Mw).
이때, 본 명세서에서 중량평균분자량은, GPC(Gel Permeation Chromatograph)로 측정한 표준 폴리스티렌에 대한 환산 수치를 의미할 수 있고, 특별하게 달리 규정하지 않는 한, 분자량은 중량평균분자량을 의미할 수 있다. 이때, 상기 중량평균분자량은 젤투과크로마토그래피(Gel Permeation Chromatography: GPC)를 이용하여 측정할 수 있다. 예컨대, 일정 농도의 샘플 시료를 준비한 후, GPC 측정 시스템 alliance 4 기기를 안정화시킨다. 기기가 안정화되면 기기에 표준 시료와 샘플 시료를 주입하여 크로마토그램을 얻어낸 다음, 분석 방법에 따라 중량평균분자량을 계산한다 (시스템: Alliance 4, 컬럼: Ultrahydrogel linear x 2, eluent: 0.1M NaNO3 (pH 7.0 phosphate buffer, flow rate: 0.1 mL/min, temp: 40℃, injection: 100μL)Herein, the weight average molecular weight in the present specification may mean a value converted to standard polystyrene measured by GPC (Gel Permeation Chromatograph), and unless otherwise specified, the molecular weight may mean a weight average molecular weight. At this time, the weight average molecular weight can be measured by Gel Permeation Chromatography (GPC). For example, after a sample of a certain concentration is prepared, the GPC measurement system alliance 4 apparatus is stabilized. When the instrument is stabilized, the standard and sample samples are injected into the instrument to obtain a chromatogram, and the weight average molecular weight is calculated according to the analytical method (system: Alliance 4, column: Ultrahydrogel linear x 2, eluent: 0.1M NaNO 3 pH 7.0 phosphate buffer, flow rate: 0.1 mL / min, temp: 40 ° C, injection: 100 μL)
상기 화학식 1로 표시되는 올리고머의 중량평균분자량(Mw)는 반복 단위의 개수에 의하여 조절될 수 있으며, 약 1,000 내지 20,000, 구체적으로 1,000 내지 15,000, 보다 구체적으로 1,000 내지 10,000 일 수 있다. 상기 올리고머의 중량평균분자량이 상기 범위 내인 경우, 이를 포함하는 전지의 기계적 강도를 효과적으로 개선할 수 있고, 가공성(성형성) 및 전지 안정성 등이 향상된 젤 폴리머 전해질을 제조할 수 있다. The weight average molecular weight (Mw) of the oligomer represented by Formula 1 may be controlled by the number of repeating units, and may be about 1,000 to 20,000, specifically 1,000 to 15,000, more specifically 1,000 to 10,000. When the weight average molecular weight of the oligomer is within the above range, it is possible to effectively improve the mechanical strength of the battery and to improve the processability (moldability) and the cell stability.
한편, 상기 단위 A 및 A'는 올리고머가 3차원 구조로 결합되어 폴리머 네트워크를 형성할 수 있도록 (메타)아크릴레이트기를 포함하는 단위이다. 상기 단위 A 및 A'는 분자 구조 내에 적어도 하나의 단관능성 또는 다관능성 (메타)아크릴레이트 또는 (메타)아크릴산을 포함하는 단량체로부터 유도될 수 있다. On the other hand, the units A and A 'are units containing a (meth) acrylate group so that oligomers are combined in a three-dimensional structure to form a polymer network. The units A and A 'may be derived from monomers comprising at least one monofunctional or multifunctional (meth) acrylate or (meth) acrylic acid in the molecular structure.
예를 들어, 상기 단위 A 및 A'는 각각 독립적으로 하기 화학식 A-1 내지 A-5로 표시되는 단위 중 적어도 하나 이상을 포함할 수 있다.For example, the units A and A 'may each independently include at least one or more units represented by the following formulas (A-1) to (A-5).
[화학식 A-1][A-1]
Figure PCTKR2018015122-appb-I000012
Figure PCTKR2018015122-appb-I000012
[화학식 A-2][A-2]
Figure PCTKR2018015122-appb-I000013
Figure PCTKR2018015122-appb-I000013
[화학식 A-3][A-3]
Figure PCTKR2018015122-appb-I000014
Figure PCTKR2018015122-appb-I000014
[화학식 A-4][A-4]
Figure PCTKR2018015122-appb-I000015
Figure PCTKR2018015122-appb-I000015
[화학식 A-5][A-5]
Figure PCTKR2018015122-appb-I000016
Figure PCTKR2018015122-appb-I000016
상기 화학식 A-1 내지 화학식 A-5에서 상기 R1은 각각 독립적으로 수소 및 탄소수 1 내지 6의 치환 또는 비치환된 알킬렌기로 이루어진 군에서 선택되는 것 일 수 있다.In the formulas (A-1) to (A-5), each of R 1 's may independently be selected from the group consisting of hydrogen and a substituted or unsubstituted alkylene group having 1 to 6 carbon atoms.
또한, 상기 단위 B 및 B'는 각각 독립적으로 아마이드기를 포함하는 단위로, 상기 올리고머를 사용하여 젤 폴리머 전해질을 구현함에 있어서, 이온 전달 특성을 조절하고, 기계적 물성 및 밀착력을 조절하는 기능을 부여하기 위한 것이다. 또한, 아마이드기를 포함하는 경우, HF의 부반응에 의하여 발생되는 음이온을 안정화시키고, HF의 발생을 억제시켜 올리고머로 형성되는 젤 폴리머 전해질의 성능을 개선시킬 수 있다.The units B and B 'each independently contain an amide group. In the implementation of the gel polymer electrolyte using the oligomer, the ion transfer characteristic is controlled, and the function of controlling mechanical properties and adhesion is given . In addition, when an amide group is included, the performance of the gel polymer electrolyte formed of an oligomer can be improved by stabilizing the anion generated by the side reaction of HF and suppressing the generation of HF.
예를 들어, 상기 단위 B 및 B'는 각각 독립적으로 하기 화학식 B-1로 표시되는 단위를 포함할 수 있다.For example, the units B and B 'may each independently include a unit represented by the following formula (B-1).
[화학식 B-1]  [Formula B-1]
Figure PCTKR2018015122-appb-I000017
Figure PCTKR2018015122-appb-I000017
상기 화학식 B-1에서,In the above formula (B-1)
R2는 탄소수 1 내지 10의 선형 또는 비선형 알킬렌기, 탄소수 3 내지 10의 치환 또는 비치환된 사이클로알킬렌기, 탄소수 6 내지 20의 치환 또는 비치환된 바이사이클로알킬렌기, 탄소수 6 내지 20의 치환 또는 비치환된 아릴기, 하기 화학식 R2-1로 표시되는 단위 및 하기 화학식 R2-2로 표시되는 단위로 이루어진 군에서 선택되는 적어도 하나 이상이다.R 2 represents a linear or non-linear alkylene group having 1 to 10 carbon atoms, a substituted or unsubstituted cycloalkylene group having 3 to 10 carbon atoms, a substituted or unsubstituted bicycloalkylene group having 6 to 20 carbon atoms, At least one selected from the group consisting of an unsubstituted aryl group, a unit represented by the following formula: R 2 -1, and a unit represented by the following formula: R 2 -2.
[화학식 R2-1][Chemical formula R 2 -1]
Figure PCTKR2018015122-appb-I000018
Figure PCTKR2018015122-appb-I000018
[화학식 R2-2][Chemical formula R 2 -2]
Figure PCTKR2018015122-appb-I000019
Figure PCTKR2018015122-appb-I000019
또 다른 예를 들어, 상기 화학식 B-1에서,As another example, in the above formula (B-1)
상기 R2는 하기 화학식 R2-3 내지 R2-8로 표시되는 단위 중 적어도 하나 이상을 포함할 수 있다.The R 2 may include at least one or more units represented by the following general formulas R 2 -3 to R 2 -8.
[화학식 R2-3][Chemical formula R 2 -3]
Figure PCTKR2018015122-appb-I000020
Figure PCTKR2018015122-appb-I000020
[화학식 R2-4][Chemical formula R 2 -4]
Figure PCTKR2018015122-appb-I000021
Figure PCTKR2018015122-appb-I000021
[화학식 R2-5][Chemical formula R 2 -5]
Figure PCTKR2018015122-appb-I000022
Figure PCTKR2018015122-appb-I000022
[화학식 R2-6][Chemical Formula R 2 -6]
Figure PCTKR2018015122-appb-I000023
Figure PCTKR2018015122-appb-I000023
[화학식 R2-7][Chemical formula R 2 -7]
Figure PCTKR2018015122-appb-I000024
Figure PCTKR2018015122-appb-I000024
[화학식 R2-8][Chemical formula R 2 -8]
Figure PCTKR2018015122-appb-I000025
Figure PCTKR2018015122-appb-I000025
또한, 상기 단위 C 및 C'는 각각 독립적으로 옥시알킬렌 기를 포함하는 단위로서, 폴리머 네트워크 내에서의 염의 해리 및 전지내의 극성이 높은 표면과의 친화력을 증가시키기 위한 것이다. 보다 구체적으로, 용매의 함침 능력, 전극 친화력 및 이온전달 능력을 조절하기 위하여 사용된다. The units C and C 'are each independently an oxyalkylene group-containing unit to increase dissociation of salts in the polymer network and increase affinity with a surface having a high polarity in a battery. More specifically, it is used to control the impregnation ability of the solvent, the electrode affinity and the ion transporting ability.
상기 단위 C 및 C'는 각각 독립적으로 하기 화학식 C-1로 표시되는 단위를 포함할 수 있다.The units C and C 'may each independently include a unit represented by the following formula (C-1).
[화학식 C-1][Chemical formula C-1]
Figure PCTKR2018015122-appb-I000026
Figure PCTKR2018015122-appb-I000026
상기 화학식 C-1에서, R3는 탄소수 1 내지 10 치환 또는 비치환된 선형 또는 비선형 알킬렌기이고, l은 1 내지 30의 정수이다.In the above formula (C-1), R 3 is a linear or non-linear alkylene group having 1 to 10 carbon atoms substituted or unsubstituted, and 1 is an integer of 1 to 30.
구체적으로, 상기 화학식 C-1에서, 상기 R3는 -CH2CH2- 또는 -CHCH3CH2- 일 수 있다.Specifically, in the above formula (C-1), R 3 may be -CH 2 CH 2 - or -CHCH 3 CH 2 -.
또한, 상기 단위 D는 실록산 기를 포함하는 단위로서, 기계적 물성과 분리막과의 친화력을 조절하기 위한 것이다. 구체적으로 폴리머 네트워크 내에서 아마이드 결합에 의한 단단한 구조 영역 이외의 유연성을 확보하기 위한 구조를 형성함과 동시에, 낮은 극성을 이용하여 폴리올레핀계 분리막 원단과의 친화력을 높일 수 있다. 특히, 폴리올레핀계 분리막 원단과의 친화력이 향상되는 경우, 저항이 감소되어 이온전도도가 보다 향상되는 효과를 동시에 구현할 수 있다. 한편, 실록산기를 포함하는 경우, HF에 의하여 발생되는 음이온을 안정화시키고, HF가 발생되는 것을 억제시켜 상기 올리고머를 포함하는 젤 폴리머 전해질의 성능을 개선시킬 수 있다.The unit D is a unit containing a siloxane group and is intended to control the mechanical properties and the affinity with the separator. Specifically, a structure for securing flexibility other than the solid structural region due to the amide bond in the polymer network can be formed, and the affinity with the polyolefin separator membrane fabric can be increased by utilizing the low polarity. In particular, when the affinity with the polyolefin-based separator membrane is improved, the effect of reducing the resistance and further improving the ionic conductivity can be realized at the same time. On the other hand, when a siloxane group is contained, stabilization of anions generated by HF and inhibition of the generation of HF can improve the performance of the oligomer-containing gel polymer electrolyte.
예를 들어, 상기 단위 D는 화학식 D-1로 표시되는 단위를 포함할 수 있다.For example, the unit D may include a unit represented by the formula D-1.
[화학식 D-1][Formula D-1]
Figure PCTKR2018015122-appb-I000027
Figure PCTKR2018015122-appb-I000027
상기 화학식 D-1에서, R8 및 R9은 탄소수 1 내지 5의 선형 또는 비선형 알킬렌기이고, R4, R5, R6 및 R7은 각각 독립적으로 수소, 탄소수 1 내지 5의 알킬기 또는 탄소수 6 내지 12인 아릴기이며, m은 1 내지 500의 정수이다.Wherein R 8 and R 9 are linear or non-linear alkylene groups having 1 to 5 carbon atoms, and R 4, R 5, R 6 and R 7 are each independently hydrogen, an alkyl group having 1 to 5 carbon atoms, An aryl group having 6 to 12 carbon atoms, and m is an integer of 1 to 500.
한편, 상기 m은 보다 바람직하게는 10 내지 500의 정수일 수 있다. 상기 m이 상기 범위를 만족할 경우 올리고머의 극성(polarity)을 낮출 수 있으므로 전지의 젖음성(wetting)이 향상될 수 있고, 리튬 금속과의 화학반응을 조절하여 전극 상에 리튬 덴드라이트(Li dendrite)가 형성되는 것을 억제하여 전지의 안전성이 향상될 수 있다. On the other hand, the above-mentioned m may more preferably be an integer of 10 to 500. When the m satisfies the above range, the polarity of the oligomer can be lowered, so that the wetting of the battery can be improved and the lithium dendrite (Li dendrite) is formed on the electrode by controlling the chemical reaction with the lithium metal So that the safety of the battery can be improved.
구체적으로는, 상기 화학식 D-1로 표시되는 단위 D는 하기 화학식 D-2로 표시되는 단위일 수 있다. Specifically, the unit D represented by the above formula (D-1) may be a unit represented by the following formula (D-2).
