WO2019088733A1 - Electrolyte for lithium secondary battery and lithium secondary battery comprising same - Google Patents

Electrolyte for lithium secondary battery and lithium secondary battery comprising same Download PDF

Info

Publication number
WO2019088733A1
WO2019088733A1 PCT/KR2018/013181 KR2018013181W WO2019088733A1 WO 2019088733 A1 WO2019088733 A1 WO 2019088733A1 KR 2018013181 W KR2018013181 W KR 2018013181W WO 2019088733 A1 WO2019088733 A1 WO 2019088733A1
Authority
WO
WIPO (PCT)
Prior art keywords
secondary battery
electrolyte
lithium secondary
formula
group
Prior art date
Application number
PCT/KR2018/013181
Other languages
French (fr)
Korean (ko)
Inventor
오정우
안경호
한준혁
이철행
Original Assignee
주식회사 엘지화학
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from KR1020180132195A external-priority patent/KR102227811B1/en
Application filed by 주식회사 엘지화학 filed Critical 주식회사 엘지화학
Priority to US16/477,348 priority Critical patent/US10950895B2/en
Priority to JP2020502292A priority patent/JP7027628B2/en
Priority to PL18874455.1T priority patent/PL3561936T3/en
Priority to EP18874455.1A priority patent/EP3561936B1/en
Priority to CN201880007159.2A priority patent/CN110178258B/en
Publication of WO2019088733A1 publication Critical patent/WO2019088733A1/en

Links

Classifications

    • 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
    • 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
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
    • H01M10/4235—Safety or regulating additives or arrangements in electrodes, separators or 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 an electrolyte for a lithium secondary battery and a lithium secondary battery comprising the same.
  • Electrochemical devices are one of the most sought-after fields of energy storage technology. Among them, attention is focused on rechargeable lithium secondary batteries.
  • the lithium secondary battery can be produced by applying the positive electrode active material and the negative electrode active material to the current collector in an appropriate thickness or by forming the active material itself into a film having an appropriate length and winding or laminating the separator together with the separator as an insulator, The electrode assembly is placed in a similar container, and then an electrolyte is injected.
  • the electrolyte may be a gel polymer electrolyte further comprising a liquid electrolyte or a matrix polymer including an electrolyte solvent in which a lithium salt is dissolved.
  • electrolyte solvent examples include ethylene carbonate, propylene carbonate, dimethoxyethane, gamma butyrolactone, N, N-dimethylformamide, tetrahydrofuran and acetonitrile.
  • the electrolyte solvent causes a side reaction at high voltage, and when stored at a high temperature for a long time, not only an oxidation reaction occurs but also a dendrite-type Li metal formed on the anode can easily react to generate an exothermic reaction.
  • the overcharge progresses above a certain SOC, the oxidation reaction of the electrolyte accelerates and the exothermic reaction between the Li metal on the surface of the negative electrode and the electrolyte formed due to excessive Li migration from the positive electrode to the negative electrode is intensified, have.
  • the present invention provides an electrolyte for a lithium secondary battery having improved wettability by lowering surface tension with respect to an electrode surface.
  • the present invention also provides a lithium secondary battery including the electrolyte for the lithium secondary battery.
  • an electrolyte for a lithium secondary battery comprising an oligomer represented by the following general formula (1) or a polymer derived from an oligomer represented by the general formula (1).
  • R 1 and R 2 are each independently a substituted or unsubstituted alkylene group having 1 to 5 carbon atoms,
  • R 3 and R 4 are each independently hydrogen or a substituted or unsubstituted alkyl group having 1 to 3 carbon atoms,
  • R 5 is hydrogen or a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms
  • R ' is an aliphatic hydrocarbon group or an aromatic hydrocarbon group
  • z is an integer of 1 to 10,
  • x is an integer of 1 to 15,
  • n is an integer of 1 to 3.
  • the aliphatic hydrocarbon group of R ' is selected from the group consisting of (a) a substituted or unsubstituted cycloalkylene group having 4 to 20 carbon atoms, a substituted or unsubstituted cycloalkenylene group having 4 to 20 carbon atoms, (B) a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, a substituted or unsubstituted alicyclic hydrocarbon group having 1 to 20 carbon atoms, a substituted or unsubstituted alicyclic hydrocarbon group having 1 to 20 carbon atoms, At least one aliphatic hydrocarbon group selected from the group consisting of a substituted or unsubstituted arylene group, an alkoxylene group, a substituted or unsubstituted alkenylene group having 2 to 20 carbon atoms, and a substituted or unsubstituted alkynylene group having 2 to 20 carbon
  • the aromatic hydrocarbon group of R ' may include at least one selected from the group consisting of a substituted or unsubstituted arylene group having 6 to 20 carbon atoms and a substituted or unsubstituted heteroarylene group having 2 to 20 carbon atoms.
  • the aliphatic hydrocarbon group of R ' is a substituted or unsubstituted cycloalkylene group having 4 to 20 carbon atoms, a substituted or unsubstituted cycloalkenylene group having 4 to 20 carbon atoms and a substituted or unsubstituted And at least one alicyclic hydrocarbon group selected from the group consisting of a heterocycloalkylene group having 2 to 20 carbon atoms.
  • the oligomer represented by the formula (1) may be at least one selected from oligomers represented by the following formulas (1a) and (1b).
  • R ' is an aliphatic hydrocarbon group or an aromatic hydrocarbon group
  • z1 and x1 are the number of repeating units
  • z1 is an integer of 1 to 10
  • x1 is an integer of any one of 1 to 15;
  • R ' is an aliphatic hydrocarbon group or an aromatic hydrocarbon group
  • z2 and x2 are the number of repeating units
  • z2 is an integer of 1 to 10
  • x2 is an integer of any one of 1 to 15.
  • the oligomer represented by Formula 1 may be at least one selected from the group consisting of oligomers represented by the following Formulas 1a-1 and 1b-1.
  • z1 and x1 are the number of repeating units
  • z1 is an integer of 1 to 10
  • x1 is an integer of any one of 1 to 15;
  • z2 and x2 are the number of repeating units
  • z2 is an integer of 1 to 10
  • x2 is an integer of any one of 1 to 15.
  • the electrolyte for a lithium secondary battery of the present invention may be a liquid electrolyte containing an oligomer represented by the general formula (1).
  • the oligomer represented by Formula 1 may be contained in an amount of 0.5 to 30% by weight, specifically 0.5 to 25% by weight based on the total weight of the electrolyte for a lithium secondary battery.
  • the electrolyte for a lithium secondary battery of the present invention may be a gel polymer electrolyte comprising an oligomer-derived polymer represented by the above formula (1).
  • the oligomer-derived polymer represented by Formula 1 may be a matrix polymer formed by polymerization of an oligomer represented by Formula 1 in the presence of a polymerization initiator to form a three-dimensional structure.
  • the oligomer-derived polymer represented by Formula 1 may be contained in an amount of 0.5 to 30% by weight, specifically 0.5 to 25% by weight based on the total weight of the electrolyte for a lithium secondary battery.
  • the lithium secondary battery including the electrolyte for a lithium secondary battery of the present invention can be provided.
  • the electrolyte for the lithium secondary battery may be a liquid electrolyte or a gel polymer electrolyte.
  • an oligomer having hydrophilic and hydrophobic functional groups or a polymer derived from such an oligomer can be used to manufacture an electrolyte for a lithium secondary battery that can improve wettability by lowering the surface tension with respect to the electrode surface and suppress side reactions of the electrolyte and the electrode. can do. Further, by including it, an increase in interfacial resistance of the electrode can be suppressed to prevent an average voltage drop, and as a result, a lithium secondary battery having improved charging / discharging efficiency can be manufactured.
  • the functional group may include “ a " to " b " carbon atoms.
  • the "alkyl group having 1 to 3 carbon atoms” means an alkyl group containing 1 to 3 carbon atoms, ie, -CH 3 , -CH 2 CH 3 , -CH 2 CH 2 CH 3 or -CH 2 (CH 2 ) CH 3 .
  • the "arylene group” means a functional group in which hydrogen atoms are separated from aromatic hydrocarbons.
  • the arylene group includes, but is not limited to, a phenylene group, a biphenylene group, a terphenylene group, a naphthylene group, or a phenanthrylene group, each of which is optionally substituted .
  • hetero means, unless otherwise defined, that at least one heteroatom selected from the group consisting of N, O, S, or P is contained in one functional group and the remainder is carbon do.
  • heterocycloalkylene group as used throughout this specification means that at least one hetero atom of N, O, S, or P exists in the ring compound having 2 to 20 carbon atoms instead of carbon.
  • substituted means that at least one hydrogen bonded to carbon is replaced with an element other than hydrogen, unless otherwise defined, and includes, for example, an alkyl group substituted with an alkyl group having 1 to 3 carbon atoms .
  • a lithium salt Organic solvent
  • an oligomer represented by the following formula (1) or an oligomer-derived polymer represented by the above formula (1) is included in one embodiment of the present invention.
  • R 1 and R 2 are each independently a substituted or unsubstituted alkylene group having 1 to 5 carbon atoms,
  • R 3 and R 4 are each independently hydrogen or a substituted or unsubstituted alkyl group having 1 to 3 carbon atoms,
  • R 5 is hydrogen or a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms
  • R ' is an aliphatic hydrocarbon group or an aromatic hydrocarbon group
  • z is an integer of 1 to 10,
  • x is an integer of 1 to 15,
  • n is an integer of 1 to 3.
  • the electrolyte for a lithium secondary battery of the present invention may be a lithium salt, an organic solvent, and a liquid electrolyte containing an oligomer represented by the formula (1).
  • the electrolyte for a lithium secondary battery of the present invention may be a gel polymer electrolyte for a lithium secondary battery comprising a lithium salt, an organic solvent, and an oligomer-derived polymer represented by the formula (1).
  • an electrolyte for a lithium secondary battery comprising a lithium salt, an organic solvent, and an oligomer represented by the formula (1).
  • the electrolyte for the lithium secondary battery may be a liquid electrolyte.
  • the lithium salt used in the lithium secondary battery electrolyte of the present invention can be used without limitation, those which are commonly used in a lithium secondary battery electrolyte, such as an anion, and containing the Li + in the lithium salt cation is F - , Cl -, Br -, I -, NO 3 -, N (CN) 2 -, BF 4 -, ClO 4 -, AlO 4 -, AlCl 4 -, PF 6 -, SbF 6 -, AsF 6 -, BF 2 C 2 O 4 -, BC 4 O 8 -, PF 4 C 2 O 4 -, PF 2 C 4 O 8 -, (CF 3) 2 PF 4 -, (CF 3) 3 PF 3 -, (CF 3 ) 4 PF 2 -, (CF 3) 5 PF -, (CF 3) 6 P -, CF 3 SO 3 -, C 4 F 9 SO 3 -, CF 3 CF 2 SO 3 -, C 4 F
  • the lithium salt may be LiCl, LiBr, LiI, LiClO 4 , LiBF 4 , LiB 10 Cl 10 , LiPF 6 , LiCF 3 SO 3 , LiCH 3 CO 2 , LiCF 3 CO 2 , LiAsF 6 , LiSbF 6 , LiAlCl 4 , LiAlO 4 , and LiCH 3 SO 3 , or a mixture of two or more thereof.
  • lithium bisperfluoroethanesulfonimide Li 2 N 2 (SO 2 C 2 F 5) 2)
  • LiFSI lithium fluorosulfonyl imide, LiN (SO 2 F) 2)
  • LiTFSI lithium (bis) trifluoromethanesulfonimide, LiN (SO 2 CF 3) 2
  • a lithium salt such as lithium already deuyeom represented by the limited without Can be used.
  • the lithium salt is LiPF 6, LiBF 4, LiCH 3 CO 2, LiCF 3 CO 2, LiCH 3 SO 3, LiFSI, LiTFSI and LiN (C 2 F 5 SO 2 ) or more danilmul selected from the group consisting of 2 or two And mixtures thereof.
  • the lithium salt can be appropriately changed within a range that is generally usable, but it can be specifically contained in the electrolyte in the range of 0.1 M to 3 M, specifically 0.8 M to 2.5 M. If the concentration of the lithium salt exceeds 3M, the viscosity of the electrolyte may increase and the lithium ion transfer effect may be lowered.
  • the organic solvent may include at least one organic solvent selected from the group consisting of a cyclic carbonate organic solvent, a linear carbonate organic solvent, a linear ester organic solvent and a cyclic ester organic solvent.
  • the organic solvent may include a cyclic carbonate-based organic solvent and a linear carbonate-based organic solvent.
  • cyclic carbonate-based organic solvent examples include ethylene carbonate (EC), propylene carbonate (PC), 1,2-butylene carbonate, 2,3-butylene carbonate, 1,2-pentylene carbonate, 2,3- Pentylene carbonate, and vinylene carbonate, or a mixture of two or more thereof.
  • organic solvents having a high viscosity such as ethylene carbonate, which has a high dielectric constant and dissociates the lithium salt in the electrolyte well .
  • the linear carbonate-based organic solvent is an organic solvent having a low viscosity and a low dielectric constant. Typical examples thereof include dimethyl carbonate (DMC), diethyl carbonate (DEC), dipropyl carbonate, ethyl methyl carbonate EMC), methyl propyl carbonate, and ethyl propyl carbonate.
  • DMC dimethyl carbonate
  • DEC diethyl carbonate
  • EMC ethyl methyl carbonate
  • propyl carbonate methyl propyl carbonate
  • ethyl propyl carbonate ethyl propyl carbonate
  • the organic solvent may further include a linear ester organic solvent and / or a cyclic ester organic solvent to produce an electrolytic solution having a high electrical conductivity.
  • linear ester organic solvents may include at least one selected from the group consisting of methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate and butyl propionate have.
  • the cyclic ester organic solvent may include at least one selected from the group consisting of? -Butyrolactone,? -Valerolactone,? -Caprolactone,? -Valerolactone and? -Caprolactone .
  • organic solvent may be added with an organic solvent commonly used in an electrolyte for a lithium secondary battery, if necessary, without limitation.
  • an ether organic solvent and a nitrile organic solvent may further include at least one organic solvent.
  • the ether-based organic solvent may include any one selected from the group consisting of dimethyl ether, diethyl ether, dipropyl ether, methyl ethyl ether, methyl propyl ether and ethyl propyl ether.
  • the nitrile organic solvent may be, for example, acetonitrile, propionitrile, butyronitrile, valeronitrile, caprilonitrile, heptanenitrile, cyclopentanecarbonitrile, cyclohexanecarbonitrile, 2-fluorobenzonitrile, 4 May include any one selected from the group consisting of fluorobenzonitrile, difluorobenzonitrile, trifluorobenzonitrile, phenylacetonitrile, 2-fluorophenylacetonitrile, 4-fluorophenylacetonitrile .
  • the electrolyte for a lithium secondary battery of the present invention may include an oligomer represented by the following formula (1).
  • R 1 and R 2 are each independently a substituted or unsubstituted alkylene group having 1 to 5 carbon atoms,
  • R 3 and R 4 are each independently hydrogen or a substituted or unsubstituted alkyl group having 1 to 3 carbon atoms,
  • R 5 is hydrogen or a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms
  • R ' is an aliphatic hydrocarbon group or an aromatic hydrocarbon group
  • z is an integer of 1 to 10,
  • x is an integer of 1 to 15,
  • n is an integer of 1 to 3.
  • the aliphatic hydrocarbon group of R ' is selected from the group consisting of (a) a substituted or unsubstituted cycloalkylene group having 4 to 20 carbon atoms, a substituted or unsubstituted cycloalkenylene group having 4 to 20 carbon atoms, (B) at least one substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, a substituted or unsubstituted C1 to C20 alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted C1 to C20 alkoxy group, a substituted or unsubstituted C2 to C20 alicyclic hydrocarbon group, And at least one linear hydrocarbon group selected from the group consisting of a substituted or unsubstituted alkenylene group having 2 to 20 carbon atoms and a substituted or unsubstituted alkynylene group having 2 to 20 carbon atoms, have.
  • the aromatic hydrocarbon group for R ' may include at least one selected from substituted or unsubstituted arylene groups having 6 to 20 carbon atoms and substituted or unsubstituted heteroarylene groups having 2 to 20 carbon atoms.
  • the aliphatic hydrocarbon group of R ' is a substituted or unsubstituted cycloalkylene group having 4 to 20 carbon atoms, a substituted or unsubstituted cycloalkenylene group having 4 to 20 carbon atoms, and a substituted or unsubstituted carbon number And at least one alicyclic hydrocarbon group selected from the group consisting of 2 to 20 heterocycloalkylene groups.
  • the oligomer represented by the formula (1) contains an acrylate-based functional group which is a hydrophilic moiety capable of forming a cross-linking bond at both ends, and also contains a siloxane group (-Si-O-) and a urethane O) - group, it is possible to lower the interfacial resistance by imparting a surfactant role in the cell and by balancing affinity with the anode or separator (SRS layer) which is a hydrophilic part and the cathode or separator fabric which is a hydrophobic part . Therefore, the electrolyte for the lithium secondary battery including the oligomer represented by the above formula (1) can further improve the wettability effect.
  • the oligomer represented by the above formula (1) forms a stable ion conductive membrane on the surface of the cathode at the time of initial charging, and at the same time suppresses the side reaction between the Li metal deposited on the surface of the anode and the electrolyte, It is possible to suppress an increase in resistance and an average voltage change during charging and discharging therefrom. Therefore, a lithium secondary battery improved in charge / discharge efficiency and high rate characteristics can be provided.
  • the oligomer represented by the general formula (1) of the present invention contains a siloxane group (- [Si-O] -) and a urethane group as repeating units of the main chain, and the oligomer additionally contains a- . That is, since the oligomer structure does not contain additional -Si- group as a repeating unit, the ratio of the functional groups at both terminals can be increased and the molecular weight of the entire polymer can be lowered. Therefore, Can further increase the content of the entire oligomer relative to an oligomer further including a -Si- group (e.g., [Si-O] -Si- structure in the main chain repeat unit). Therefore, the reaction rate of the gel polymer can be advantageously taken, and the hardness of the gel polymer can be increased to enhance the hardness of the whole cell, so that it can be more advantageously used for safety evaluation such as impact evaluation which gives physical impact.
  • a siloxane group - [Si-O] -
  • the oligomer represented by the formula (1) may be at least one selected from the group consisting of oligomers represented by the following formulas (1a) and (1b).
  • R ' is an aliphatic hydrocarbon group or an aromatic hydrocarbon group
  • z1 and x1 are the number of repeating units
  • z1 is an integer of 1 to 10
  • x1 is an integer of any one of 1 to 15;
  • R ' is an aliphatic hydrocarbon group or an aromatic hydrocarbon group
  • z2 and x2 are the number of repeating units
  • z2 is an integer of 1 to 10
  • x2 is an integer of any one of 1 to 15.
  • the oligomer represented by Formula 1 may be selected from the group consisting of oligomers represented by the following Formulas 1a-1 and 1b-1.
  • z1 and x1 are the number of repeating units
  • z1 is an integer of 1 to 10
  • x1 is an integer of any one of 1 to 15;
  • z2 and x2 are the number of repeating units
  • z2 is an integer of 1 to 10
  • x2 is an integer of any one of 1 to 15.
  • the weight average molecular weight (Mw) of the oligomer represented by the formula (1) can be controlled by the number of repeating units, and is about 1,000 g / mol to 100,000 g / mol, specifically 1,000 g / mol to 50,000 g / Specifically from 1,000 g / mol to 10,000 g / mol.
  • Mw weight average molecular weight
  • the weight average molecular weight of the oligomer is less than 1,000 g / mol, the electrochemical stability and the role of the surfactant can not be expected, and since the functional group content is low, the effect of suppressing the side reaction of the electrode surface may be insignificant. / mol, the solubility in an organic solvent may be lowered.
  • the weight average molecular weight may mean a value converted to standard polystyrene measured by Gel Permeation Chromatography (GPC), and unless otherwise specified, the molecular weight may mean a weight average molecular weight.
  • GPC Gel Permeation Chromatography
  • the GPC conditions are measured using an Agilent 1200 series.
  • the column used herein may be a PL mixed B column of Agilent, and THF may be used as a solvent.
  • the oligomer represented by Formula 1 is used in an amount of 0.5 to 30% by weight, specifically 0.5 to 25% by weight, more specifically 0.5 to 10% by weight, based on the total weight of the electrolyte for a lithium secondary battery, By weight to 0.5% by weight to 5% by weight.
  • the content of the oligomer represented by the general formula (1) is 0.5% by weight or more, the control of reactivity with lithium metal and the electrochemical stability effect can be expected. When the content is less than 30% by weight, And at the same time, it is possible to prevent the disadvantages such as deterioration of the ion conductivity by improving the movement restriction of the lithium ion. If the content of the oligomer represented by the above formula (1) is more than 30% by weight, the solubility of the oligomer in the electrolyte decreases and the viscosity of the electrolyte increases, thereby decreasing the ionic conductivity of the electrolyte. As a result, the voltage drop of the battery may be caused due to an increase in the interface resistance of the electrode.
  • the electrolyte for a lithium secondary battery of the present invention can prevent degradation of the non-aqueous electrolyte due to decomposition of the non-aqueous electrolyte in an environment of high output, further improve low temperature high rate discharge characteristics, high temperature stability, overcharge prevention,
  • the composition may further include additional additives capable of forming a more stable ion conductive film on the surface of the electrode.
  • Such additional additives may include at least one selected from the group consisting of a sulfonate compound, a halogen-substituted carbonate compound, a nitrile compound, a cyclic sulfite compound, and a cyclic carbonate compound.
  • the sul- tonic compound may be selected from the group consisting of 1,3-propane sultone (PS), 1,4-butane sul- thone, ethene sul- thone, 1,3-propene sul- thone (PRS), 1,4- 3-propenesultone, and the like.
  • the sulfone compound may be contained in an amount of 5% by weight or less based on the total weight of the nonaqueous electrolyte solution. If the content of the sulfonate compound in the nonaqueous electrolyte exceeds 5 wt%, a thick film of excess additive may be formed, resulting in increased resistance and deterioration of output.
  • the halogen-substituted carbonate compound is fluoroethylene carbonate (FEC), and may be contained in an amount of 5 wt% or less based on the total weight of the non-aqueous electrolyte. If the content of the halogen-substituted carbonate compound exceeds 5% by weight, the cell swelling performance may deteriorate.
  • FEC fluoroethylene carbonate
  • the nitrile compound may be at least one selected from the group consisting of succinonitrile, adiponitrile (Adn), acetonitrile, propionitrile, butyronitrile, valeronitrile, caprylonitrile, heptanenitrile, cyclopentanecarbonitrile, cyclohexanecarbonitrile, In the group consisting of 2-fluorobenzonitrile, 4-fluorobenzonitrile, difluorobenzonitrile, trifluorobenzonitrile, phenylacetonitrile, 2-fluorophenylacetonitrile, and 4-fluorophenylacetonitrile At least one compound selected.
  • the nitrile compound may be contained in an amount of 8% by weight or less based on the total weight of the nonaqueous electrolyte solution. If the total content of the nitrile compound in the nonaqueous electrolyte exceeds 8 wt%, resistance increases due to an increase in the film formed on the surface of the electrode, and battery performance may be deteriorated.
  • cyclic sulfite-based compound examples include ethylene sulfite, methyl ethylene sulfite, ethyl ethylene sulfite, 4,5-dimethylethylene sulfite, 4,5-diethyl ethylene sulfite, - dimethylpropylene sulfite, 4,5-diethylpropylene sulfite, 4,6-dimethylpropylene sulfite, 4,6-diethylpropylene sulfite and 1,3-butylene glycol sulfite. Based on the total weight of the nonaqueous electrolyte solution. If the content of the cyclic sulfite-based compound exceeds 5% by weight, a thick film of excess additive may be formed, resulting in increased resistance and deterioration of output.
  • the cyclic carbonate compound may be vinylene carbonate (VC) or vinylethylene carbonate.
  • the cyclic carbonate compound may include up to 3% by weight based on the total weight of the non-aqueous electrolyte. If the content of the cyclic carbonate compound in the non-aqueous electrolyte exceeds 3% by weight, the cell swelling inhibition performance may deteriorate.
  • the additional additive may be a cyclic carbonate-based compound.
  • additional additives may be used in admixture of two or more, and may be contained in an amount of 20 wt% or less, specifically 0.01 wt% to 20 wt%, preferably 0.1 wt% to 10 wt%, based on the total amount of the electrolytic solution. If the content of the additive additive is less than 0.01% by weight, the effect of improving the low temperature power of the battery and improving the high-temperature storage characteristics and high-temperature lifetime characteristics are insignificant. If the content of the additive additive exceeds 20% by weight, There is a possibility that a side reaction in the electrolytic solution is excessive.
  • the additive for forming the SEI film when excessively added, it can not be sufficiently decomposed at a high temperature, and may be present in the electrolyte solution at room temperature without being reacted or precipitated. As a result, a side reaction in which the lifetime or the resistance characteristic of the secondary battery is lowered may occur.
  • a lithium salt, an organic solvent, and an oligomer-derived polymer represented by the above formula (1) A lithium salt, an organic solvent, and an oligomer-derived polymer represented by the above formula (1).
  • the electrolyte for a lithium secondary battery can be formed by thermally polymerizing a composition for a gel polymer electrolyte comprising the lithium salt, the organic solvent, the oligomer represented by the Formula 1, and a polymerization initiator.
  • the oligomer-derived polymer represented by Formula 1 may include a matrix polymer formed by crosslinking the oligomer represented by Formula 1 in a three-dimensional structure in the presence of a polymerization initiator.
  • the electrolyte for a lithium secondary battery of the present invention may be a gel electrolyte in which a non-aqueous electrolyte in which the lithium salt is dissolved is contained in a matrix polymer formed by crosslinking the oligomer represented by Formula 1 in a three-dimensional structure.
  • the description of the lithium salt and the organic solvent, and the type and concentration of the oligomer contained in the gel polymer electrolyte composition for preparing the electrolyte for a lithium secondary battery according to the present invention is the same as that described above, It is omitted.
  • the oligomer represented by Formula 1 may be used in an amount of 0.5 to 30% by weight, specifically 0.5 to 25% by weight, more preferably 0.5 to 10% by weight, based on the total weight of the gel polymer electrolyte composition, Specifically 0.5% to 5% by weight.
  • the content of the oligomer represented by Formula 1 is within the above range, that is, in the range of 0.5 wt% to 30 wt%, a polymer network having excellent mechanical strength can be formed, and thus a secondary battery having improved performance can be manufactured.
  • the content of the oligomer represented by the general formula (1) is 0.5% by weight or more based on the total weight of the composition for a gel polymer electrolyte, the polymer matrix by oligomer can be easily formed and the mechanical strength of the gel polymer electrolyte can be secured have.
  • the content of the oligomer represented by the general formula (1) is 30% by weight or less based on the total weight of the composition for a gel polymer electrolyte, an increase in resistance due to the addition of an excessive amount of oligomer is prevented, The wettability can be improved and the pre-gel reaction can be prevented. Furthermore, the ion conductivity can be secured by improving the movement limitation of lithium ions, and the cycle life characteristics can be improved.
  • the amount of the oligomer represented by Formula 1 is more than 30% by weight, the solubility of the oligomer in the composition for a gel polymer electrolyte is lowered, and the viscosity of the composition is increased to deteriorate the wettability, A voltage drop of < / RTI >
  • the oligomer-derived polymer represented by Formula 1 is used in an amount of 0.5 to 30 wt%, specifically 0.5 to 25 wt%, more specifically 0.5 to 10 wt%, based on the total weight of the electrolyte for a lithium secondary battery, More specifically from 0.5% to 5% by weight.
  • the oligomer-derived polymer represented by Formula 1 is a matrix polymer in which the oligomer represented by Formula 1 is formed into a three-dimensional structure by thermal polymerization reaction, and its content is the oligomer represented by Formula 1 contained in the composition for a gel polymer electrolyte Is preferably the same as the content of .
  • the content of the oligomer-derived polymer represented by the above-mentioned formula (1) is 0.5 weight% or more, the same physical properties as the mechanical strength of the gel polymer electrolyte can be secured. If it is 30% by weight or less, the increase in resistance due to the addition of an excessive amount of oligomer can be prevented, and the ionic conductivity can be ensured by restricting the movement restriction of lithium ions. If the content of the oligomer-derived polymer represented by the above formula (1) is more than 30% by weight, the ion conductivity of the electrolyte is lowered, and the voltage drop of the battery may be caused due to an increase in the interface resistance with the electrode.
  • the oligomer-based polymer represented by the above formula (1) forms a stable ion conductive film on the electrode surface at the time of initial charging, suppresses side reactions between Li metal deposited on the surface of the cathode upon overcharging and the electrolyte, It is possible to suppress an increase in the interfacial resistance of the electrode and an average voltage change during charging and discharging resulting from the increase in the resistance of the electrode relative to the electrolyte for the conventional lithium secondary battery.