[화학식 D-2][Formula D-2]
Figure PCTKR2018015122-appb-I000028
Figure PCTKR2018015122-appb-I000028
상기 화학식 D-2에서, R4, R5, R6 및 R7은 각각 독립적으로 수소, 탄소수 1 내지 5의 알킬기 또는 탄소수 6 내지 12인 아릴기이며, 상기 화학식 D-2에서 m은 1 내지 500의 정수, 보다 바람직하게는 10 내지 500의 정수일 수 있다.In Formula (D-2), R 4, R 5, R 6, and R 7 are each independently hydrogen, an alkyl group having 1 to 5 carbon atoms, or an aryl group having 6 to 12 carbon atoms. An integer of 500 to 500, and more preferably an integer of 10 to 500. [
더 구체적으로는, 상기 화학식 D-2로 표시되는 단위 D는 하기 화학식 D-3 및 D-4으로 표시되는 단위 중 하나를 포함하는 것일 수 있다.More specifically, the unit D represented by the formula (D-2) may include one of the units represented by the following formulas (D-3) and (D-4).
[화학식 D-3][Formula D-3]
Figure PCTKR2018015122-appb-I000029
Figure PCTKR2018015122-appb-I000029
[화학식 D-4][Formula D-4]
Figure PCTKR2018015122-appb-I000030
Figure PCTKR2018015122-appb-I000030
상기 화학식 D-3 및 상기 화학식 D-4에서 m은 각각 1 내지 500의 정수이다. 보다 바람직하게는 10 내지 500의 정수일 수 있다. 상기 m이 상기 범위를 만족하는 경우, 상기 단위가 포함된 올리고머를 사용하여 제조되는 젤 폴리머 전해질의 난연 특성을 개선할 수 있고, 리튬 메탈 전극과의 화학반응을 제어할 수 있어 전지의 안정성이 향상될 수 있다. In the above formulas D-3 and D-4, m is an integer of 1 to 500, respectively. And more preferably an integer of 10 to 500. [ When m satisfies the above range, it is possible to improve the flame retardant property of the gel polymer electrolyte produced using the oligomer containing the unit, and to control the chemical reaction with the lithium metal electrode, thereby improving the stability of the battery .
한편, 상기 올리고머는 젤 폴리머 전해질용 조성물 100 중량부에 대하여 0.5 중량부 내지 20 중량부, 바람직하게는 1.0 중량부 내지 20 중량부, 보다 바람직하게는 1.5 중량부 내지 20 중량부의 함량으로 포함될 수 있다. 상기 올리고머의 함량이 0.5 중량부 미만일 경우 젤 폴리머 전해질을 형성하기 위한 올리고머 간의 네트워크 반응이 형성되기 어렵고, 상기 올리고머의 함량이 20 중량부를 초과하는 경우 젤 폴리머 전해질의 점도가 일정 수준을 초과하여 전지 내 함침성, 젖음성(wetting) 저하 및 전기화학적 안정성이 저해될 수 있다. On the other hand, the oligomer may be contained in an amount of 0.5 to 20 parts by weight, preferably 1.0 to 20 parts by weight, more preferably 1.5 to 20 parts by weight based on 100 parts by weight of the composition for a gel polymer electrolyte . When the content of the oligomer is less than 0.5 part by weight, a network reaction between oligomers for forming a gel polymer electrolyte is difficult to be formed. When the oligomer content exceeds 20 parts by weight, the gel polymer electrolyte has a viscosity exceeding a certain level, Impregnation, wetting degradation and electrochemical stability may be impaired.
첨가제additive
다음으로, 첨가제에 대하여 설명한다.Next, the additives will be described.
본 발명에서, 첨가제는 이미드계 화합물, Si-N계 결합을 갖는 화합물 나이트릴계 화합물, 포스페이트계 화합물 및 보레이트계 화합물로 이루어진 군에서 선택되는 적어도 하나 이상의 화합물을 포함하는 것일 수 있다.In the present invention, the additive may include at least one compound selected from the group consisting of an imide compound, a compound having a Si-N bond, a nitrile compound, a phosphate compound and a borate compound.
상기 겔 폴리머 전해질 조성물에는 올리고머 이외에, 리튬염 및 비수계 용매가 포함되어 있는데, 일반적으로 리튬염으로서, 이온전도도가 높은 불화물계 리튬염이 많이 사용되고 있다. 그러나, 불화물계 리튬염의 화학적 반응에 의해 발생되는 음이온은 미량의 수분과 반응하면서 HF와 같은 부산물을 생성하고, 이와 같은 부산물은 유기 용매의 분해와 전극 부반응을 일으켜 전지의 성능이 지속적으로 저하될 수 있다. 또한, 상기와 음이온 및 부산물들에 의하여 이차 전지의 고온 저장성 또한 저하될 수 있다.The gel polymer electrolyte composition includes a lithium salt and a non-aqueous solvent in addition to an oligomer. In general, a fluoride-based lithium salt having a high ionic conductivity is widely used as a lithium salt. However, the anions generated by the chemical reaction of the fluoride-based lithium salts react with a trace amount of water to produce by-products such as HF, and such by-products cause decomposition of the organic solvent and electrode side reactions, have. Also, the high temperature storability of the secondary battery may be deteriorated due to the negative ions and by-products.
보다 구체적으로, 예를 들어, 리튬염으로서 LiPF6를 사용하는 경우, 음이온인 PF6 -가 음극 쪽에서 전자를 잃게 되며 PF5 가 생성될 수 있다. 이때, 하기와 같은 화학반응이 연쇄적으로 진행될 수 있다.More specifically, for example, when LiPF 6 is used as the lithium salt, PF 6 - which is an anion may lose electrons on the cathode side and PF 5 may be generated. At this time, the following chemical reactions can proceed in a cascade.
Figure PCTKR2018015122-appb-I000031
Figure PCTKR2018015122-appb-I000031
상기 연쇄적인 반응이 진행되는 경우, 발생되는 HF를 비롯한 다른 부산물에 의하여 유기 용매의 분해나 전극과의 부반응이 발생되어 전지의 성능이 지속적으로 저하될 수 있다.If the chain reaction proceeds, the decomposition of the organic solvent or the side reaction with the electrode may occur due to HF or other by-products generated, and the performance of the battery may be continuously deteriorated.
상기와 같은 부반응을 억제하기 위해서는 전해질 내에 존재하는 수분을 제거하는 방법, HF 스캐빈저(scavenger)를 사용하여 HF의 발생을 억제시키는 방법, 리튬염으로부터 발생되는 음이온을 고정하고 안정화시키는 방법 등을 사용할 수 있다. In order to suppress such side reactions, a method of removing water present in the electrolyte, a method of suppressing the generation of HF by using an HF scavenger, a method of stabilizing and stabilizing anions generated from a lithium salt, and the like Can be used.
예를 들어, 상기 이미드계 화합물 및 상기 Si-N계 결합을 갖는 화합물은 하기 반응 메커니즘과 같이 H2O를 고정시켜 전극 내 수분을 제거할 수 있고, 전해질 내의 리튬염으로부터 발생되는 음이온과의 반응을 조절할 수 있으므로 불순물인 HF가 발생되는 것을 억제할 수 있다. For example, the imide compound and the compound having the Si-N bond can fix the H 2 O as shown in the following reaction mechanism to remove moisture in the electrode, react with the anion generated from the lithium salt in the electrolyte It is possible to suppress the generation of HF which is an impurity.
[반응 메커니즘][Reaction Mechanism]
Figure PCTKR2018015122-appb-I000032
Figure PCTKR2018015122-appb-I000032
한편, 본 발명에 따른 상기 올리고머를 첨가제와 함께 사용하여 젤 폴리머 전해질을 형성하는 동안 HF가 발생할 수 있는데, 상기 HF는 폴리머 구조를 붕괴시켜 전해질이 제대로 형성되지 않을 수 있다. 이때, 상기 첨가제를 함께 사용하는 경우, HF 발생 억제 및 HF에 의하여 발생되는 음이온을 안정화시켜 젤 폴리머 전해질을 용이하게 형성할 수 있다. 또한, 제조된 젤 폴리머 전해질을 상온에서 보관하는 동안 HF 발생을 억제시켜 젤 폴리머가 손상되는 것을 방지하고, 기계적 물성을 일정수준 이상으로 유지시킬 수 있다.Meanwhile, the oligomer according to the present invention may be used together with an additive to form HF during the formation of the gel polymer electrolyte. The HF may collapse the polymer structure, and the electrolyte may not be properly formed. At this time, when the additives are used together, the gel polymer electrolyte can be easily formed by stabilizing anions generated by HF generation and HF. In addition, it is possible to prevent the gel polymer from being damaged by suppressing the generation of HF during the storage of the gel polymer electrolyte at room temperature, and to maintain the mechanical properties at a certain level or more.
구체적으로, 상기 이미드계 화합물은 하기 화학식 2로 표시되는 카보디이미드계 화합물을 포함하는 것일 수 있다.Specifically, the imide compound may include a carbodiimide compound represented by the following formula (2).
[화학식 2] (2)
Figure PCTKR2018015122-appb-I000033
Figure PCTKR2018015122-appb-I000033
상기 화학식 2에서, R10 및 R10'은 각각 독립적으로, 탄소수 1 내지 12의 알킬기 및 탄소수 3 내지 12의 사이클로알킬기로 이루어진 군에서 선택되는 것이다.In Formula 2, R 10 and R 10 'are each independently selected from the group consisting of an alkyl group having 1 to 12 carbon atoms and a cycloalkyl group having 3 to 12 carbon atoms.
보다 바람직하게는, 상기 이미드계 화합물은 N,N'-디사이클로펜틸카보디이미드, N,N'-디사이클로헥실카보디이미드 및 N,N'-디사이클로헵틸카보디이미드로 이루어진 군에서 선택되는 적어도 하나 이상의 화합물을 포함하는 것일 수 있으나, 이에 한정되는 것은 아니다.More preferably, the imide compound is selected from the group consisting of N, N'-dicyclopentylcarbodiimide, N, N'-dicyclohexylcarbodiimide and N, N'-dicycloheptylcarbodiimide But it is not limited thereto.
또한, 상기 Si-N계 결합을 갖는 화합물은, 하기 화학식 3으로 표시되는 화합물을 포함하는 것일 수 있다.In addition, the compound having Si-N bond may include a compound represented by the following general formula (3).
[화학식 3](3)
Figure PCTKR2018015122-appb-I000034
Figure PCTKR2018015122-appb-I000034
상기 화학식 3에서, R11은 수소 또는 탄소수 1 내지 5의 알킬기가 치환 또는 비치환된 실릴기이고, R12 및 R13은 각각 독립적으로, 수소, 치환 또는 비치환된 탄소수 1 내지 5의 알킬기, 헤테로 원자가 치환 또는 비치환된 탄소수 1 내지 5의 알킬기 및 탄소수 1 내지 5의 알킬기가 치환 또는 비치환된 실릴기로 이루어진 군에서 선택되는 것이며, 상기 헤테로 원자는 산소(O), 질소(N) 및 황(S)으로 이루어진 군에서 선택되는 어느 하나 이상의 원자일 수 있다.Wherein R 11 is hydrogen or a substituted or unsubstituted silyl group having 1 to 5 carbon atoms, R 12 and R 13 are each independently selected from the group consisting of hydrogen, a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms, Wherein the hetero atom is selected from the group consisting of a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms and a substituted or unsubstituted silyl group having an alkyl group having 1 to 5 carbon atoms and the hetero atom is selected from the group consisting of oxygen (O), nitrogen (N) (S). &Lt; / RTI &gt;
구체적으로, 상기 화학식 3으로 표시되는 화합물은, 1,1,1,3,3,3-헥사메틸디실라잔, 헵타메틸디실라잔, N,N-디에틸아미노 트리메틸실란 및 N,N,O-트리스(트리메틸실릴)하이드록시아민으로 이루어진 군에서 선택되는 적어도 하나 이상의 화합물을 포함하는 것일 수 있다.Specifically, the compound represented by the general formula (3) is preferably selected from the group consisting of 1,1,1,3,3,3-hexamethyldisilazane, heptamethyldisilazane, N, N-diethylaminotrimethylsilane, O-tris (trimethylsilyl) hydroxyamine, and the like.
보다 바람직하게는 상기 Si-N계 결합을 갖는 화합물은, 1,1,3,3,3-헥사메틸디실라잔일 수 있으나, 이에 한정되는 것은 아니다. More preferably, the compound having the Si-N bond can be 1,1,3,3,3-hexamethyldisilazane, but is not limited thereto.
또 다른 예를 들어, 상기 나이트릴계 화합물은 나이트릴에 있는 비공유 전자쌍을 통하여 을 통하여 전지 내 리튬염 음이온을 고정시키고, 안정화시킬 수 있다. In another example, the nitrile compound can stabilize and stabilize the lithium salt anion in the cell through a non-covalent electron pair in the nitrile.
구체적으로, 상기 나이트릴계 화합물은, 하기 화학식 4-1 및 4-2로 표시되는 화합물로 이루어진 군에서 선택되는 적어도 하나 이상의 화합물을 포함하는 것일 수 있다.Specifically, the nitrile compound may include at least one compound selected from the group consisting of compounds represented by the following formulas (4-1) and (4-2).
[화학식 4-1][Formula 4-1]
Figure PCTKR2018015122-appb-I000035
Figure PCTKR2018015122-appb-I000035
상기 화학식 4-1에서, R14는 치환 또는 비치환된 탄소수 1 내지 5의 알킬기 및 치환 또는 비치환된 탄소수 1 내지 5의 알케닐기로 이루어진 군에서 선택되는 것이다.In Formula 4-1, R 14 is selected from the group consisting of a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms and a substituted or unsubstituted alkenyl group having 1 to 5 carbon atoms.
[화학식 4-2] [Formula 4-2]
Figure PCTKR2018015122-appb-I000036
Figure PCTKR2018015122-appb-I000036
상기 화학식 4-2에서, R15는 치환 또는 비치환된 탄소수 1 내지 5의 알킬렌기 및 치환 또는 비치환된 탄소수 1 내지 5의 알케닐기로 이루어진 군에서 선택되는 것이다.In Formula 4-2, R 15 is selected from the group consisting of a substituted or unsubstituted alkylene group having 1 to 5 carbon atoms and a substituted or unsubstituted alkenyl group having 1 to 5 carbon atoms.
구체적으로, 상기 나이트릴계 화합물은, 아디포나이트릴, 숙시노나이트릴, 글루타로나이트릴, 피멜로나이트릴, 헵트-3-엔디나이트릴, 수베로나이트릴, 세바코나이트릴, 부티로나이트릴 및 헥스-3-엔디나이트릴로 이루어진 군에서 선택되는 적어도 하나 이상의 화합물을 포함하는 것일 수 있다. Specifically, the nitrile compound is at least one compound selected from the group consisting of adiponitrile, succinonitrile, glutaronitrile, pimelonitrile, hept-3-adnitlinyl, And hex-3-enedinitrile.
보다 바람직하게는 상기 화학식 4-1 및 4-2로 표시되는 화합물은, 숙시노나이트릴일 수 있으나, 이에 한정되는 것은 아니다. More preferably, the compounds represented by the above formulas (4-1) and (4-2) may be succinonitrile, but are not limited thereto.
한편, 상기 포스페이트(phosphate)계 화합물 및 보레이트계 화합물은 HF 스캐빈저로서 HF가 발생하는 것을 억제시킬 수 있다. 보다 구체적으로, 상기 리튬염으로부터 생성되는 음이온 또는 부산물(예를 들어, PF6 - 또는 PF5)이 루이스 염기(Lewis base)로 작용하고, 상기 포스페이트계 화합물 및 보레이트계 화합물이 루이스 산(Lewis acid)으로 작용한다. 이때, 상기 음이온 및 부산물이 루이스 산-염기 반응에 의하여 안정화되어 상기 연쇄 반응을 억제시킬 수 있다.On the other hand, the phosphate-based compound and the borate-based compound can inhibit the generation of HF as an HF scavenger. More specifically, an anion or a by-product (for example, PF 6 - or PF 5 ) produced from the lithium salt acts as a Lewis base, and the phosphate compound and the borate compound act as a Lewis acid ). At this time, the anion and the by-product may be stabilized by the Lewis acid-base reaction to inhibit the chain reaction.
구체적으로, 상기 포스페이트계 화합물은 트리스(트리메틸실릴)포스페이트 및 트리스(트리메틸)포스페이트로 이루어진 군에서 선택되는 적어도 하나 이상의 화합물을 포함할 수 있다.Specifically, the phosphate-based compound may include at least one compound selected from the group consisting of tris (trimethylsilyl) phosphate and tris (trimethyl) phosphate.
또한, 상기 보레이트계 화합물은 리튬테트라플루오로보레이트 및 트리스(트리메틸실릴)보레이트로 이루어진 군에서 선택되는 적어도 하나 이상의 화합물을 포함할 수 있다.In addition, the borate compound may include at least one compound selected from the group consisting of lithium tetrafluoroborate and tris (trimethylsilyl) borate.
한편, 상기 첨가제는 젤 폴리머 전해질용 조성물 100 중량부에 대하여 0.1 중량부 내지 30 중량부, 바람직하게는 0.1 중량부 내지 10 중량부의 함량으로 포함될 수 있다. 첨가제 함량이 상기 범위를 만족할 경우, 전지 성능을 해치지 않고 음이온 안정화를 통한 젤 폴리머 구조를 유지할 수 있다. The additive may be added in an amount of 0.1 to 30 parts by weight, preferably 0.1 to 10 parts by weight based on 100 parts by weight of the composition for a gel polymer electrolyte. When the content of the additive is within the above range, the gel polymer structure can be maintained by stabilizing the anion without deteriorating the battery performance.
중합개시제Polymerization initiator
다음으로, 상기 중합개시제에 대하여 설명한다.Next, the polymerization initiator will be described.
상기 중합개시제는 본 발명의 올리고머를 중합시켜 3차원 구조로 결합된 폴리머 네트워크를 형성시키기 위한 것으로, 당 업계에 알려진 통상적인 중합개시제가 제한없이 사용될 수 있다. 상기 중합개시제는 중합방식에 따라서, 광 중합개시제 또는 열 중합개시제를 사용할 수 있다.The polymerization initiator is for polymerizing the oligomer of the present invention to form a polymer network bonded in a three-dimensional structure, and conventional polymerization initiators known in the art can be used without limitation. The polymerization initiator may be a photo polymerization initiator or a thermal polymerization initiator depending on the polymerization method.
구체적으로, 상기 광 중합개시제는 대표적인 예로 2-히드록시-2-메틸프로피오페논(HMPP), 1-히드록시-시클로헥실페닐-케톤, 벤조페논, 2-히드록시-1-[4-(2-히드록시에톡시)페닐]-2-메틸-1-프로파논, 옥시-페닐아세틱 애씨드 2-[2-옥소-2 페닐-아세톡시-에톡시]-에틸 에스테르, 옥시-페닐-아세틱 2-[2-히드록시에톡시]-에틸 에스테르, 알파-디메톡시-알파-페닐아세토페논, 2-벤질-2-(디메틸아미노)-1-[4-(4-몰포리닐)페닐]-1-부타논, 2-메틸-1-[4-(메틸티오)페닐]-2-(4-몰포리닐)-1-프로파논, 디페닐 (2,4,6-트리메틸벤조일)-포스핀 옥사이드, 비스(2,4,6-트리메틸 벤조일)-페닐 포스핀 옥사이드, 비스(에타 5-2,4-시클로펜타디엔-1-일), 비스[2,6-디플루오로-3-(1H-피롤-1-일)페닐]티타늄, 4-이소부틸페닐-4'-메틸페닐아이오도늄, 헥사플루오로포스페이트, 및 메틸 벤조일포메이트로 이루어진 군으로부터 선택된 적어도 하나 이상의 화합물을 포함할 수 있다.Specifically, the photopolymerization initiator is exemplified by 2-hydroxy-2-methylpropiophenone (HMPP), 1-hydroxy-cyclohexylphenyl-ketone, benzophenone, 2- Phenyl-acetic acid, 2- [2-oxo-2-phenyl-acetoxy-ethoxy] -ethyl ester, oxy-phenyl-acetic acid 2-benzyl-2- (dimethylamino) -1- [4- (4-morpholinyl) phenyl] (2,4,6-trimethylbenzoyl) -1-butanone, 2-methyl-1- [4- (methylthio) phenyl] -2- (Bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, bis (eta 5-2,4-cyclopentadien-1-yl), bis [2,6-difluoro- Methylphenyl iodonium, hexafluorophosphate, and methylbenzoylformate, in the presence of at least one compound selected from the group consisting of 3- (1H-pyrrol-1-yl) phenyl] titanium, It may include at least one or more compounds selected from the following group:
또한, 상기 열 중합개시제는 그 대표적인 예로 벤조일 퍼옥사이드(benzoyl peroxide), 아세틸 퍼옥사이드(acetyl peroxide), 디라우릴 퍼옥사이드(dilauryl peroxide), 디-tert-부틸 퍼옥사이드(di-tert-butyl peroxide), t-부틸 퍼옥시-2-에틸-헥사노에이트(t-butyl peroxy-2-ethyl-hexanoate), 큐밀 하이드로퍼옥사이드(cumyl hydroperoxide) 및 하이드로겐 퍼옥사이드(hydrogen peroxide), 2,2'-아조비스(2-시아노부탄), 2,2'-아조비스(메틸부티로니트릴), 2,2'-아조비스(이소부티로니트릴)(AIBN; 2,2'-Azobis(iso-butyronitrile)) 및 2,2'-아조비스디메틸-발레로니트릴(AMVN; 2,2'-Azobisdimethyl-Valeronitrile)로 이루어진 군에서 선택된 적어도 하나 이상의 화합물을 포함할 수 있다.Examples of the thermal polymerization initiator include benzoyl peroxide, acetyl peroxide, dilauryl peroxide, di-tert-butyl peroxide, t-butyl peroxy-2-ethyl-hexanoate, cumyl hydroperoxide and hydrogen peroxide, 2,2'-dicyclohexylcarbodiimide, Azobis (isobutyronitrile), azobis (2-cyanobutane), 2,2'-azobis (methylbutyronitrile), 2,2'-azobis And at least one compound selected from the group consisting of 2,2'-azobisdimethyl-valeronitrile (AMVN).
상기 중합개시제는 전지 내에서 30℃ 내지 100℃의 열에 의해 분해되거나 상온(5℃ 내지 30℃)에서 UV와 같은 광(light)에 의해 분해되어 라디칼을 형성하고, 자유라디칼 중합에 의해 가교 결합을 형성하여 올리고머가 중합될 수 있도록 할 수 있다.The polymerization initiator is decomposed by heat at 30 to 100 ° C in a battery or decomposed by light such as UV at room temperature (5 to 30 ° C) to form radicals, and crosslinking is effected by free radical polymerization So that the oligomer can be polymerized.
한편, 상기 중합개시제는 올리고머 100 중량부에 대하여, 0.01 중량부 내지 5 중량부, 바람직하게는 0.05 중량부 내지 5 중량부, 보다 바람직하게는 0.1 중량부 내지 5 중량부의 양으로 사용될 수 있다. 중합개시제의 함량이 상기 범위 내로 사용되면, 전지 성능에 악영향을 미칠 수 있는 미반응 중합개시제의 양을 최소화할 수 있다. 또한, 상기 범위 내로 중합개시제가 포함되는 경우, 젤 화가 적절하게 이루어질 수 있다. The polymerization initiator may be used in an amount of 0.01 to 5 parts by weight, preferably 0.05 to 5 parts by weight, more preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the oligomer. When the content of the polymerization initiator is used within the above range, the amount of the unreacted polymerization initiator which may adversely affect battery performance can be minimized. When a polymerization initiator is contained within the above range, gelation can be appropriately performed.
리튬염Lithium salt
다음으로, 상기 리튬염에 대하여 설명한다. Next, the lithium salt will be described.
리튬염은 리튬 이차전지 내에서 전해질 염으로서 사용되는 것으로서, 이온을 전달하기 위한 매개체로서 사용되는 것이다. 통상적으로, 리튬염은 LiPF6, LiBF4, LiSbF6, LiAsF6, LiClO4, LiN(C2F5SO2)2, LiN(CF3SO2)2, CF3SO3Li, LiC(CF3SO2)3, LiC4BO8, LiTFSI, LiFSI, 및 LiClO4로 이루어진 군에서 선택되는 적어도 하나 이상의 화합물을 포함할 수 있으며, 바람직하게는 LiPF6를 포함할 수 있으나, 이에 한정되는 것은 아니다.The lithium salt is used as an electrolyte salt in a lithium secondary battery and is used as an agent for transferring ions. Typically, the lithium salt is selected from the group consisting of LiPF 6 , LiBF 4 , LiSbF 6 , LiAsF 6 , LiClO 4 , LiN (C 2 F 5 SO 2 ) 2 , LiN (CF 3 SO 2 ) 2 , CF 3 SO 3 Li, LiC 3 SO 2 ) 3 , LiC 4 BO 8 , LiTFSI, LiFSI, and LiClO 4 , preferably LiPF 6 , but is not limited thereto .
한편, 상기 리튬염은 0.5 내지 5M, 바람직하게는 0.5 내지 4M로포함될 수 있다. 리튬염의 함량이 상기 범위 미만일 경우 전해질 내 리튬 이온의 농도가 낮아 전지의 충방전이 제대로 이루어지지 않을 수 있고, 상기 범위를 초과할 경우 젤 폴리머 전해질의 점도가 높아져 전지 내 젖음성(wetting)이 저하될 수 있어 전지 성능을 악화시킬 수 있다. On the other hand, the lithium salt may be contained at 0.5 to 5M, preferably 0.5 to 4M. When the content of the lithium salt is less than the above range, the lithium ion concentration in the electrolyte is low, so that the charge and discharge of the battery may not be performed properly. If the content exceeds the above range, the viscosity of the gel polymer electrolyte increases and wetting in the battery decreases So that the battery performance can be deteriorated.
비수계 용매Non-aqueous solvent
다음으로, 비수계 용매에 대하여 설명한다.Next, the non-aqueous solvent will be described.
본 발명에서, 비수계 용매는 리튬 이차전지에 통상적으로 사용되는 전해액 용매로서, 예를 들면 에테르, 에스테르(Acetate류, Propionate류), 아미드, 선형 카보네이트 또는 환형 카보네이트, 니트릴(아세토니트릴, SN 등) 등을 각각 단독으로 또는 2종 이상 혼합하여 사용할 수 있다.In the present invention, the non-aqueous solvent is, for example, ether, ester (Acetate, Propionate), amide, linear carbonate or cyclic carbonate, nitrile (acetonitrile, SN etc.) May be used alone or in combination of two or more.
그 중에서 대표적으로 환형 카보네이트, 선형 카보네이트 또는 이들의 혼합물인 카보네이트 화합물을 포함하는 카보네이트계 전해액 용매를 사용할 수 있다.Among them, a carbonate-based electrolyte solvent containing a carbonate compound, which is typically a cyclic carbonate, a linear carbonate, or a mixture thereof, may be used.
상기 환형 카보네이트 화합물의 구체적인 예로는 에틸렌 카보네이트(EC), 프로필렌 카보네이트(PC), 1,2-부틸렌 카보네이트, 2,3-부틸렌 카보네이트, 1,2-펜틸렌 카보네이트, 2,3-펜틸렌 카보네이트, 비닐렌 카보네이트, 및 이들의 할로겐화물로 이루어진 군에서 선택되는 단일 화합물 또는 적어도 2종 이상의 혼합물이 있다. 또한, 상기 선형 카보네이트 화합물의 구체적인 예로는 디메틸 카보네이트(DMC), 디에틸 카보네이트(DEC), 디프로필 카보네이트(DPC), 에틸메틸 카보네이트(EMC), 메틸프로필 카보네이트(MPC) 및 에틸프로필 카보네이트(EPC)로 이루어진 군에서 선택된 화합물 또는 적어도 2종 이상의 혼합물 등이 대표적으로 사용될 수 있으나, 이에 한정되는 것은 아니다. Specific examples of the cyclic carbonate compound include ethylene carbonate (EC), propylene carbonate (PC), 1,2-butylene carbonate, 2,3-butylene carbonate, 1,2-pentylene carbonate, Carbonate, vinylene carbonate, and halides thereof, or a mixture of at least two or more thereof. Specific examples of the linear carbonate compound include dimethyl carbonate (DMC), diethyl carbonate (DEC), dipropyl carbonate (DPC), ethyl methyl carbonate (EMC), methyl propyl carbonate (MPC) and ethyl propyl carbonate (EPC) , Or a mixture of at least two of these compounds may be used. However, the present invention is not limited thereto.