  • the oligomer-derived polymer represented by the above formula (1) has the ability to dissociate the lithium salt to improve the lithium ion mobility.
  • it is a stable repeating unit of the main chain and is extremely stable electrochemically. (-Si-O-) and the like, it is possible to control the side reaction of the lithium ion (Li + ) and the decomposition reaction of the lithium salt, 2 can be reduced. Therefore, ignition or the like can be suppressed at the time of overcharging, and the stability of the secondary battery can be further improved.
  • the oligomer-derived polymer represented by Formula 1 of the present invention contains a siloxane group (- [Si-O] -) and a urethane group as repeating units of the main chain, It is preferable not to include it. That is, since the oligomer structure does not contain additional -Si- group as a repeating unit, the ratio of the functional groups at both terminals can be increased and the molecular weight of the entire polymer can be lowered. Therefore, Can further increase the content of the entire oligomer relative to an oligomer further including a -Si- group (e.g., [Si-O] -Si- structure in the main chain repeat unit). Therefore, the reaction rate of the gel polymer can be advantageously taken, and the hardness of the gel polymer can be increased to enhance the hardness of the whole cell, so that it can be more advantageously used for safety evaluation such as impact evaluation which gives physical impact.
  • a siloxane group - [Si-O] -
  • the polymerization initiator used for preparing the gel polymer electrolyte may be a conventional polymerization initiator known in the art.
  • the polymerization initiator may be decomposed by heat to form a radical, and react with an oligomer represented by the general formula (1) by free radical polymerization to form a gel polymer electrolyte.
  • the polymerization initiator may be an azo-based polymerization initiator or a peroxide-based polymerization initiator.
  • Typical examples thereof include benzoyl peroxide, acetyl peroxide, dilauryl peroxide, Di-tert-butyl peroxide, t-butyl peroxy-2-ethyl-hexanoate, cumyl hydroperoxide, And at least one peroxide compound selected from the group consisting of hydrogen peroxide and at least one peroxide compound selected from the group consisting of 2,2'-azobis (2-cyanobutane), dimethyl 2,2'-azobis Azobis (iso-butyronitrile)) and 2,2'-azobis (isobutyronitrile) (2,2'-azobis (isobutyronitrile)
  • a group consisting of 2'-azobisdimethyl-valeronitrile (AMVN) Emitter may include at least one azo compound selected.
  • the polymerization initiator may be decomposed by heat in a secondary battery at 30 ° C to 100 ° C, specifically 60 ° C to 80 ° C, or decomposed at room temperature (5 ° C to 30 ° C) to form radicals, and free radicals
  • the polymerizable oligomer reacts with the acrylate-based compound by polymerization to form a gel polymer electrolyte.
  • the polymerization initiator may be included in an amount of about 0.01 part by weight to about 20 parts by weight, specifically about 5 parts by weight, based on 100 parts by weight of the entire oligomer.
  • the gelation reaction is easily performed to increase the gel polymer conversion
  • Gel polymer electrolyte properties can be ensured, the unreacted polymerization initiator after the polymerization reaction can be prevented from causing side reactions, and the wettability of the electrolyte solution to the electrode can be improved.
  • nitrogen or oxygen gas is generated in the process of generating radicals by heat or the like.
  • This gas generation is most likely to lead to a gas trap or a gas bubbling phenomenon in the process of forming a gel polymer electrolyte.
  • Such gas generation causes defects in the gel polyelectrolyte, resulting in deterioration of electrolyte quality. Therefore, when the polymerization initiator is included in the above range, it is possible to more effectively prevent the disadvantage that a large amount of gas is generated.
  • the electrolyte for the lithium secondary battery may be a liquid electrolyte or a gel polymer electrolyte.
  • the lithium secondary battery of the present invention When the electrolyte for a lithium secondary battery is a liquid electrolyte, the lithium secondary battery of the present invention includes an anode assembly, a cathode assembly, and a separator layer selectively interposed between the anode assembly and the cathode assembly, , And injecting an electrolyte for a lithium secondary battery of the present invention.
  • the electrolyte for a lithium secondary battery is a gel polymer electrolyte comprising a polymer matrix formed by polymerization between oligomers represented by Formula 1
  • the lithium secondary battery of the present invention may include a positive electrode, a negative electrode, And then the electrolyte assembly for a lithium secondary battery is injected and cured to form an electrode assembly.
  • the in-situ polymerization may be performed by E-BEAM, gamma ray, room temperature or high temperature aging process, and thermal polymerization may be performed according to one embodiment of the present invention.
  • the polymerization time is about 2 minutes to 48 hours
  • the thermal polymerization temperature may be 60 to 100 ⁇ ⁇ , specifically 60 to 80 ⁇ ⁇ .
  • the positive electrode, the negative electrode, and the separator may be any of those conventionally manufactured and used in the production of a lithium secondary battery.
  • the positive electrode may be manufactured by forming a positive electrode mixture layer on the positive electrode current collector.
  • the positive electrode mixture layer may be formed by coating a positive electrode slurry containing a positive electrode active material, a binder, a conductive material and a solvent on a positive electrode collector, followed by drying and rolling.
  • 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-Y Mn Y O 2 (where, 0 ⁇ Y ⁇ 1), LiMn 2-z Ni z O 4 ( here, 0 ⁇ Z ⁇ 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., (in which LiCo 1-Y2 Mn Y2 O 2 , 0 ⁇ Y2 ⁇ 1), LiMn 2-z1 Co z1 O 4 ( here, 0 ⁇ z1 ⁇ 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 1/3 Mn 1/3 Co 1 / 3 ) O 2 , 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 and Li (Ni 0.8 Mn 0.1 Co 0.1 ) O 2 ), or lithium nickel cobalt aluminum oxide (e.g., Li (Ni 0.8 Co 0.15 Al 0.05 ) O 2, etc.) and the like.
  • lithium nickel cobalt aluminum oxide e.g., Li (Ni 0.8 Co 0.15 Al 0.05 ) O 2, etc.
  • the cathode active material may be contained in an amount of 40% by weight to 90% by weight, specifically 40% by weight to 75% by weight, based on the total weight of the solid content in the cathode slurry.
  • the binder is a component that assists in bonding of the active material to the conductive material and bonding to the current collector, and is usually added in an amount of 1 to 30 wt% based on the total weight of the solid content in the positive electrode slurry.
  • binders include polyvinylidene fluoride (PVDF), polyvinyl alcohol, carboxymethylcellulose (CMC), starch, hydroxypropylcellulose, regenerated cellulose, polyvinylpyrrolidone, tetrafluoroethylene (Ethylene-propylene-diene terpolymer (EPDM), sulfonated EPDM, styrene-butadiene rubber, fluorine rubber, various copolymers and the like.
  • PVDF polyvinylidene fluoride
  • CMC carboxymethylcellulose
  • EPDM tetrafluoroethylene
  • EPDM tetrafluoroethylene
  • EPDM sulfonated EPDM
  • Such a conductive material is not particularly limited as long as it has electrical conductivity without causing chemical changes in the battery.
  • 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 is usually added in an amount of 1 to 30% by weight based on the total weight of the solid content in the positive electrode slurry.
  • the conductive material may be selected from the group consisting of acetylene black series such as Chevron Chemical Company, Denka Singapore Private Limited, Gulf Oil Company products, Ketjenblack, EC series Armak Company), Vulcan XC-72 (Cabot Company) and Super P (Timcal Co.), and the like.
  • acetylene black series such as Chevron Chemical Company, Denka Singapore Private Limited, Gulf Oil Company products, Ketjenblack, EC series Armak Company), Vulcan XC-72 (Cabot Company) and Super P (Timcal Co.), and the like.
  • the solvent may include an organic solvent such as N-methyl-2-pyrrolidone (NMP), and may be used in an amount that provides a preferable viscosity when the positive electrode active material and optionally a binder and a conductive material are included.
  • NMP N-methyl-2-pyrrolidone
  • the solid content in the slurry containing the cathode active material, and optionally the binder and the conductive material may be 10 wt% to 70 wt%, preferably 20 wt% to 60 wt%.
  • the cathode may be a metal electrode using a metal or a quasi-metal thin film alone, or a structure in which the metal or a quasi metal thin film is stacked on an anode current collector.
  • the metal or metalloid may be selected from the group consisting of Li, Cu, Ni, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Si, Sb, Pb, In, Zn, Ba, Sn, Ag, Pt, and Au.
  • the cathode may be a Li metal electrode.
  • the negative electrode may be formed by using a metal electrode alone or by stacking a metal or metalloid thin film on the negative electrode current collector, or by forming a negative electrode mixture layer on the negative electrode current collector.
  • the negative electrode mixture layer may be formed by coating a negative electrode current collector with a slurry containing a negative electrode active material, a binder, a conductive material, a solvent, and the like, followed by drying and rolling.
  • the anode current collector generally has a thickness of 3 to 500 mu m.
  • 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.
  • 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.
  • the negative electrode active material may be at least one selected from the group consisting of a carbon material capable of reversibly intercalating / deintercalating lithium ions, a metal composite oxide, a material capable of doping and dedoping lithium, and a transition metal oxide And may further include one or more.
  • the carbonaceous material capable of reversibly intercalating / deintercalating lithium ions is not particularly limited as long as it is a carbonaceous anode active material generally used in a lithium ion secondary battery.
  • the carbonaceous material include crystalline carbon, Amorphous carbon or any combination thereof.
  • the crystalline carbon include graphite such as natural graphite or artificial graphite in the form of amorphous, plate-like, flake, spherical or fiber, and examples of the amorphous carbon include soft carbon (soft carbon) Or hard carbon, mesophase pitch carbide, fired coke, and the like.
  • Si As the material capable of doping and dedoping lithium, Si, SiO x (0 ⁇ x? 2), Si-Y alloy (Y is an alkali metal, an alkaline earth metal, a Group 13 element, a Group 14 element, Rare earth elements and combinations thereof, but not Si), Sn, SnO 2 , Sn-Y (wherein Y is at least one element selected from the group consisting of alkali metals, alkaline earth metals, Group 13 elements, Group 14 elements, Element and an element selected from the group consisting of combinations thereof, and not Sn), and at least one of them may be mixed with SiO 2 .
  • Si-Y alloy Y is an alkali metal, an alkaline earth metal, a Group 13 element, a Group 14 element, Rare earth elements and combinations thereof, but not Si
  • Sn, SnO 2 Sn-Y (wherein Y is at least one element selected from the group consisting of alkali metals, alkaline earth metals, Group 13 elements, Group 14 elements, Element
  • the element Y may be at least one element selected from the group consisting of Mg, Ca, Sr, Ba, Ra, Sc, Y, Ti, Zr, Hf, Rf, V, Nb, Ta, Db, Cr, Mo, W, Sg, Pb, Ru, Os, Hs, Rh, Ir, Pd, Pt, Cu, Ag, Au, Zn, Cd, B, Al, Ga, Sn, In, Ge, P, As, Sb, Bi, Te, Po, and combinations thereof.
  • transition metal oxide examples include lithium-containing titanium composite oxide (LTO), vanadium oxide, lithium vanadium oxide, and the like.
  • the negative active material may be contained in an amount of 80% by weight to 99% by weight based on the total weight of the solid content in the negative electrode slurry.
  • the binder is a component that assists in bonding between the conductive material, the active material and the current collector, and is usually added in an amount of 1 to 30% by weight based on the total weight of the solid content in the negative electrode slurry.
  • 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 conductive material is a component for further improving the conductivity of the negative electrode active material and may be added in an amount of 1 to 20 wt% based on the total weight of the solid content in the negative electrode slurry.
  • Such a conductive material is not particularly limited as long as it has electrical conductivity without causing chemical changes in the battery.
  • the solvent may include water or an organic solvent such as NMP, alcohol, etc., and may be used in an amount in which the negative electrode active material and, optionally, a binder, a conductive material, and the like are contained in a desired viscosity.
  • the slurry containing the negative electrode active material and, optionally, the binder and the conductive material may be contained in such a manner that the solid concentration of the slurry is 50% by weight to 75% by weight, preferably 50% by weight to 65% by weight.
  • the separation membrane blocks the internal short circuit of both electrodes and impregnates the electrolyte.
  • the separation membrane composition is prepared by mixing a polymer resin, a filler and a solvent, and then the separation membrane composition is directly coated on the electrode and dried Or may be formed by casting and drying the separation membrane composition on a support, and then laminating the separation membrane film peeled off from the support on the electrode.
  • the separator may be a porous polymer film commonly used, such as a porous polymer film made of a polyolefin-based polymer such as an ethylene homopolymer, a propylene homopolymer, an ethylene / butene copolymer, an ethylene / hexene copolymer, and an ethylene / methacrylate copolymer
  • the polymer film may be used alone or as a laminate thereof, or may be a nonwoven fabric made of a conventional porous nonwoven fabric, for example, glass fiber of high melting point, polyethylene terephthalate fiber or the like, but is not limited thereto.
  • the pore diameter of the porous separation membrane is generally 0.01 to 50 ⁇ m, and the porosity may be 5 to 95%.
  • the thickness of the porous separator may be generally in the range of 5 to 300 mu m.
  • 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.
  • NCM LiNi 3/5 Co 1/5 Mn 1/5 O 2 ; NCM
  • carbon black as a conductive material
  • PVDF polyvinylidene fluoride
  • NMP N-methyl-2-pyrrolidone
  • the positive electrode mixture slurry was applied to an aluminum (Al) thin film having a thickness of about 20 ⁇ and dried to produce a positive electrode, followed by a roll press to prepare a positive electrode.
  • a lithium metal electrode was used as a cathode.
  • the positive electrode, the negative electrode and a separator composed of three layers of polypropylene / polyethylene / polypropylene (PP / PE / PP) were sequentially laminated to produce an electrode assembly.
  • the assembled electrode assembly was housed in the battery case, and the electrolyte for the lithium secondary battery was injected and stored at room temperature for 2 days to prepare a coin cell type lithium secondary battery including a liquid electrolyte for a lithium secondary battery.
  • a liquid electrolyte for a lithium secondary battery and a coin cell type lithium secondary battery comprising the same were prepared in the same manner as in Example 1, except that 20 g of the oligomer represented by the formula (1a-1) was contained in 80 g of the organic solvent at the time of preparing the liquid electrolyte. (See Table 1 below).
  • a liquid electrolyte for a lithium secondary battery and a coin cell type lithium secondary battery comprising the same were prepared in the same manner as in Example 1 except that 10 g of the oligomer represented by the general formula (1a-1) was contained in 90 g of the organic solvent in the production of the liquid electrolyte. (See Table 1 below).
  • a liquid electrolyte for a lithium secondary battery and a coin cell type lithium secondary battery comprising the same were prepared in the same manner as in Example 1 except that 25 g of the oligomer represented by the formula (1a-1) was added to 75 g of the organic solvent at the time of preparing the liquid electrolyte. (See Table 1 below).
  • a liquid electrolyte for a lithium secondary battery and a coin cell type lithium secondary battery comprising the same were prepared in the same manner as in Example 1 except that 30 g of the oligomer represented by the formula (1a-1) was contained in 70 g of the organic solvent in the production of the liquid electrolyte. (See Table 1 below).
  • a liquid electrolyte for a lithium secondary battery and a coin cell type lithium secondary battery comprising the same were prepared in the same manner as in Example 1, except that 33 g of the oligomer represented by the formula (1a-1) was contained in 67 g of the organic solvent in the production of the liquid electrolyte. (See Table 1 below).
  • a liquid electrolyte for a lithium secondary battery and a coin cell type lithium secondary battery comprising the same were prepared in the same manner as in Example 1 except that the oligomer represented by the general formula (1a-1) was not included in the preparation of the liquid electrolyte See Table 1).
  • Example 1 Liquid electrolyte for lithium secondary battery Lithium salt Amount of organic solvent added (g) Oligomer The Addition amount (g) Example 1 1M LiPF 6 99.5 1a-1 0.5 Example 2 1M LiPF 6 80 1a-1 20 Example 3 1M LiPF 6 90 1a-1 10 Example 4 1M LiPF 6 90 1b-1 10 Example 5 1M LiPF 6 75 1a-1 25 Example 6 1M LiPF 6 70 1a-1 30 Example 7 1M LiPF 6 67 1a-1 33 Comparative Example 1 1M LiPF 6 100 - - Comparative Example 2 1M LiPF 6 99.5 2 0.5
  • a lithium secondary battery comprising a gel polymer electrolyte
  • LiNi 3/5 Co 1/5 Mn 1/5 O 2 as a positive electrode active material
  • carbon black as a conductive material
  • PVDF polyvinylidene fluoride
  • NMP solvent N-methyl-2-pyrrolidone
  • the positive electrode mixture slurry was applied to an aluminum (Al) thin film having a thickness of about 20 ⁇ and dried to produce a positive electrode, followed by a roll press to prepare a positive electrode.
  • a lithium metal electrode was used as a cathode.
  • the positive electrode, the negative electrode and a separator composed of three layers of polypropylene / polyethylene / polypropylene (PP / PE / PP) were sequentially laminated to produce an electrode assembly.
  • the assembled electrode assembly was housed in the battery case, and the composition for a gel polymer electrolyte for a lithium secondary battery was injected thereinto, heated at 60 ° C. for 24 hours and stored at room temperature for 2 days to contain a gel polymer electrolyte for a lithium secondary battery Coin cell type lithium secondary battery.
  • a coin cell type lithium secondary battery comprising a composition for a gel polymer electrolyte for a lithium secondary battery and a gel polymer electrolyte for a lithium secondary battery produced from the composition was prepared (see Table 2 below).
  • Example 8 A coin cell type lithium secondary battery comprising a composition for a gel polymer electrolyte for a lithium secondary battery and a gel polymer electrolyte for a lithium secondary battery produced from the composition was prepared (see Table 2 below).
  • a coin cell type lithium secondary battery comprising a composition for a gel polymer electrolyte for a lithium secondary battery and a gel polymer electrolyte for a lithium secondary battery produced therefrom was prepared in the same manner as in Example 10 (see Table 2 below).
  • composition for a gel polymer electrolyte 25 g of the oligomer represented by the formula 1a-1, 74 g of the organic solvent, 25 g of dimethyl 2,2'-azobis (2-methylpropionate) (CAS No. 2589-57 -3) was added to prepare a gel polymer electrolyte composition for a lithium secondary battery, a composition for a gel polymer electrolyte for a lithium secondary battery and a gel polymer for a lithium secondary battery produced therefrom were prepared in the same manner as in Example 8 A coin cell type lithium secondary battery containing an electrolyte was prepared (see Table 2 below).
  • the gel polymer electrolyte composition In the preparation of the gel polymer electrolyte composition, 30 g of the oligomer represented by the general formula (1a-1), dimethyl 2,2'-azobis (2-methylpropionate) (CAS No. 2589-57 -3) was added to prepare a gel polymer electrolyte composition for a lithium secondary battery, a composition for a gel polymer electrolyte for a lithium secondary battery and a gel polymer for a lithium secondary battery produced therefrom were prepared in the same manner as in Example 8 A coin cell type lithium secondary battery containing an electrolyte was prepared (see Table 2 below).
  • a composition for a gel polymer electrolyte and a composition for a gel polymer electrolyte were prepared in the same manner as in Example 9, except that the oligomer represented by Formula 2 was used instead of the oligomer represented by Formula 1a-1 in the preparation of the gel polymer electrolyte composition (See Table 2 below). ≪ tb > < TABLE >
  • Example 8 1M LiPF 6 99.49 1a-1 0.5 0.01
  • Example 9 1M LiPF 6 79.9 1a-1 20 0.1
  • Example 10 1M LiPF 6 89.9 1a-1 10 0.1
  • Example 11 1M LiPF 6 89.9 1b-1 10 0.1
  • Example 12 1M LiPF 6 74.9 1a-1 25 0.1
  • Example 13 1M LiPF 6 69.85 1a-1 30 0.15
  • Li / Li (150 ⁇ ) symmetry beaker cell) system manufactured by using Li foil was prepared, and then the liquid electrolyte for secondary battery prepared in Examples 1 to 7 and the secondary battery prepared in Comparative Examples 1 and 2 And a liquid electrolyte for a battery were respectively injected.
  • the charge transfer resistance (Rct) measured after 2 hours while flowing 10 mV alternating current using Electrochemical Impedance Spectroscopy (EIS) is shown in Table 3 below.
  • the initial charge transfer resistance value in Table 3 indicates the charge transfer resistance value after injecting the Li / Li electrode into the electrolyte.
  • Example 2 82 Example 3 97
  • Example 4 105 Example 5 75
  • Example 6 52 Example 7 50 Comparative Example 1 7,510 Comparative Example 2 330
  • the secondary of Example 3 which contains an oligomer represented by the general formula (1a-1) in which the content ratio of the siloxane group (-Si-O-) having a low number of acrylate groups at the end and a low reactivity with Li ions is relatively high,
  • the effect of suppressing the chemical reaction between the Li metal and the electrolyte is superior to that of the liquid electrolyte for a lithium secondary battery of Example 4 including the oligomer represented by the formula 1b-1 in the same amount, Low.
  • the wettability of the electrolyte becomes lower and the relative Li metal /
  • the chemical reaction between the Li metal and the electrolyte occurs under an environmental condition in which Li precipitation is induced such as overcharging and the like and the by-products produced by the decomposition of the electrolyte solution are laminated on the Li metal surface. Therefore, the charge transfer resistance value is about 330 ohms As compared with the electrolyte for lithium secondary batteries of Examples 1 to 7.
  • the gel of Example 10 which contains an oligomer represented by the general formula (1a-1) in which the content ratio of the siloxane group (-Si-O-) having a low number of acrylate groups at the end and a low reactivity with Li ion is relatively high
  • the polymer electrolyte composition since the chemical reactivity between the Li metal and the electrolyte is reduced and the surface diffusion reaction is suppressed as compared with the gel polymer electrolyte composition of Example 11 containing the same amount of the oligomer represented by the general formula (1b-1) The resistance increase rate is relatively low.
  • the lithium secondary batteries having the liquid electrolyte for lithium secondary batteries prepared in Examples 1 to 7 and the lithium secondary batteries having the liquid electrolyte for lithium secondary batteries prepared in Comparative Examples 1 and 2 were respectively charged at room temperature (25 ° C) / 4.2 V Constant current - The battery was fully charged at a constant voltage, and discharged at SOC 50% to 2.5 C for 10 seconds to perform initial charging and discharging.
  • Comparative Example 2 in which the lithium secondary battery of Comparative Example 1 having a liquid electrolyte having a liquid electrolyte for a lithium secondary battery not containing an oligomer and the liquid electrolyte for a lithium secondary battery comprising an oligomer represented by Formula 2
  • the initial resistance values are respectively 135 mohm and 93 mohm, which is higher than those of the lithium secondary batteries of Examples 1 to 6.
  • the voltage drop of the lithium secondary battery having the gel polymer electrolyte prepared in Examples 8 to 13 and the lithium polymer secondary cell having the gel polymer electrolyte prepared in Comparative Example 3 was measured in the same manner as in Experimental Example 3, The initial resistance of each cell was measured through the obtained voltage drop, and it is shown in Table 6 below.
  • Example 9 59
  • Example 10 69
  • Example 11 62
  • Example 12 55
  • Example 13 75 Comparative Example 3 100
  • the generation of by-products can be suppressed due to the decrease in reactivity between the Li metal and the electrolyte, 76 mohm or less.
  • the initial resistance value is 100 mohm, which is higher than that of the lithium secondary batteries of Examples 8 to 13.
  • the lithium secondary batteries having the liquid electrolyte for lithium secondary batteries manufactured in Examples 1 to 6 and the lithium secondary batteries having the liquid electrolyte for lithium secondary batteries prepared in Comparative Examples 1 and 2 were subjected to voltage driving ranges of 3.0 V to 4.2 V Under a constant current of 0.33 C / 4.2 V at a constant current of -25 V and a discharge of SOC 50% to 2.5 C for 10 seconds. Subsequently, the charge and discharge process was repeated three times at 25 ° C and 0.33C / 0.33C under a voltage driving range of 3.0 V to 4.2 V, and the discharge capacity after the last 3 cycles was measured with a PNE-0506 charge / discharge device (manufacturer: PNE solution, 5V, 6A). The results are shown in Table 7 below.
  • Example 1 63.2
  • Example 2 71.2
  • Example 3 69.2
  • Example 4 67.4
  • Example 5 73.5
  • Example 6 64.1 Comparative Example 1 59.7 Comparative Example 2 60.5
  • the discharge capacity of the lithium secondary battery having the liquid electrolyte for lithium secondary batteries manufactured in Examples 1 to 6 after 3 cycles is mostly 63.2 mAh or more.
  • a liquid electrolyte comprising an oligomer represented by the general formula (1a-1) in which the content ratio of a siloxane group (-Si-O-) having a low number of acrylate groups at a terminal and a low reactivity with Li ions is relatively high
  • the discharge capacity of the lithium secondary battery of Example 3 is further improved as compared with the lithium secondary battery of Example 4 having the liquid electrolyte containing the oligomer represented by Formula 1b-1.
  • the lithium secondary batteries having the gel polymer electrolyte prepared in Examples 8 to 13 and the gel polymer electrolyte prepared in Comparative Example 3 were prepared in the same manner as in Experimental Example 5, (capacity) were measured, and the results are shown in Table 8 below.
  • the discharge capacity was 52.4 mAh, which was higher than that of the lithium secondary batteries of Examples 8 to 13 .
  • the lithium secondary battery manufactured in Examples 1 to 14 and the lithium secondary batteries prepared in Comparative Examples 1 to 3 were subjected to SOC 100% using a PNE-0506 charge / discharge device (PNE solution, 5V, 6A, , And the temperature was measured at SOC 140% after overcharging under 1C, bakelite plate (insulation condition) and 8.3V (cutoff) condition.
  • Table 9 The results are shown in Table 9 below.
  • Example 1 Temperature at 140% SOC (° C) Liquid electrolyte Example 1 67
  • Example 2 56
  • Example 3 61
  • Example 4 62
  • Example 5 53
  • Example 6 58
  • Example 7 Comparative Example 1
  • Comparative Example 2 75
  • Example 8 62
  • Example 9 48
  • Example 10 52
  • Example 11 53
  • Example 12 42
  • Example 13 48
  • Example 14 59 Comparative Example 3 69
  • the lithium secondary battery having a liquid electrolyte for a lithium secondary battery manufactured in Examples 1 to 6 exhibits a temperature of less than 67 ° C at an SOC of 140%.
  • the lithium secondary battery having the gel polymer electrolyte prepared in Examples 8 to 14 exhibits a SOC of 140% to 62 ° C or less.
  • the lithium secondary batteries prepared in Examples 1 to 14 and the lithium secondary batteries prepared in Comparative Examples 1 to 3 were charged to 4.25 V at 1 C / 1 C at 45 ⁇ , left to stand for 10 minutes, And discharged until 3.0 V was reached. The charge and discharge were performed as one cycle, and 500 cycles of charge and discharge were performed.
  • Capacity retention ratio (%) (capacity after 500 cycles / capacity after one cycle) x 100
  • Example 1 Liquid electrolyte
  • Example 2 94.2
  • Example 3 93.5
  • Example 4 93.1
  • Example 5 95.5
  • Example 6 91.1
  • Example 7 87.2 Comparative
  • Example 2 72
  • Example 8 89.2
  • Example 9 92.0
  • Example 10 91.5
  • Example 11 90.5
  • Example 12 92.9
  • Example 13 87.4
  • Example 14 82.5 Comparative Example 3 78.5
  • the lithium secondary battery having the liquid electrolyte for a lithium secondary battery manufactured in Examples 1 to 7 has a capacity retention rate of 87.2% or more even after 500 cycles.

Abstract

The present invention relates to an electrolyte for a lithium secondary battery and a lithium secondary battery comprising the same. Specifically, the present invention relates to an electrolyte for a lithium secondary battery comprising a lithium salt, an organic solvent, and an oligomer represented by formula 1 or an oligomer-derived polymer represented by formula 1 described in the present specification; and a lithium secondary battery which comprises the same, thereby inhibiting reactivity with a lithium metal to enhance the general performance thereof.

Description

리튬 이차전지용 전해질 및 이를 포함하는 리튬 이차전지Electrolyte for Lithium Secondary Battery and Lithium Secondary Battery Including the same
관련 출원(들)과의 상호 인용Cross-reference with related application (s)
본 출원은 2017년 11월 03일자 한국 특허 출원 제2017-0146223호 및 2018년 10월 31일자 한국 특허 출원 제2018-0132195호에 기초한 우선권의 이익을 주장하며, 해당 한국 특허 출원의 문헌에 개시된 모든 내용은 본 명세서의 일부로서 포함된다.This application claims the benefit of priority based on Korean Patent Application No. 2017-0146223, dated November 03, 2017, and Korean Patent Application No. 2018-0132195, dated October 31, 2018, all of which are incorporated herein by reference in their entirety The contents of which are incorporated herein by reference.
기술분야Technical field
본 발명은 리튬 이차전지용 전해질 및 이를 포함하는 리튬 이차전지에 관한 것이다.The present invention relates to an electrolyte for a lithium secondary battery and a lithium secondary battery comprising the same.
최근 에너지 저장 기술에 대한 관심이 갈수록 높아지고 있다. 특히, 휴대폰, 캠코더 및 노트북 PC, 나아가서는 전기자동차에까지 그 적용분야가 확대되면서, 에너지 저장 기술을 개발하기 위한 연구와 노력이 점점 구체화되고 있다.Recently, interest in energy storage technology is increasing. Especially, as the application fields of cell phones, camcorders, notebook PCs and even electric vehicles are expanding, research and efforts for developing energy storage technologies are becoming more and more specified.
전기화학소자는 이러한 에너지 저장 기술 분야 중에서 가장 주목받고 있는 분야이며, 그 중에서도 충방전이 가능한 리튬 이차전지에 대한 관심이 대두되고 있다.BACKGROUND OF THE INVENTION [0002] Electrochemical devices are one of the most sought-after fields of energy storage technology. Among them, attention is focused on rechargeable lithium secondary batteries.
리튬 이차전지는 양극 활물질 및 음극 활물질을 적당한 두께로 집전체에 도포하거나, 또는 활물질 자체를 적당한 길이의 필름 형상으로 형성한 다음, 절연체인 세퍼레이터와 함께 감거나 적층하여 전극조립체를 제조하고, 캔 또는 이와 유사한 용기에 전극조립체를 넣은 후, 전해질을 주입하는 공정에 의해 제조된다.The lithium secondary battery can be produced by applying the positive electrode active material and the negative electrode active material to the current collector in an appropriate thickness or by forming the active material itself into a film having an appropriate length and winding or laminating the separator together with the separator as an insulator, The electrode assembly is placed in a similar container, and then an electrolyte is injected.
이때, 상기 전해질은 일반적으로 리튬염이 용해된 전해액 용매를 포함하는 액체 전해질 또는 매트릭스 폴리머를 더 포함하는 겔 폴리머 전해질을 사용할 수 있다.At this time, the electrolyte may be a gel polymer electrolyte further comprising a liquid electrolyte or a matrix polymer including an electrolyte solvent in which a lithium salt is dissolved.
상기 전해액 용매로는 에틸렌카보네이트, 프로필렌카보네이트, 디메톡시에탄, 감마부티로락톤, N,N-디메틸포름아미드, 테트라하이드로푸란 또는 아세트니트릴 등을 들 수 있다. Examples of the electrolyte solvent include ethylene carbonate, propylene carbonate, dimethoxyethane, gamma butyrolactone, N, N-dimethylformamide, tetrahydrofuran and acetonitrile.
한편, 상기 전해액 용매는 고전압 시 부반응을 야기하고, 고온에서 장시간 보관할 경우 산화반응이 야기될 뿐만 아니라, 음극에 형성된 덴드라이트(dendrite)형태의 Li 금속과 쉽게 반응해 발열반응을 일으킬 수 있다. 특히, 과충전이 일정 SOC 이상으로 진행되는 경우 전해질의 산화반응이 가속화되고 양극에서 음극으로의 과한 Li 이동으로 인해 형성되는 음극 표면의 Li 금속과 전해액 간의 발열반응이 심화되어 전지가 발화, 폭발될 수 있다.On the other hand, the electrolyte solvent causes a side reaction at high voltage, and when stored at a high temperature for a long time, not only an oxidation reaction occurs but also a dendrite-type Li metal formed on the anode can easily react to generate an exothermic reaction. In particular, when the overcharge progresses above a certain SOC, the oxidation reaction of the electrolyte accelerates and the exothermic reaction between the Li metal on the surface of the negative electrode and the electrolyte formed due to excessive Li migration from the positive electrode to the negative electrode is intensified, have.
이에, 리튬 이차전지의 안정성 향상과 고출력 특성 향상을 위하여, 전해질의 젖음(wetting) 특성을 높일 수 있을 뿐만 아니라, 리튬 금속과의 반응성이 억제된 리튬 이차전지용 전해질에 대한 개발이 필요한 실정이다.Accordingly, in order to improve the stability of the lithium secondary battery and to improve the high output characteristic, it is necessary to develop an electrolyte for a lithium secondary battery in which the wetting property of the electrolyte can be enhanced and reactivity with the lithium metal is suppressed.
선행기술문헌Prior art literature
대한민국 공개특허공보 제2014-0066163호Korean Patent Laid-Open Publication No. 2014-0066163
본 발명은 전극 표면과의 표면장력을 낮춰 젖음성이 향상된 리튬 이차전지용 전해질을 제공하고자 한다.The present invention provides an electrolyte for a lithium secondary battery having improved wettability by lowering surface tension with respect to an electrode surface.
또한, 본 발명은 상기 리튬 이차전지용 전해질을 포함하는 리튬 이차전지를 제공하고자 한다.The present invention also provides a lithium secondary battery including the electrolyte for the lithium secondary battery.
상기 과제를 해결하기 위하여, 본 발명의 일 실시예에서는In order to solve the above problems, in one embodiment of the present invention
리튬염, Lithium salt,
유기용매 및Organic solvents and
하기 화학식 1로 표시되는 올리고머 또는 화학식 1로 표시되는 올리고머 유래의 폴리머를 포함하는 리튬 이차전지용 전해질을 제공한다.There is provided an electrolyte for a lithium secondary battery comprising an oligomer represented by the following general formula (1) or a polymer derived from an oligomer represented by the general formula (1).
[화학식 1][Chemical Formula 1]
Figure PCTKR2018013181-appb-I000001
Figure PCTKR2018013181-appb-I000001
상기 화학식 1에서,In Formula 1,
R1 및 R2는 각각 독립적으로 치환 또는 비치환된 탄소수 1 내지 5의 알킬렌기이고,R 1 and R 2 are each independently a substituted or unsubstituted alkylene group having 1 to 5 carbon atoms,
R3 및 R4는 각각 독립적으로 수소 또는 치환 또는 비치환된 탄소수 1 내지 3의 알킬기이고,R 3 and R 4 are each independently hydrogen or a substituted or unsubstituted alkyl group having 1 to 3 carbon atoms,
R5는 수소 또는 치환 또는 비치환된 탄소수 1 내지 5의 알킬기이고,R 5 is hydrogen or a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms,
R'는 지방족 탄화수소기 또는 방향족 탄화수소기이고,R 'is an aliphatic hydrocarbon group or an aromatic hydrocarbon group,
z 및 x 는 반복단위 수이며,z and x are the number of repeating units,
z는 1 내지 10 중 어느 하나의 정수이고,z is an integer of 1 to 10,
x는 1 내지 15 중 어느 하나의 정수이며,x is an integer of 1 to 15,
n은 1 내지 3 중 어느 하나의 정수이다.and n is an integer of 1 to 3.
구체적으로, 상기 화학식 1에서, 상기 R'의 지방족 탄화수소기는 (a) 치환 또는 비치환된 탄소수 4 내지 20의 사이클로알킬렌기, 치환 또는 비치환된 탄소수 4 내지 20의 사이클로알케닐렌기 및 치환 또는 비치환된 탄소수 2 내지 20의 헤테로사이클로알킬렌기로 이루어진 군으로부터 선택된 적어도 하나의 지환족 탄화수소기 및 (b) 치환 또는 비치환된 탄소수 1 내지 20의 알킬렌기, 치환 또는 비치환된 탄소수 1 내지 20의 알콕실렌기, 치환 또는 비치환된 탄소수 2 내지 20의 알케닐렌기 및 치환 또는 비치환된 탄소수 2 내지 20의 알키닐렌기로 이루어진 군으로부터 선택된 적어도 하나의 선형 탄화수소기로 이루어진 군으로부터 선택된 적어도 하나의 지방족 탄화수소기로 이루어진 군으로부터 선택된 적어도 하나를 포함하고, Specifically, in the formula (1), the aliphatic hydrocarbon group of R 'is selected from the group consisting of (a) a substituted or unsubstituted cycloalkylene group having 4 to 20 carbon atoms, a substituted or unsubstituted cycloalkenylene group having 4 to 20 carbon atoms, (B) a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, a substituted or unsubstituted alicyclic hydrocarbon group having 1 to 20 carbon atoms, a substituted or unsubstituted alicyclic hydrocarbon group having 1 to 20 carbon atoms, At least one aliphatic hydrocarbon group selected from the group consisting of a substituted or unsubstituted arylene group, an alkoxylene group, a substituted or unsubstituted alkenylene group having 2 to 20 carbon atoms, and a substituted or unsubstituted alkynylene group having 2 to 20 carbon atoms, And at least one group selected from the group consisting of
상기 R'의 방향족 탄화수소기는 치환 또는 비치환된 탄소수 6 내지 20의 아릴렌기 및 치환 또는 비치환된 탄소수 2 내지 20의 헤테로아릴렌기로 이루어진 군으로부터 선택된 적어도 하나를 포함할 수 있다.The aromatic hydrocarbon group of R 'may include at least one selected from the group consisting of a substituted or unsubstituted arylene group having 6 to 20 carbon atoms and a substituted or unsubstituted heteroarylene group having 2 to 20 carbon atoms.
보다 구체적으로, 상기 화학식 1 에서, 상기 R'의 지방족 탄화수소기는 치환 또는 비치환된 탄소수 4 내지 20의 사이클로알킬렌기, 치환 또는 비치환된 탄소수 4 내지 20의 사이클로알케닐렌기 및 치환 또는 비치환된 탄소수 2 내지 20의 헤테로사이클로알킬렌기로 이루어진 군으로부터 선택된 적어도 하나의 지환족 탄화수소기를 포함할 수 있다.More specifically, in the above formula (1), the aliphatic hydrocarbon group of R 'is a substituted or unsubstituted cycloalkylene group having 4 to 20 carbon atoms, a substituted or unsubstituted cycloalkenylene group having 4 to 20 carbon atoms and a substituted or unsubstituted And at least one alicyclic hydrocarbon group selected from the group consisting of a heterocycloalkylene group having 2 to 20 carbon atoms.
한편, 상기 화학식 1로 표시되는 올리고머는 하기 화학식 1a 및 1b로 표시되는 올리고머들로 이루어진 군으로부터 선택된 적어도 어느 하나일 수 있다. The oligomer represented by the formula (1) may be at least one selected from oligomers represented by the following formulas (1a) and (1b).
[화학식 1a][Formula 1a]
Figure PCTKR2018013181-appb-I000002
Figure PCTKR2018013181-appb-I000002
상기 화학식 1a에서,In formula (1a)
R'는 지방족 탄화수소기 또는 방향족 탄화수소기이고,R 'is an aliphatic hydrocarbon group or an aromatic hydrocarbon group,
z1 및 x1는 반복단위 수이며,z1 and x1 are the number of repeating units,
z1는 1 내지 10 중 어느 하나의 정수이고,z1 is an integer of 1 to 10,
x1는 1 내지 15 중 어느 하나의 정수이다.x1 is an integer of any one of 1 to 15;
[화학식 1b][Chemical Formula 1b]
Figure PCTKR2018013181-appb-I000003
Figure PCTKR2018013181-appb-I000003
상기 화학식 1b에서,In the above formula (1b)
R'는 지방족 탄화수소기 또는 방향족 탄화수소기이고,R 'is an aliphatic hydrocarbon group or an aromatic hydrocarbon group,
z2 및 x2는 반복단위 수이며,z2 and x2 are the number of repeating units,
z2는 1 내지 10 중 어느 하나의 정수이고,z2 is an integer of 1 to 10,
x2는 1 내지 15 중 어느 하나의 정수이다.and x2 is an integer of any one of 1 to 15. [
보다 구체적으로, 상기 화학식 1로 표시되는 올리고머는 하기 화학식 1a-1 및 1b-1로 표시되는 올리고머들로 이루어진 군으로부터 선택된 적어도 어느 하나일 수 있다.More specifically, the oligomer represented by Formula 1 may be at least one selected from the group consisting of oligomers represented by the following Formulas 1a-1 and 1b-1.
[화학식 1a-1] [Formula 1a-1]
Figure PCTKR2018013181-appb-I000004
Figure PCTKR2018013181-appb-I000004
상기 화학식 1a-1에서,In the above formula (1a-1)
z1 및 x1는 반복단위 수이며,z1 and x1 are the number of repeating units,
z1는 1 내지 10 중 어느 하나의 정수이고,z1 is an integer of 1 to 10,
x1는 1 내지 15 중 어느 하나의 정수이다.x1 is an integer of any one of 1 to 15;
[화학식 1b-1][Chemical Formula 1b-1]
Figure PCTKR2018013181-appb-I000005
Figure PCTKR2018013181-appb-I000005
상기 화학식 1b-1에서,In the above formula (1b-1)
z2 및 x2는 반복단위 수이며,z2 and x2 are the number of repeating units,
z2는 1 내지 10 중 어느 하나의 정수이고,z2 is an integer of 1 to 10,
x2는 1 내지 15 중 어느 하나의 정수이다.and x2 is an integer of any one of 1 to 15. [
상기 본 발명의 리튬 이차전지용 전해질은 상기 화학식 1로 표시되는 올리고머를 포함하는 액체 전해질일 수 있다.The electrolyte for a lithium secondary battery of the present invention may be a liquid electrolyte containing an oligomer represented by the general formula (1).
이때, 상기 화학식 1로 표시되는 올리고머는 리튬 이차전지용 전해질 전체 중량을 기준으로 0.5 중량% 내지 30 중량%, 구체적으로 0.5 중량% 내지 25 중량%로 포함될 수 있다.In this case, the oligomer represented by Formula 1 may be contained in an amount of 0.5 to 30% by weight, specifically 0.5 to 25% by weight based on the total weight of the electrolyte for a lithium secondary battery.
또한, 본 발명의 리튬 이차전지용 전해질은 상기 화학식 1로 표시되는 올리고머 유래의 폴리머를 포함하는 겔 폴리머 전해질일 수 있다.In addition, the electrolyte for a lithium secondary battery of the present invention may be a gel polymer electrolyte comprising an oligomer-derived polymer represented by the above formula (1).
이때, 상기 화학식 1로 표시되는 올리고머 유래의 폴리머는 중합개시제 존재하에서 화학식 1로 표시되는 올리고머가 중합하여 3차원 구조로 형성된 매트릭스 폴리머일 수 있다.Here, the oligomer-derived polymer represented by Formula 1 may be a matrix polymer formed by polymerization of an oligomer represented by Formula 1 in the presence of a polymerization initiator to form a three-dimensional structure.
또한, 상기 화학식 1로 표시되는 올리고머 유래의 폴리머는 리튬 이차전지용 전해질 전체 중량을 기준으로 0.5 중량% 내지 30 중량%, 구체적으로 0.5 중량% 내지 25 중량%로 포함될 수 있다.The oligomer-derived polymer represented by Formula 1 may be contained in an amount of 0.5 to 30% by weight, specifically 0.5 to 25% by weight based on the total weight of the electrolyte for a lithium secondary battery.
또한, 본 발명의 일 실시예에서는In an embodiment of the present invention,
본 발명의 리튬 이차전지용 전해질을 포함하는 리튬 이차전지를 제공할 수 있다.The lithium secondary battery including the electrolyte for a lithium secondary battery of the present invention can be provided.
이때, 상기 리튬 이차전지용 전해질은 액체 전해질 또는 겔 폴리머 전해질일 수 있다.At this time, the electrolyte for the lithium secondary battery may be a liquid electrolyte or a gel polymer electrolyte.
본 발명에 따르면 친수성 및 소수성 관능기를 가지는 올리고머 또는 이러한 올리고머 유래의 폴리머를 포함함으로써, 전극 표면과의 표면장력을 낮춰 젖음성이 향상되고, 전해액과 전극의 부반응을 억제할 수 있는 리튬 이차전지용 전해질을 제조할 수 있다. 또한, 이를 포함함으로써, 전극의 계면저항 증가를 억제하여 평균 전압 강하를 방지할 수 있고, 이로 인해 충방전 효율이 향상된 리튬 이차전지를 제조할 수 있다.According to the present invention, an oligomer having hydrophilic and hydrophobic functional groups or a polymer derived from such an oligomer can be used to manufacture an electrolyte for a lithium secondary battery that can improve wettability by lowering the surface tension with respect to the electrode surface and suppress side reactions of the electrolyte and the electrode. can do. Further, by including it, an increase in interfacial resistance of the electrode can be suppressed to prevent an average voltage drop, and as a result, a lithium secondary battery having improved charging / discharging efficiency can be manufactured.
이하, 본 발명을 더욱 상세하게 설명한다. Hereinafter, the present invention will be described in more detail.
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.
한편, 본 명세서에서 사용되는 용어는 단지 예시적인 실시예들을 설명하기 위해 사용된 것으로, 본 발명을 한정하려는 의도는 아니다. 단수의 표현은 문맥상 명백하게 다르게 뜻하지 않는 한, 복수의 표현을 포함한다. In the meantime, the terminology used herein is used only to describe exemplary embodiments and is not intended to limit the present 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.
본 명세서에서, "%"는 명시적인 다른 표시가 없는 한 중량%를 의미한다.In the present specification, "% " means weight% unless otherwise indicated.
본 명세서 내에서 "탄소수 a 내지 b"의 기재에 있어서, "a" 및 "b"는 구체적인 작용기에 포함되는 탄소 원자의 개수를 의미한다. 즉, 상기 작용기는 "a" 내지 "b" 개의 탄소원자를 포함할 수 있다. 예를 들어, "탄소수 1 내지 3의 알킬기"는 1 내지 3 개의 탄소 원자를 포함하는 알킬기, 즉 -CH3, -CH2CH3, -CH2CH2CH3 또는 -CH2(CH2)CH3을 의미한다. In the description of the "carbon number a to b" in the present specification, "a" and "b" refer to the number of carbon atoms contained in the specific functional group. That is, the functional group may include " a " to " b " carbon atoms. For example, the "alkyl group having 1 to 3 carbon atoms" means an alkyl group containing 1 to 3 carbon atoms, ie, -CH 3 , -CH 2 CH 3 , -CH 2 CH 2 CH 3 or -CH 2 (CH 2 ) CH 3 .
본 명세서에서, 상기 "아릴렌기"란 방향족 탄화수소에서 수소 원자가 떨어진 형태의 작용기를 의미한다. 일 구현예에서 상기 아릴렌기는 페닐렌기, 바이페닐릴렌기, 터페닐릴렌기, 나프틸렌기, 또는 페난트릴렌기 등을 포함하나, 이들로 한정되지 않으며, 이들 각각은 다른 구현예에서 선택적으로 치환될 수 있다.In the present specification, the "arylene group" means a functional group in which hydrogen atoms are separated from aromatic hydrocarbons. In one embodiment, the arylene group includes, but is not limited to, a phenylene group, a biphenylene group, a terphenylene group, a naphthylene group, or a phenanthrylene group, each of which is optionally substituted .
또한, 본 명세서에서 "헤테로"란 별도의 정의가 없는 한，하나의 작용기 내에 N, 0, S, 또는 P로 이루어진 군에서 선택되는 헤테로 원자를 적어도 한 개를 함유하고, 나머지는 탄소인 것을 의미한다. In the present specification, "hetero" means, unless otherwise defined, that at least one heteroatom selected from the group consisting of N, O, S, or P is contained in one functional group and the remainder is carbon do.
또한, 본 명세서 전반에서 "헤테로사이클로알킬렌기"란 탄소수 2 내지 20으로 이루어진 고리 화합물 내에 탄소 대신 N, O, S, 또는 P의 헤테로 원자가 적어도 하나 이상 존재하는 것을 의미한다. The term "heterocycloalkylene group" as used throughout this specification means that at least one hetero atom of N, O, S, or P exists in the ring compound having 2 to 20 carbon atoms instead of carbon.
또한, 본 명세서에서, "치환"이란 별도의 정의가 없는 한, 탄소에 결합된 적어도 하나 이상의 수소가 수소 이외의 원소로 치환된 것을 의미하며, 예를 들면, 탄소수 1 내지 3의 알킬기로 치환된 것을 의미한다.In the present specification, the term " substituted " means that at least one hydrogen bonded to carbon is replaced with an element other than hydrogen, unless otherwise defined, and includes, for example, an alkyl group substituted with an alkyl group having 1 to 3 carbon atoms .
리튬 이차전지용 전해질Electrolytes for lithium secondary batteries
구체적으로, 본 발명의 일 실시예에서는 리튬염; 유기용매; 및 하기 화학식 1로 표시되는 올리고머 또는 상기 화학식 1로 표시되는 올리고머 유래 폴리머;를 포함하는 리튬 이차전지용 전해질을 제공할 수 있다.Specifically, in one embodiment of the present invention, a lithium salt; Organic solvent; And an oligomer represented by the following formula (1) or an oligomer-derived polymer represented by the above formula (1).
[화학식 1][Chemical Formula 1]
Figure PCTKR2018013181-appb-I000006
Figure PCTKR2018013181-appb-I000006
상기 화학식 1에서,In Formula 1,
R1 및 R2는 각각 독립적으로 치환 또는 비치환된 탄소수 1 내지 5의 알킬렌기이고,R 1 and R 2 are each independently a substituted or unsubstituted alkylene group having 1 to 5 carbon atoms,
R3 및 R4는 각각 독립적으로 수소 또는 치환 또는 비치환된 탄소수 1 내지 3의 알킬기이고,R 3 and R 4 are each independently hydrogen or a substituted or unsubstituted alkyl group having 1 to 3 carbon atoms,
R5는 수소 또는 치환 또는 비치환된 탄소수 1 내지 5의 알킬기이고,R 5 is hydrogen or a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms,
R'는 지방족 탄화수소기 또는 방향족 탄화수소기이고,R 'is an aliphatic hydrocarbon group or an aromatic hydrocarbon group,
z 및 x 는 반복단위 수이며,z and x are the number of repeating units,
z는 1 내지 10 중 어느 하나의 정수이고,z is an integer of 1 to 10,
x는 1 내지 15 중 어느 하나의 정수이며,x is an integer of 1 to 15,
n은 1 내지 3 중 어느 하나의 정수이다.and n is an integer of 1 to 3.
구체적으로, 상기 본 발명의 리튬 이차전지용 전해질은 리튬염, 유기용매, 및 상기 화학식 1로 표시되는 올리고머를 포함하는 액체 전해질일 수 있다.Specifically, the electrolyte for a lithium secondary battery of the present invention may be a lithium salt, an organic solvent, and a liquid electrolyte containing an oligomer represented by the formula (1).
또한, 상기 본 발명의 리튬 이차전지용 전해질은 리튬염, 유기용매, 및 상기 화학식 1로 표시되는 올리고머 유래 폴리머를 포함하는 리튬 이차전지용 겔 폴리머 전해질일 수 있다.Also, the electrolyte for a lithium secondary battery of the present invention may be a gel polymer electrolyte for a lithium secondary battery comprising a lithium salt, an organic solvent, and an oligomer-derived polymer represented by the formula (1).
(1) 리튬 이차전지용 액체 전해질(1) Liquid electrolyte for lithium secondary battery
본 발명의 일 실시예에서는 리튬염, 유기용매, 및 상기 화학식 1로 표시되는 올리고머를 포함하는 리튬 이차전지용 전해질을 제공한다. In one embodiment of the present invention, there is provided an electrolyte for a lithium secondary battery comprising a lithium salt, an organic solvent, and an oligomer represented by the formula (1).
이때, 상기 리튬 이차전지용 전해질은 액체 전해질일 수 있다.At this time, the electrolyte for the lithium secondary battery may be a liquid electrolyte.
(1-1) 리튬염(1-1) Lithium salt
한편, 본 발명의 리튬 이차전지용 전해질에 사용되는 리튬염은 리튬 이차전지용 전해질에 통상적으로 사용되는 것들이 제한 없이 사용될 수 있으며, 예를 들어 상기 리튬염의 양이온으로 Li+를 포함하고, 음이온으로는 F-, Cl-, Br-, I-, NO3 -, N(CN)2 -, BF4 -, ClO4 -, AlO4 -, AlCl4 -, PF6 -, SbF6 -, AsF6 -, BF2C2O4 -, BC4O8 -, PF4C2O4 -, PF2C4O8 -, (CF3)2PF4 -, (CF3)3PF3 -, (CF3)4PF2 -, (CF3)5PF-, (CF3)6P-, CF3SO3 -, C4F9SO3 -, CF3CF2SO3 -, (CF3SO2)2N-, (FSO2)2N-, CF3CF2(CF3)2CO-, (CF3SO2)2CH-, (SF5)3C-, (CF3SO2)3C-, CF3(CF2)7SO3 -, CF3CO2 -, CH3CO2 -, SCN- 및 (CF3CF2SO2)2N-로 이루어진 군으로부터 선택된 적어도 어느 하나를 들 수 있다. 구체적으로, 상기 리튬염은 LiCl, LiBr, LiI, LiClO4, LiBF4, LiB10Cl10, LiPF6, LiCF3SO3, LiCH3CO2, LiCF3CO2, LiAsF6, LiSbF6, LiAlCl4, LiAlO4, 및 LiCH3SO3으로 이루어진 군으로부터 선택된 단일물 또는 2종 이상의 혼합물을 포함할 수 있고, 이들 외에도 리튬 이차전지의 전해액에 통상적으로 사용되는 LiBETI (lithium bisperfluoroethanesulfonimide, LiN(SO2C2F5)2), LiFSI (lithium fluorosulfonyl imide, LiN(SO2F)2), 및 LiTFSI (lithium (bis)trifluoromethanesulfonimide, LiN(SO2CF3)2)로 나타내는 리튬 이미드염과 같은 리튬염을 제한 없이 사용할 수 있다. 구체적으로 리튬염은 LiPF6, LiBF4, LiCH3CO2, LiCF3CO2, LiCH3SO3, LiFSI, LiTFSI 및 LiN(C2F5SO2)2으로 이루어진 군으로부터 선택된 단일물 또는 2종 이상의 혼합물을 포함할 수 있다. On the other hand, the lithium salt used in the lithium secondary battery electrolyte of the present invention can be used without limitation, those which are commonly used in a lithium secondary battery electrolyte, such as an anion, and containing the Li + in the lithium salt cation is F - , Cl -, Br -, I -, NO 3 -, N (CN) 2 -, BF 4 -, ClO 4 -, AlO 4 -, AlCl 4 -, PF 6 -, SbF 6 -, AsF 6 -, BF 2 C 2 O 4 -, BC 4 O 8 -, PF 4 C 2 O 4 -, PF 2 C 4 O 8 -, (CF 3) 2 PF 4 -, (CF 3) 3 PF 3 -, (CF 3 ) 4 PF 2 -, (CF 3) 5 PF -, (CF 3) 6 P -, CF 3 SO 3 -, C 4 F 9 SO 3 -, CF 3 CF 2 SO 3 -, (CF 3 SO 2) 2 N -, (FSO 2) 2 N -, CF 3 CF 2 (CF 3) 2 CO -, (CF 3 SO 2) 2 CH -, (SF 5) 3 C -, (CF 3 SO 2) 3 C - , CF 3 (CF 2 ) 7 SO 3 - , CF 3 CO 2 - , CH 3 CO 2 - , SCN - and (CF 3 CF 2 SO 2 ) 2 N - have. Specifically, the lithium salt may be LiCl, LiBr, LiI, LiClO 4 , LiBF 4 , LiB 10 Cl 10 , LiPF 6 , LiCF 3 SO 3 , LiCH 3 CO 2 , LiCF 3 CO 2 , LiAsF 6 , LiSbF 6 , LiAlCl 4 , LiAlO 4 , and LiCH 3 SO 3 , or a mixture of two or more thereof. In addition to these, lithium bisperfluoroethanesulfonimide (LiBETI) (Li 2 N 2 (SO 2 C 2 F 5) 2), LiFSI (lithium fluorosulfonyl imide, LiN (SO 2 F) 2), and LiTFSI (lithium (bis) trifluoromethanesulfonimide, LiN (SO 2 CF 3) 2) a lithium salt such as lithium already deuyeom represented by the limited without Can be used. Specifically, the lithium salt is LiPF 6, LiBF 4, LiCH 3 CO 2, LiCF 3 CO 2, LiCH 3 SO 3, LiFSI, LiTFSI and LiN (C 2 F 5 SO 2 ) or more danilmul selected from the group consisting of 2 or two And mixtures thereof.