특히, 상기 카보네이트계 전해액 용매 중 환형 카보네이트인 프로필렌 카보네이트 및 에틸렌 카보네이트는 고점도의 유기 용매로서 유전율이 높아 전해액 내의 리튬염을 잘 해리시키므로 바람직하게 사용될 수 있으며, 이러한 환형 카보네이트에 에틸메틸 카보네이트, 디에틸 카보네이트 또는 디메틸 카보네이트와 같은 저점도, 저유전율 선형 카보네이트를 적당한 비율로 혼합하여 사용하면 높은 전기 전도율을 가지는 전해액을 만들 수 있어서 더욱 바람직하게 사용될 수 있다. In particular, propylene carbonate and ethylene carbonate, which are cyclic carbonates in the carbonate electrolyte solution, are highly viscous organic solvents having a high dielectric constant and can dissociate the lithium salt in the electrolytic solution well. Thus, cyclic carbonates such as ethylmethyl carbonate, diethyl carbonate Or a low viscosity, low dielectric constant linear carbonate such as dimethyl carbonate in an appropriate ratio can be used to more advantageously use an electrolytic solution having a high electrical conductivity.
또한, 상기 전해액 용매 중 에스테르로는 메틸 아세테이트, 에틸 아세테이트, 프로필 아세테이트, 메틸 프로피오네이트, 에틸 프로피오네이트, γ-부티로락톤, γ-발레로락톤, γ-카프로락톤, α-발레로락톤 및 ε-카프로락톤으로 이루어진 군에서 선택되는 단일 화합물 또는 적어도 2종 이상의 혼합물을 사용할 수 있으나, 이에 한정되는 것은 아니다. Examples of the esters in the electrolyte solvent include methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate,? -Butyrolactone,? -Valerolactone,? -Caprolactone,? -Valerolactone And? -Caprolactone, or a mixture of at least two of them, but the present invention is not limited thereto.
본 발명의 일 실시예에 따른 젤 폴리머 전해질용 조성물은 상기 기재된 성분들 이외에, 올리고머의 폴리머 네트워크 형성 반응의 효율성 증대와 저항 감소 효과를 부여하기 위하여, 당 업계에 알려진 이러한 물성을 구현할 수 있는 기타 첨가제, 무기물 입자 등을 선택적으로 더 함유할 수 있다.The composition for a gel polymer electrolyte according to an embodiment of the present invention may further include other additives capable of realizing such physical properties known in the art in order to increase the efficiency of polymer network formation reaction and reduce resistance of the oligomer, , Inorganic particles, and the like.
상기 기타 첨가제로는, 예를 들면, VC (Vinylene Carbonate), VEC(vinyl ethylene carbonate), PS(Propane sultone), SN(succinonitrile), AdN(Adiponitrile), ESa(ethylene　sulfate), PRS (Propene Sultone), FEC(fluoroethylene　carbonate), LiPO2F2, LiODFB(Lithium difluorooxalatoborate), LiBOB(Lithium bis-(oxalato)borate), TMSPa(3-trimethoxysilanyl-propyl-N-aniline), TMSPi(Tris(trimethylsilyl) Phosphite), LiBF4 등의 첨가제를 모두 적용 가능하다.Examples of the other additives include VC (vinylene carbonate), VEC (vinyl ethylene carbonate), PS (propane sultone), SN (succinonitrile), AdN (adiponitrile), ESa (ethylene sulfate), PRS , TMSPa (3-trimethoxysilanyl-propyl-N-aniline), TMSPi (Tris (trimethylsilyl) Phosphite), LiPO 2 F 2 , LiODFB (Lithium difluorooxalatoborate), LiBOB (Lithium bis- , LiBF 4, and the like.
또한, 상기 무기물 입자로는, 유전율 상수가 5 이상인 BaTiO3, BaTiO3, Pb(Zr,Ti)O3 (PZT), Pb1-aLaaZr1-bTibO3 (PLZT, 여기서, 0<a<1, 0<b<1임), Pb(Mg1/3Nb2/3)O3-PbTiO3 (PMN-PT), 하프니아(HfO2), SrTiO3, SnO2, CeO2, MgO, NiO, CaO, ZnO, ZrO2, Y2O3, Al2O3, TiO2, SiC 및 이들의 혼합체로부터 이루어진 군에서 선택되는 단일 화합물 또는 적어도 2종 이상의 혼합물 등이 사용될 수 있다.The inorganic particles may be BaTiO 3 , BaTiO 3 , Pb (Zr, Ti) O 3 (PZT), Pb 1 -a La a Zr 1-b Ti b O 3 (PLZT, Pb (Mg 1/3 Nb 2/3 ) O 3 -PbTiO 3 (PMN-PT), hafnia (HfO 2 ), SrTiO 3 , SnO 2 , CeO 2 2 , MgO, NiO, CaO, ZnO, ZrO 2 , Y 2 O 3 , Al 2 O 3 , TiO 2 , SiC and mixtures thereof, or a mixture of at least two or more thereof .
이외에도 리튬 이온 전달 능력을 갖는 무기물 입자, 즉 리튬포스페이트 (Li3PO4), 리튬티타늄포스페이트 (LicTid(PO4)3, 0<d<2, 0<d<3), 리튬알루미늄티타늄포스페이트 (Lia1Alb1Tic1(PO4)3, 0<a1<2, 0<b1<1, 0<c1<3), 14Li2O-9Al2O3-38TiO2-39P2O5 등과 같은 (LiAlTiP)a2Ob2 계열 글래스(glass) (0<a2<4, 0<b2<13), 리튬란탄티타네이트 (Lia3Lab3TiO3, 0<a3<2, 0<b3<3), Li3.25Ge0.25P0.75S4 등과 같은 리튬게르마니움티오포스페이트 (Lia4Geb4Pc2Sd, 0<a4<4, 0<b4<1, 0<c2<1, 0<d<5), Li3N 등과 같은 리튬나이트라이드 (Lia5Nb5, 0<a5<4, 0<b5<2), Li3PO4-Li2S-SiS2 등과 같은 SiS2 계열 글래스 (Lia6Sib6Sc3, 0<a6<3, 0<b6<2, 0<c4<4), LiI-Li2S-P2S5 등과 같은 P2S5 계열 글래스 (Lia7Pb7Sc5, 0<a7<3, 0<b7<3, 0<c5<7) 또는 이들의 혼합물 등이 사용될 수 있다. In addition, inorganic particles having lithium ion transferring ability, that is, lithium phosphate (Li 3 PO 4 ), lithium titanium phosphate (Li c Ti d (PO 4 ) 3 , 0 <d <2, 0 <d <3) as phosphate (Li a1 Al b1 Ti c1 ( PO 4) 3, 0 <a1 <2, 0 <b1 <1, 0 <c1 <3), 14Li 2 O-9Al 2 O 3 -38TiO 2 -39P 2 O 5 like (LiAlTiP) a2 O b2 series glass (glass) (0 <a2 < 4, 0 <b2 <13), lithium lanthanum titanate (Li a3 La b3 TiO 3, 0 <a3 <2, 0 <b3 <3) (Li a4 Ge b4 P c2 S d , 0 <a4 <4, 0 <b4 <1, 0 <c2 <1, 0 <d <5) such as Li 3.25 Ge 0.25 P 0.75 S 4 ), Li 3 lithium nitride such as N (Li a5 N b5, 0 <a5 <4, 0 <b5 <2), Li 3 PO 4 -Li 2 SiS 2 based glass, such as S-SiS 2 (Li a6 Si b6 S c3, 0 <a6 < 3, 0 <b6 <2, 0 <c4 <4), LiI-Li 2 SP 2 S 5 P 2 S , such as 5 series glass (Li a7 P b7 S c5, 0 <a7 <3, 0 <b7 <3, 0 <c5 <7), or a mixture thereof.
<젤 폴리머 전해질>&Lt; Gel polymer electrolyte &
이하, 본 발명에 따른 젤 폴리머 전해질에 대하여 설명한다.Hereinafter, the gel polymer electrolyte according to the present invention will be described.
본 발명의 일 구현예에 따르면, 상기 젤 폴리머 전해질 조성물을 이용하여 제조되는 젤 폴리머 전해질이다.According to an embodiment of the present invention, the gel polymer electrolyte is prepared using the gel polymer electrolyte composition.
종래 젤 폴리머 전해질은 액체 전해질에 비하여 이온전도도 등이 낮고, 고체 고분자 전해질과 비교하는 경우 안정성 및 기계적 물성이 상대적으로 취약하다는 문제점이 있다.Conventional gel polymer electrolytes have lower ionic conductivity than liquid electrolytes and have relatively poor stability and mechanical properties when compared with solid polymer electrolytes.
그러나, 본 발명에 따른 젤 폴리머 전해질은, 불소가 치환 또는 비치환된 탄소수 1 내지 5의 알킬렌기를 포함하는 단위 A, 각각 독립적으로 아마이드기를 포함하는 단위 B 및 B', 각각 독립적으로 (메타)아크릴레이트 기를 포함하는 단위 C 및 C'를 포함하는 올리고머로 폴리머 네트워크를 형성하여, 이온 전도성 및 기계적 물성을 개선시킬 수 있다.However, the gel polymer electrolyte according to the present invention is characterized in that fluorine is a unit A comprising a substituted or unsubstituted alkylene group having 1 to 5 carbon atoms, units B and B 'each independently containing an amide group, By forming a polymer network with oligomers comprising units C and C 'comprising an acrylate group, ionic conductivity and mechanical properties can be improved.
또한, 본 발명의 젤 폴리머 전해질 조성물은 첨가제를 포함하므로, 상기 젤 폴리머 전해질 조성물로 전해질을 제조하는 경우, HF가 형성되는 것 또는 HF가 전해질과 반응하는 것을 억제할 수 있어 전지의 안전성을 개선할 수 있다. In addition, since the gel polymer electrolyte composition of the present invention contains an additive, when the electrolyte is prepared from the gel polymer electrolyte composition, the formation of HF or the reaction of HF with the electrolyte can be inhibited, .
한편, 본 발명에 따른 젤 폴리머 전해질은, 당 업계에 알려진 통상적인 방법에 따라 젤 폴리머 전해질용 조성물을 중합시켜 형성된 것이다. 일반적으로, 젤 폴리머 전해질은 in-situ 중합 또는 코팅 중합에 의하여 제조될 수 있다.Meanwhile, the gel polymer electrolyte according to the present invention is formed by polymerizing a composition for a gel polymer electrolyte according to a conventional method known in the art. Generally, gel polymer electrolytes can be prepared by in-situ polymerization or coating polymerization.
보다 구체적으로, in-situ 중합은 (a) 양극, 음극, 및 상기 양극과 음극 사이에 개재(介在)된 분리막으로 이루어진 전극 조립체를 전지 케이스에 삽입하는 단계 및 (b) 상기 전지 케이스에 본 발명에 따른 젤 폴리머 전해질용 조성물을 주입한 후 중합하는 단계를 거쳐 젤 폴리머 전해질을 제조하는 방법이다.More specifically, the in-situ polymerization includes the steps of (a) inserting an electrode assembly comprising a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode into a battery case, and (b) And injecting a composition for a gel polymer electrolyte according to the method of the present invention, followed by polymerization, to prepare a gel polymer electrolyte.
리튬 이차 전지 내 in-situ 중합 반응은 E-BEAM, 감마선, 상온/고온 에이징 공정을 통하여 가능하며, 본 발명의 일 실시예에 따르면 열 중합 또는 광 중합을 통해 진행될 수 있다. 이때, 중합 시간은 대략 2분 내지 12시간 정도 소요되며, 열 중합 온도는 30℃ 내지 100℃ 가 될 수 있고, 광 중합 온도는 상온(5℃ 내지 30℃)이 될 수 있다.The in-situ polymerization in the lithium secondary battery can be performed by E-BEAM, gamma ray, room temperature / high temperature aging process, and may be performed through thermal polymerization or photopolymerization according to one embodiment of the present invention. In this case, the polymerization time is about 2 minutes to 12 hours, the thermal polymerization temperature may be 30 to 100 ° C, and the light polymerization temperature may be room temperature (5 to 30 ° C).
보다 구체적으로 리튬 이차 전지 내 in-situ 중합 반응은 상기 젤 폴리머 전해질 조성물을 전지셀에 주액한 후, 중합 반응을 통한 젤화를 거쳐 젤 폴리머 전해질을 형성시키는 것이다.More specifically, an in-situ polymerization reaction in a lithium secondary battery is performed by injecting the gel polymer electrolyte composition into a battery cell, and then gelating through a polymerization reaction to form a gel polymer electrolyte.
또 다른 방법으로는, 상기 젤 폴리머 전해질 조성물을 전극 및 분리막 일 표면에 코팅하고, 열이나 UV와 같은 광을 이용하여 경화(젤화)시킨 다음, 젤 폴리머 전해질이 형성된 전극 및/또는 분리막을 권취 또는 적층하여 전극 조립체를 제조하고, 이를 전지 케이스에 삽입하고 기존 액체 전해액을 재주액하여 제조할 수도 있다. Alternatively, the gel polymer electrolyte composition may be coated on one surface of an electrode and a separator, cured (gelled) using heat such as heat or UV, and then the electrode and / The electrode assembly may be manufactured by inserting the electrode assembly into the battery case and reusing the existing liquid electrolyte.