상기 리튬염은 통상적으로 사용 가능한 범위 내에서 적절히 변경할 수 있으나, 구체적으로 전해질 내에 0.1 M 내지 3M, 구체적으로 0.8M 내지 2.5M로 포함될 수 있다. 만약, 상기 리튬염의 농도가 3M을 초과하는 경우 전해질의 점도가 증가하여 리튬 이온 이동 효과가 저하될 수 있다.The lithium salt can be appropriately changed within a range that is generally usable, but it can be specifically contained in the electrolyte in the range of 0.1 M to 3 M, specifically 0.8 M to 2.5 M. If the concentration of the lithium salt exceeds 3M, the viscosity of the electrolyte may increase and the lithium ion transfer effect may be lowered.
(1-2) 유기용매(1-2) Organic solvent
상기 유기용매는 환형 카보네이트계 유기용매, 선형 카보네이트계 유기용매, 선형 에스테르계 유기용매 및 환형 에스테르계 유기용매로 이루어진 군으로부터 선택된 적어도 하나 이상의 유기용매를 포함할 수 있다.The organic solvent may include at least one organic solvent selected from the group consisting of a cyclic carbonate organic solvent, a linear carbonate organic solvent, a linear ester organic solvent and a cyclic ester organic solvent.
구체적으로, 상기 유기용매로는 환형 카보네이트계 유기용매 및 선형 카보네이트계 유기용매를 포함할 수 있다. Specifically, the organic solvent may include a cyclic carbonate-based organic solvent and a linear carbonate-based organic solvent.
상기 환형 카보네이트계 유기용매는 그 구체적인 예로 에틸렌 카보네이트(EC), 프로필렌 카보네이트(PC), 1,2-부틸렌 카보네이트, 2,3-부틸렌 카보네이트, 1,2-펜틸렌카보네이트, 2,3-펜틸렌 카보네이트 및 비닐렌 카보네이트로 이루어진 군으로부터 선택되는 어느 하나 또는 이들 중 2종 이상의 혼합물을 들 수 있으며, 이 중에서도 고점도의 유기용매로서 유전율이 높아 전해질 내의 리튬염을 잘 해리시키는 에틸렌 카보네이트를 포함할 수 있다.Specific examples of the cyclic carbonate-based organic solvent include ethylene carbonate (EC), propylene carbonate (PC), 1,2-butylene carbonate, 2,3-butylene carbonate, 1,2-pentylene carbonate, 2,3- Pentylene carbonate, and vinylene carbonate, or a mixture of two or more thereof. Of these, organic solvents having a high viscosity, such as ethylene carbonate, which has a high dielectric constant and dissociates the lithium salt in the electrolyte well .
또한, 상기 선형 카보네이트계 유기용매는 저점도 및 저유전율을 가지는 유기용매로서, 그 대표적인 예로 디메틸 카보네이트(dimethyl carbonate, DMC), 디에틸 카보네이트(diethyl carbonate, DEC), 디프로필 카보네이트, 에틸메틸 카보네이트(EMC), 메틸프로필 카보네이트 및 에틸프로필 카보네이트로 이루어진 군으로부터 선택되는 적어도 어느 하나를 포함할 수 있다. The linear carbonate-based organic solvent is an organic solvent having a low viscosity and a low dielectric constant. Typical examples thereof include dimethyl carbonate (DMC), diethyl carbonate (DEC), dipropyl carbonate, ethyl methyl carbonate EMC), methyl propyl carbonate, and ethyl propyl carbonate.
또한, 상기 유기용매는 높은 전기 전도율을 갖는 전해액을 제조하기 위하여, 선형 에스테르계 유기용매 및/또는 환형 에스테르계 유기용매를 더 포함할 수도 있다.In addition, the organic solvent may further include a linear ester organic solvent and / or a cyclic ester organic solvent to produce an electrolytic solution having a high electrical conductivity.
이러한 선형 에스테르계 유기용매는 그 구체적인 예로 메틸 아세테이트, 에틸 아세테이트, 프로필 아세테이트, 메틸 프로피오네이트, 에틸 프로피오네이트, 프로필 프로피오네이트 및 부틸 프로피오네이트로 이루어진 군으로부터 선택되는 적어도 하나를 포함할 수 있다.Specific examples of such linear ester organic solvents may include at least one selected from the group consisting of methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate and butyl propionate have.
또한, 상기 환형 에스테르계 유기용매로는 γ-부티로락톤, γ-발레로락톤, γ-카프로락톤, σ-발레로락톤, ε-카프로락톤으로 이루어진 군으로부터 선택되는 적어도 하나를 포함할 수 있다.The cyclic ester organic solvent may include at least one selected from the group consisting of? -Butyrolactone,? -Valerolactone,? -Caprolactone,? -Valerolactone and? -Caprolactone .
또한, 상기 유기용매는 필요에 따라 리튬 이차전지용 전해액에 통상적으로 사용되는 유기용매를 제한 없이 추가하여 사용할 수 있다. 예를 들면, 에테르계 유기용매 및 니트릴계 유기용매 중 적어도 하나 이상의 유기용매를 추가로 포함할 수도 있다.In addition, the organic solvent may be added with an organic solvent commonly used in an electrolyte for a lithium secondary battery, if necessary, without limitation. For example, an ether organic solvent and a nitrile organic solvent may further include at least one organic solvent.
상기 에테르계 유기용매로는 디메틸에테르, 디에틸에테르, 디프로필 에테르, 메틸에틸에테르, 메틸프로필 에테르 및 에틸프로필 에테르로 이루어진 군으로부터 선택되는 어느 하나를 포함할 수 있다.The ether-based organic solvent may include any one selected from the group consisting of dimethyl ether, diethyl ether, dipropyl ether, methyl ethyl ether, methyl propyl ether and ethyl propyl ether.
상기 니트릴계 유기용매는 예를 들면, 아세토니트릴, 프로피오니트릴, 부티로니트릴, 발레로니트릴, 카프릴로니트릴, 헵탄니트릴, 사이클로펜탄 카보니트릴, 사이클로헥산 카보니트릴, 2-플루오로벤조니트릴, 4-플루오로벤조니트릴, 다이플루오로벤조니트릴, 트리플루오로벤조니트릴, 페닐아세토니트릴, 2-플루오로페닐아세토니트릴, 4-플루오로페닐아세토니트릴로 이루어진 군에서 선택되는 어느 하나를 포함할 수 있다.The nitrile organic solvent may be, for example, acetonitrile, propionitrile, butyronitrile, valeronitrile, caprilonitrile, heptanenitrile, cyclopentanecarbonitrile, cyclohexanecarbonitrile, 2-fluorobenzonitrile, 4 May include any one selected from the group consisting of fluorobenzonitrile, difluorobenzonitrile, trifluorobenzonitrile, phenylacetonitrile, 2-fluorophenylacetonitrile, 4-fluorophenylacetonitrile .
(1-3) 화학식 1로 표시되는 화합물(1-3) A compound represented by the formula (1)
본 발명의 리튬 이차전지용 전해질은 하기 화학식 1로 표시되는 올리고머를 포함할 수 있다.The electrolyte for a lithium secondary battery of the present invention may include an oligomer represented by the following formula (1).
[화학식 1][Chemical Formula 1]
Figure PCTKR2018013181-appb-I000007
Figure PCTKR2018013181-appb-I000007
상기 화학식 1에서,In Formula 1,
R1 및 R2는 각각 독립적으로 치환 또는 비치환된 탄소수 1 내지 5의 알킬렌기이고,R 1 and R 2 are each independently a substituted or unsubstituted alkylene group having 1 to 5 carbon atoms,
R3 및 R4는 각각 독립적으로 수소 또는 치환 또는 비치환된 탄소수 1 내지 3의 알킬기이고,R 3 and R 4 are each independently hydrogen or a substituted or unsubstituted alkyl group having 1 to 3 carbon atoms,
R5는 수소 또는 치환 또는 비치환된 탄소수 1 내지 5의 알킬기이고,R 5 is hydrogen or a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms,
R'는 지방족 탄화수소기 또는 방향족 탄화수소기이고,R 'is an aliphatic hydrocarbon group or an aromatic hydrocarbon group,
z 및 x 는 반복단위 수이며,z and x are the number of repeating units,
z는 1 내지 10 중 어느 하나의 정수이고,z is an integer of 1 to 10,
x는 1 내지 15 중 어느 하나의 정수이며,x is an integer of 1 to 15,
n은 1 내지 3 중 어느 하나의 정수이다.and n is an integer of 1 to 3.
이때, 상기 화학식 1에서, 상기 R'의 지방족 탄화수소기는 (a) 치환 또는 비치환된 탄소수 4 내지 20의 사이클로알킬렌기, 치환 또는 비치환된 탄소수 4 내지 20의 사이클로알케닐렌기 및 치환 또는 비치환된 탄소수 2 내지 20의 헤테로사이클로알킬렌기로 이루어진 군으로부터 선택된 적어도 하나의 지환족 탄화수소기 및 (b) 치환 또는 비치환된 탄소수 1 내지 20의 알킬렌기, 치환 또는 비치환된 탄소수 1 내지 20의 알콕실렌기, 치환 또는 비치환된 탄소수 2 내지 20의 알케닐렌기 및 치환 또는 비치환된 탄소수 2 내지 20의 알키닐렌기로 이루어진 군으로부터 선택된 적어도 하나의 선형 탄화수소기로 이루어진 군으로부터 선택된 적어도 하나를 포함할 수 있다.In the formula (1), the aliphatic hydrocarbon group of R 'is selected from the group consisting of (a) a substituted or unsubstituted cycloalkylene group having 4 to 20 carbon atoms, a substituted or unsubstituted cycloalkenylene group having 4 to 20 carbon atoms, (B) at least one substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, a substituted or unsubstituted C1 to C20 alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted C1 to C20 alkoxy group, a substituted or unsubstituted C2 to C20 alicyclic hydrocarbon group, And at least one linear hydrocarbon group selected from the group consisting of a substituted or unsubstituted alkenylene group having 2 to 20 carbon atoms and a substituted or unsubstituted alkynylene group having 2 to 20 carbon atoms, have.
또한, 상기 R'의 방향족 탄화수소기는 치환 또는 비치환된 탄소수 6 내지 20의 아릴렌기 및 치환 또는 비치환된 탄소수 2 내지 20의 헤테로아릴렌기로부터 선택된 적어도 하나를 포함할 수 있다.The aromatic hydrocarbon group for R 'may include at least one selected from substituted or unsubstituted arylene groups having 6 to 20 carbon atoms and substituted or unsubstituted heteroarylene groups having 2 to 20 carbon atoms.
구체적으로, 상기 화학식 1 에서, 상기 R'의 지방족 탄화수소기는 치환 또는 비치환된 탄소수 4 내지 20의 사이클로알킬렌기, 치환 또는 비치환된 탄소수 4 내지 20의 사이클로알케닐렌기 및 치환 또는 비치환된 탄소수 2 내지 20의 헤테로사이클로알킬렌기로 이루어진 군으로부터 선택된 적어도 하나의 지환족 탄화수소기를 포함할 수 있다.Specifically, in Formula 1, the aliphatic hydrocarbon group of R 'is a substituted or unsubstituted cycloalkylene group having 4 to 20 carbon atoms, a substituted or unsubstituted cycloalkenylene group having 4 to 20 carbon atoms, and a substituted or unsubstituted carbon number And at least one alicyclic hydrocarbon group selected from the group consisting of 2 to 20 heterocycloalkylene groups.
상기 화학식 1로 표시되는 올리고머는 양 말단에 자체적으로 가교 결합을 형성할 수 있는 친수성 부분인 아크릴레이트계 작용기를 함유하는 동시에, 소수성 부분인 실록산기(-Si-O-)와 우레탄(-N-C(O)O-)기를 포함하기 때문에, 전지 내에서 계면활성제 역할을 부여하여, 친수성 부분인 양극 또는 분리막(SRS층)과 소수성 부분인 음극 또는 분리막 원단과 균형적인 친화성에 의해 계면 저항을 낮출 수 있다. 따라서, 상기 화학식 1로 표시되는 올리고머를 포함하는 리튬 이차전지용 전해질은 젖음성 효과가 보다 향상될 수 있다. The oligomer represented by the formula (1) contains an acrylate-based functional group which is a hydrophilic moiety capable of forming a cross-linking bond at both ends, and also contains a siloxane group (-Si-O-) and a urethane O) - group, it is possible to lower the interfacial resistance by imparting a surfactant role in the cell and by balancing affinity with the anode or separator (SRS layer) which is a hydrophilic part and the cathode or separator fabric which is a hydrophobic part . Therefore, the electrolyte for the lithium secondary battery including the oligomer represented by the above formula (1) can further improve the wettability effect.
또한, 상기 화학식 1로 표시되는 올리고머는 초기 충전시 음극 표면에 안정한 이온전도성 피막을 형성하는 동시에 과충전 시 음극 표면에 석출된 Li 금속과 전해질의 부반응을 억제함으로써, 기존 리튬 이차전지용 전해질 대비 전극의 계면 저항 증가 및 이로부터 발생하는 충방전시 평균전압 변화를 억제할 수 있다. 따라서, 충방전 효율 및 고율특성이 개선된 리튬 이차전지를 제공할 수 있다.The oligomer represented by the above formula (1) forms a stable ion conductive membrane on the surface of the cathode at the time of initial charging, and at the same time suppresses the side reaction between the Li metal deposited on the surface of the anode and the electrolyte, It is possible to suppress an increase in resistance and an average voltage change during charging and discharging therefrom. Therefore, a lithium secondary battery improved in charge / discharge efficiency and high rate characteristics can be provided.
한편, 본 발명의 화학식 1로 표시되는 올리고머는 주사슬의 반복단위로 실록산기(-[Si-O]-)와 우레탄기를 포함하며, 올리고머는 구조 내에 실록산기와 함께 -Si-기를 추가로 포함하지 않는 것이 바람직하다. 즉, 상기 올리고머 구조 내에 반복단위로 추가의 -Si-기를 포함하지 않음으로써, 양 말단의 관능기의 비율을 높이고, 전체 고분자의 분자량을 낮출 수 있기 때문에, 전해질 내 동일 함량을 투입한다고 가정하는 경우 구조 내에 -Si-기를 추가로 포함하는 올리고머 (예컨대, 주사슬 반복단위로 -[Si-O]-Si-구조 포함) 대비 전체 올리고머의 함량을 늘려줄 수 있다. 따라서, 겔 고분자의 반응속도를 유리하게 가져갈 수 있고, 겔 고분자의 경도를 높여 전체 전지의 경도를 강화시킬 수 있으므로, 물리적인 충격을 주는 안전성 평가, 예컨대 충격 평가에 보다 유리하게 작용할 수 있다.On the other hand, the oligomer represented by the general formula (1) of the present invention contains a siloxane group (- [Si-O] -) and a urethane group as repeating units of the main chain, and the oligomer additionally contains a- . That is, since the oligomer structure does not contain additional -Si- group as a repeating unit, the ratio of the functional groups at both terminals can be increased and the molecular weight of the entire polymer can be lowered. Therefore, Can further increase the content of the entire oligomer relative to an oligomer further including a -Si- group (e.g., [Si-O] -Si- structure in the main chain repeat unit). Therefore, the reaction rate of the gel polymer can be advantageously taken, and the hardness of the gel polymer can be increased to enhance the hardness of the whole cell, so that it can be more advantageously used for safety evaluation such as impact evaluation which gives physical impact.
구체적으로, 상기 화학식 1로 표시되는 올리고머는 하기 화학식 1a 및 1b로 표시되는 올리고머들로 이루어진 군으로부터 선택된 적어도 어느 하나일 수 있다.Specifically, the oligomer represented by the formula (1) may be at least one selected from the group consisting of oligomers represented by the following formulas (1a) and (1b).
[화학식 1a][Formula 1a]
Figure PCTKR2018013181-appb-I000008
Figure PCTKR2018013181-appb-I000008
상기 화학식 1a에서,In formula (1a)
R'는 지방족 탄화수소기 또는 방향족 탄화수소기이고,R 'is an aliphatic hydrocarbon group or an aromatic hydrocarbon group,
z1 및 x1는 반복단위 수이며,z1 and x1 are the number of repeating units,
z1는 1 내지 10 중 어느 하나의 정수이고,z1 is an integer of 1 to 10,
x1는 1 내지 15 중 어느 하나의 정수이다.x1 is an integer of any one of 1 to 15;
[화학식 1b][Chemical Formula 1b]
Figure PCTKR2018013181-appb-I000009
Figure PCTKR2018013181-appb-I000009
상기 화학식 1b에서,In the above formula (1b)
R'는 지방족 탄화수소기 또는 방향족 탄화수소기이고,R 'is an aliphatic hydrocarbon group or an aromatic hydrocarbon group,
z2 및 x2는 반복단위 수이며,z2 and x2 are the number of repeating units,
z2는 1 내지 10 중 어느 하나의 정수이고,z2 is an integer of 1 to 10,
x2는 1 내지 15 중 어느 하나의 정수이다.and x2 is an integer of any one of 1 to 15. [
보다 구체적으로, 상기 화학식 1로 표시되는 올리고머는 하기 화학식 1a-1 및 1b-1로 표시되는 올리고머들로 이루어진 군으로부터 선택된 어느 하나일 수 있다.More specifically, the oligomer represented by Formula 1 may be selected from the group consisting of oligomers represented by the following Formulas 1a-1 and 1b-1.
[화학식 1a-1][Formula 1a-1]
Figure PCTKR2018013181-appb-I000010
Figure PCTKR2018013181-appb-I000010
상기 화학식 1a-1에서,In the above formula (1a-1)
z1 및 x1는 반복단위 수이며,z1 and x1 are the number of repeating units,
z1는 1 내지 10 중 어느 하나의 정수이고,z1 is an integer of 1 to 10,
x1는 1 내지 15 중 어느 하나의 정수이다.x1 is an integer of any one of 1 to 15;
[화학식 1b-1][Chemical Formula 1b-1]
Figure PCTKR2018013181-appb-I000011
Figure PCTKR2018013181-appb-I000011
상기 화학식 1b-1에서,In the above formula (1b-1)
z2 및 x2는 반복단위 수이며,z2 and x2 are the number of repeating units,
z2는 1 내지 10 중 어느 하나의 정수이고,z2 is an integer of 1 to 10,
x2는 1 내지 15 중 어느 하나의 정수이다.and x2 is an integer of any one of 1 to 15. [
이러한 화학식 1로 표시되는 올리고머의 중량평균분자량(Mw)은 반복 단위의 개수에 의해 조절될 수 있으며, 약 1,000 g/mol 내지 100,000 g/mol, 구체적으로 1,000 g/mol 내지 50,000 g/mol, 더욱 구체적으로 1,000 g/mol 내지 10,000 g/mol 일 수 있다. 상기 올리고머의 중량평균분자량이 상기 범위 내인 경우, 전해액 젖음성 효과를 개선할 수 있다. 아울러, 필요에 따라 여러 가지 관능기를 치환시키기 용이하기 때문에, 다양한 제반 성능 개선 효과를 얻을 수 있다.The weight average molecular weight (Mw) of the oligomer represented by the formula (1) can be controlled by the number of repeating units, and is about 1,000 g / mol to 100,000 g / mol, specifically 1,000 g / mol to 50,000 g / Specifically from 1,000 g / mol to 10,000 g / mol. When the weight average molecular weight of the oligomer is within the above range, the electrolyte wettability effect can be improved. In addition, since it is easy to replace various functional groups as necessary, various various performance improving effects can be obtained.
상기 올리고머의 중량 평균분자량이 1,000 g/mol 미만이면, 전기화학적 안정성 및 계면활성제의 역할 등을 기대할 수 없고, 관능기 함량이 낮아지기 때문에 전극 표면의 부반응 억제 효과가 미미할 수 있고, 중량평균분자량이 100,000 g/mol을 초과하면, 유기용매에 대한 용해도가 저하될 수 있는 단점이 있다.If the weight average molecular weight of the oligomer is less than 1,000 g / mol, the electrochemical stability and the role of the surfactant can not be expected, and since the functional group content is low, the effect of suppressing the side reaction of the electrode surface may be insignificant. / mol, the solubility in an organic solvent may be lowered.
상기 중량평균분자량은 겔투과크로마토그래피(Gel Permeation Chromatography: GPC)로 측정한 표준 폴리스티렌에 대한 환산 수치를 의미할 수 있고, 특별하게 달리 규정하지 않는 한, 분자량은 중량평균분자량을 의미할 수 있다. 예컨대, 본 발명에서는 GPC 조건으로 Agilent社 1200시리즈를 이용하여 측정하며, 이때 사용된 컬럼은 Agilent社 PL mixed B 컬럼을 이용할 수 있고, 용매는 THF를 사용할 수 있다.The weight average molecular weight may mean a value converted to standard polystyrene measured by Gel Permeation Chromatography (GPC), and unless otherwise specified, the molecular weight may mean a weight average molecular weight. For example, in the present invention, the GPC conditions are measured using an Agilent 1200 series. The column used herein may be a PL mixed B column of Agilent, and THF may be used as a solvent.
한편, 상기 화학식 1로 표시되는 올리고머는 리튬 이차전지용 전해질 전체 중량을 기준으로 0.5 중량% 내지 30 중량%, 구체적으로 0.5 중량% 내지 25 중량%, 보다 구체적으로 0.5 중량% 내지 10 중량%, 더욱 구체적으로 0.5 중량% 내지 5 중량%로 포함될 수 있다.On the other hand, the oligomer represented by Formula 1 is used in an amount of 0.5 to 30% by weight, specifically 0.5 to 25% by weight, more specifically 0.5 to 10% by weight, based on the total weight of the electrolyte for a lithium secondary battery, By weight to 0.5% by weight to 5% by weight.
상기 화학식 1로 표시되는 올리고머의 함량이 0.5 중량% 이상인 경우에 리튬 메탈과의 반응성 제어 및 전기화학적 안정성 효과를 기대할 수 있고, 30 중량% 이하인 경우에 과량의 올리고머 첨가에 따른 저항 증가를 방지하여 젖음성을 확보함과 동시에, 리튬 이온의 이동 제한을 개선하여 이온전도도 저하와 같은 단점을 방지할 수 있다. 만약, 상기 화학식 1로 표시되는 올리고머의 함량이 30 중량%를 초과하면, 전해액에 대한 올리고머의 용해도가 낮아지면서 전해액의 점도가 커져 전해질의 이온전도도가 저하된다. 그 결과, 전극의 계면저항 증가로 인해 전지의 전압 강하가 야기될 수 있다.When the content of the oligomer represented by the general formula (1) is 0.5% by weight or more, the control of reactivity with lithium metal and the electrochemical stability effect can be expected. When the content is less than 30% by weight, And at the same time, it is possible to prevent the disadvantages such as deterioration of the ion conductivity by improving the movement restriction of the lithium ion. If the content of the oligomer represented by the above formula (1) is more than 30% by weight, the solubility of the oligomer in the electrolyte decreases and the viscosity of the electrolyte increases, thereby decreasing the ionic conductivity of the electrolyte. As a result, the voltage drop of the battery may be caused due to an increase in the interface resistance of the electrode.
(1-4) 부가적 첨가제(1-4) Additional additives
또한, 본 발명의 리튬 이차전지용 전해질은 고출력의 환경에서 비수전해액이 분해되어 음극 붕괴가 유발되는 것을 방지하거나, 저온 고율방전 특성, 고온 안정성, 과충전 방지, 고온 저장 시 팽윤 개선 효과 등을 더욱 향상시키기 위하여, 상기 화학식 1의 화합물 이외에 전극 표면에 보다 안정한 이온전도성 피막을 형성할 수 있는 부가적 첨가제들을 더 포함할 수 있다.In addition, the electrolyte for a lithium secondary battery of the present invention can prevent degradation of the non-aqueous electrolyte due to decomposition of the non-aqueous electrolyte in an environment of high output, further improve low temperature high rate discharge characteristics, high temperature stability, overcharge prevention, In addition to the compound of Formula 1, the composition may further include additional additives capable of forming a more stable ion conductive film on the surface of the electrode.
이러한 부가적 첨가제는 그 대표적인 예로 설톤계 화합물, 할로겐 치환된 카보네이트계 화합물, 니트릴계 화합물, 환형 설파이트계 화합물, 및 환형 카보네이트계 화합물로 이루어진 군으로부터 선택된 적어도 하나 이상을 포함할 수 있다. Such additional additives may include at least one selected from the group consisting of a sulfonate compound, a halogen-substituted carbonate compound, a nitrile compound, a cyclic sulfite compound, and a cyclic carbonate compound.
상기 설톤계 화합물은 1,3-프로판 설톤(PS), 1,4-부탄 설톤, 에텐설톤, 1,3-프로펜 설톤(PRS), 1,4-부텐 설톤, 및 1-메틸-1,3-프로펜 설톤으로 이루어진 군으로부터 선택된 적어도 하나 이상의 화합물을 들 수 있다. 상기 설톤계 화합물은 비수전해액 전체 중량을 기준으로 5중량% 이하로 포함될 수 있다. 상기 비수전해액 중에 설톤계 화합물의 함량이 5중량%를 초과하는 경우, 과량의 첨가제의 의한 두꺼운 피막이 형성되어 저항 증가와 출력 열화가 발생할 수 있다.The sul- tonic compound may be selected from the group consisting of 1,3-propane sultone (PS), 1,4-butane sul- thone, ethene sul- thone, 1,3-propene sul- thone (PRS), 1,4- 3-propenesultone, and the like. The sulfone compound may be contained in an amount of 5% by weight or less based on the total weight of the nonaqueous electrolyte solution. If the content of the sulfonate compound in the nonaqueous electrolyte exceeds 5 wt%, a thick film of excess additive may be formed, resulting in increased resistance and deterioration of output.
또한, 상기 할로겐 치환된 카보네이트계 화합물은 플루오로에틸렌 카보네이트(FEC))를 들 수 있으며, 비수전해액 전체 중량을 기준으로 5중량% 이하로 포함할 수 있다. 상기 할로겐 치환된 카보네이트계 화합물의 함량이 5중량%를 초과하는 경우, 셀 팽윤 성능이 열화될 수 있다.The halogen-substituted carbonate compound is fluoroethylene carbonate (FEC), and may be contained in an amount of 5 wt% or less based on the total weight of the non-aqueous electrolyte. If the content of the halogen-substituted carbonate compound exceeds 5% by weight, the cell swelling performance may deteriorate.
또한, 상기 니트릴계 화합물은 숙시노니트릴, 아디포니트릴(Adn), 아세토니트릴, 프로피오니트릴, 부티로니트릴, 발레로니트릴, 카프릴로니트릴, 헵탄니트릴, 싸이클로펜탄 카보니트릴, 싸이클로헥산 카보니트릴, 2-플루오로벤조니트릴, 4-플루오로벤조니트릴, 다이플루오로벤조니트릴, 트리플루오로벤조니트릴, 페닐아세토니트릴, 2-플루오로페닐아세토니트릴, 및 4-플루오로페닐아세토니트릴로 이루어진 군에서 선택되는 적어도 하나 이상의 화합물을 들 수 있다.The nitrile compound may be at least one selected from the group consisting of succinonitrile, adiponitrile (Adn), acetonitrile, propionitrile, butyronitrile, valeronitrile, caprylonitrile, heptanenitrile, cyclopentanecarbonitrile, cyclohexanecarbonitrile, In the group consisting of 2-fluorobenzonitrile, 4-fluorobenzonitrile, difluorobenzonitrile, trifluorobenzonitrile, phenylacetonitrile, 2-fluorophenylacetonitrile, and 4-fluorophenylacetonitrile At least one compound selected.
상기 니트릴계 화합물은 비수전해액 전체 중량을 기준으로 8중량% 이하로 포함될 수 있다. 상기 비수전해액 중에 니트릴계 화합물의 전체 함량이 8중량%를 초과하는 경우, 전극 표면에 형성되는 피막 증가로 저항이 커져, 전지 성능이 열화될 수 있다. The nitrile compound may be contained in an amount of 8% by weight or less based on the total weight of the nonaqueous electrolyte solution. If the total content of the nitrile compound in the nonaqueous electrolyte exceeds 8 wt%, resistance increases due to an increase in the film formed on the surface of the electrode, and battery performance may be deteriorated.
또한, 상기 환형 설파이트계 화합물로는 에틸렌 설파이트, 메틸 에틸렌 설파이트, 에틸 에틸렌 설파이트, 4,5-디메틸 에틸렌 설파이트, 4,5-디에틸 에틸렌 설파이트, 프로필렌 설파이트, 4,5-디메틸 프로필렌 설파이트, 4,5-디에틸 프로필렌설파이트, 4,6-디메틸 프로필렌 설파이트, 4,6-디에틸 프로필렌 설파이트, 1,3-부틸렌 글리콜 설파이트 등을 들 수 있으며, 비수전해액 전체 중량을 기준으로 5중량% 이하로 포함할 수 있다. 상기 환형 설파이트계 화합물의 함량이 5중량%를 초과하는 경우, 과량의 첨가제의 의한 두꺼운 피막이 형성되어 저항 증가와 출력 열화가 발생할 수 있다.Examples of the cyclic sulfite-based compound include ethylene sulfite, methyl ethylene sulfite, ethyl ethylene sulfite, 4,5-dimethylethylene sulfite, 4,5-diethyl ethylene sulfite, - dimethylpropylene sulfite, 4,5-diethylpropylene sulfite, 4,6-dimethylpropylene sulfite, 4,6-diethylpropylene sulfite and 1,3-butylene glycol sulfite. Based on the total weight of the nonaqueous electrolyte solution. If the content of the cyclic sulfite-based compound exceeds 5% by weight, a thick film of excess additive may be formed, resulting in increased resistance and deterioration of output.
또한, 상기 환형 카보네이트계 화합물은 비닐렌카보네이트(VC) 또는 비닐에틸렌 카보네이트를 들 수 있으며, 비수전해액 전체 중량을 기준으로 3중량% 이하로 포함할 수 있다. 상기 비수전해액 중에 환형 카보네이트계 화합물의 함량이 3중량%를 초과하는 경우, 셀 팽윤 억제 성능이 열화될 수 있다.The cyclic carbonate compound may be vinylene carbonate (VC) or vinylethylene carbonate. The cyclic carbonate compound may include up to 3% by weight based on the total weight of the non-aqueous electrolyte. If the content of the cyclic carbonate compound in the non-aqueous electrolyte exceeds 3% by weight, the cell swelling inhibition performance may deteriorate.
보다 구체적으로, 상기 부가적 첨가제는 환형 카보네이트계 화합물일 수 있다.More specifically, the additional additive may be a cyclic carbonate-based compound.
상기 부가적 첨가제들은 2 종 이상이 혼합 사용 가능하며, 전해액 총량을 기준으로 20 중량%이하, 구체적으로 0.01 중량% 내지 20 중량%, 바람직하게는 0.1 내지 10 중량%로 포함될 수 있다. 상기 부가적 첨가제의 함량이 0.01 중량% 보다 적으면 전지의 저온 출력 개선 및 고온 저장 특성 및 고온 수명 특성 개선의 효과가 미미하고, 상기 부가적 첨가제의 함량이 20 중량%를 초과하면 전지의 충방전시 전해액 내의 부반응이 과도하게 발생할 가능성이 있다. 특히, 상기 SEI 막 형성용 첨가제들이 과량으로 첨가될 시에 고온에서 충분히 분해되지 못하여, 상온에서 전해액 내에서 미반응물 또는 석출된 채로 존재하고 있을 수 있다. 이에 따라 이차전지의 수명 또는 저항특성이 저하되는 부반응이 발생될 수 있다.These additional additives may be used in admixture of two or more, and may be contained in an amount of 20 wt% or less, specifically 0.01 wt% to 20 wt%, preferably 0.1 wt% to 10 wt%, based on the total amount of the electrolytic solution. If the content of the additive additive is less than 0.01% by weight, the effect of improving the low temperature power of the battery and improving the high-temperature storage characteristics and high-temperature lifetime characteristics are insignificant. If the content of the additive additive exceeds 20% by weight, There is a possibility that a side reaction in the electrolytic solution is excessive. In particular, when the additive for forming the SEI film is excessively added, it can not be sufficiently decomposed at a high temperature, and may be present in the electrolyte solution at room temperature without being reacted or precipitated. As a result, a side reaction in which the lifetime or the resistance characteristic of the secondary battery is lowered may occur.
(2) 리튬 이차전지용 겔 폴리머 전해질(2) Gel polymer electrolyte for lithium secondary battery
또한, 본 발명의 일 실시예에서는Also, In one embodiment of the present invention
리튬염, 유기용매, 및 상기 화학식 1로 표시되는 올리고머 유래 폴리머를 포함하는 리튬 이차전지용 전해질을 제공한다. A lithium salt, an organic solvent, and an oligomer-derived polymer represented by the above formula (1).
상기 리튬 이차전지용 전해질은 상기 리튬염, 유기용매, 상기 화학식 1로 표시되는 올리고머 및 중합개시제를 포함하는 겔 폴리머 전해질용 조성물을 열 중합하여 형성할 수 있다.The electrolyte for a lithium secondary battery can be formed by thermally polymerizing a composition for a gel polymer electrolyte comprising the lithium salt, the organic solvent, the oligomer represented by the Formula 1, and a polymerization initiator.
한편, 상기 화학식 1로 표시되는 올리고머 유래 폴리머는 중합개시제 존재 하에서 상기 화학식 1로 표시되는 올리고머가 3차원 구조로 가교 결합되면서 형성된 매트릭스 폴리머를 포함할 수 있다. On the other hand, the oligomer-derived polymer represented by Formula 1 may include a matrix polymer formed by crosslinking the oligomer represented by Formula 1 in a three-dimensional structure in the presence of a polymerization initiator.
이러한 본 발명의 리튬 이차전지용 전해질은 상기 화학식 1로 표시되는 올리고머가 3차원 구조로 가교 결합되면서 형성된 매트릭스 폴리머 내에 상기 리튬염이 용해된 비수전해액이 포함된 형태의 겔 상 전해질일 수 있다.The electrolyte for a lithium secondary battery of the present invention may be a gel electrolyte in which a non-aqueous electrolyte in which the lithium salt is dissolved is contained in a matrix polymer formed by crosslinking the oligomer represented by Formula 1 in a three-dimensional structure.
한편, 상기 본 발명의 리튬 이차전지용 전해질을 제조하기 위하여 제공되는 겔 폴리머 전해질용 조성물에 포함되는 리튬염 및 유기용매, 및 올리고머의 종류 및 농도 등에 관한 설명은 전술한 내용과 중복되므로, 그 기재를 생략한다.The description of the lithium salt and the organic solvent, and the type and concentration of the oligomer contained in the gel polymer electrolyte composition for preparing the electrolyte for a lithium secondary battery according to the present invention is the same as that described above, It is omitted.
이때, 상기 화학식 1로 표시되는 올리고머는 겔 폴리머 전해질용 조성물 전체 중량을 기준으로 0.5 중량% 내지 30 중량%, 구체적으로 0.5 중량% 내지 25 중량%, 보다 구체적으로 0.5 중량% 내지 10 중량%, 더욱 구체적으로 0.5 중량% 내지 5 중량%로 포함될 수 있다. The oligomer represented by Formula 1 may be used in an amount of 0.5 to 30% by weight, specifically 0.5 to 25% by weight, more preferably 0.5 to 10% by weight, based on the total weight of the gel polymer electrolyte composition, Specifically 0.5% to 5% by weight.
상기 화학식 1로 표시되는 올리고머의 함량이 상기 범위, 즉 0.5 중량% 내지 30 중량% 범위로 포함되면 기계적 강도가 우수한 고분자 네트워크를 형성할 수 있으므로, 제반 성능이 향상된 이차전지를 제조할 수 있다. 구체적으로, 화학식 1로 표시되는 올리고머의 함량이 겔 폴리머 전해질용 조성물 전체 중량을 기준으로 0.5 중량% 이상이면 올리고머에 의한 고분자 매트릭스가 용이하게 형성될 수 있고, 겔 고분자 전해질의 기계적 강도를 확보할 수 있다. 또한, 화학식 1로 표시되는 올리고머의 함량이 겔 폴리머 전해질용 조성물 전체 중량을 기준으로 30 중량% 이하이면, 과량의 올리고머 첨가에 따른 저항 증가를 방지하고, 적절한 점도를 확보하여 겔 폴리머 전해질용 조성물의 웨팅성을 개선할 수 있고, 프리-겔 반응을 방지할 수 있다. 더욱이, 리튬 이온의 이동 제한을 개선하여 이온전도도를 확보하여, 사이클 수명 특성을 향상시킬 수 있다. 만약, 상기 화학식 1로 표시되는 올리고머의 함량이 30 중량%를 초과하면, 겔 폴리머 전해질용 조성물에 대한 올리고머의 용해도가 낮아지면서 조성물의 점도가 커져 웨팅성이 저하되고, 전극의 계면저항 증가하여 전지의 전압 강하가 야기될 수 있다.When the content of the oligomer represented by Formula 1 is within the above range, that is, in the range of 0.5 wt% to 30 wt%, a polymer network having excellent mechanical strength can be formed, and thus a secondary battery having improved performance can be manufactured. Specifically, if the content of the oligomer represented by the general formula (1) is 0.5% by weight or more based on the total weight of the composition for a gel polymer electrolyte, the polymer matrix by oligomer can be easily formed and the mechanical strength of the gel polymer electrolyte can be secured have. When the content of the oligomer represented by the general formula (1) is 30% by weight or less based on the total weight of the composition for a gel polymer electrolyte, an increase in resistance due to the addition of an excessive amount of oligomer is prevented, The wettability can be improved and the pre-gel reaction can be prevented. Furthermore, the ion conductivity can be secured by improving the movement limitation of lithium ions, and the cycle life characteristics can be improved. If the amount of the oligomer represented by Formula 1 is more than 30% by weight, the solubility of the oligomer in the composition for a gel polymer electrolyte is lowered, and the viscosity of the composition is increased to deteriorate the wettability, A voltage drop of < / RTI >
한편, 상기 화학식 1로 표시되는 올리고머 유래 폴리머는 리튬 이차전지용 전해질 전체 중량을 기준으로 0.5 중량% 내지 30 중량%, 구체적으로 0.5 중량% 내지 25 중량%, 보다 구체적으로 0.5 중량% 내지 10 중량%, 더욱 구체적으로 0.5 중량% 내지 5 중량%로 포함될 수 있다. On the other hand, the oligomer-derived polymer represented by Formula 1 is used in an amount of 0.5 to 30 wt%, specifically 0.5 to 25 wt%, more specifically 0.5 to 10 wt%, based on the total weight of the electrolyte for a lithium secondary battery, More specifically from 0.5% to 5% by weight.
즉, 상기 화학식 1로 표시되는 올리고머 유래 폴리머는 열중합 반응에 의해 화학식 1로 표시되는 올리고머가 3차원 구조로 형성된 매트릭스 폴리머로서, 그 함량은 겔 폴리머 전해질용 조성물에 포함되는 화학식 1로 표시되는 올리고머의 함량과 동일한 것이 바람직하다. .That is, the oligomer-derived polymer represented by Formula 1 is a matrix polymer in which the oligomer represented by Formula 1 is formed into a three-dimensional structure by thermal polymerization reaction, and its content is the oligomer represented by Formula 1 contained in the composition for a gel polymer electrolyte Is preferably the same as the content of .
이때, 상기 화학식 1로 표시되는 올리고머 유래 폴리머의 함량이 0.5 중량% 이상이면 겔 고분자 전해질의 기계적 강도와 같은 물성을 확보할 수 있다. 또한, 30 중량% 이하이면, 과량의 올리고머 첨가에 따른 저항 증가를 방지하고, 리튬 이온의 이동 제한을 개선하여 이온전도도를 확보할 수 있다. 만약, 상기 화학식 1로 표시되는 올리고머 유래 폴리머의 함량이 30 중량%를 초과하면, 전해질의 이온전도도가 저하되고, 전극과의 계면저항 증가로 인해 전지의 전압 강하가 야기될 수 있다.At this time, when the content of the oligomer-derived polymer represented by the above-mentioned formula (1) is 0.5 weight% or more, the same physical properties as the mechanical strength of the gel polymer electrolyte can be secured. If it is 30% by weight or less, the increase in resistance due to the addition of an excessive amount of oligomer can be prevented, and the ionic conductivity can be ensured by restricting the movement restriction of lithium ions. If the content of the oligomer-derived polymer represented by the above formula (1) is more than 30% by weight, the ion conductivity of the electrolyte is lowered, and the voltage drop of the battery may be caused due to an increase in the interface resistance with the electrode.
앞서 전술한 바와 같이, 또한, 상기 화학식 1로 표시되는 올리고머 유래 폴리머는 초기 충전시 전극 표면에 안정한 이온전도성 피막을 형성하는 동시에 과충전 시 음극 표면에 석출된 Li 금속과 전해질의 부반응을 억제하고, 양극과의 산화 반응을 억제함으로써, 기존 리튬 이차전지용 전해질 대비 전극의 계면 저항 증가 및 이로부터 발생하는 충방전시 평균전압 변화를 억제할 수 있다.As described above, the oligomer-based polymer represented by the above formula (1) forms a stable ion conductive film on the electrode surface at the time of initial charging, suppresses side reactions between Li metal deposited on the surface of the cathode upon overcharging and the electrolyte, It is possible to suppress an increase in the interfacial resistance of the electrode and an average voltage change during charging and discharging resulting from the increase in the resistance of the electrode relative to the electrolyte for the conventional lithium secondary battery.
뿐만 아니라, 상기 화학식 1로 표시되는 올리고머 유래 폴리머는 리튬염을 해리하는 능력을 보유하고 있어 리튬 이온 이동성을 향상시킬 수 있고, 특히 주사슬의 반복단위로 전기화학적으로 매우 안정하고, Li 이온과의 반응성이 낮은 실록산기(-Si-O-)등의 관능기를 포함하기 때문에, 리튬 이온 (Li+)의 부반응 및 리튬염(salt)의 분해 반응 등을 제어할 수 있으므로, 과충전 시에 CO 또는 CO2 등의 가스 발생을 저감할 수 있다. 따라서, 과충전 시에 발화 등을 억제하여 이차전지의 안정성을 보다 향상시킬 수 있다. In addition, the oligomer-derived polymer represented by the above formula (1) has the ability to dissociate the lithium salt to improve the lithium ion mobility. In particular, it is a stable repeating unit of the main chain and is extremely stable electrochemically. (-Si-O-) and the like, it is possible to control the side reaction of the lithium ion (Li + ) and the decomposition reaction of the lithium salt, 2 can be reduced. Therefore, ignition or the like can be suppressed at the time of overcharging, and the stability of the secondary battery can be further improved.
한편, 본 발명의 화학식 1로 표시되는 올리고머 유래 폴리머는 주사슬의 반복단위로 실록산기(-[Si-O]-)와 우레탄기를 포함하며, 올리고머는 구조 내에 실록산기와 함께 -Si-기를 추가로 포함하지 않는 것이 바람직하다. 즉, 상기 올리고머 구조 내에 반복단위로 추가의 -Si-기를 포함하지 않음으로써, 양 말단의 관능기의 비율을 높이고, 전체 고분자의 분자량을 낮출 수 있기 때문에, 전해질 내 동일 함량을 투입한다고 가정하는 경우 구조 내에 -Si-기를 추가로 포함하는 올리고머 (예컨대, 주사슬 반복단위로 -[Si-O]-Si-구조 포함) 대비 전체 올리고머의 함량을 늘려줄 수 있다. 따라서, 겔 고분자의 반응속도를 유리하게 가져갈 수 있고, 겔 고분자의 경도를 높여 전체 전지의 경도를 강화시킬 수 있으므로, 물리적인 충격을 주는 안전성 평가, 예컨대 충격 평가에 보다 유리하게 작용할 수 있다. On the other hand, the oligomer-derived polymer represented by Formula 1 of the present invention contains a siloxane group (- [Si-O] -) and a urethane group as repeating units of the main chain, It is preferable not to include it. That is, since the oligomer structure does not contain additional -Si- group as a repeating unit, the ratio of the functional groups at both terminals can be increased and the molecular weight of the entire polymer can be lowered. Therefore, Can further increase the content of the entire oligomer relative to an oligomer further including a -Si- group (e.g., [Si-O] -Si- structure in the main chain repeat unit). Therefore, the reaction rate of the gel polymer can be advantageously taken, and the hardness of the gel polymer can be increased to enhance the hardness of the whole cell, so that it can be more advantageously used for safety evaluation such as impact evaluation which gives physical impact.
(2-1) 중합개시제(2-1) Polymerization initiator
한편, 상기 겔 폴리머 전해질 제조를 위해 사용되는 중합개시제는 당 업계에 알려진 통상적인 중합개시제가 사용될 수 있다. 예를 들면, 상기 중합개시제는 열에 의해 분해되어 라디칼을 형성하고, 자유라디칼 중합에 의해 화학식 1로 표시되는 올리고머와 반응하여 겔 폴리머 전해질을 형성할 수 있다.On the other hand, the polymerization initiator used for preparing the gel polymer electrolyte may be a conventional polymerization initiator known in the art. For example, the polymerization initiator may be decomposed by heat to form a radical, and react with an oligomer represented by the general formula (1) by free radical polymerization to form a gel polymer electrolyte.
구체적으로, 상기 중합개시제는 아조계 중합개시제 또는 퍼옥사이드계 중합개시제를 사용할 수 있으며, 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)로 이루어진 군으로부터 선택된 적어도 하나 이상의 퍼옥사이드계 화합물, 또는 2,2'-아조비스(2-시아노부탄), 디메틸 2,2'-아조비스(2-메틸프로피오네이트), 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 군으로부터 선택된 적어도 하나 이상의 아조계 화합물을 들 수 있다.Specifically, the polymerization initiator may be an azo-based polymerization initiator or a peroxide-based polymerization initiator. Typical examples thereof include benzoyl peroxide, acetyl peroxide, dilauryl peroxide, Di-tert-butyl peroxide, t-butyl peroxy-2-ethyl-hexanoate, cumyl hydroperoxide, And at least one peroxide compound selected from the group consisting of hydrogen peroxide and at least one peroxide compound selected from the group consisting of 2,2'-azobis (2-cyanobutane), dimethyl 2,2'-azobis Azobis (iso-butyronitrile)) and 2,2'-azobis (isobutyronitrile) (2,2'-azobis (isobutyronitrile) A group consisting of 2'-azobisdimethyl-valeronitrile (AMVN) Emitter may include at least one azo compound selected.
상기 중합개시제는 이차전지 내에서 열, 비제한적인 예로 30℃ 내지 100℃, 구체적으로 60℃ 내지 80℃의 열에 의해 분해되거나 상온(5℃ 내지 30℃)에서 분해되어 라디칼을 형성하고, 자유라디칼 중합에 의해 중합성 올리고머가 아크릴레이트계 화합물과 반응하여 겔 폴리머 전해질을 형성할 수 있다.The polymerization initiator may be decomposed by heat in a secondary battery at 30 ° C to 100 ° C, specifically 60 ° C to 80 ° C, or decomposed at room temperature (5 ° C to 30 ° C) to form radicals, and free radicals The polymerizable oligomer reacts with the acrylate-based compound by polymerization to form a gel polymer electrolyte.
상기 중합개시제는 상기 올리고머 전체 100 중량부를 기준으로 약 0.01 중량부 내지 약 20 중량부, 구체적으로 5 중량부로 포함될 수 있으며, 상기 범위로 포함되는 경우 겔화 반응을 용이하게 실시하여, 겔 고분자 전환율을 높여 겔 고분자 전해질 특성이 확보할 수 있고, 중합 반응 후 미반응 중합개시제가 남아 부반응을 야기하는 것을 방지할 수 있으며, 전극에 대한 전해액의 웨팅성을 향상시킬 수 있다. The polymerization initiator may be included in an amount of about 0.01 part by weight to about 20 parts by weight, specifically about 5 parts by weight, based on 100 parts by weight of the entire oligomer. When the oligomer is included in the above range, the gelation reaction is easily performed to increase the gel polymer conversion Gel polymer electrolyte properties can be ensured, the unreacted polymerization initiator after the polymerization reaction can be prevented from causing side reactions, and the wettability of the electrolyte solution to the electrode can be improved.
특히, 일부 중합개시제의 경우 열 등에 의하여 라디칼이 발생하는 과정에서 질소 혹은 산소 가스가 발생하기도 한다. 이러한 가스 발생은 겔 고분자 전해질 형성 과정에서 가스 트랩 또는 가스 버블링 현상으로 이어지는 경우가 대다수이다. 이러한 가스 발생의 경우 겔 고분자 전해질 내에서 결함(defect)을 야기하기 때문에 전해질 품질 저하로 나타난다. 따라서, 중합개시제가 상기 범위로 포함되는 경우 가스가 다량 발생하는 등의 단점을 보다 효과적으로 방지할 수 있다. Particularly, in the case of some polymerization initiators, nitrogen or oxygen gas is generated in the process of generating radicals by heat or the like. This gas generation is most likely to lead to a gas trap or a gas bubbling phenomenon in the process of forming a gel polymer electrolyte. Such gas generation causes defects in the gel polyelectrolyte, resulting in deterioration of electrolyte quality. Therefore, when the polymerization initiator is included in the above range, it is possible to more effectively prevent the disadvantage that a large amount of gas is generated.
이차전지Secondary battery
또한, 본 발명의 일 실시예에서는In an embodiment of the present invention,
음극, 양극, 상기 음극 및 양극 사이에 개재된 분리막, 및 본 발명의 리튬 이차전지용 전해질을 포함하는 리튬 이차전지를 제공할 수 있다.A separator interposed between the cathode and the anode, and a lithium secondary battery including the electrolyte for the lithium secondary battery of the present invention.
상기 리튬 이차전지용 전해질은 액체 전해질 또는 겔 폴리머 전해질일 수 있다.The electrolyte for the lithium secondary battery may be a liquid electrolyte or a gel polymer electrolyte.
상기 리튬 이차전지용 전해질이 액체 전해질인 경우, 본 발명의 리튬 이차전지는 양극, 음극 및 양극과 음극 사이에 선택적으로 개재된 분리막이 순차적으로 적층되어 이루어진 전극조립체를 이차전지 케이스 또는 외장재에 수납한 다음, 본 발명의 리튬 이차전지용 전해질을 주입하여 제조할 수 있다. When the electrolyte for a lithium secondary battery is a liquid electrolyte, the lithium secondary battery of the present invention includes an anode assembly, a cathode assembly, and a separator layer selectively interposed between the anode assembly and the cathode assembly, , And injecting an electrolyte for a lithium secondary battery of the present invention.
또한, 상기 리튬 이차전지용 전해질이 상기 화학식 1로 표시되는 올리고머 간의 중합에 의해 형성된 폴리머 매트릭스를 포함하는 겔 폴리머 전해질인 경우, 본 발명의 리튬 이차전지는 양극, 음극, 및 양극과 음극 사이에 선택적으로 개재된 분리막이 순차적으로 적층되어 이루어진 전극조립체를 이차전지 케이스 또는 외장재에 수납한 다음, 상기 리튬 이차전지용 전해질 조성물을 주입한 후 경화 반응시켜 제조될 수 있다.In the case where the electrolyte for a lithium secondary battery is a gel polymer electrolyte comprising a polymer matrix formed by polymerization between oligomers represented by Formula 1, the lithium secondary battery of the present invention may include a positive electrode, a negative electrode, And then the electrolyte assembly for a lithium secondary battery is injected and cured to form an electrode assembly.
예를 들면, 이차전지의 내부에서 리튬 이차전지용 전해질을 주입한 in-situ 중합 반응을 실시하여 형성될 수 있다. 상기 in-situ 중합 반응은 전자빔(E-BEAM), 감마선, 상온 또는 고온 에이징 공정을 통하여 가능하며, 본 발명의 일 실시예에 따르면 열 중합을 통해 진행될 수 있다. 이때, 중합 시간은 대략 2분 내지 48시간 정도 소요되며, 열 중합 온도는 60℃ 내지 100℃, 구체적으로 60℃ 내지 80℃ 가 될 수 있다.For example, it can be formed by carrying out an in-situ polymerization reaction in which an electrolyte for a lithium secondary battery is injected into a secondary battery. The in-situ polymerization may be performed by E-BEAM, gamma ray, room temperature or high temperature aging process, and thermal polymerization may be performed according to one embodiment of the present invention. In this case, the polymerization time is about 2 minutes to 48 hours, and the thermal polymerization temperature may be 60 to 100 占 폚, specifically 60 to 80 占 폚.
한편, 본 발명의 리튬 이차전지에서 상기 양극, 음극 및 분리막은 리튬 이차전지 제조 시에 통상적인 방법으로 제조되어 사용되던 것들이 모두 사용될 수 있다.Meanwhile, in the lithium secondary battery of the present invention, the positive electrode, the negative electrode, and the separator may be any of those conventionally manufactured and used in the production of a lithium secondary battery.
(1) 양극(1) anode
먼저, 상기 양극은 양극 집전체 상에 양극 합제층을 형성하여 제조할 수 있다. 상기 양극 합제층은 양극활물질, 바인더, 도전재 및 용매 등을 포함하는 양극 슬러리를 양극 집전체 상에 코팅한 후, 건조 및 압연하여 형성할 수 있다.First, the positive electrode may be manufactured by forming a positive electrode mixture layer on the positive electrode current collector. The positive electrode mixture layer may be formed by coating a positive electrode slurry containing a positive electrode active material, a binder, a conductive material and a solvent on a positive electrode collector, followed by drying and rolling.
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-YMnYO2(여기에서, 0<Y<1), LiMn2-zNizO4(여기에서, 0＜Z＜2) 등), 리튬-니켈-코발트계 산화물(예를 들면, LiNi1-Y1CoY1O2(여기에서, 0<Y1<1) 등), 리튬-망간-코발트계 산화물(예를 들면, LiCo1-Y2MnY2O2(여기에서, 0<Y2<1), LiMn2-z1Coz1O4(여기에서, 0＜Z1＜2) 등), 리튬-니켈-망간-코발트계 산화물(예를 들면, Li(NipCoqMnr1)O2(여기에서, 0＜p＜1, 0＜q＜1, 0＜r1＜1, p+q+r1=1) 또는 Li(Nip1Coq1Mnr2)O4(여기에서, 0＜p1＜2, 0＜q1＜2, 0＜r2＜2, p1+q1+r2=2) 등), 또는 리튬-니켈-코발트-전이금속(M) 산화물(예를 들면, Li(Nip2Coq2Mnr3MS2)O2(여기에서, M은 Al, Fe, V, Cr, Ti, Ta, Mg 및 Mo로 이루어지는 군으로부터 선택되고, p2, q2, r3 및 s2는 각각 독립적인 원소들의 원자분율로서, 0＜p2＜1, 0＜q2＜1, 0＜r3＜1, 0＜s2＜1, p2+q2+r3+s2=1이다)) 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-Y Mn Y O 2 (where, 0 <Y <1), LiMn 2-z Ni z O 4 ( here, 0 <Z <2) and the like), lithium-nickel-cobalt oxide (e. g., in LiNi 1-Y1 Co Y1 O 2 ( here, 0 <Y1 <1) and the like), lithium-manganese-cobalt oxide (e. g., (in which LiCo 1-Y2 Mn Y2 O 2 , 0 <Y2 <1), LiMn 2-z1 Co z1 O 4 ( here, 0 <z1 <2) and the like), lithium-nickel -manganese-cobalt oxide (e.g., Ni p Co q Mn r1 (Li) O 2 (here, 0 <p <1, 0 <q <1, 0 <r1 <1, p + q + r1 = 1) or Li (Ni p1 Co q1 Mn r2) O 4 (here, 0 <p1 <2, 0 <q1 <2, 0 <r2 <2, p1 + q1 + r2 = 2) , etc.), or a lithium- nickel-cobalt-transition metal (M) oxide (e.g., Li (Ni Co p2 q2 Mn r3 M S2) O 2 (here, Wherein M is selected from the group consisting of Al, Fe, V, Cr, Ti, Ta, Mg and Mo, and p2, q2, r3 and s2 are atomic fractions of independent elements, 0 <p2 < 1, 0 <r3 <1, 0 <s2 <1, and p2 + q2 + r3 + s2 = 1)), and any one or two 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(Ni1/3Mn1/3Co1/3)O2, Li(Ni0.6Mn0.2Co0.2)O2, Li(Ni0.5Mn0.3Co0.2)O2, Li(Ni0.7Mn0.15Co0.15)O2 및 Li(Ni0.8Mn0.1Co0.1)O2 등), 또는 리튬 니켈코발트알루미늄 산화물(예를 들면, Li(Ni0.8Co0.15Al0.05)O2 등) 등일 수 있다.Among these, the lithium composite metal oxide may be LiCoO 2 , LiMnO 2 , LiNiO 2 , lithium nickel manganese cobalt oxide (for example, Li (Ni 1/3 Mn 1/3 Co 1 / 3 ) O 2 , 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 and Li (Ni 0.8 Mn 0.1 Co 0.1 ) O 2 ), or lithium nickel cobalt aluminum oxide (e.g., Li (Ni 0.8 Co 0.15 Al 0.05 ) O 2, etc.) and the like.
상기 양극 활물질은 양극 슬러리 중 고형분의 전체 중량을 기준으로 40 중량% 내지 90 중량%, 구체적으로 40 중량% 내지 75 중량%로 포함될 수 있다.The cathode active material may be contained in an amount of 40% by weight to 90% by weight, specifically 40% by weight to 75% by weight, based on the total weight of the solid content in the cathode slurry.