<리튬 이차 전지><Lithium secondary battery>
다음으로, 본 발명에 따른 리튬 이차 전지에 대해 설명한다. 본 발명의 또 다른 실시예에 따른 이차 전지는, 음극, 양극, 상기 양극 및 음극 사이에 개재된 분리막 및 젤 폴리머 전해질을 포함한다. 상기 젤 폴리머 전해질은 상술한 내용과 동일하므로, 구체적인 설명을 생략한다.Next, a lithium secondary battery according to the present invention will be described. A secondary battery according to another embodiment of the present invention includes a cathode, an anode, a separator interposed between the anode and the cathode, and a gel polymer electrolyte. The gel polymer electrolyte is the same as that described above, so a detailed description thereof will be omitted.
양극anode
상기 양극은 양극 집전체 상에 양극 활물질, 바인더, 도전재 및 용매 등을 포함하는 양극 합제 슬러리를 코팅하여 제조할 수 있다.The anode may be prepared by coating a cathode mixture slurry containing a cathode active material, a binder, a conductive material, and a solvent on a cathode collector.
상기 양극 집전체는 당해 전지에 화학적 변화를 유발하지 않으면서 도전성을 가진 것이라면 특별히 제한되는 것은 아니며, 예를 들어, 스테인리스 스틸, 알루미늄, 니켈, 티탄, 소성 탄소, 또는 알루미늄이나 스테인리스 스틸의 표면에 카본, 니켈, 티탄, 은 등으로 표면 처리한 것 등이 사용될 수 있다. The positive electrode collector is not particularly limited as long as it has electrical conductivity without causing chemical change in the battery. For example, the positive electrode collector may be formed of a metal such as carbon, stainless steel, aluminum, nickel, titanium, sintered carbon, , Nickel, titanium, silver, or the like may be used.
상기 양극 활물질은 리튬의 가역적인 인터칼레이션 및 디인터칼레이션이 가능한 화합물로서, 구체적으로는 코발트, 망간, 니켈 또는 알루미늄과 같은 1종 이상의 금속과 리튬을 포함하는 리튬 복합금속 산화물을 포함할 수 있다. 보다 구체적으로, 상기 리튬 복합금속 산화물은 리튬-망간계 산화물(예를 들면, LiMnO2, LiMn2O4 등), 리튬-코발트계 산화물(예를 들면, LiCoO2 등), 리튬-니켈계 산화물(예를 들면, LiNiO2 등), 리튬-니켈-망간계 산화물(예를 들면, LiNi1-Y1MnY1O2(여기에서, 0<Y1<1), LiMn2-z1Niz1O4(여기에서, 0＜Z1＜2) 등), 리튬-니켈-코발트계 산화물(예를 들면, LiNi1-Y2CoY2O2(여기에서, 0<Y2<1) 등), 리튬-망간-코발트계 산화물(예를 들면, LiCo1-Y3MnY3O2(여기에서, 0<Y3<1), LiMn2-z2Coz2O4(여기에서, 0＜Z2＜2) 등), 리튬-니켈-망간-코발트계 산화물(예를 들면, Li(Nip1Coq1Mnr1)O2(여기에서, 0＜p1＜1, 0＜q1＜1, 0＜r1＜1, p1+q1+r1=1) 또는 Li(Nip2Coq2Mnr2)O4(여기에서, 0＜p2＜2, 0＜q2＜2, 0＜r2＜2, p2+q2+r2=2) 등), 또는 리튬-니켈-코발트-전이금속(M) 산화물(예를 들면, Li(Nip3Coq3Mnr3MS1)O2(여기에서, M은 Al, Fe, V, Cr, Ti, Ta, Mg 및 Mo로 이루어지는 군으로부터 선택되고, p3, q3, r3 및 s1은 각각 독립적인 원소들의 원자분율로서, 0＜p3＜1, 0＜q3＜1, 0＜r3＜1, 0＜s1＜1, p3+q3+r3+s1=1이다) 등) 등을 들 수 있으며, 이들 중 어느 하나 또는 둘 이상의 화합물이 포함될 수 있다. The cathode active material is a compound capable of reversibly intercalating and deintercalating lithium, and may specifically include a lithium composite metal oxide including lithium and at least one metal such as cobalt, manganese, nickel, or aluminum have. More specifically, the lithium composite metal oxide may be at least one selected from the group consisting of lithium-manganese-based oxides (for example, LiMnO 2 and LiMn 2 O 4 ), lithium-cobalt oxides (for example, LiCoO 2 ), lithium- (for example, LiNiO 2 and the like), lithium-nickel-manganese-based oxide (for example, LiNi 1-Y1 Mn Y1 O 2 (here, 0 <Y1 <1), LiMn 2-z1 Ni z1 O 4 ( here, 0 <Z1 <2) and the like), lithium-nickel-cobalt oxide (e. g., in LiNi 1-Y2 Co Y2 O 2 ( here, 0 <Y2 <1) and the like), lithium-manganese-cobalt oxide (e. g., LiCo 1-Y3 Mn Y3 O 2 (here, 0 <Y3 <1), LiMn 2-z2 Co z2 O 4 ( here, 0 <z2 <2) and the like), lithium-nickel -manganese-cobalt oxide (e.g., Ni p1 Co q1 Mn r1 (Li) O 2 (here, 0 <p1 <1, 0 <q1 <1, 0 <r1 <1, p1 + q1 + r1 = 1) or Li (Ni p2 Co q2 Mn r2) O 4 (here, 0 <p2 <2, 0 <q2 <2, 0 <r2 <2, p2 + q2 + r2 = 2) , etc.), or a lithium- nickel-cobalt-transition metal (M) oxide (e.g., Li (Ni Co p3 q3 Mn r3 M S1) O 2 ( Wherein M is selected from the group consisting of Al, Fe, V, Cr, Ti, Ta, Mg and Mo, and p3, q3, r3 and s1 are atomic fractions of independent elements, 0 <p3 < 0 <q3 <1, 0 <r3 <1, 0 <s1 <1, p3 + q3 + r3 + s1 = 1), etc., and any one or more of these compounds may be included.
이중에서도 전지의 용량 특성 및 안정성을 높일 수 있다는 점에서 상기 리튬 복합금속 산화물은 LiCoO2, LiMnO2, LiNiO2, 리튬 니켈망간코발트 산화물(예를 들면, Li(Ni0.6Mn0.2Co0.2)O2, Li(Ni0.5Mn0.3Co0.2)O2, 또는 Li(Ni0.8Mn0.1Co0.1)O2 등), 또는 리튬 니켈코발트알루미늄 산화물(예를 들면, LiNi0.8Co0.15Al0.05O2 등) 등일 수 있으며, 리튬 복합금속 산화물을 형성하는 구성원소의 종류 및 함량비 제어에 따른 개선 효과의 현저함을 고려할 때 상기 리튬 복합금속 산화물은 Li(Ni0.6Mn0.2Co0.2)O2, Li(Ni0.5Mn0.3Co0.2)O2, Li(Ni0.7Mn0.15Co0.15)O2 또는 Li(Ni0.8Mn0.1Co0.1)O2 등일 수 있으며, 이들 중 어느 하나 또는 둘 이상의 혼합물이 사용될 수 있다.The lithium composite metal oxide may be LiCoO 2 , LiMnO 2 , LiNiO 2 , lithium nickel manganese cobalt oxide (for example, Li (Ni 0.6 Mn 0.2 Co 0.2 ) O 2 , Li (Ni 0.5 Mn 0.3 Co 0.2) O 2 or Li (Ni 0.8 Mn 0.1 Co 0.1 ) O 2 ), or lithium nickel cobalt aluminum oxide (e.g., LiNi 0.8 Co 0.15 Al 0.05 O 2 , etc.) or the like Considering the remarkable improvement effect according to the kind and content ratio of constituent elements forming the lithium composite metal oxide, the lithium composite metal oxide is Li (Ni 0.6 Mn 0.2 Co 0.2 ) O 2 , Li (Ni 0.5 Mn 0.3 Co 0.2 ) O 2, Li (Ni 0.7 Mn 0.15 Co 0.15) O 2 or Li (Ni 0.8 Mn 0.1 Co 0.1 ) O 2 and the like, any one or a mixture of two or more may be used of which have.
상기 양극 활물질은 양극 합제 슬러리 중 용매를 제외한 고형물 전체 중량을 기준으로 60 중량% 내지 98 중량%, 바람직하게는 70 중량% 내지 98 중량%, 보다 바람직하게는 80 중량% 내지 98 중량%로 포함될 수 있다. The cathode active material may be contained in the cathode mixture slurry in an amount of 60 to 98% by weight, preferably 70 to 98% by weight, more preferably 80 to 98% by weight, based on the total weight of the solids excluding the solvent have.
상기 바인더는 활물질과 도전재 등의 결합과 집전체에 대한 결합에 조력하는 성분이다.The binder is a component that assists in bonding of the active material to the conductive material and bonding to the current collector.
이러한 바인더의 예로는, 폴리불화비닐리덴, 폴리비닐알코올, 카르복시메틸셀룰로오스(CMC), 전분, 히드록시프로필셀룰로오스, 재생 셀룰로오스, 폴리비닐피롤리돈, 테트라플루오로에틸렌, 폴리에틸렌(PE), 폴리프로필렌, 에틸렌-프로필렌-디엔 테르 폴리머(EPDM), 술폰화 EPDM, 스티렌-부타디엔 고무, 불소 고무, 다양한 공중합체 등을 들 수 있다.Examples of such binders include polyvinylidene fluoride, polyvinyl alcohol, carboxymethylcellulose (CMC), starch, hydroxypropylcellulose, regenerated cellulose, polyvinylpyrrolidone, tetrafluoroethylene, polyethylene (PE) , Ethylene-propylene-diene terpolymer (EPDM), sulfonated EPDM, styrene-butadiene rubber, fluorine rubber, various copolymers and the like.
통상적으로 상기 바인더는 양극 합제 슬러리 중 용매를 제외한 고형물 전체 중량을 기준으로 1 중량% 내지 20 중량%, 바람직하게는 1 중량% 내지 15 중량%, 보다 바람직하게는 1 중량% 내지 10 중량%로 포함될 수 있다. Typically, the binder is included in the positive electrode material mixture slurry in an amount of 1% by weight to 20% by weight, preferably 1% by weight to 15% by weight, more preferably 1% by weight to 10% by weight, based on the total weight of the solids excluding the solvent .
상기 도전재는 양극 활물질의 도전성을 더욱 향상시키기 위한 성분이다.The conductive material is a component for further improving the conductivity of the cathode active material.
상기 도전재는 당해 전지에 화학적 변화를 유발하지 않으면서 도전성을 가진 것이라면 특별히 제한되는 것은 아니며, 예를 들어, 그라파이트; 카본블랙, 아세틸렌 블랙, 케첸 블랙, 채널 블랙, 퍼니스 블랙, 램프 블랙, 서멀 블랙 등의 탄소계 물질; 탄소 섬유나 금속 섬유 등의 도전성 섬유; 불화 카본, 알루미늄, 니켈 분말 등의 금속 분말; 산화아연, 티탄산 칼륨 등의 도전성 위스키; 산화 티탄 등의 도전성 금속 산화물; 폴리페닐렌 유도체 등의 도전성 소재 등이 사용될 수 있다. 시판되고 있는 도전재의 구체적인 예로는 아세틸렌 블랙 계열인 쉐브론 케미칼 컴퍼니(Chevron Chemical Company)나 덴카 블랙(Denka Singapore Private Limited), 걸프 오일 컴퍼니(Gulf Oil Company) 제품 등), 케트젠블랙(Ketjenblack), EC 계열(아르막 컴퍼니(Armak Company) 제품), 불칸(Vulcan) XC-72(캐보트 컴퍼니(Cabot Company) 제품) 및 수퍼(Super) P(Timcal 사 제품) 등이 있다.The conductive material is not particularly limited as long as it has electrical conductivity without causing chemical changes in the battery, for example, graphite; Carbon-based materials such as carbon black, acetylene black, ketjen black, channel black, furnace black, lamp black, and thermal black; Conductive fibers such as carbon fiber and metal fiber; Metal powders such as carbon fluoride, aluminum, and nickel powder; Conductive whiskey such as zinc oxide and potassium titanate; Conductive metal oxides such as titanium oxide; Conductive materials such as polyphenylene derivatives and the like can be used. Concrete examples of commercially available conductive materials include acetylene black series such as Chevron Chemical Company, Denka Singapore Private Limited, Gulf Oil Company, etc.), Ketjenblack, EC (Armak Company), Vulcan XC-72 (Cabot Company), and Super P (Timcal).
통상적으로 상기 도전재는, 양극 합제 슬러리 중 용매를 제외한 고형물 전체 중량을 기준으로 1 중량% 내지 20 중량%, 바람직하게는 1 중량% 내지 15 중량%, 보다 바람직하게는 1 중량% 내지 10 중량%로 포함될 수 있다. Typically, the conductive material is used in an amount of 1 to 20% by weight, preferably 1 to 15% by weight, more preferably 1 to 10% by weight, based on the total weight of the solid material excluding the solvent, .
상기 용매는 NMP(N-메틸-2-피롤리돈) 등의 유기 용매를 포함할 수 있으며, 상기 양극 활물질, 및 선택적으로 바인더 및 도전재 등을 포함할 때 바람직한 점도가 되는 양으로 사용될 수 있다. 예를 들면, 양극 활물질, 및 선택적으로 바인더 및 도전재를 포함하는 고형분의 농도가 50 중량% 내지 95 중량%, 바람직하게는 70 중량% 내지 95 중량%, 보다 바람직하게는 70 중량% 내지 90 중량%가 되도록 포함될 수 있다. The solvent may include an organic solvent such as NMP (N-methyl-2-pyrrolidone), and may be used in an amount that makes it desirable to contain the cathode active material, and optionally, a binder and a conductive material . For example, the concentration of the solid content including the positive electrode active material, and optionally the binder and the conductive material is 50 wt% to 95 wt%, preferably 70 wt% to 95 wt%, more preferably 70 wt% to 90 wt% %. &Lt; / RTI &gt;
음극cathode
상기 음극은 예를 들어, 음극 집전체 상에 음극 활물질, 바인더, 도전재 및 용매 등을 포함하는 음극 합제 슬러리를 코팅하여 제조하거나, 탄소(C) 전극 또는 금속 자체를 음극으로 사용할 수 있다.The negative electrode may be prepared, for example, by coating a negative electrode current collector with a negative electrode mixture slurry containing a negative electrode active material, a binder, a conductive material and a solvent, or a carbon (C) electrode or metal itself as a negative electrode.
예를 들어, 상기 음극 집전체 상에 음극 합제 슬러리를 코팅하여 음극을 제조하는 경우, 상기 음극 집전체는 일반적으로 3 내지 500㎛의 두께를 가진다. 이러한 음극 집전체는, 당해 전지에 화학적 변화를 유발하지 않으면서 높은 도전성을 가지는 것이라면 특별히 제한되는 것은 아니며, 예를 들어, 구리, 스테인리스 스틸, 알루미늄, 니켈, 티탄, 소성 탄소, 구리나 스테인리스 스틸의 표면에 카본, 니켈, 티탄, 은 등으로 표면 처리한 것, 알루미늄-카드뮴 합금 등이 사용될 수 있다. 또한, 양극 집전체와 마찬가지로, 표면에 미세한 요철을 형성하여 음극 활물질의 결합력을 강화시킬 수도 있으며, 필름, 시트, 호일, 네트, 다공질체, 발포체, 부직포체 등 다양한 형태로 사용될 수 있다.For example, when a negative electrode is manufactured by coating a negative electrode mixture slurry on the negative electrode collector, the negative electrode collector generally has a thickness of 3 to 500 μm. The negative electrode current collector is not particularly limited as long as it has high conductivity without causing chemical change in the battery. Examples of the negative electrode current collector include copper, stainless steel, aluminum, nickel, titanium, sintered carbon, copper or stainless steel Surface-treated with carbon, nickel, titanium, silver or the like, aluminum-cadmium alloy, or the like can be used. In addition, like the positive electrode collector, fine unevenness can be formed on the surface to enhance the bonding force of the negative electrode active material, and it can be used in various forms such as films, sheets, foils, nets, porous bodies, foams and nonwoven fabrics.
상기 음극 활물질로는 천연흑연, 인조흑연, 탄소질재료; 리튬 함유 티타늄 복합 산화물(LTO), Si, Sn, Li, Zn, Mg, Cd, Ce, Ni 또는 Fe인 금속류(Me); 상기 금속류(Me)로 구성된 합금류; 상기 금속류(Me)의 산화물(MeOx); 및 상기 금속류(Me)와 탄소와의 복합체로 이루어진 군으로부터 선택된 1종 또는 2종 이상의 음극 활물질을 들 수 있다. Examples of the negative electrode active material include natural graphite, artificial graphite, carbonaceous material; Lithium-containing titanium composite oxide (LTO), metals (Me) with Si, Sn, Li, Zn, Mg, Cd, Ce, Ni or Fe; An alloy composed of the metal (Me); An oxide of the metal (Me) (MeOx); And a composite of the metal (Me) and the carbon (C).
상기 음극 활물질은 음극 합제 슬러리 중 용매를 제외한 고형물 전체 중량을 기준으로 80 중량% 내지 99 중량%, 바람직하게는 85 중량% 내지 99 중량%, 보다 바람직하게는 90 중량% 내지 98 중량%로 포함될 수 있다. The negative electrode active material may include 80 wt% to 99 wt%, preferably 85 wt% to 99 wt%, and more preferably 90 wt% to 98 wt% based on the total weight of the solid material excluding the solvent in the negative electrode material mixture slurry have.
상기 바인더는 도전재, 활물질 및 집전체 간의 결합에 조력하는 성분이다. 이러한 바인더의 예로는, 폴리비닐리덴플루오라이드(PVDF), 폴리비닐알코올, 카르복시메틸셀룰로우즈(CMC), 전분, 히드록시프로필셀룰로우즈, 재생 셀룰로우즈, 폴리비닐피롤리돈, 테트라플루오로에틸렌, 폴리에틸렌, 폴리프로필렌, 에틸렌-프로필렌-디엔 폴리머(EPDM), 술폰화-EPDM, 스티렌-부타디엔 고무, 불소 고무, 이들의 다양한 공중합체 등을 들 수 있다.The binder is a component that assists in bonding between the conductive material, the active material, and the current collector. Examples of such binders include polyvinylidene fluoride (PVDF), polyvinyl alcohol, carboxymethylcellulose (CMC), starch, hydroxypropylcellulose, regenerated cellulose, polyvinylpyrrolidone, tetrafluoroethylene Examples thereof include ethylene, polyethylene, polypropylene, ethylene-propylene-diene polymer (EPDM), sulfonated-EPDM, styrene-butadiene rubber, fluorine rubber and various copolymers thereof.
통상적으로 상기 바인더는, 음극 합제 슬러리 중 용매를 제외한 고형물 전체 중량을 기준으로 1 중량% 내지 20 중량%, 바람직하게는 1 중량% 내지 15 중량%, 보다 바람직하게는 1 중량% 내지 10 중량%로 포함될 수 있다. Typically, the binder is used in an amount of 1 wt% to 20 wt%, preferably 1 wt% to 15 wt%, more preferably 1 wt% to 10 wt% based on the total weight of the solid material excluding the solvent in the negative electrode material mixture slurry .
상기 도전재는 음극 활물질의 도전성을 더욱 향상시키기 위한 성분이다. 이러한 도전재는 당해 전지에 화학적 변화를 유발하지 않으면서 도전성을 가진 것이라면 특별히 제한되는 것은 아니며, 예를 들어, 천연 흑연이나 인조 흑연 등의 흑연; 아세틸렌 블랙, 케첸 블랙, 채널 블랙, 퍼네이스 블랙, 램프 블랙, 서멀 블랙 등의 카본블랙; 탄소 섬유나 금속 섬유 등의 도전성 섬유; 불화 카본, 알루미늄, 니켈 분말 등의 금속 분말; 산화아연, 티탄산 칼륨 등의 도전성 위스키; 산화티탄 등의 도전성 금속 산화물; 폴리페닐렌 유도체 등의 도전성 소재 등이 사용될 수 있다.The conductive material is a component for further improving the conductivity of the negative electrode active material. Such a conductive material is not particularly limited as long as it has electrical conductivity without causing chemical changes in the battery, for example, graphite such as natural graphite or artificial graphite; Carbon black such as acetylene black, ketjen black, channel black, furnace black, lamp black, and thermal black; Conductive fibers such as carbon fiber and metal fiber; Metal powders such as carbon fluoride, aluminum, and nickel powder; Conductive whiskey such as zinc oxide and potassium titanate; Conductive metal oxides such as titanium oxide; Conductive materials such as polyphenylene derivatives and the like can be used.
상기 도전재는 음극 합제 슬러리 중 용매를 제외한 고형물 전체 중량을 기준으로 1 중량% 내지 20 중량%, 바람직하게는 1 중량% 내지 15 중량%, 보다 바람직하게는 1 중량% 내지 10 중량%로 포함될 수 있다. The conductive material may include 1 wt% to 20 wt%, preferably 1 wt% to 15 wt%, and more preferably 1 wt% to 10 wt% based on the total weight of the solid material excluding the solvent in the negative electrode material mixture slurry .
상기 용매는 물 또는 NMP(N-메틸-2-피롤리돈) 등의 유기용매를 포함할 수 있으며, 상기 음극 활물질, 및 선택적으로 바인더 및 도전재 등을 포함할 때 바람직한 점도가 되는 양으로 사용될 수 있다. 예를 들면, 음극 활물질, 및 선택적으로 바인더 및 도전재를 포함하는 고형분의 농도가 50 중량% 내지 95 중량%, 바람직하게 70 중량% 내지 90 중량%가 되도록 포함될 수 있다. The solvent may include water or an organic solvent such as NMP (N-methyl-2-pyrrolidone), and may be used in an amount that is preferred to contain the negative electrode active material, and optionally a binder and a conductive material. . For example, the concentration of the solid material including the negative electrode active material, and optionally the binder and the conductive material may be 50 wt% to 95 wt%, preferably 70 wt% to 90 wt%.
상기 음극으로서, 금속 자체를 사용하는 경우, 금속 박막 자체 또는 상기 음극 집전체 상에 금속을 물리적으로 접합, 압연 또는 증착 등을 시키는 방법으로 제조할 수 있다. 상기 증착하는 방식은 금속을 전기적 증착법 또는 화학적 증착법(chemical vapor deposition)을 사용할 수 있다.When the metal itself is used as the negative electrode, the negative electrode may be manufactured by a method of physically bonding a metal to the metal thin film itself or the negative electrode collector, followed by rolling or vapor deposition. The deposition may be performed using an electric or chemical vapor deposition method.
예를 들어, 상기 금속 박막 자체 또는 상기 음극 집전체 상에 접합/압연/증착되는 금속은 리튬(Li), 니켈(Ni), 주석(Sn), 구리(Cu) 및 인듐(In)으로 이루어진 군에서 선택되는 1종의 금속 또는 2종의 금속의 합금 등을 포함할 수 있다. For example, the metal to be bonded / rolled / deposited on the metal thin film itself or on the negative electrode current collector may include lithium (Li), nickel (Ni), tin (Sn), copper (Cu), and indium Or an alloy of two kinds of metals, and the like.
분리막Membrane
또한, 분리막으로는 종래에 분리막으로 사용된 통상적인 다공성 고분자 필름, 예를 들어 에틸렌 단독중합체, 프로필렌 단독중합체, 에틸렌/부텐 공중합체, 에틸렌/헥센 공중합체 및 에틸렌/메타크릴레이트 공중합체 등과 같은 폴리올레핀계 고분자로 제조한 다공성 고분자 필름을 단독으로 또는 이들을 적층하여 사용할 수 있으며, 또는 통상적인 다공성 부직포, 예를 들어 고융점의 유리 섬유, 폴리에틸렌테레프탈레이트 섬유 등으로 된 부직포를 사용할 수 있으나, 이에 한정되는 것은 아니다.As the separator, a conventional porous polymer film conventionally used as a separator, for example, a polyolefin such as an ethylene homopolymer, a propylene homopolymer, an ethylene / butene copolymer, an ethylene / hexene copolymer, and an ethylene / methacrylate copolymer A porous polymer film made of a high molecular weight polymer may be used alone or in a laminated manner, or a nonwoven fabric made of a conventional porous nonwoven fabric such as a glass fiber having a high melting point, a polyethylene terephthalate fiber or the like may be used. It is not.
본 발명의 리튬 이차전지의 외형은 특별한 제한이 없으나, 캔을 사용한 원통형, 각형, 파우치(pouch)형 또는 코인(coin)형 등이 될 수 있다.The external shape of the lithium secondary battery of the present invention is not particularly limited, but may be a cylindrical shape, a square shape, a pouch shape, a coin shape, or the like using a can.
본 발명의 다른 실시예에 따르면, 상기 리튬 이차 전지를 단위 셀로 포함하는 전지 모듈 및 이를 포함하는 전지 팩을 제공한다. 상기 전지 모듈 및 전지 팩은 고용량, 높은 율속 특성 및 사이틀 특성을 갖는 상기 리튬 이차전지를 포함하므로, 전기자동차, 하이브리드 전기자동차, 플러그-인 하이브리드 전기자동차 및 전력 저장용 시스템으로 이루어진 군에서 선택되는 중대형 디바이스의 전원으로 이용될 수 있다.According to another embodiment of the present invention, there is provided a battery module including the lithium secondary battery as a unit cell and a battery pack including the same. Since the battery module and the battery pack include the lithium secondary battery having a high capacity, a high rate-limiting characteristic, and a cycling characteristic, the battery module and the battery pack can be suitably used as a middle- or large- And can be used as a power source of the device.
이하, 구체적인 실시예를 통해 본 발명을 보다 구체적으로 설명한다. 다만, 하기 실시예는 본 발명의 이해를 돕기 위한 예시일 뿐, 본 발명의 범위를 한정하는 것은 아니다. 본 기재의 범주 및 기술사상 범위 내에서 다양한 변경 및 수정이 가능함은 당업자에게 있어서 명백한 것이며, 이러한 변형 및 수정이 첨부된 특허청구범위에 속하는 것은 당연한 것이다.Hereinafter, the present invention will be described more specifically by way of specific examples. However, the following examples are provided only to facilitate understanding of the present invention and are not intended to limit the scope of the present invention. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope and spirit of the present invention, and it is obvious that such variations and modifications are within the scope of the appended claims.
[실시예] [Example]
1. 실시예 11. Example 1
(1) 젤 폴리머 전해질용 조성물 제조(1) Preparation of Composition for Gel Polymer Electrolyte
에틸렌 카보네이트(EC), 에틸메틸 카보네이트(EMC)를 3:7 부피비로 혼합하고, LiPF6를 0.7 M, LiFSI를 0.3 M을 투입하여 혼합 용매를 제조한 다음, 상기 제조된 혼합 용매 91.78g에 화학식 1-5의 올리고머 (중량평균분자량 5000) 5g 및 첨가제로서 N,N'-디사이클로헥실카보디이미드 0.2g, 중합개시제(AIBN) 0.02g, 기타 첨가제로서 비닐렌 카보네이트(Vinylene Carbonate, VC) 1.5g, 프로판 설톤(Propane sultone, PS) 0.5g, 에틸렌 설페이트(ethylene　sulfate, ESa) 1g를 첨가하여 젤 폴리머 전해질용 조성물을 제조하였다. Ethylene carbonate (EC) and ethyl methyl carbonate (EMC) were mixed in a volume ratio of 3: 7, and 0.7 M of LiPF 6 and 0.3 M of LiFSI were added to prepare a mixed solvent. Then, 91.78 g of the mixed solvent 5 g of an oligomer (weight average molecular weight: 5000) of 1 to 5 and 0.2 g of N, N'-dicyclohexylcarbodiimide as an additive, 0.02 g of a polymerization initiator (AIBN), 1.5 g of vinylene carbonate g, 0.5 g of propane sultone (PS) and 1 g of ethylene sulfate (ESa) were added to prepare a gel polymer electrolyte composition.