상기 바인더는 활물질과 도전재 등의 결합과 집전체에 대한 결합에 조력하는 성분으로서, 통상적으로 양극 슬러리 중 고형분의 전체 중량을 기준으로 1 내지 30 중량%로 첨가된다. 이러한 바인더의 예로는, 폴리비닐리덴플루오라이드(PVDF), 폴리비닐알코올, 카르복시메틸셀룰로우즈(CMC), 전분, 히드록시프로필셀룰로우즈, 재생 셀룰로우즈, 폴리비닐피롤리돈, 테트라플루오로에틸렌, 폴리에틸렌, 폴리프로필렌, 에틸렌-프로필렌-디엔 테르 폴리머(EPDM), 술폰화 EPDM, 스티렌-부타디엔 고무, 불소 고무, 다양한 공중합체 등을 들 수 있다.The binder is a component that assists in bonding of the active material to the conductive material and bonding to the current collector, and is usually added in an amount of 1 to 30 wt% based on the total weight of the solid content in the positive electrode slurry. Examples of such binders include polyvinylidene fluoride (PVDF), polyvinyl alcohol, carboxymethylcellulose (CMC), starch, hydroxypropylcellulose, regenerated cellulose, polyvinylpyrrolidone, tetrafluoroethylene (Ethylene-propylene-diene terpolymer (EPDM), sulfonated EPDM, styrene-butadiene rubber, fluorine rubber, various copolymers and the like.
이러한 도전재는 당해 전지에 화학적 변화를 유발하지 않으면서 도전성을 가진 것이라면 특별히 제한되는 것은 아니며, 예를 들어, 카본블랙, 아세틸렌 블랙, 케첸 블랙, 채널 블랙, 퍼니스 블랙, 램프 블랙, 또는 서멀 블랙 등의 탄소 분말; 결정구조가 매우 발달된 천연 흑연, 인조흑연, 또는 그라파이트 등의 흑연 분말; 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. Such a conductive material is not particularly limited as long as it has electrical conductivity without causing chemical changes in the battery. For example, carbon black, acetylene black, ketjen black, channel black, furnace black, lamp black, Carbon powder; Graphite powder such as natural graphite, artificial graphite, or graphite with a highly developed crystal structure; 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 통상적으로 양극 슬러리 중 고형분의 전체 중량을 기준으로 1 내지 30 중량%로 첨가된다. The conductive material is usually added in an amount of 1 to 30% by weight based on the total weight of the solid content in the positive electrode slurry.
상기 도전재는 아세틸렌 블랙 계열인 쉐브론 케미칼 컴퍼니(Chevron Chemical Company)나 덴카 블랙(Denka Singapore Private Limited), 걸프 오일 컴퍼니(Gulf Oil Company) 제품 등), 케첸 블랙(Ketjenblack), EC 계열(아르막 컴퍼니(Armak Company) 제품), 불칸(Vulcan) XC-72(캐보트 컴퍼니(Cabot Company) 제품) 및 수퍼(Super) P(Timcal 사 제품) 등의 명칭으로 시판되고 있는 것을 사용할 수도 있다.The conductive material may be selected from the group consisting of acetylene black series such as Chevron Chemical Company, Denka Singapore Private Limited, Gulf Oil Company products, Ketjenblack, EC series Armak Company), Vulcan XC-72 (Cabot Company) and Super P (Timcal Co.), and the like.
상기 용매는 NMP(N-methyl-2-pyrrolidone) 등의 유기용매를 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 슬러리 중의 고형분 농도가 10 중량% 내지 70 중량%, 바람직하게 20 중량% 내지 60 중량%가 되도록 포함될 수 있다.The solvent may include an organic solvent such as N-methyl-2-pyrrolidone (NMP), and may be used in an amount that provides a preferable viscosity when the positive electrode active material and optionally a binder and a conductive material are included. For example, the solid content in the slurry containing the cathode active material, and optionally the binder and the conductive material may be 10 wt% to 70 wt%, preferably 20 wt% to 60 wt%.
(2) 음극(2) cathode
상기 음극은 금속 또는 준금속 박막을 단독으로 사용한 메탈 전극이거나, 또는 음극 집전체 상에 상기 금속 또는 준금속 박막이 적층된 구조로 이루어진 것일 수 있다.The cathode may be a metal electrode using a metal or a quasi-metal thin film alone, or a structure in which the metal or a quasi metal thin film is stacked on an anode current collector.
이때, 상기 금속 또는 준금속은 Li, Cu, Ni, Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Si, Sb, Pb, In, Zn, Ba, Ra, Ge, Al, Sn, Ag, Pt 및 Au으로 이루어진 군으로부터 선택되는 적어도 하나일 수 있다. The metal or metalloid may be selected from the group consisting of Li, Cu, Ni, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Si, Sb, Pb, In, Zn, Ba, Sn, Ag, Pt, and Au.
구체적으로, 상기 음극은 Li 메탈 전극을 이용할 수 있다.Specifically, the cathode may be a Li metal electrode.
한편, 상기 음극은 메탈 전극을 단독으로 사용하거나, 또는 음극 집전체 상에 금속 또는 준금속 박막이 적층된 구조로 이루어진 외에도, 음극 집전체 상에 음극 합제층을 형성하여 제조한 것을 이용할 수도 있다. The negative electrode may be formed by using a metal electrode alone or by stacking a metal or metalloid thin film on the negative electrode current collector, or by forming a negative electrode mixture layer on the negative electrode current collector.
이러한 음극 합제층은 음극 집전체 상에 음극활물질, 바인더, 도전재 및 용매 등을 포함하는 슬러리를 코팅한 후, 건조 및 압연하여 형성할 수 있다.The negative electrode mixture layer may be formed by coating a negative electrode current collector with a slurry containing a negative electrode active material, a binder, a conductive material, a solvent, and the like, followed by drying and rolling.
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.The anode current collector generally has a thickness of 3 to 500 mu m. 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.
또한, 상기 음극 활물질은 리튬 이온을 가역적으로 인터칼레이션/디인터칼레이션할 수 있는 탄소 물질, 금속 복합 산화물, 리튬을 도프 및 탈도프할 수 있는 물질, 및 전이 금속 산화물로 이루어진 군으로부터 선택된 적어도 하나 이상을 더 포함할 수도 있다. Further, the negative electrode active material may be at least one selected from the group consisting of a carbon material capable of reversibly intercalating / deintercalating lithium ions, a metal composite oxide, a material capable of doping and dedoping lithium, and a transition metal oxide And may further include one or more.
상기 리튬 이온을 가역적으로 인터칼레이션/디인터칼레이션할 수 있는 탄소 물질로는, 리튬 이온 이차전지에서 일반적으로 사용되는 탄소계 음극 활물질이라면 특별히 제한 없이 사용할 수 있으며, 그 대표적인 예로는 결정질 탄소, 비정질 탄소 또는 이들을 함께 사용할 수 있다. 상기 결정질 탄소의 예로는 무정형, 판상, 인편상(flake), 구형 또는 섬유형의 천연 흑연 또는 인조 흑연과 같은 흑연을 들 수 있고, 상기 비정질 탄소의 예로는 소프트 카본(soft carbon: 저온 소성 탄소) 또는 하드 카본(hard carbon), 메조페이스 피치 탄화물, 소성된 코크스 등을 들 수 있다.The carbonaceous material capable of reversibly intercalating / deintercalating lithium ions is not particularly limited as long as it is a carbonaceous anode active material generally used in a lithium ion secondary battery. Examples of the carbonaceous material include crystalline carbon, Amorphous carbon or any combination thereof. Examples of the crystalline carbon include graphite such as natural graphite or artificial graphite in the form of amorphous, plate-like, flake, spherical or fiber, and examples of the amorphous carbon include soft carbon (soft carbon) Or hard carbon, mesophase pitch carbide, fired coke, and the like.
상기 금속 복합 산화물로는 PbO, PbO2, Pb2O3, Pb3O4, Sb2O3, Sb2O4, Sb2O5, GeO, GeO2, Bi2O3, Bi2O4, Bi2O5, LixFe2O3(0≤x≤1), LixWO2(0≤x≤1), 및 SnxMe1-xMe'yOz (Me: Mn, Fe, Pb, Ge; Me': Al, B, P, Si, 주기율표의 1족, 2족, 3족 원소, 할로겐; 0<x=1; 1≤y≤3; 1≤z≤8) 로 이루어진 군에서 선택되는 것이 사용될 수 있다.In the metal composite oxide is PbO, PbO 2, Pb 2 O 3, Pb 3 O 4, Sb 2 O 3, Sb 2 O 4, Sb 2 O 5, GeO, GeO 2, Bi 2 O 3, Bi 2 O 4 , Bi 2 O 5 , Li x Fe 2 O 3 (0? X? 1), Li x WO 2 (0? X? 1), and Sn x Me 1-x Me y y z , Pb, Ge, Me ': Al, B, P, Si, Group 1, Group 2, Group 3 elements of the periodic table, Halogen; 0 <x = 1; 1? Y? 3; May be used.
상기 리튬을 도프 및 탈도프할 수 있는 물질로는 Si, SiOx(0<x≤2), Si-Y 합금(상기 Y는 알칼리 금속, 알칼리 토금속, 13족 원소, 14족 원소, 전이금속, 희토류 원소 및 이들의 조합으로 이루어진 군에서 선택되는 원소이며, Si은 아님), Sn, SnO2, Sn-Y(상기 Y는 알칼리 금속, 알칼리 토금속, 13족 원소, 14족 원소, 전이금속, 희토류 원소 및 이들의 조합으로 이루어진 군에서 선택되는 원소이며, Sn은 아님) 등을 들 수 있고, 또한 이들 중 적어도 하나와 SiO2를 혼합하여 사용할 수도 있다. 상기 원소 Y로는 Mg, Ca, Sr, Ba, Ra, Sc, Y, Ti, Zr, Hf, Rf, V, Nb, Ta, Db, Cr, Mo, W, Sg, Tc, Re, Bh, Fe, Pb, Ru, Os, Hs, Rh, Ir, Pd, Pt, Cu, Ag, Au, Zn, Cd, B, Al, Ga, Sn, In, Ge, P, As, Sb, Bi, S, Se, Te, Po, 및 이들의 조합으로 이루어진 군에서 선택될 수 있다.As the material capable of doping and dedoping lithium, Si, SiO x (0 <x? 2), Si-Y alloy (Y is an alkali metal, an alkaline earth metal, a Group 13 element, a Group 14 element, Rare earth elements and combinations thereof, but not Si), Sn, SnO 2 , Sn-Y (wherein Y is at least one element selected from the group consisting of alkali metals, alkaline earth metals, Group 13 elements, Group 14 elements, Element and an element selected from the group consisting of combinations thereof, and not Sn), and at least one of them may be mixed with SiO 2 . The element Y may be at least one element selected from the group consisting of Mg, Ca, Sr, Ba, Ra, Sc, Y, Ti, Zr, Hf, Rf, V, Nb, Ta, Db, Cr, Mo, W, Sg, Pb, Ru, Os, Hs, Rh, Ir, Pd, Pt, Cu, Ag, Au, Zn, Cd, B, Al, Ga, Sn, In, Ge, P, As, Sb, Bi, Te, Po, and combinations thereof.
상기 전이 금속 산화물로는 리튬 함유 티타늄 복합 산화물(LTO), 바나듐 산화물, 리튬 바나듐 산화물 등을 들 수 있다.Examples of the transition metal oxide include lithium-containing titanium composite oxide (LTO), vanadium oxide, lithium vanadium oxide, and the like.
상기 음극 활물질은 음극 슬러리 중 고형분의 전체 중량을 기준으로 80 중량% 내지 99 중량%로 포함될 수 있다.The negative active material may be contained in an amount of 80% by weight to 99% by weight based on the total weight of the solid content in the negative electrode slurry.
상기 바인더는 도전재, 활물질 및 집전체 간의 결합에 조력하는 성분으로서, 통상적으로 음극 슬러리 중 고형분의 전체 중량을 기준으로 1 내지 30 중량%로 첨가된다.　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, and is usually added in an amount of 1 to 30% by weight based on the total weight of the solid content in the negative electrode slurry. 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.
상기 도전재는 음극 활물질의 도전성을 더욱 향상시키기 위한 성분으로서, 음극 슬러리 중 고형분의 전체 중량을 기준으로 1 내지 20 중량%로 첨가될 수 있다.　이러한 도전재는 당해 전지에 화학적 변화를 유발하지 않으면서 도전성을 가진 것이라면 특별히 제한되는 것은 아니며, 예를 들어, 카본블랙, 아세틸렌 블랙, 케첸 블랙, 채널 블랙, 퍼니스 블랙, 램프 블랙, 또는 서멀 블랙 등의 탄소 분말; 결정구조가 매우 발달된 천연 흑연, 인조흑연, 또는 그라파이트 등의 흑연 분말; 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 and may be added in an amount of 1 to 20 wt% based on the total weight of the solid content in the negative electrode slurry. Such a conductive material is not particularly limited as long as it has electrical conductivity without causing chemical changes in the battery. For example, carbon black, acetylene black, ketjen black, channel black, furnace black, lamp black, Carbon powder; Graphite powder such as natural graphite, artificial graphite, or graphite with a highly developed crystal structure; 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 용매는 물 또는 NMP, 알코올 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 슬러리 중의 고형분 농도가 50 중량% 내지 75 중량%, 바람직하게 50 중량% 내지 65 중량%가 되도록 포함될 수 있다.The solvent may include water or an organic solvent such as NMP, alcohol, etc., and may be used in an amount in which the negative electrode active material and, optionally, a binder, a conductive material, and the like are contained in a desired viscosity. For example, the slurry containing the negative electrode active material and, optionally, the binder and the conductive material may be contained in such a manner that the solid concentration of the slurry is 50% by weight to 75% by weight, preferably 50% by weight to 65% by weight.
(3) 분리막(3) The membrane
또한, 상기 분리막은 양 전극의 내부 단락을 차단하고 전해질을 함침하는 역할을 하는 것으로, 고분자 수지, 충진제 및 용매를 혼합하여 분리막 조성물을 제조한 다음, 상기 분리막 조성물을 전극 상부에 직접 코팅 및 건조하여 분리막 필름을 형성하거나, 상기 분리막 조성물을 지지체 상에 캐스팅 및 건조된 후, 상기 지지체로부터 박리된 분리막 필름을 전극 상부에 라미네이션하여 형성할 수 있다. In addition, the separation membrane blocks the internal short circuit of both electrodes and impregnates the electrolyte. The separation membrane composition is prepared by mixing a polymer resin, a filler and a solvent, and then the separation membrane composition is directly coated on the electrode and dried Or may be formed by casting and drying the separation membrane composition on a support, and then laminating the separation membrane film peeled off from the support on the electrode.
상기 분리막은 통상적으로 사용되는 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.The separator may be a porous polymer film commonly used, such as a porous polymer film made of a polyolefin-based polymer such as an ethylene homopolymer, a propylene homopolymer, an ethylene / butene copolymer, an ethylene / hexene copolymer, and an ethylene / methacrylate copolymer The polymer film may be used alone or as a laminate thereof, or may be a nonwoven fabric made of a conventional porous nonwoven fabric, for example, glass fiber of high melting point, polyethylene terephthalate fiber or the like, but is not limited thereto.
이때, 상기 다공성 분리막의 기공 직경은 일반적으로 0.01 내지 50㎛이고, 기공도는 5 내지 95%일 수 있다. 또한 상기 다공성 분리막의 두께는 일반적으로 5 내지 300㎛ 범위일 수 있다. At this time, the pore diameter of the porous separation membrane is generally 0.01 to 50 μm, and the porosity may be 5 to 95%. The thickness of the porous separator may be generally in the range of 5 to 300 mu m.
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.
이하, 본 발명을 구체적으로 설명하기 위해 실시예를 들어 상세하게 설명하기로 한다. 그러나 본 발명에 따른 실시예는 여러 가지 다른 형태로 변형될 수 있으며, 본 발명의 범위가 아래에서 상술하는 실시예에 한정되는 것으로 해석되어서는 안 된다. 본 발명의 실시예는 당업계에서 평균적인 지식을 가진 자에게 본 발명을 보다 완전하게 설명하기 위해서 제공되는 것이다.BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to examples. However, the embodiments according to the present invention can be modified into various other forms, and the scope of the present invention should not be construed as being limited to the embodiments described below. The embodiments of the present invention are provided to enable those skilled in the art to more fully understand the present invention.
실시예Example
I. 액체 전해질을 포함하는 리튬 이차전지I. Lithium Secondary Battery Containing Liquid Electrolyte
실시예 1Example 1
(리튬 이차전지용 액체 전해질 제조)(Preparation of Liquid Electrolyte for Lithium Secondary Battery)
1M LiPF6가 용해된 유기용매(에틸렌 카보네이트(EC):에틸메틸카보네이트(EMC) = 3:7 부피비) 99.5g에 화학식 1a-1로 표시되는 올리고머 (중량평균분자량(Mw): 3,000, z1=10, x1=3) 0.5g을 첨가하여 리튬 이차전지용 액체 전해질을 제조하였다(하기 표 1 참조). (Weight average molecular weight (Mw): 3,000, z1 = 1) was added to 99.5 g of 1 M LiPF 6 -containing organic solvent (ethylene carbonate (EC): ethyl methyl carbonate (EMC) = 3: 10, x1 = 3) was added to prepare a liquid electrolyte for a lithium secondary battery (see Table 1 below).
(전극조립체 제조) (Manufacture of electrode assembly)
양극 활물질로 (LiNi3/5Co1/5Mn1/5O2; NCM),), 도전재로 카본 블랙(carbon black) 및 바인더로 폴리비닐리덴플루오라이드(PVDF)를 94:3:3의 중량 비율로 용매인 N-메틸-2-피롤리돈(NMP)에 첨가하여 양극 혼합물 슬러리 (고형분 함량: 65 중량%)를 제조하였다. 상기 양극 혼합물 슬러리를 두께가 20㎛ 정도의 양극 집전체인 알루미늄(Al) 박막에 도포하고, 건조하여 양극을 제조한 후, 롤 프레스(roll press)를 실시하여 양극을 제조하였다.(LiNi 3/5 Co 1/5 Mn 1/5 O 2 ; NCM) as a positive electrode active material, carbon black as a conductive material, and polyvinylidene fluoride (PVDF) as a binder in a ratio of 94: 3: 3 To the solvent N-methyl-2-pyrrolidone (NMP) to prepare a positive electrode mixture slurry (solid content: 65 wt%). The positive electrode mixture slurry was applied to an aluminum (Al) thin film having a thickness of about 20 탆 and dried to produce a positive electrode, followed by a roll press to prepare a positive electrode.
음극으로 리튬 메탈 전극을 사용하였다.A lithium metal electrode was used as a cathode.
상기 양극, 음극 및 폴리프로필렌/폴리에틸렌/폴리프로필렌 (PP/PE/PP) 3층으로 이루어진 분리막을 순차적으로 적층하여 전극조립체를 제조하였다.The positive electrode, the negative electrode and a separator composed of three layers of polypropylene / polyethylene / polypropylene (PP / PE / PP) were sequentially laminated to produce an electrode assembly.
(이차전지 제조)(Secondary Battery Manufacturing)
전지 케이스 내에 상기 조립된 전극조립체를 수납하고, 상기 리튬 이차전지용 전해질을 주입한 후 2일 동안 상온에서 저장하여 리튬 이차전지용 액체 전해질을 포함하는 코인 셀형 리튬 이차전지를 제조하였다.The assembled electrode assembly was housed in the battery case, and the electrolyte for the lithium secondary battery was injected and stored at room temperature for 2 days to prepare a coin cell type lithium secondary battery including a liquid electrolyte for a lithium secondary battery.
실시예 2.Example 2.
액체 전해질 제조 시에, 유기용매 80g에 화학식 1a-1로 표시되는 올리고머 20g을 포함하는 것을 제외하고는 상기 실시예 1과 마찬가지의 방법으로 리튬 이차전지용 액체 전해질 및 이를 포함하는 코인셀형 리튬 이차전지를 제조하였다(하기 표 1 참조).A liquid electrolyte for a lithium secondary battery and a coin cell type lithium secondary battery comprising the same were prepared in the same manner as in Example 1, except that 20 g of the oligomer represented by the formula (1a-1) was contained in 80 g of the organic solvent at the time of preparing the liquid electrolyte. (See Table 1 below).
실시예 3.Example 3.
액체 전해질 제조 시에, 유기용매 90 g에 화학식 1a-1로 표시되는 올리고머 10g을 포함하는 것을 제외하고는 상기 실시예 1과 마찬가지의 방법으로 리튬 이차전지용 액체 전해질 및 이를 포함하는 코인셀형 리튬 이차전지를 제조하였다(하기 표 1 참조).A liquid electrolyte for a lithium secondary battery and a coin cell type lithium secondary battery comprising the same were prepared in the same manner as in Example 1 except that 10 g of the oligomer represented by the general formula (1a-1) was contained in 90 g of the organic solvent in the production of the liquid electrolyte. (See Table 1 below).
실시예 4.Example 4.
액체 전해질 제조 시에, 화학식 1a-1로 표시되는 올리고머 대신 화학식 1b-1로 표시되는 올리고머(중량평균분자량(Mw): 5000, z2=8, x2=6)를 사용하는 것을 제외하고는 상기 실시예 3과 마찬가지의 방법으로 리튬 이차전지용 액체 전해질 및 이를 포함하는 코인셀형 리튬 이차전지를 제조하였다(하기 표 1 참조).Except that the oligomer (weight average molecular weight (Mw): 5000, z2 = 8, x2 = 6) represented by the formula (1b-1) was used instead of the oligomer represented by the formula (1a-1) A liquid electrolyte for a lithium secondary battery and a coin cell type lithium secondary battery comprising the same were prepared in the same manner as in Example 3 (see Table 1 below).
실시예 5.Example 5.
액체 전해질 제조 시에, 유기용매 75g에 화학식 1a-1로 표시되는 올리고머 25g을 포함하는 것을 제외하고는 상기 실시예 1과 마찬가지의 방법으로 리튬 이차전지용 액체 전해질 및 이를 포함하는 코인셀형 리튬 이차전지를 제조하였다(하기 표 1 참조).A liquid electrolyte for a lithium secondary battery and a coin cell type lithium secondary battery comprising the same were prepared in the same manner as in Example 1 except that 25 g of the oligomer represented by the formula (1a-1) was added to 75 g of the organic solvent at the time of preparing the liquid electrolyte. (See Table 1 below).
실시예 6.Example 6.
액체 전해질 제조 시에, 유기용매 70 g에 화학식 1a-1로 표시되는 올리고머 30g을 포함하는 것을 제외하고는 상기 실시예 1과 마찬가지의 방법으로 리튬 이차전지용 액체 전해질 및 이를 포함하는 코인셀형 리튬 이차전지를 제조하였다(하기 표 1 참조).A liquid electrolyte for a lithium secondary battery and a coin cell type lithium secondary battery comprising the same were prepared in the same manner as in Example 1 except that 30 g of the oligomer represented by the formula (1a-1) was contained in 70 g of the organic solvent in the production of the liquid electrolyte. (See Table 1 below).
실시예 7.Example 7.
액체 전해질 제조 시에, 유기용매 67 g에 화학식 1a-1로 표시되는 올리고머 33g을 포함하는 것을 제외하고는 상기 실시예 1과 마찬가지의 방법으로 리튬 이차전지용 액체 전해질 및 이를 포함하는 코인셀형 리튬 이차전지를 제조하였다(하기 표 1 참조).A liquid electrolyte for a lithium secondary battery and a coin cell type lithium secondary battery comprising the same were prepared in the same manner as in Example 1, except that 33 g of the oligomer represented by the formula (1a-1) was contained in 67 g of the organic solvent in the production of the liquid electrolyte. (See Table 1 below).
비교예 1.Comparative Example 1
액체 전해질 제조 시에, 화학식 1a-1로 표시되는 올리고머를 포함하지 않는 것을 제외하고는 상기 실시예 1과 마찬가지의 방법으로 리튬 이차전지용 액체 전해질 및 이를 포함하는 코인셀형 리튬 이차전지를 제조하였다(하기 표 1 참조).A liquid electrolyte for a lithium secondary battery and a coin cell type lithium secondary battery comprising the same were prepared in the same manner as in Example 1 except that the oligomer represented by the general formula (1a-1) was not included in the preparation of the liquid electrolyte See Table 1).
비교예 2.Comparative Example 2
액체 전해질 제조 시에, 화학식 1a-1로 표시되는 올리고머 대신 하기 화학식 2로 표시되는 올리고머(중량평균분자량(Mw) 7,800; o: 35; p: 30; q: 20)를 포함하는 것을 제외하고는 상기 실시예 1과 마찬가지의 방법으로 리튬 이차전지용 액체 전해질 및 이를 포함하는 코인셀형 리튬 이차전지를 제조하였다(하기 표 1 참조).Except that an oligomer (weight average molecular weight (Mw) 7,800; o: 35; p: 30; q: 20) represented by the following formula 2 was used instead of the oligomer represented by the formula A liquid electrolyte for a lithium secondary battery and a coin cell type lithium secondary battery comprising the same were prepared in the same manner as in Example 1 (see Table 1 below).
[화학식 2](2)
Figure PCTKR2018013181-appb-I000012
Figure PCTKR2018013181-appb-I000012
리튬 이차전지용 액체 전해질Liquid electrolyte for lithium secondary battery
리튬염Lithium salt 유기용매 첨가량 (g)Amount of organic solvent added (g) 올리고머Oligomer
화학식The 첨가량(g)Addition amount (g)
실시예 1Example 1 1M LiPF6 1M LiPF 6 99.599.5 1a-11a-1 0.50.5
실시예 2Example 2 1M LiPF6 1M LiPF 6 8080 1a-11a-1 2020
실시예 3Example 3 1M LiPF6 1M LiPF 6 9090 1a-11a-1 1010
실시예 4Example 4 1M LiPF6 1M LiPF 6 9090 1b-11b-1 1010
실시예 5Example 5 1M LiPF6 1M LiPF 6 7575 1a-11a-1 2525
실시예 6Example 6 1M LiPF6 1M LiPF 6 7070 1a-11a-1 3030
실시예 7Example 7 1M LiPF6 1M LiPF 6 6767 1a-11a-1 3333
비교예 1Comparative Example 1 1M LiPF6 1M LiPF 6 100100 -- --
비교예 2Comparative Example 2 1M LiPF6 1M LiPF 6 99.599.5 22 0.50.5
II. 겔 폴리머 전해질을 포함하는 리튬 이차전지II. A lithium secondary battery comprising a gel polymer electrolyte
실시예 8.Example 8.
(리튬 이차전지용 겔 폴리머 전해질용 조성물 제조)(Preparation of Composition for Gel Polymer Electrolyte for Lithium Secondary Battery)
1M LiPF6가 용해된 유기용매(에틸렌 카보네이트(EC):에틸메틸카보네이트(EMC) = 3:7 부피비) 99.49g에 화학식 1a-1로 표시되는 올리고머 (중량평균분자량(Mw): 3,000, z1=10, x1=3) 0.5g 및 중합개시제인 디메틸 2,2'-아조비스(2-메틸프로피오네이트) (CAS No. 2589-57-3) 0.01g을 첨가하여 리튬 이차전지용 겔 폴리머 전해질용 조성물을 제조하였다(하기 표 2 참조). (Weight average molecular weight (Mw): 3,000, z1 = 1) was added to 99.49 g of an organic solvent (ethylene carbonate (EC): ethylmethyl carbonate (EMC) = 3: 7 by volume) in which 1 M LiPF 6 was dissolved. 10, x1 = 3) and 0.01 g of dimethyl 2,2'-azobis (2-methylpropionate) (CAS No. 2589-57-3) as a polymerization initiator were added thereto to prepare a gel polymer electrolyte for a lithium secondary battery A composition was prepared (see Table 2 below).
(전극조립체 제조)(Manufacture of electrode assembly)
양극 활물질로 (LiNi3/5Co1/5Mn1/5O2), 도전재로 카본 블랙(carbon black) 및 바인더로 폴리비닐리덴플루오라이드(PVDF)를 94:3:3의 중량 비율로 용매인 N-메틸-2-피롤리돈(NMP)에 첨가하여 양극 혼합물 슬러리 (고형분 함량: 65 중량%)를 제조하였다. 상기 양극 혼합물 슬러리를 두께가 20㎛ 정도의 양극 집전체인 알루미늄(Al) 박막에 도포하고, 건조하여 양극을 제조한 후, 롤 프레스(roll press)를 실시하여 양극을 제조하였다.(LiNi 3/5 Co 1/5 Mn 1/5 O 2) as a positive electrode active material, carbon black as a conductive material, and polyvinylidene fluoride (PVDF) as a binder in a weight ratio of 94: 3: 3 Was added to the solvent N-methyl-2-pyrrolidone (NMP) to prepare a positive electrode mixture slurry (solid content: 65 wt%). The positive electrode mixture slurry was applied to an aluminum (Al) thin film having a thickness of about 20 탆 and dried to produce a positive electrode, followed by a roll press to prepare a positive electrode.
음극으로 리튬 메탈 전극을 사용하였다.A lithium metal electrode was used as a cathode.
상기 양극, 음극 및 폴리프로필렌/폴리에틸렌/폴리프로필렌 (PP/PE/PP) 3층으로 이루어진 분리막을 순차적으로 적층하여 전극조립체를 제조하였다.The positive electrode, the negative electrode and a separator composed of three layers of polypropylene / polyethylene / polypropylene (PP / PE / PP) were sequentially laminated to produce an electrode assembly.
(이차전지 제조)(Secondary Battery Manufacturing)
전지 케이스 내에 상기 조립된 전극조립체를 수납하고, 상기 리튬 이차전지용 겔 폴리머 전해질용 조성물을 주입한 후 60℃에서 24 시간 동안 열중합한 다음, 2일 동안 상온에서 저장하여 리튬 이차전지용 겔 폴리머 전해질을 포함하는 코인 셀형 리튬 이차전지를 제조하였다.The assembled electrode assembly was housed in the battery case, and the composition for a gel polymer electrolyte for a lithium secondary battery was injected thereinto, heated at 60 ° C. for 24 hours and stored at room temperature for 2 days to contain a gel polymer electrolyte for a lithium secondary battery Coin cell type lithium secondary battery.
실시예 9.Example 9.
겔 폴리머 전해질용 조성물 제조 시에, 유기용매 79.9g에 화학식 1a-1로 표시되는 올리고머 (중량평균분자량(Mw): 3,000, z1=10, x1=3) 20g 및 중합개시제인 디메틸 2,2'-아조비스(2-메틸프로피오네이트) (CAS No. 2589-57-3) 0.1g을 첨가하여 리튬 이차전지용 겔 폴리머 전해질용 조성물을 제조하는 것을 제외하고는 상기 실시예 8과 마찬가지의 방법으로 리튬 이차전지용 겔 폴리머 전해질용 조성물 및 이로부터 제조된 리튬 이차전지용 겔 폴리머 전해질을 포함하는 코인 셀형 리튬 이차전지를 제조하였다(하기 표 2 참조).20 g of an oligomer (weight average molecular weight (Mw): 3,000, z1 = 10, x1 = 3) represented by the formula 1a-1 and 20 g of dimethyl 2,2 ' -Azobis (2-methylpropionate) (CAS No. 2589-57-3) was added to prepare a composition for a gel polymer electrolyte for a lithium secondary battery according to the same manner as in Example 8 A coin cell type lithium secondary battery comprising a composition for a gel polymer electrolyte for a lithium secondary battery and a gel polymer electrolyte for a lithium secondary battery produced from the composition was prepared (see Table 2 below).
실시예 10.Example 10.
겔 폴리머 전해질용 조성물 제조 시에, 유기용매 89.9g에 화학식 1a-1로 표시되는 올리고머 (중량평균분자량(Mw): 3,000, z1=10, x1=3) 10g 및 중합개시제인 디메틸 2,2'-아조비스(2-메틸프로피오네이트) (CAS No. 2589-57-3) 0.1g을 첨가하여 리튬 이차전지용 겔 폴리머 전해질용 조성물을 제조하는 것을 제외하고는 상기 실시예 8과 마찬가지의 방법으로 리튬 이차전지용 겔 폴리머 전해질용 조성물 및 이로부터 제조된 리튬 이차전지용 겔 폴리머 전해질을 포함하는 코인 셀형 리튬 이차전지를 제조하였다(하기 표 2 참조).10 g of the oligomer (weight average molecular weight (Mw): 3,000, z1 = 10, x1 = 3) represented by the general formula (1a-1) and 10 g of dimethyl 2,2 ' -Azobis (2-methylpropionate) (CAS No. 2589-57-3) was added to prepare a composition for a gel polymer electrolyte for a lithium secondary battery according to the same manner as in Example 8 A coin cell type lithium secondary battery comprising a composition for a gel polymer electrolyte for a lithium secondary battery and a gel polymer electrolyte for a lithium secondary battery produced from the composition was prepared (see Table 2 below).
실시예 11.Example 11.
겔 폴리머 전해질용 조성물 제조 시에, 화학식 1a-1로 표시되는 올리고머 대신 화학식 1b-1로 표시되는 올리고머(중량평균분자량(Mw): 5,000, z2=8, x2=6)를 사용하는 것을 제외하고는 상기 실시예 10과 마찬가지의 방법으로 리튬 이차전지용 겔 폴리머 전해질용 조성물 및 이로부터 제조된 리튬 이차전지용 겔 폴리머 전해질을 포함하는 코인 셀형 리튬 이차전지를 제조하였다(하기 표 2 참조).Except that the oligomer (weight average molecular weight (Mw): 5,000, z2 = 8, x2 = 6) represented by the general formula (1b-1) was used instead of the oligomer represented by the general formula (1a-1) in the preparation of the gel polymer electrolyte composition , A coin cell type lithium secondary battery comprising a composition for a gel polymer electrolyte for a lithium secondary battery and a gel polymer electrolyte for a lithium secondary battery produced therefrom was prepared in the same manner as in Example 10 (see Table 2 below).
실시예 12.Example 12.
겔 폴리머 전해질용 조성물 제조 시에, 유기용매 74.9g에 화학식 1a-1로 표시되는 올리고머 25g, 중합개시제인 디메틸 2,2'-아조비스(2-메틸프로피오네이트) (CAS No. 2589-57-3) 0.1g을 첨가하여 리튬 이차전지용 겔 폴리머 전해질용 조성물을 제조하는 것을 제외하고는 상기 실시예 8과 마찬가지의 방법으로 리튬 이차전지용 겔 폴리머 전해질용 조성물 및 이로부터 제조된 리튬 이차전지용 겔 폴리머 전해질을 포함하는 코인 셀형 리튬 이차전지를 제조하였다(하기 표 2 참조).In the preparation of the composition for a gel polymer electrolyte, 25 g of the oligomer represented by the formula 1a-1, 74 g of the organic solvent, 25 g of dimethyl 2,2'-azobis (2-methylpropionate) (CAS No. 2589-57 -3) was added to prepare a gel polymer electrolyte composition for a lithium secondary battery, a composition for a gel polymer electrolyte for a lithium secondary battery and a gel polymer for a lithium secondary battery produced therefrom were prepared in the same manner as in Example 8 A coin cell type lithium secondary battery containing an electrolyte was prepared (see Table 2 below).
실시예 13.Example 13.
겔 폴리머 전해질용 조성물 제조 시에, 유기용매 69.85g에 화학식 1a-1로 표시되는 올리고머 30g, 중합개시제인 디메틸 2,2'-아조비스(2-메틸프로피오네이트) (CAS No. 2589-57-3) 0.15g을 첨가하여 리튬 이차전지용 겔 폴리머 전해질용 조성물을 제조하는 것을 제외하고는 상기 실시예 8과 마찬가지의 방법으로 리튬 이차전지용 겔 폴리머 전해질용 조성물 및 이로부터 제조된 리튬 이차전지용 겔 폴리머 전해질을 포함하는 코인 셀형 리튬 이차전지를 제조하였다(하기 표 2 참조).In the preparation of the gel polymer electrolyte composition, 30 g of the oligomer represented by the general formula (1a-1), dimethyl 2,2'-azobis (2-methylpropionate) (CAS No. 2589-57 -3) was added to prepare a gel polymer electrolyte composition for a lithium secondary battery, a composition for a gel polymer electrolyte for a lithium secondary battery and a gel polymer for a lithium secondary battery produced therefrom were prepared in the same manner as in Example 8 A coin cell type lithium secondary battery containing an electrolyte was prepared (see Table 2 below).
실시예 14.Example 14.
겔 폴리머 전해질용 조성물 제조 시에, 유기용매 66.85g에 화학식 1a-1로 표시되는 올리고머 33g, 중합개시제인 디메틸 2,2'-아조비스(2-메틸프로피오네이트) (CAS No. 2589-57-3) 0.15g을 첨가하여 리튬 이차전지용 겔 폴리머 전해질용 조성물을 제조하는 것을 제외하고는 상기 실시예 8과 마찬가지의 방법으로 리튬 이차전지용 겔 폴리머 전해질용 조성물 및 이로부터 제조된 리튬 이차전지용 겔 폴리머 전해질을 포함하는 코인 셀형 리튬 이차전지를 제조하였다(하기 표 2 참조).In the preparation of the gel polymer electrolyte composition, 33.8 g of the oligomer represented by the formula (1a-1), dimethyl 2,2'-azobis (2-methylpropionate) (CAS No. 2589-57 -3) was added to prepare a gel polymer electrolyte composition for a lithium secondary battery, a composition for a gel polymer electrolyte for a lithium secondary battery and a gel polymer for a lithium secondary battery produced therefrom were prepared in the same manner as in Example 8 A coin cell type lithium secondary battery containing an electrolyte was prepared (see Table 2 below).
비교예 3.Comparative Example 3
겔 폴리머 전해질용 조성물 제조 시에, 상기 화학식 1a-1로 표시되는 올리고머 대신 상기 화학식 2로 표시되는 올리고머를 포함하는 것을 제외하고는 상기 실시예 9와 마찬가지의 방법으로 겔 폴리머 전해질용 조성물 및 이를 포함하는 코인셀형 리튬 이차전지를 제조하였다(하기 표 2 참조).A composition for a gel polymer electrolyte and a composition for a gel polymer electrolyte were prepared in the same manner as in Example 9, except that the oligomer represented by Formula 2 was used instead of the oligomer represented by Formula 1a-1 in the preparation of the gel polymer electrolyte composition (See Table 2 below). &Lt; tb &gt; &lt; TABLE &gt;
겔 폴리머 전해질용 조성물Composition for gel polymer electrolyte
리튬염Lithium salt 유기용매 첨가량 (g)Amount of organic solvent added (g) 올리고머Oligomer 중합개시제 첨가량(g)Addition amount of polymerization initiator (g)
화학식The 첨가량 (g)Addition amount (g)
실시예 8Example 8 1M LiPF6 1M LiPF 6 99.4999.49 1a-11a-1 0.50.5 0.010.01
실시예 9Example 9 1M LiPF6 1M LiPF 6 79.979.9 1a-11a-1 2020 0.10.1
실시예 10Example 10 1M LiPF6 1M LiPF 6 89.989.9 1a-11a-1 1010 0.10.1
실시예 11Example 11 1M LiPF6 1M LiPF 6 89.989.9 1b-11b-1 1010 0.10.1
실시예 12Example 12 1M LiPF6 1M LiPF 6 74.974.9 1a-11a-1 2525 0.10.1
실시예 13Example 13 1M LiPF6 1M LiPF 6 69.8569.85 1a-11a-1 3030 0.150.15
실시예 14 Example 14 1M LiPF6 1M LiPF 6 66.8566.85 1a-11a-1 3333 0.150.15
비교예 3Comparative Example 3 1M LiPF6 1M LiPF 6 99.4999.49 22 0.50.5 0.010.01
실험예Experimental Example
실험예 1: 리튬 금속에 대한 액체 전해질의 반응성 평가 (1) Experimental Example 1: Evaluation of Reactivity of Liquid Electrolyte to Lithium Metal (1)
Li 호일을 이용하여 제조된 3극 전지(Li/Li(150㎛) symmetry beaker cell) 시스템을 제작한 다음, 실시예 1 내지 7에서 제조된 이차전지용 액체 전해질과 비교예 1 및 2에서 제조된 이차전지용 액체 전해질을 각각 주입하였다.(Li / Li (150 탆) symmetry beaker cell) system manufactured by using Li foil was prepared, and then the liquid electrolyte for secondary battery prepared in Examples 1 to 7 and the secondary battery prepared in Comparative Examples 1 and 2 And a liquid electrolyte for a battery were respectively injected.
이어서, 전기화학 임피던스 분광법(Electrochemical Impedance Spectroscopy, EIS)을 이용하여 10mV 교류 전류를 흘려주면서 2 시간 후에 측정된 전하이동 저항값(Charge transfer resistance; Rct)을 하기 표 3에 기재하였다. 이때, 하기 표 3에서 초기 전하 이동 저항값은 Li/Li전극을 전해액에 주입한 후 전하 이동 저항값을 나타낸다. Next, the charge transfer resistance (Rct) measured after 2 hours while flowing 10 mV alternating current using Electrochemical Impedance Spectroscopy (EIS) is shown in Table 3 below. In this case, the initial charge transfer resistance value in Table 3 indicates the charge transfer resistance value after injecting the Li / Li electrode into the electrolyte.
실시예Example 전하 이동 저항값 (ohm)Charge transfer resistance value (ohm)
초기 저항Initial resistance 2020
실시예 1Example 1 250250
실시예 2Example 2 8282
실시예 3Example 3 9797
실시예 4Example 4 105105
실시예 5Example 5 7575
실시예 6Example 6 5252
실시예 7Example 7 5050
비교예 1Comparative Example 1 7,5107,510
비교예 2Comparative Example 2 330330
일반적으로, 리튬 이차전지용 전해질과 Li 금속과의 화학 반응이 발생하는 경우, Li 금속 표면에 전해액 분해에 의해 생성된 부산물이 적층되면서 전하 이동 저항값(Rct)이 증가하게 된다. Generally, when a chemical reaction occurs between an electrolyte for a lithium secondary battery and a Li metal, by-products generated by electrolytic solution decomposition are deposited on the surface of the Li metal, thereby increasing the charge transfer resistance value Rct.
이때, 상기 표 3을 살펴보면, 실시예 1 내지 6의 리튬 이차전지용 액체 전해질의 경우, Li 금속/전해질 간의 반응이 제어되어 2 시간 후에도 전하 이동 저항값(Rct)이 250 ohm 이하로 낮은 것을 알 수 있다. As shown in Table 3, in the case of the liquid electrolyte for lithium secondary batteries of Examples 1 to 6, the reaction between the Li metal and the electrolyte was controlled so that the charge transfer resistance value Rct was as low as 250 ohm or less even after 2 hours have.
특히, 말단에 아크릴레이트기 개수가 적어 상대적으로 Li 이온과의 반응성이 낮은 실록산기(-Si-O-)의 함량비가 상대적으로 높은 화학식 1a-1로 표시되는 올리고머를 포함하는 실시예 3의 이차전지용 액체 전해질의 경우, 동일 함량의 화학식 1b-1로 표시되는 올리고머를 포함하는 실시예 4의 리튬 이차전지용 액체 전해질에 비하여 Li 금속과 전해질 간의 화학적 반응을 억제하는 효과가 우수하기 때문에, 저항 증가율이 낮은 것을 알 수 있다. Particularly, the secondary of Example 3, which contains an oligomer represented by the general formula (1a-1) in which the content ratio of the siloxane group (-Si-O-) having a low number of acrylate groups at the end and a low reactivity with Li ions is relatively high, In the case of the liquid electrolyte for a battery, since the effect of suppressing the chemical reaction between the Li metal and the electrolyte is superior to that of the liquid electrolyte for a lithium secondary battery of Example 4 including the oligomer represented by the formula 1b-1 in the same amount, Low.
또한, 올리고머를 과량으로 포함하는 실시예 7의 리튬 이차전지용 액체 전해질의 경우, 리튬 금속과의 반응성이 억제되어, 전하 이동 저항값(Rct)이 올리고머가 소량 포함된 실시예 1의 리튬 이차전지용 액체 전해질 보다 낮은 것을 알 수 있다.Further, in the case of the liquid electrolyte for a lithium secondary battery of Example 7 containing an oligomer in an excess amount, the reactivity with the lithium metal was suppressed, and the liquid for lithium secondary battery of Example 1 containing a small amount of the charge transfer resistance (Rct) Which is lower than that of the electrolyte.
반면에, 올리고머를 포함하지 않는 비교예 1의 리튬 이차전지용 액체 전해질의 경우, Li 금속/전해액 간의 반응에 의한 Li 금속 표면에 부산물이 증가하면서 전하 이동 저항값(Rct)이 7,510 ohm 으로 크게 증가한 것을 알 수 있다.On the other hand, in the case of the liquid electrolyte for a lithium secondary battery of Comparative Example 1 which did not contain an oligomer, the charge transfer resistance value Rct was greatly increased to 7,510 ohms while the byproducts increased on the Li metal surface due to the reaction between the Li metal / electrolyte Able to know.
또한, 화학식 1의 올리고머 대신 올리고머 구조 중에 소수성이 Si 단위를 더 포함하는 화학식 2의 올리고머를 포함하는 비교예 2의 리튬 이차전지용 액체 전해질의 경우, 전해액의 젖음성이 낮아지면서 상대적으로 Li 금속/전해질 간의 반응이 커져, 과충전 등과 같은 Li 석출이 유도되는 환경 조건하에서도 Li 금속/전해질 간의 화학 반응이 일어나, Li 금속 표면에 전해액 분해에 의해 생성된 부산물이 적층되었기 때문에, 전하 이동 저항 값이 약 330 ohm 으로 실시예 1 내지 7의 리튬 이차전지용 전해질에 비하여 열위한 것을 알 수 있다.Further, in the case of the liquid electrolyte for a lithium secondary battery of Comparative Example 2, which contains an oligomer of formula (2) further comprising a Si unit in the oligomer structure instead of the oligomer of the formula (1), the wettability of the electrolyte becomes lower and the relative Li metal / The chemical reaction between the Li metal and the electrolyte occurs under an environmental condition in which Li precipitation is induced such as overcharging and the like and the by-products produced by the decomposition of the electrolyte solution are laminated on the Li metal surface. Therefore, the charge transfer resistance value is about 330 ohms As compared with the electrolyte for lithium secondary batteries of Examples 1 to 7.
실험예 2: 리튬 금속에 대한 겔 폴리머 전해질용 조성물의 반응성 평가 (2) Experimental Example 2: Evaluation of Reactivity of Compositions for Gel Polymer Electrolyte to Lithium Metal (2)
실험예 1과 같은 방법으로 실시예 8 내지 14에서 제조된 겔 폴리머 전해질용 조성물과 비교예 3에서 제조된 겔 폴리머 전해질용 조성물에 대한 리튬 금속과의 반응성을 평가하고, 그 결과를 하기 표 4에 나타내었다.The reactivity between the composition for a gel polymer electrolyte prepared in Examples 8 to 14 and the composition for a gel polymer electrolyte prepared in Comparative Example 3 was evaluated in the same manner as in Experimental Example 1, Respectively.
실시예Example 전하 이동 저항값 (ohm)Charge transfer resistance value (ohm)
실시예 8Example 8 120120
실시예 9Example 9 2929
실시예 10Example 10 4747
실시예 11Example 11 5151
실시예 12Example 12 2323
실시예 13Example 13 3232
실시예 14Example 14 3030
비교예 3Comparative Example 3 305305
상기 표 4를 살펴보면, 실시예 8 내지 14의 겔 폴리머 전해질용 조성물의 경우, Li 금속/전해질 간의 반응이 제어되어 계면 저항 값이 120 ohm 이하로 낮은 것을 알 수 있다. As shown in Table 4, in the compositions for gel polymer electrolytes of Examples 8 to 14, the reaction between the Li metal / electrolyte was controlled and the interface resistance value was as low as 120 ohm or less.
특히, 말단에 아크릴레이트기 개수가 적어 상대적으로 Li 이온과의 반응성이 낮은 실록산기(-Si-O-)의 함량비가 상대적으로 높은 화학식 1a-1로 표시되는 올리고머를 포함하는 실시예 10의 겔 폴리머 전해질용 조성물의 경우, 동일 함량의 화학식 1b-1로 표시되는 올리고머를 포함하는 실시예 11의 겔 폴리머 전해질용 조성물에 비하여 Li 금속과 전해질 간의 화학적 반응성이 감소하여 표면 확산 반응이 억제되었기 때문에, 저항 증가율이 상대적으로 낮은 것을 알 수 있다. In particular, the gel of Example 10, which contains an oligomer represented by the general formula (1a-1) in which the content ratio of the siloxane group (-Si-O-) having a low number of acrylate groups at the end and a low reactivity with Li ion is relatively high In the case of the polymer electrolyte composition, since the chemical reactivity between the Li metal and the electrolyte is reduced and the surface diffusion reaction is suppressed as compared with the gel polymer electrolyte composition of Example 11 containing the same amount of the oligomer represented by the general formula (1b-1) The resistance increase rate is relatively low.
반면에, 화학식 1의 올리고머 대신 올리고머 구조 중에 소수성이 Si 단위를 더 포함하는 화학식 2의 올리고머를 포함하는 비교예 3의 겔 폴리머 전해질용 조성물의 경우, 전해액의 젖음성이 낮아지면서 상대적으로 Li 금속/전해질 간의 반응이 커져, Li 금속 표면에 전해액 분해에 의해 생성된 부산물이 다량 적층되었기 때문에 계면 저항값(Rct)이 약 305 ohm 으로 높은 것을 알 수 있다.On the other hand, in the case of the composition for a gel polymer electrolyte of Comparative Example 3 comprising an oligomer of the formula (2) further comprising a hydrophobic Si unit in the oligomer structure instead of the oligomer of the formula (1), the wettability of the electrolyte is lowered, And the surface resistance value Rct is about 305 ohm because the by-products generated by the electrolytic solution decomposition are deposited on the Li metal surface in a large amount.
실험예 3. 액체 전해질의 저항 특성 평가 (1)Experimental Example 3. Evaluation of Resistance Characteristic of Liquid Electrolyte (1)
상기 실시예 1 내지 7에서 제조된 리튬 이차전지용 액체 전해질을 구비한 리튬 이차전지와 비교예 1 및 2에서 제조된 리튬 이차전지용 액체 전해질을 구비한 리튬 이차전지를 각각 실온(25℃)에서 0.33C/4.2V 정전류-정전압으로 만충전하고, SOC 50%에서 2.5C로 10초간 방전하여 초기 충방전을 수행하였다. The lithium secondary batteries having the liquid electrolyte for lithium secondary batteries prepared in Examples 1 to 7 and the lithium secondary batteries having the liquid electrolyte for lithium secondary batteries prepared in Comparative Examples 1 and 2 were respectively charged at room temperature (25 ° C) / 4.2 V Constant current - The battery was fully charged at a constant voltage, and discharged at SOC 50% to 2.5 C for 10 seconds to perform initial charging and discharging.
그 다음, PNE-0506 충방전기(제조사: (주)PNE 솔루션, 5V, 6A)를 사용하여 초기 전압을 측정하였다.Next, the initial voltage was measured using a PNE-0506 charge / discharge device (manufacturer: PNE solution, 5V, 6A).
이어서, 각각의 리튬 이차전지용 액체 전해질을 구비한 이차전지에 대하여 25℃에서 SOC 50% 상태에서 3C로 10초간 방전 펄스(pulse)를 준 상태에서 나타나는 전압 강하를 측정하고, 얻어진 전압 강하량을 통해 각각의 셀에 대한 초기 저항을 산출하고, 이를 하기 표 5에 기재하였다. 이때, 상기 전압 강하는 PNE-0506 충방전기(제조사: (주)PNE 솔루션, 5V, 6A)를 사용하여 측정하였다. Subsequently, voltage drops appearing in a state in which a discharge pulse is applied for 10 seconds at 3C under the condition of SOC 50% at 25 DEG C is measured for each secondary battery having a liquid electrolyte for a lithium secondary battery, and the voltage drop And the results are shown in Table 5. &lt; tb &gt; &lt; TABLE &gt; At this time, the voltage drop was measured using a PNE-0506 charge / discharge device (manufacturer: PNE solution, 5V, 6A).
2.5C, 10sec 저항 (mohm) 2.5C, 10 sec resistance (mohm)
실시예 1Example 1 7979
실시예 2Example 2 4848
실시예 3Example 3 5353
실시예 4Example 4 5757
실시예 5Example 5 4242
실시예 6Example 6 7676
실시예 7Example 7 9797
비교예 1Comparative Example 1 135135
비교예 2Comparative Example 2 9393
상기 표 5를 참고하면, 본 발명의 실시예 1 내지 6의 리튬 이차전지용 액체 전해질을 구비한 리튬 이차전지의 경우, 앞서 실험예 1의 결과와 같이 Li 금속과 전해질 간의 반응성 감소로 부산물이 생성을 억제할 수 있기 때문에 초기 저항값이 대부분 79 mohm 이하로 낮은 것을 알 수 있다.In the case of the lithium secondary battery having the liquid electrolyte for a lithium secondary battery according to Examples 1 to 6 of the present invention, as shown in the above Experimental Example 1, by-products were formed due to a decrease in reactivity between the Li metal and the electrolyte. It can be seen that the initial resistance value is as low as 79 mohm or less.
한편, 올리고머를 과량으로 포함하는 리튬 이차전지용 액체 전해질을 구비한 액체 전해질을 구비한 실시예 7의 리튬 이차전지의 경우, 과량의 올리고머에 대한 부반응이 증가되어 초기 기 저항값이 97 mohm 으로 증가된 것을 알 수 있다.On the other hand, in the case of the lithium secondary battery of Example 7 having a liquid electrolyte including a liquid electrolyte for a lithium secondary battery including an oligomer in excess, the side reaction to excessive oligomer was increased, and the initial resistance value was increased to 97 mohm .
반면에, 올리고머를 포함하지 않는 리튬 이차전지용 액체 전해질을 구비한 액체 전해질을 구비한 비교예 1의 리튬 이차전지 및 화학식 2로 표시되는 올리고머를 포함하는 리튬 이차전지용 액체 전해질을 구비한 비교예 2의 리튬 이차전지의 경우, Li 금속과 전해질의 반응이 커 전극 표면에 부산물이 증가하기 때문에, 초기 저항 값이 각각 135 mohm 및 93 mohm 으로 실시예 1 내지 6의 리튬 이차전지 대비 증가한 것을 알 수 있다.On the other hand, in Comparative Example 2 in which the lithium secondary battery of Comparative Example 1 having a liquid electrolyte having a liquid electrolyte for a lithium secondary battery not containing an oligomer and the liquid electrolyte for a lithium secondary battery comprising an oligomer represented by Formula 2 In the case of the lithium secondary battery, since the reaction between the Li metal and the electrolyte is increased and the byproducts increase on the electrode surface, the initial resistance values are respectively 135 mohm and 93 mohm, which is higher than those of the lithium secondary batteries of Examples 1 to 6.
실험예 4. 겔 폴리머 전해질용 조성물의 저항 특성 평가 (2)Experimental Example 4. Evaluation of Resistance Characteristic of Composition for Gel Polymer Electrolyte (2)
상기 실험예 3과 같은 방법으로 실시예 8 내지 13에서 제조된 겔 폴리머 전해질을 구비한 리튬 이차전지와 비교예 3에서 제조된 겔 폴리머 전해질을 구비한 리튬 이차전지에 대한 전압 강하를 측정한 후, 얻어진 전압 강하량을 통해 각각의 셀에 대한 초기 저항을 측정하고, 이를 하기 표 6에 나타내었다.The voltage drop of the lithium secondary battery having the gel polymer electrolyte prepared in Examples 8 to 13 and the lithium polymer secondary cell having the gel polymer electrolyte prepared in Comparative Example 3 was measured in the same manner as in Experimental Example 3, The initial resistance of each cell was measured through the obtained voltage drop, and it is shown in Table 6 below.
실시예Example 2.5C, 10sec 저항 (mohm)2.5C, 10 sec resistance (mohm)
실시예 8Example 8 7676
실시예 9Example 9 5959
실시예 10Example 10 6969
실시예 11Example 11 6262
실시예 12Example 12 5555
실시예 13Example 13 7575
비교예 3Comparative Example 3 100100
상기 표 6을 참고하면, 본 발명의 실시예 8 내지 13의 겔 폴리머 전해질을 구비한 리튬 이차전지의 경우, Li 금속과 전해질 간의 반응성 감소로 부산물이 생성을 억제할 수 있기 때문에 초기 저항값이 대부분 76 mohm 이하로 낮은 것을 알 수 있다.Referring to Table 6, in the case of the lithium secondary battery having the gel polymer electrolytes according to Examples 8 to 13 of the present invention, the generation of by-products can be suppressed due to the decrease in reactivity between the Li metal and the electrolyte, 76 mohm or less.
반면에, 비교예 3의 겔 폴리머 전해질을 구비한 리튬 이차전지의 경우, Li 금속과 전해질의 반응이 커 전극 표면에 부산물이 증가하기 때문에, Li 금속과 전해질의 반응이 커 전극 표면에 부산물이 증가하기 때문에, 초기 저항 값이 100 mohm 으로 실시예 8 내지 13의 리튬 이차전지 대비 증가한 것을 알 수 있다.On the other hand, in the case of the lithium secondary battery having the gel polymer electrolyte of Comparative Example 3, the reaction between the Li metal and the electrolyte was increased, and the byproducts on the electrode surface increased. , It can be seen that the initial resistance value is 100 mohm, which is higher than that of the lithium secondary batteries of Examples 8 to 13.