(2) 리튬 이차 전지 제조(2) Production of lithium secondary battery
양극 활물질로 (LiNi1/3Co1/3Mn1/3O2; NCM) 94 중량%, 도전재로 카본 블랙(carbon black) 3 중량%, 바인더로 PVDF 3 중량%를 용매인 N-메틸-2-피롤리돈(NMP)에 첨가하여 양극 합제 슬러리를 제조하였다. 상기 양극 합제 슬러리를 두께가 20㎛ 정도의 양극 집전체인 알루미늄(Al) 박막에 도포 후 건조시킨 뒤, 롤 프레스(roll press)를 실시하여 양극을 제조하였다.94% by weight of a positive electrode active material (LiNi 1/3 Co 1/3 Mn 1/3 O 2 ; NCM), 3% by weight of carbon black as a conductive material and 3% by weight of PVDF as a binder were dissolved in a solvent N-methyl -2-pyrrolidone (NMP) to prepare a positive electrode mixture slurry. The positive electrode material mixture slurry was applied to an aluminum (Al) thin film as a positive electrode current collector having a thickness of about 20 mu m, dried, and then rolled to produce a positive electrode.
음극 활물질로 탄소 분말, 바인더로 PVDF, 도전재로 카본 블랙(carbon black)을 각각 96 중량%, 3 중량% 및 1 중량%로 하여 용매인 NMP에 첨가하여 음극 합제 슬러리를 제조하였다. 상기 음극 합제 슬러리를 두께가 10㎛의 음극 집전체인 구리(Cu) 박막에 도포 후 건조시킨 뒤, 롤 프레스(roll press)를 실시하여 음극을 제조하였다.The negative electrode mixture slurry was prepared by adding carbon powder as a negative electrode active material, PVDF as a binder and carbon black as a conductive material to 96 wt%, 3 wt% and 1 wt%, respectively, as a solvent. The negative electrode material mixture slurry was applied to a copper (Cu) thin film as an anode current collector having a thickness of 10 mu m, dried, and then rolled to produce a negative electrode.
상기 양극, 음극 및 폴리프로필렌/폴리에틸렌/폴리프로필렌 (PP/PE/PP) 3층으로 이루어진 분리막을 이용하여 전극조립체를 제조하였으며, 상기 전극조립체에 상기 제조된 젤 폴리머 전해질용 조성물을 주입한 후 2일 방치 후 60 ℃로 24시간 가열하여 젤 폴리머 전해질을 포함하는 리튬 이차 전지를 제조하였다.The electrode assembly was manufactured using the separator composed of the anode, the cathode and the three layers of polypropylene / polyethylene / polypropylene (PP / PE / PP). After the composition for the gel polymer electrolyte was injected into the electrode assembly, Followed by heating at 60 DEG C for 24 hours to prepare a lithium secondary battery containing the gel polymer electrolyte.
2. 실시예 22. Example 2
상기 실시예 1에서, 첨가제로서, N,N'-디사이클로헥실카보디이미드 0.2g 대신 1,1,3,3,3-헥사메틸디실라잔을 0.5g을 첨가한 것을 제외하고는 실시예 1과 동일한 방법으로 젤 폴리머 전해질을 포함하는 리튬 이차 전지를 제조하였다. In Example 1, except that 0.5 g of 1,1,3,3,3-hexamethyldisilazane was used instead of 0.2 g of N, N'-dicyclohexylcarbodiimide as an additive, 1, a lithium secondary battery including a gel polymer electrolyte was prepared .
3. 실시예 33. Example 3
상기 실시예 1에서, 첨가제로서, N,N'-디사이클로헥실카보디이미드 0.2g 대신 숙시노나이트릴을 2g을 첨가한 것을 제외하고는 실시예 1과 동일한 방법으로 젤 폴리머 전해질을 포함하는 리튬 이차 전지를 제조하였다.In the same manner as in Example 1 except that 2 g of succinonitrile was used instead of 0.2 g of N, N'-dicyclohexylcarbodiimide as an additive in Example 1, lithium containing gel polymer electrolyte A secondary battery was manufactured.
4. 실시예 44. Example 4
상기 실시예 1에서, 첨가제로서, N,N'-디사이클로헥실카보디이미드 0.2g 대신 1,1,1,3,3,3-헥사메틸디실라잔을 0.5g, 숙시노나이트릴을 2g 및 아디포나이트릴 2g을 첨가한 것을 제외하고는 실시예 1과 동일한 방법으로 젤 폴리머 전해질을 포함하는 리튬 이차 전지를 제조하였다.In Example 1, 0.5 g of 1,1,1,3,3,3-hexamethyldisilazane and 2 g of succinonitrile were used instead of 0.2 g of N, N'-dicyclohexylcarbodiimide as an additive. And adiponitrile (2 g) were added to the lithium secondary battery, a lithium secondary battery including a gel polymer electrolyte was prepared.
5. 실시예 55. Example 5
상기 실시예 1에서, 첨가제로서, N,N'-디사이클로헥실카보디이미드 0.2g 대신 리튬테트라플루오로보레이트를 2g 첨가한 것을 제외하고는 실시예 1과 동일한 방법으로 젤 폴리머 전해질을 포함하는 리튬 이차 전지를 제조하였다.In the same manner as in Example 1 except that 2 g of lithium tetrafluoroborate was used instead of 0.2 g of N, N'-dicyclohexylcarbodiimide as an additive in Example 1, lithium containing a gel polymer electrolyte A secondary battery was manufactured.
[비교예] [Comparative Example]
1. 비교예 11. Comparative Example 1
(1) 전해액 제조(1) Preparation of electrolyte
에틸렌 카보네이트(EC)와 에틸메틸 카보네이트(EMC)를 3:7 부피비로 혼합하고, LiPF6를 0.7M, LiFSI 0.3M을 투입한 후, 기타 첨가제로서, 비닐렌 카보네이트(Vinylene Carbonate, VC) 1.5g, 프로판 설톤(Propane sultone, PS) 0.5g, 에틸렌 설페이트(ethylene　sulfate, ESa) 1g을 첨가하여 전해액을 제조하였다.Ethylene carbonate (EC) and ethyl methyl carbonate (EMC) were mixed at a volume ratio of 3: 7, and LiPF 6 and LiFSI 0.3M were added. Then, 1.5 g of Vinylene Carbonate (VC) , 0.5 g of propane sultone (PS) and 1 g of ethylene sulfate (ESa) were added to prepare an electrolytic solution.
(2) 리튬 이차 전지 제조 (2) Production of lithium secondary battery
양극 활물질로 (LiNi1/3Co1/3Mn1/3O2; NCM) 94 중량%, 도전재로 카본 블랙(carbon black) 3 중량%, 바인더로 PVDF 3 중량%를 용매인 N-메틸-2-피롤리돈(NMP)에 첨가하여 양극 합제 슬러리를 제조하였다. 상기 양극 합제 슬러리를 두께가 20㎛ 정도의 양극 집전체인 알루미늄(Al) 박막에 도포 후 건조시킨 뒤, 롤 프레스(roll press)를 실시하여 양극을 제조하였다.94% by weight of a positive electrode active material (LiNi 1/3 Co 1/3 Mn 1/3 O 2 ; NCM), 3% by weight of carbon black as a conductive material and 3% by weight of PVDF as a binder were dissolved in a solvent N-methyl -2-pyrrolidone (NMP) to prepare a positive electrode mixture slurry. The positive electrode material mixture slurry was applied to an aluminum (Al) thin film as a positive electrode current collector having a thickness of about 20 mu m, dried, and then rolled to produce a positive electrode.
음극 활물질로 탄소 분말, 바인더로 PVDF, 도전재로 카본 블랙(carbon black)을 각각 96 중량%, 3 중량% 및 1 중량%로 하여 용매인 NMP에 첨가하여 음극 합제 슬러리를 제조하였다. 상기 음극 합제 슬러리를 두께가 10㎛의 음극 집전체인 구리(Cu) 박막에 도포 후 건조시킨 뒤, 롤 프레스(roll press)를 실시하여 음극을 제조하였다.The negative electrode mixture slurry was prepared by adding carbon powder as a negative electrode active material, PVDF as a binder and carbon black as a conductive material to 96 wt%, 3 wt% and 1 wt%, respectively, as a solvent. The negative electrode material mixture slurry was applied to a copper (Cu) thin film as an anode current collector having a thickness of 10 mu m, dried, and then rolled to produce a negative electrode.
상기 양극, 음극 및 폴리프로필렌/폴리에틸렌/폴리프로필렌 (PP/PE/PP) 3층으로 이루어진 분리막을 이용하여 전극조립체를 제조하였으며, 상기 전극조립체에 상기 제조된 전해액을 주입하여 리튬 이차 전지를 제조하였다.The electrode assembly was manufactured using the separator composed of the anode, the cathode and the three layers of polypropylene / polyethylene / polypropylene (PP / PE / PP), and the prepared electrolyte was injected into the electrode assembly to produce a lithium secondary battery .
2. 비교예 22. Comparative Example 2
상기 실시예 1에서, 올리고머로서, 화학식 1-5의 올리고머 5g 대신 디펜타에리트리톨 펜타아크릴레이트(dipentaerythritol pentaacrylate)로 이루어진 아크릴레이트계 올리고머를 5g 사용하는 것을 제외하고는 실시예 1과 동일한 방법으로 젤 폴리머 전해질을 포함하는 리튬 이차 전지를 제조하였다.In the same manner as in Example 1 except that 5 g of an oligomer composed of dipentaerythritol pentaacrylate instead of 5 g of the oligomer of the formula (1-5) was used as the oligomer in Example 1, A lithium secondary battery including a polymer electrolyte was prepared.
3. 비교예 33. Comparative Example 3
상기 실시예 1에서, 첨가제를 사용하지 않은 것을 제외하고는 실시예 1과 동일한 방법으로 젤 폴리머 전해질을 포함하는 리튬 이차 전지를 제조하였다.In Example 1, a lithium secondary battery including a gel polymer electrolyte was prepared in the same manner as in Example 1, except that an additive was not used.
[실험예] [Experimental Example]
1. 실험예 11. Experimental Example 1
상기 실시예 1 내지 5 및 비교예 1 내지 3에 따라 제조된 리튬 이차 전지에 대하여 25℃에서 SOC (state of charge) 50%로 맞춰준 후, 2.5C rate 방전 pulse로 10초 동안 방전을 진행하여, 그때 생기는 전압 강하량을 통해 각각의 리튬 이차 전지에 대한 저항값을 확인하였다. 그 결과를 측정된 저항 값 및 전압 강하 값을 하기 표 1에 나타내었다.The lithium secondary batteries prepared according to Examples 1 to 5 and Comparative Examples 1 to 3 were set to have a SOC (state of charge) of 50% at 25 ° C., followed by discharging for 10 seconds at 2.5 C rate discharge pulse , And the resistance value for each lithium secondary battery was confirmed through the voltage drop at that time. The measured resistance values and voltage drop values are shown in Table 1 below.
Figure PCTKR2018015122-appb-T000001
Figure PCTKR2018015122-appb-T000001
상기 표 1을 참조할 때, 비교예들에 의하여 제조되는 전지보다 실시예들에 의하여 제조된 전지 내 저항의 값이 더 작고, 전압 강하 또한 적은 것을 확인할 수 있다.Referring to Table 1, it can be seen that the values of the resistance in the battery manufactured according to the embodiments are smaller than those of the batteries manufactured by the comparative examples, and the voltage drop is also small.
2. 실험예 2: 전지의 Rct 저항 측정2. Experimental Example 2: Rct resistance measurement of battery
상기 실시예 1 내지 5 및 비교예 1 내지 3에 따라 제조된 리튬 이차 전지에 대하여 SOC 50%, 25℃ 온도 조건에서 1시간 동안 둔 후 1KHz-1mHz까지 스캔하면서 전지의 Rct 저항(Resistance to charge transfer)을 측정하여 표 2에 나타내었다. 이때 교류 전류의 진폭은 10mV이었으며, 전지의 직류전위(DC potential)은 3.68V이었다. The lithium secondary batteries prepared according to Examples 1 to 5 and Comparative Examples 1 to 3 were allowed to stand for 1 hour under conditions of SOC 50% and 25 ° C, and were then scanned to 1 KHz-1 mHz. The Rct resistance ) Were measured and are shown in Table 2. At this time, the amplitude of the alternating current was 10 mV, and the DC potential of the battery was 3.68 V.
Figure PCTKR2018015122-appb-T000002
Figure PCTKR2018015122-appb-T000002
상기 표 2를 참조하면, 비교예들에 의하여 제조된 전지 내 Rct 저항이 더 큰 것을 확인할 수 있다. 이는 실시예들에 의하여 제조된 전지에 비하여 염의 음이온으로부터 유발되는 부반응에 의하여 Rct 저항(계면 저항)이 더 커진 것으로 보인다.Referring to Table 2, it can be seen that the Rct resistance in the battery manufactured by the comparative examples is larger. This indicates that the Rct resistance (interfacial resistance) is larger due to the side reaction induced from the anion of the salt, as compared with the battery produced by the embodiments.
3. 실험예 3: 고온 안전성 실험3. Experimental Example 3: High Temperature Safety Test
상기 실시예 1 내지 5 및 비교예 1 내지 3에 따라 제조된 이차전지에 대하여, 각각의 이차전지를 60℃ 온도 조건에서 SOC 100% 상태(4.15 V)로 10주(10weeks) 동안 고온 저장하였다. 이후, 1주 단위로 각주마다 25에서 SOC 50%을 맞춰준 후, 5C rate로 방전 pulse로 10초 동안 방전시켜 저항값을 측정한 후, 초기(0주)에 측정된 저항값을 기준으로 저항 변화율을 측정하였다. 그 결과를 하기 표 3에 나타내었다.Each of the secondary batteries prepared according to Examples 1 to 5 and Comparative Examples 1 to 3 was stored at a high temperature for 10 weeks (10weeks) under a condition of SOC 100% (4.15 V) at a temperature of 60 ° C. Thereafter, the SOC 50% was set at 25 per foot for each week, and the resistance value was measured by discharging for 10 seconds with a discharge pulse at 5C rate. Then, the resistance was measured based on the resistance value measured at the initial (0 week) The rate of change was measured. The results are shown in Table 3 below.
Figure PCTKR2018015122-appb-T000003
Figure PCTKR2018015122-appb-T000003
상기 표 3을 참조하면, 비교예들에 의하여 제조된 전지에 비하여, 고온에서 실시예들에 의하여 제조된 전지의 저항 증가율이 현저히 낮은 것을 확인할 수 있다.Referring to Table 3, it can be seen that the resistance increase rate of the battery manufactured by the embodiments at a high temperature is significantly lower than that of the battery manufactured by the comparative examples.

Claims (14)

  1. 하기 화학식 1로 표시되는 올리고머; 첨가제; 중합개시제; 리튬염; 및 비수계 용매를 포함하고,An oligomer represented by the following formula (1); additive; A polymerization initiator; Lithium salts; And a non-aqueous solvent,
    상기 첨가제는 이미드계 화합물, Si-N계 결합을 갖는 화합물, 나이트릴계 화합물, 포스페이트계 화합물 및 보레이트계 화합물로 이루어진 군에서 선택되는 적어도 하나 이상의 화합물을 포함하는 것인 젤 폴리머 전해질용 조성물:Wherein the additive comprises at least one compound selected from the group consisting of a imide compound, a compound having Si-N bond, a nitrile compound, a phosphate compound and a borate compound.
    [화학식 1][Chemical Formula 1]
    Figure PCTKR2018015122-appb-I000037
    Figure PCTKR2018015122-appb-I000037
    상기 화학식 1에서,In Formula 1,
    상기 A 및 A'는 각각 독립적으로 (메타)아크릴레이트기를 포함하는 단위이고,Each of A and A 'is independently a unit containing a (meth) acrylate group,
    상기 B 및 B'는 각각 독립적으로 아마이드기를 포함하는 단위이며,B and B 'each independently represent an amide group-containing unit,
    상기 C 및 C'는 각각 독립적으로 옥시알킬렌기를 포함하는 단위이고,Each of C and C 'is independently a unit containing an oxyalkylene group,
    상기 D는 실록산기를 포함하는 단위이며,D is a unit containing a siloxane group,
    k는 1 내지 100의 정수이다. k is an integer of 1 to 100;
  2. 제1항에 있어서,The method according to claim 1,
    상기 이미드계 화합물은,The imide-
    하기 화학식 2로 표시되는 카보디이미드계 화합물을 포함하는 것인 젤 폴리머 전해질용 조성물:A composition for a gel polymer electrolyte comprising a carbodiimide compound represented by the following Formula 2:
    [화학식 2](2)
    Figure PCTKR2018015122-appb-I000038
    Figure PCTKR2018015122-appb-I000038
    상기 화학식 2에서, R10 및 R10'은 각각 독립적으로, 탄소수 1 내지 12의 알킬기 및 탄소수 3 내지 12의 사이클로알킬기로 이루어진 군에서 선택되는 것이다.In Formula 2, R 10 and R 10 'are each independently selected from the group consisting of an alkyl group having 1 to 12 carbon atoms and a cycloalkyl group having 3 to 12 carbon atoms.
  3. 제1항에 있어서,The method according to claim 1,
    상기 이미드계 화합물은, N,N'-디사이클로펜틸카보디이미드, N,N'-디사이클로헥실카보디이미드 및 N,N'-디사이클로헵틸카보디이미드로 이루어진 군에서 선택되는 적어도 하나 이상의 화합물을 포함하는 것인 젤 폴리머 전해질용 조성물.The imide compound may be at least one selected from the group consisting of N, N'-dicyclopentylcarbodiimide, N, N'-dicyclohexylcarbodiimide and N, N'-dicycloheptylcarbodiimide &Lt; / RTI &gt; wherein the composition comprises a compound of formula &lt; RTI ID = 0.0 &gt;
  4. 제1항에 있어서,The method according to claim 1,
    상기 Si-N계 결합을 갖는 화합물은, The compound having the Si-N system bond,
    하기 화학식 3으로 표시되는 화합물을 포함하는 것인 젤 폴리머 전해질용 조성물:A composition for a gel polymer electrolyte comprising a compound represented by the following formula (3): &lt; EMI ID =
    [화학식 3](3)
    Figure PCTKR2018015122-appb-I000039
    Figure PCTKR2018015122-appb-I000039
    상기 화학식 3에서, R11 는 수소 또는 탄소수 1 내지 5의 알킬기가 치환 또는 비치환된 실릴기이고, R12 및 R13은 각각 독립적으로, 수소, 치환 또는 비치환된 탄소수 1 내지 5의 알킬기, 헤테로 원자가 치환 또는 비치환된 탄소수 1 내지 5의 알킬기 및 탄소수 1 내지 5의 알킬기가 치환 또는 비치환된 실릴기로 이루어진 군에서 선택되는 것이며, 상기 헤테로 원자는 산소(O), 질소(N) 및 황(S)으로 이루어진 군에서 선택되는 어느 하나 이상의 원자일 수 있다.In Formula 3, R 11 is hydrogen or a silyl group in which the alkyl group having 1 to 5 carbon atoms is substituted or unsubstituted, R 12 and R 13 are each independently selected from the group consisting of hydrogen, a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms, Wherein the hetero atom is selected from the group consisting of a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms and a substituted or unsubstituted silyl group having an alkyl group having 1 to 5 carbon atoms and the hetero atom is selected from the group consisting of oxygen (O), nitrogen (N) (S). &Lt; / RTI &gt;
  5. 제1항에 있어서,The method according to claim 1,
    상기 Si-N계 결합을 갖는 화합물은, 1,1,1,3,3,3-헥사메틸디실라잔, 헵타메틸디실라잔, N,N-디에틸아미노 트리메틸실란 및 N,N,O-트리스(트리메틸실릴)하이드록시아민으로 이루어진 군에서 선택되는 적어도 하나 이상의 화합물을 포함하는 것인 젤 폴리머 전해질용 조성물.The compound having the Si-N system bond may be at least one selected from the group consisting of 1,1,1,3,3,3-hexamethyldisilazane, heptamethyldisilazane, N, N-diethylaminotrimethylsilane and N, N, O -Tris (trimethylsilyl) hydroxyamine, wherein the composition comprises at least one compound selected from the group consisting of tris (trimethylsilyl) hydroxyamine.
  6. 제1항에 있어서,The method according to claim 1,
    상기 나이트릴계 화합물은,The nitrile-
    하기 화학식 4-1 및 4-2로 표시되는 화합물로 이루어진 군에서 선택되는 적어도 하나 이상의 화합물을 포함하는 것인 젤 폴리머 전해질용 조성물:And at least one compound selected from the group consisting of compounds represented by the following formulas (4-1) and (4-2):
    [화학식 4-1][Formula 4-1]
    Figure PCTKR2018015122-appb-I000040
    Figure PCTKR2018015122-appb-I000040
    상기 화학식 4-1에서, R14는 치환 또는 비치환된 탄소수 1 내지 5의 알킬기 및 치환 또는 비치환된 탄소수 1 내지 5의 알케닐기로 이루어진 군에서 선택되는 것이고,In the formula 4-1, R 14 is selected from the group consisting of a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms and a substituted or unsubstituted alkenyl group having 1 to 5 carbon atoms,
    [화학식 4-2][Formula 4-2]
    Figure PCTKR2018015122-appb-I000041
    Figure PCTKR2018015122-appb-I000041
    상기 화학식 4-2에서, R15는 치환 또는 비치환된 탄소수 1 내지 5의 알킬렌기 및 치환 또는 비치환된 탄소수 1 내지 5의 알케닐기로 이루어진 군에서 선택되는 것이다.In Formula 4-2, R 15 is selected from the group consisting of a substituted or unsubstituted alkylene group having 1 to 5 carbon atoms and a substituted or unsubstituted alkenyl group having 1 to 5 carbon atoms.
  7. 제1항에 있어서,The method according to claim 1,
    상기 나이트릴계 화합물은, 아디포나이트릴, 숙시노나이트릴, 글루타로나이트릴, 피멜로나이트릴, 헵트-3-엔디나이트릴, 수베로나이트릴, 세바코나이트릴, 부티로나이트릴 및 헥스-3-엔디나이트릴로 이루어진 군에서 선택되는 적어도 하나 이상의 화합물을 포함하는 것인 젤 폴리머 전해질용 조성물.Wherein the nitrile compound is selected from the group consisting of adiponitrile, succinonitrile, glutaronitrile, pimelonitrile, hept-3-adnitlinyl, suveronitrile, sebaconitrile, butyronitrile, And at least one compound selected from the group consisting of 3-aminonitrile and 3-indinitrile.
  8. 제1항에 있어서,The method according to claim 1,
    상기 포스페이트계 화합물은, 트리스(트리메틸실릴)포스페이트 및 트리스(트리메틸)포스페이트로 이루어진 군에서 선택되는 적어도 하나 이상의 화합물을 포함하는 것인 젤 폴리머 전해질용 조성물.Wherein the phosphate-based compound comprises at least one compound selected from the group consisting of tris (trimethylsilyl) phosphate and tris (trimethyl) phosphate.
  9. 제1항에 있어서,The method according to claim 1,
    상기 보레이트계 화합물은 리튬테트라플루오로보레이트 및 트리스(트리메틸실릴)보레이트로 이루어진 군에서 선택되는 적어도 하나 이상의 화합물을 포함하는 것인 젤 폴리머 전해질용 조성물.Wherein the borate compound comprises at least one compound selected from the group consisting of lithium tetrafluoroborate and tris (trimethylsilyl) borate.
  10. 제1항에 있어서,The method according to claim 1,
    상기 첨가제는 상기 젤 폴리머 전해질용 조성물 100 중량부에 대하여 0.1 중량부 내지 30 중량부로 포함되는 것인 젤 폴리머 전해질용 조성물.Wherein the additive is included in an amount of 0.1 to 30 parts by weight based on 100 parts by weight of the composition for a gel polymer electrolyte.
  11. 제1항에 있어서,The method according to claim 1,
    상기 A 및 A'는 각각 독립적으로 하기 화학식 A-1 내지 A-5로 표시되는 단위 중 적어도 하나 이상을 포함하는 것인 젤 폴리머 전해질용 조성물:Wherein A and A 'each independently comprise at least one or more units represented by the following formulas (A-1) to (A-5):
    [화학식 A-1][A-1]
    Figure PCTKR2018015122-appb-I000042
    Figure PCTKR2018015122-appb-I000042
    [화학식 A-2][A-2]
    Figure PCTKR2018015122-appb-I000043
    Figure PCTKR2018015122-appb-I000043
    [화학식 A-3][A-3]
    Figure PCTKR2018015122-appb-I000044
    Figure PCTKR2018015122-appb-I000044
    [화학식 A-4][A-4]
    Figure PCTKR2018015122-appb-I000045
    Figure PCTKR2018015122-appb-I000045
    [화학식 A-5][A-5]
    Figure PCTKR2018015122-appb-I000046
    Figure PCTKR2018015122-appb-I000046
    상기 화학식 A-1 내지 화학식 A-5에서 상기 R1은 각각 독립적으로 수소 및 탄소수 1 내지 6의 치환 또는 비치환된 알킬렌기로 이루어진 군에서 선택되는 것 일 수 있다.In the formulas (A-1) to (A-5), each of R 1 's may independently be selected from the group consisting of hydrogen and a substituted or unsubstituted alkylene group having 1 to 6 carbon atoms.
  12. 제1항에 있어서,The method according to claim 1,
    상기 올리고머는 하기 화학식 1-1 내지 1-5로 표시되는 화합물로 이루어진 군에서 선택되는 적어도 하나 이상의 화합물을 포함하는 것인 젤 폴리머 전해질용 조성물:Wherein the oligomer comprises at least one compound selected from the group consisting of compounds represented by the following formulas (1-1) to (1-5):
    [화학식 1-1][Formula 1-1]
    Figure PCTKR2018015122-appb-I000047
    Figure PCTKR2018015122-appb-I000047
    [화학식 1-2][Formula 1-2]
    Figure PCTKR2018015122-appb-I000048
    Figure PCTKR2018015122-appb-I000048
    [화학식 1-3][Formula 1-3]
    Figure PCTKR2018015122-appb-I000049
    Figure PCTKR2018015122-appb-I000049
    [화학식 1-4][Formula 1-4]
    Figure PCTKR2018015122-appb-I000050
    Figure PCTKR2018015122-appb-I000050
    [화학식 1-5][Formula 1-5]
    Figure PCTKR2018015122-appb-I000051
    Figure PCTKR2018015122-appb-I000051
    상기 화학식 1-1 내지 1-5에서, n, o, p는 각각 독립적으로 1 내지 30의 정수이고, q는 1 내지 100의 정수이다.In the above formulas 1-1 to 1-5, n, o and p are each independently an integer of 1 to 30, and q is an integer of 1 to 100.
  13. 청구항 1의 젤 폴리머 전해질용 조성물을 이용하여 제조되는 젤 폴리머 전해질.A gel polymer electrolyte produced by using the gel polymer electrolyte composition of claim 1.
  14. 양극;anode;
    음극;cathode;
    상기 양극과 음극 사이에 개재되는 분리막; 및A separator interposed between the anode and the cathode; And
    청구항 13의 젤 폴리머 전해질을 포함하는 리튬 이차 전지.A lithium secondary battery comprising the gel polymer electrolyte according to claim 13.
PCT/KR2018/015122 2017-11-30 2018-11-30 Composition for gel polymer electrolyte, gel polymer electrolyte prepared by means of same, and lithium secondary battery comprising same WO2019108031A1 (en)

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