실험예 5: 액체 전해질의 방전 용량 평가(1)EXPERIMENTAL EXAMPLE 5 Evaluation of Discharge Capacity of Liquid Electrolyte (1)
상기 실시예 1 내지 6에서 제조된 리튬 이차전지용 액체 전해질을 구비한 리튬 이차전지와 비교예 1 및 2에서 제조된 리튬 이차전지용 액체 전해질을 구비한 리튬 이차전지에 각각 3.0V 내지 4.2V 전압 구동 범위하에 25℃에서 0.33C/4.2V 정전류-정전압으로 만충전하고, SOC 50%에서 2.5C로 10초간 방전하여 충방전을 수행하였다. 이어서, 상기 충방전 과정을 3.0V 내지 4.2V 전압 구동 범위하에 25℃에서 0.33C/0.33C로 3 사이클을 반복한 다음, 마지막 3 사이클 후의 방전 용량을 PNE-0506 충방전기(제조사: (주)PNE 솔루션, 5V, 6A)를 사용하여 측정하였다. 그 결과를 하기 표 7에 나타내었다. The lithium secondary batteries having the liquid electrolyte for lithium secondary batteries manufactured in Examples 1 to 6 and the lithium secondary batteries having the liquid electrolyte for lithium secondary batteries prepared in Comparative Examples 1 and 2 were subjected to voltage driving ranges of 3.0 V to 4.2 V Under a constant current of 0.33 C / 4.2 V at a constant current of -25 V and a discharge of SOC 50% to 2.5 C for 10 seconds. Subsequently, the charge and discharge process was repeated three times at 25 ° C and 0.33C / 0.33C under a voltage driving range of 3.0 V to 4.2 V, and the discharge capacity after the last 3 cycles was measured with a PNE-0506 charge / discharge device (manufacturer: PNE solution, 5V, 6A). The results are shown in Table 7 below.
0.33C 방전 용량 (mAh)0.33 C discharge capacity (mAh)
실시예 1Example 1 63.263.2
실시예 2Example 2 71.271.2
실시예 3Example 3 69.269.2
실시예 4Example 4 67.467.4
실시예 5Example 5 73.573.5
실시예 6Example 6 64.164.1
비교예 1Comparative Example 1 59.759.7
비교예 2Comparative Example 2 60.560.5
상기 표 7을 살펴보면, 실시예 1 내지 6에서 제조된 리튬 이차전지용 액체 전해질을 구비한 리튬 이차전지의 경우 3 사이클 후의 방전 용량이 대부분 63.2 mAh 이상인 것을 알 수 있다. Referring to Table 7, it can be seen that the discharge capacity of the lithium secondary battery having the liquid electrolyte for lithium secondary batteries manufactured in Examples 1 to 6 after 3 cycles is mostly 63.2 mAh or more.
특히, 말단에 아크릴레이트기 개수가 적어 상대적으로 Li 이온과의 반응성이 낮은 실록산기(-Si-O-)의 함량비가 상대적으로 높은 화학식 1a-1로 표시되는 올리고머를 포함하는 액체 전해질을 구비한 실시예 3의 리튬 이차전지의 경우, 화학식 1b-1로 표시되는 올리고머를 포함하는 액체 전해질을 구비한 실시예 4의 리튬 이차전지에 비하여 방전 용량이 보다 개선된 것을 알 수 있다.Particularly, a liquid electrolyte comprising an oligomer represented by the general formula (1a-1) in which the content ratio of a siloxane group (-Si-O-) having a low number of acrylate groups at a terminal and a low reactivity with Li ions is relatively high It can be seen that the discharge capacity of the lithium secondary battery of Example 3 is further improved as compared with the lithium secondary battery of Example 4 having the liquid electrolyte containing the oligomer represented by Formula 1b-1.
반면에, 올리고머를 포함하지 않는 리튬 이차전지용 액체 전해질을 구비한 비교예 1의 리튬 이차전지 및 화학식 2로 표시되는 올리고머를 포함하는 리튬 이차전지용 액체 전해질을 구비한 비교예 2의 리튬 이차전지의 경우, 3 사이클 후의 방전 용량이 각각 59.7 mAh 및 60.5 mAh로 본 발명의 실시예 1 내지 6의 리튬 이차전지에 비하여 열위한 것을 알 수 있다.On the other hand, in the case of the lithium secondary battery of Comparative Example 2 comprising the lithium secondary battery of Comparative Example 1 having a liquid electrolyte for a lithium secondary battery not containing an oligomer and the liquid electrolyte for a lithium secondary battery comprising an oligomer represented by Formula 2 , And the discharge capacities after 3 cycles are 59.7 mAh and 60.5 mAh, respectively, as compared with the lithium secondary batteries of Examples 1 to 6 of the present invention.
실험예 6: 겔 폴리머 전해질의 방전 용량 평가 (2)EXPERIMENTAL EXAMPLE 6 Evaluation of Discharge Capacity of Gel Polymer Electrolyte (2)
상기 실험예 5와 마찬가지의 방법으로 상기 실시예 8 내지 13에서 제조된 겔 폴리머 전해질을 구비한 리튬 이차전지와 비교예 3에서 제조된 겔 폴리머 전해질을 구비한 리튬 이차전지에 대한 3 사이클 후의 방전 용량(capacity)을 측정하고, 그 결과를 하기 표 8에 나타내었다. The lithium secondary batteries having the gel polymer electrolyte prepared in Examples 8 to 13 and the gel polymer electrolyte prepared in Comparative Example 3 were prepared in the same manner as in Experimental Example 5, (capacity) were measured, and the results are shown in Table 8 below.
실시예Example 0.33C 방전 용량 (mAh)0.33 C discharge capacity (mAh)
실시예 8Example 8 61.261.2
실시예 9Example 9 64.764.7
실시예 10Example 10 63.563.5
실시예 11Example 11 62.562.5
실시예 12Example 12 65.965.9
실시예 13Example 13 57.957.9
비교예 3Comparative Example 3 52.452.4
상기 표 8에 나타낸 바와 같이, 실시예 8 내지 13에서 제조된 겔 폴리머 전해질을 구비한 리튬 이차전지의 경우 3 사이클 후의 방전 용량이 대부분 57.9 mAh 이상으로 높은 것을 알 수 있다.As shown in Table 8, in the case of the lithium secondary battery having the gel polymer electrolyte prepared in Examples 8 to 13, the discharge capacity after 3 cycles was as high as 57.9 mAh or more.
반면에, 화학식 2로 표시되는 올리고머를 포함하는 겔 폴리머 전해질을 구비한 비교예 3의 리튬 이차전지의 경우, 방전 용량이 각각 52.4 mAh 으로 본 발명의 실시예 8 내지 13의 리튬 이차전지에 비하여 열위한 것을 알 수 있다.On the other hand, in the case of the lithium secondary battery of Comparative Example 3 having the gel polymer electrolyte containing the oligomer represented by Formula 2, the discharge capacity was 52.4 mAh, which was higher than that of the lithium secondary batteries of Examples 8 to 13 .
실험예 7: 과충전 안정성 평가 실험Experimental Example 7: Experiment for evaluation of overcharge stability
상기 실시예 1 내지 14에서 제조된 리튬 이차전지와 비교예 1 내지 3에서 제조된 리튬 이차전지에 대해 PNE-0506 충방전기(제조사: (주)PNE 솔루션, 5V, 6A)를 사용하여 SOC 100% 상태에서 1C, bakelite plate (단열조건), 8.3V (컷 오프) 조건으로 과충전을 실시한 후, SOC 140%에서의 온도를 측정하였다. 그 결과를 하기 표 9에 나타내었다.The lithium secondary battery manufactured in Examples 1 to 14 and the lithium secondary batteries prepared in Comparative Examples 1 to 3 were subjected to SOC 100% using a PNE-0506 charge / discharge device (PNE solution, 5V, 6A, , And the temperature was measured at SOC 140% after overcharging under 1C, bakelite plate (insulation condition) and 8.3V (cutoff) condition. The results are shown in Table 9 below.
SOC 140%에서의 온도(℃)Temperature at 140% SOC (° C)
액체전해질Liquid electrolyte 실시예 1Example 1 6767
실시예 2Example 2 5656
실시예 3Example 3 6161
실시예 4Example 4 6262
실시예 5Example 5 5353
실시예 6Example 6 5858
실시예 7Example 7 7171
비교예 1Comparative Example 1 8282
비교예 2Comparative Example 2 7575
겔 폴리머전해질Gel polymer electrolyte 실시예 8Example 8 6262
실시예 9Example 9 4848
실시예 10Example 10 5252
실시예 11Example 11 5353
실시예 12Example 12 4242
실시예 13Example 13 4848
실시예 14 Example 14 5959
비교예 3Comparative Example 3 6969
상기 표 9를 참조하면, 실시예 1 내지 6에서 제조된 리튬 이차전지용 액체 전해질을 구비한 리튬 이차전지는 SOC 140%에서 67℃ 이하의 온도를 보이는 것을 알 수 있다. Referring to Table 9, it can be seen that the lithium secondary battery having a liquid electrolyte for a lithium secondary battery manufactured in Examples 1 to 6 exhibits a temperature of less than 67 ° C at an SOC of 140%.
반면에, 올리고머를 포함하지 않는 액체 전해질을 구비한 비교예 1의 리튬 이차전지 및 화학식 2로 표시되는 올리고머를 포함하는 액체 전해질을 구비한 비교예 2의 리튬 이차전지의 경우, SOC 140%에서 각각 82℃ 및 75℃로 실시예 1 내지 6 에서 제조된 리튬 이차전지용 액체 전해질을 구비한 리튬 이차전지 대비 열위한 것을 알 수 있다.On the other hand, in the case of the lithium secondary battery of Comparative Example 1 having the liquid electrolyte containing no oligomer and Comparative Example 2 having the liquid electrolyte containing the oligomer represented by Formula 2, the SOC of 140% 82 &lt; 0 &gt; C and 75 &lt; [deg.] &Gt; C for the lithium secondary battery having the liquid electrolyte for lithium secondary battery manufactured in Examples 1 to 6.
한편, 올리고머를 과량으로 포함하는 실시예 7의 액체 전해질을 구비한 리튬 이차전지의 경우, 과량의 올리고머에 대한 부반응이 증가되어 SOC 140%에서 리튬 이차전지의 온도가 71℃로 실시예 1 내지 6 에서 제조된 리튬 이차전지용 액체 전해질을 구비한 이차전지 대비 증가하는 것을 알 수 있다.On the other hand, in the case of a lithium secondary battery having a liquid electrolyte of Example 7 containing an oligomer in an excessive amount, side reactions with excessive oligomers were increased, and the temperature of the lithium secondary battery at SOC of 140% The secondary battery having the liquid electrolyte for a lithium secondary battery according to the present invention.
또한, 상기 표 9를 참조하면, 실시예 8 내지 14에서 제조된 겔 폴리머 전해질을 구비한 리튬 이차전지는 SOC 140%에서 62℃ 이하의 온도를 보이는 것을 알 수 있다. In addition, referring to Table 9, it can be seen that the lithium secondary battery having the gel polymer electrolyte prepared in Examples 8 to 14 exhibits a SOC of 140% to 62 ° C or less.
반면에, 올리고머를 포함하지 않는 겔 폴리머 전해질을 구비한 비교예 3의 리튬 이차전지의 경우, SOC 140%에서 69℃로 실시예 8 내지 14에서 제조된 리튬 이차전지 대비 열위한 것을 알 수 있다.On the other hand, in the case of the lithium secondary battery of Comparative Example 3 having a gel polymer electrolyte containing no oligomer, it can be seen that the SOC is 140% to 69 ° C, compared with the lithium secondary batteries prepared in Examples 8 to 14.
실험예 8: 사이클 수명 특성 평가 실험Experiment 8: Evaluation test of cycle life characteristics
상기 실시예 1 내지 14에서 제조된 리튬 이차전지와 비교예 1 내지 3에서 제조된 리튬 이차전지에 대해 45℃에서 1C/1C로 4.25V까지 충전을 실시한 후, 10분간 방치한 다음, 1C/1C 3.0V가 될 때까지 방전하였다. 상기 충방전을 1 사이클로 하여 500 사이클 충방전을 실시하였다. The lithium secondary batteries prepared in Examples 1 to 14 and the lithium secondary batteries prepared in Comparative Examples 1 to 3 were charged to 4.25 V at 1 C / 1 C at 45 캜, left to stand for 10 minutes, And discharged until 3.0 V was reached. The charge and discharge were performed as one cycle, and 500 cycles of charge and discharge were performed.
이때, 첫 번째 사이클후의 용량과 500 번째 사이클 후의 용량을 PNE-0506 충방전기(제조사: (주)PNE 솔루션, 5V, 6A)를 사용하여 측정하고, 용량을 하기 식 (1)에 대입하여 용량 유지율(capacity retention)을 측정하였다. 그 결과를 하기 표 10에 나타내었다.At this time, the capacity after the first cycle and the capacity after the 500th cycle were measured using a PNE-0506 charge / discharge machine (manufacturer: PNE solution, 5V, 6A by the manufacturer), and the capacity was substituted into the following formula (capacity retention) was measured. The results are shown in Table 10 below.
식 (1): 용량 유지율(%) = (500회 사이클 후 용량/1회 사이클 후 용량) × 100(1): Capacity retention ratio (%) = (capacity after 500 cycles / capacity after one cycle) x 100
500사이클 후 용량 유지율(%)Capacity retention after 500 cycles (%)
액체전해질Liquid electrolyte 실시예 1Example 1 91.291.2
실시예 2Example 2 94.294.2
실시예 3Example 3 93.593.5
실시예 4Example 4 93.193.1
실시예 5Example 5 95.595.5
실시예 6Example 6 91.191.1
실시예 7Example 7 87.287.2
비교예 1Comparative Example 1 6161
비교예 2Comparative Example 2 7272
겔 폴리머전해질Gel polymer electrolyte 실시예 8Example 8 89.289.2
실시예 9Example 9 92.092.0
실시예 10Example 10 91.591.5
실시예 11Example 11 90.590.5
실시예 12Example 12 92.992.9
실시예 13Example 13 87.487.4
실시예 14 Example 14 82.582.5
비교예 3Comparative Example 3 78.578.5
상기 표 10을 살펴보면, 실시예 1 내지 7에서 제조된 리튬 이차전지용 액체 전해질을 구비한 리튬 이차전지는 500회 사이클을 진행한 후에도 87.2% 이상의 용량 보유율을 확보할 수 있음을 알 수 있다.Referring to Table 10, it can be seen that the lithium secondary battery having the liquid electrolyte for a lithium secondary battery manufactured in Examples 1 to 7 has a capacity retention rate of 87.2% or more even after 500 cycles.
반면에, 올리고머를 포함하지 않는 액체 전해질을 구비한 비교예 1의 리튬 이차전지 및 화학식 2로 표시되는 올리고머를 포함하는 액체 전해질을 구비한 비교예 2의 리튬 이차전지의 경우, 500 사이클 후 용량 유지율이 각각 61% 및 72%로 실시예 1 내지 7 에서 제조된 리튬 이차전지용 액체 전해질을 구비한 리튬 이차전지 대비 열위한 것을 알 수 있다.On the other hand, in the case of the lithium secondary battery of Comparative Example 2 having the lithium secondary battery of Comparative Example 1 and the liquid electrolyte containing the oligomer represented by Formula 2, which had a liquid electrolyte containing no oligomer, To 61% and 72%, respectively, for the lithium secondary battery having the liquid electrolyte for lithium secondary battery manufactured in Examples 1 to 7.
또한, 상기 표 10을 참조하면, 실시예 8 내지 14에서 제조된 겔 폴리머 전해질을 구비한 리튬 이차전지는 500회 사이클을 진행한 후에도 82.5% 이상의 용량 보유율을 확보할 수 있음을 알 수 있다.In addition, referring to Table 10, it can be seen that the capacity of the lithium secondary battery having the gel polymer electrolyte prepared in Examples 8 to 14 can be maintained at 82.5% or more even after 500 cycles.
반면에, 올리고머를 포함하지 않는 겔 폴리머 전해질을 구비한 비교예 3의 리튬 이차전지의 경우, 500 사이클 후 용량 유지율이 78.5%로, 실시예 8 내지 14에서 제조된 리튬 이차전지 대비 열위한 것을 알 수 있다.On the other hand, in the case of the lithium secondary battery of Comparative Example 3 having a gel polymer electrolyte containing no oligomer, the capacity retention ratio after 500 cycles was 78.5%, which was higher than that of the lithium secondary battery prepared in Examples 8 to 14 .

Claims (16)

  1. 리튬염, Lithium salt,
    유기용매 및Organic solvents and
    하기 화학식 1로 표시되는 올리고머 또는 화학식 1로 표시되는 올리고머 유래의 폴리머를 포함하는 것인 리튬 이차전지용 전해질:1. An electrolyte for a lithium secondary battery comprising an oligomer represented by the following general formula (1) or an oligomer-derived polymer represented by the general formula (1)
    [화학식 1][Chemical Formula 1]
    Figure PCTKR2018013181-appb-I000013
    Figure PCTKR2018013181-appb-I000013
    상기 화학식 1에서,In Formula 1,
    R1 및 R2는 각각 독립적으로 치환 또는 비치환된 탄소수 1 내지 5의 알킬렌기이고,R 1 and R 2 are each independently a substituted or unsubstituted alkylene group having 1 to 5 carbon atoms,
    R3 및 R4는 각각 독립적으로 수소 또는 치환 또는 비치환된 탄소수 1 내지 3의 알킬기이고,R 3 and R 4 are each independently hydrogen or a substituted or unsubstituted alkyl group having 1 to 3 carbon atoms,
    R5는 수소 또는 치환 또는 비치환된 탄소수 1 내지 5의 알킬기이고,R 5 is hydrogen or a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms,
    R'는 지방족 탄화수소기 또는 방향족 탄화수소기이고,R 'is an aliphatic hydrocarbon group or an aromatic hydrocarbon group,
    z 및 x 는 반복단위 수이며,z and x are the number of repeating units,
    z는 1 내지 10 중 어느 하나의 정수이고,z is an integer of 1 to 10,
    x는 1 내지 15 중 어느 하나의 정수이며,x is an integer of 1 to 15,
    n은 1 내지 3 중 어느 하나의 정수이다.and n is an integer of 1 to 3.
  2. 청구항 1에 있어서,The method according to claim 1,
    상기 화학식 1 에서, 상기 R'의 지방족 탄화수소기는 In the above formula (1), the aliphatic hydrocarbon group of R '
    (a) 치환 또는 비치환된 탄소수 4 내지 20의 사이클로알킬렌기, 치환 또는 비치환된 탄소수 4 내지 20의 사이클로알케닐렌기 및 치환 또는 비치환된 탄소수 2 내지 20의 헤테로사이클로알킬렌기로 이루어진 군으로부터 선택된 적어도 하나의 지환족 탄화수소기 및 (b) 치환 또는 비치환된 탄소수 1 내지 20의 알킬렌기, 치환 또는 비치환된 탄소수 1 내지 20의 알콕실렌기, 치환 또는 비치환된 탄소수 2 내지 20의 알케닐렌기 및 치환 또는 비치환된 탄소수 2 내지 20의 알키닐렌기로 이루어진 군으로부터 선택된 적어도 하나의 선형 탄화수소기로 이루어진 군으로부터 선택된 적어도 하나를 포함하고, (a) a substituted or unsubstituted cycloalkylene group having 4 to 20 carbon atoms, a substituted or unsubstituted cycloalkenylene group having 4 to 20 carbon atoms and a substituted or unsubstituted heterocycloalkylene group having 2 to 20 carbon atoms, (B) a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, a substituted or unsubstituted alkoxysilylene group having 1 to 20 carbon atoms, a substituted or unsubstituted C2 to C20 aliphatic hydrocarbon group, And at least one linear hydrocarbon group selected from the group consisting of substituted or unsubstituted alkynylene groups having 2 to 20 carbon atoms,
    상기 R'의 방향족 탄화수소기는 치환 또는 비치환된 탄소수 6 내지 20의 아릴렌기; 또는 치환 또는 비치환된 탄소수 2 내지 20의 헤테로아릴렌기로부터 선택된 적어도 하나를 포함하는 것인 리튬 이차전지용 전해질.The aromatic hydrocarbon group of R 'is a substituted or unsubstituted arylene group having 6 to 20 carbon atoms; Or a substituted or unsubstituted heteroarylene group having 2 to 20 carbon atoms.
  3. 청구항 1에 있어서,The method according to claim 1,
    상기 화학식 1 에서, 상기 R'의 지방족 탄화수소기는 치환 또는 비치환된 탄소수 4 내지 20의 사이클로알킬렌기, 치환 또는 비치환된 탄소수 4 내지 20의 사이클로알케닐렌기 및 치환 또는 비치환된 탄소수 2 내지 20의 헤테로사이클로알킬렌기로 이루어진 군으로부터 선택된 적어도 하나의 지환족 탄화수소기를 포함하는 것인 리튬 이차전지용 전해질.In the above formula (1), the aliphatic hydrocarbon group of R 'is a substituted or unsubstituted cycloalkylene group having 4 to 20 carbon atoms, a substituted or unsubstituted cycloalkenylene group having 4 to 20 carbon atoms and a substituted or unsubstituted C2 to C20 And at least one alicyclic hydrocarbon group selected from the group consisting of a cycloalkylene group and a heterocycloalkylene group.
  4. 청구항 1에 있어서,The method according to claim 1,
    상기 화학식 1로 표시되는 올리고머는 하기 화학식 1a 및 1b로 표시되는 올리고머들로 이루어진 군으로부터 선택된 적어도 어느 하나인 것인 리튬 이차전지용 전해질:Wherein the oligomer represented by Formula 1 is at least one selected from the group consisting of oligomers represented by the following Formulas 1a and 1b:
    [화학식 1a][Formula 1a]
    Figure PCTKR2018013181-appb-I000014
    Figure PCTKR2018013181-appb-I000014
    상기 화학식 1a에서,In formula (1a)
    R'는 지방족 탄화수소기 또는 방향족 탄화수소기이고,R 'is an aliphatic hydrocarbon group or an aromatic hydrocarbon group,
    z1 및 x1는 반복단위 수이며,z1 and x1 are the number of repeating units,
    z1는 1 내지 10 중 어느 하나의 정수이고,z1 is an integer of 1 to 10,
    x1는 1 내지 15 중 어느 하나의 정수이다.x1 is an integer of any one of 1 to 15;
    [화학식 1b][Chemical Formula 1b]
    Figure PCTKR2018013181-appb-I000015
    Figure PCTKR2018013181-appb-I000015
    상기 화학식 1b에서,In the above formula (1b)
    R'는 지방족 탄화수소기 또는 방향족 탄화수소기이고,R 'is an aliphatic hydrocarbon group or an aromatic hydrocarbon group,
    z2 및 x2는 반복단위 수이며,z2 and x2 are the number of repeating units,
    z2는 1 내지 10 중 어느 하나의 정수이고,z2 is an integer of 1 to 10,
    x2는 1 내지 15 중 어느 하나의 정수이다.and x2 is an integer of any one of 1 to 15. [
  5. 청구항 1에 있어서,The method according to claim 1,
    상기 화학식 1로 표시되는 올리고머는 하기 화학식 1a-1 및 1b-1로 표시되는 올리고머들로 이루어진 군으로부터 선택된 적어도 어느 하나인 것인 리튬 이차전지용 전해질:Wherein the oligomer represented by Formula 1 is at least one selected from the group consisting of oligomers represented by the following Formulas 1a-1 and 1b-1:
    [화학식 1a-1] [Formula 1a-1]
    Figure PCTKR2018013181-appb-I000016
    Figure PCTKR2018013181-appb-I000016
    상기 화학식 1a-1에서,In the above formula (1a-1)
    z1 및 x1는 반복단위 수이며,z1 and x1 are the number of repeating units,
    z1는 1 내지 10 중 어느 하나의 정수이고,z1 is an integer of 1 to 10,
    x1는 1 내지 15 중 어느 하나의 정수이다.x1 is an integer of any one of 1 to 15;
    [화학식 1b-1][Chemical Formula 1b-1]
    Figure PCTKR2018013181-appb-I000017
    Figure PCTKR2018013181-appb-I000017
    상기 화학식 1b-1에서,In the above formula (1b-1)
    z2 및 x2는 반복단위 수이며,z2 and x2 are the number of repeating units,
    z2는 1 내지 10 중 어느 하나의 정수이고,z2 is an integer of 1 to 10,
    x2는 1 내지 15 중 어느 하나의 정수이다.and x2 is an integer of any one of 1 to 15. [
  6. 청구항 1에 있어서,The method according to claim 1,
    상기 리튬 이차전지용 전해질은 상기 화학식 1로 표시되는 올리고머를 포함하는 액체 전해질인 것인 리튬 이차전지용 전해질.Wherein the electrolyte for a lithium secondary battery is a liquid electrolyte comprising an oligomer represented by the general formula (1).
  7. 청구항 6에 있어서,The method of claim 6,
    상기 화학식 1로 표시되는 올리고머는 리튬 이차전지용 전해질 전체 중량을 기준으로 0.5 중량% 내지 30 중량%로 포함되는 것인 리튬 이차전지용 전해질.Wherein the oligomer represented by Formula 1 is contained in an amount of 0.5 to 30% by weight based on the total weight of the electrolyte for a lithium secondary battery.
  8. 청구항 6에 있어서, The method of claim 6,
    상기 화학식 1로 표시되는 올리고머는 리튬 이차전지용 전해질 전체 중량을 기준으로 0.5 중량% 내지 25 중량%로 포함되는 것인 리튬 이차전지용 전해질.Wherein the oligomer represented by Formula 1 is contained in an amount of 0.5 wt% to 25 wt% based on the total weight of the electrolyte for a lithium secondary battery.
  9. 청구항 1에 있어서,The method according to claim 1,
    상기 리튬 이차전지용 전해질은 상기 화학식 1로 표시되는 올리고머 유래의 폴리머를 포함하는 겔 폴리머 전해질인 것인 리튬 이차전지용 전해질.Wherein the electrolyte for a lithium secondary battery is a gel polymer electrolyte comprising an oligomer-derived polymer represented by Formula 1 above.
  10. 청구항 9에 있어서,The method of claim 9,
    상기 화학식 1로 표시되는 올리고머 유래의 폴리머는 중합개시제 존재하에서 화학식 1로 표시되는 올리고머가 중합하여 3차원 구조로 형성된 매트릭스 폴리머인 것인 리튬 이차전지용 전해질.Wherein the oligomer-derived polymer represented by Formula 1 is a matrix polymer formed by polymerization of an oligomer represented by Formula 1 in the presence of a polymerization initiator to have a three-dimensional structure.
  11. 청구항 9에 있어서,The method of claim 9,
    상기 화학식 1로 표시되는 올리고머 유래 폴리머는 리튬 이차전지용 전해질 전체 중량을 기준으로 0.5 중량% 내지 30 중량%로 포함되는 것인 리튬 이차전지용 전해질.Wherein the oligomeric polymer represented by Formula 1 is contained in an amount of 0.5% by weight to 30% by weight based on the total weight of the electrolyte for a lithium secondary battery.
  12. 청구항 9에 있어서, The method of claim 9,
    상기 화학식 1로 표시되는 올리고머 유래 폴리머는 리튬 이차전지용 전해질 전체 중량을 기준으로 0.5 중량% 내지 25 중량%로 포함되는 것인 리튬 이차전지용 전해질.Wherein the oligomeric polymer represented by Formula 1 is contained in an amount of 0.5 wt% to 25 wt% based on the total weight of the electrolyte for a lithium secondary battery.
  13. 양극, 음극, 분리막 및 청구항 1의 리튬 이차전지용 전해질을 포함하는 리튬 이차전지.A lithium secondary battery comprising an anode, a cathode, a separator, and an electrolyte for a lithium secondary battery according to claim 1.
  14. 청구항 13에 있어서,14. The method of claim 13,
    상기 리튬 이차전지용 전해질은 액체 전해질인 것인 리튬 이차전지.Wherein the electrolyte for the lithium secondary battery is a liquid electrolyte.
  15. 청구항 13에 있어서,14. The method of claim 13,
    상기 리튬 이차전지용 전해질은 겔 폴리머 전해질인 것인 리튬 이차전지.Wherein the electrolyte for the lithium secondary battery is a gel polymer electrolyte.
  16. 청구항 13에 있어서,14. The method of claim 13,
    상기 음극은 금속 또는 준금속 박막을 단독으로 사용한 메탈 전극이거나, 또는 음극 집전체 상에 상기 금속 또는 준금속 박막이 적층된 구조로 이루어진 것인 리튬 이차전지.Wherein the negative electrode is a metal electrode using a metal or a quasi-metal thin film alone, or a structure in which the metal or a quasi metal thin film is laminated on an anode current collector.
PCT/KR2018/013181 2017-11-03 2018-11-01 Electrolyte for lithium secondary battery and lithium secondary battery comprising same WO2019088733A1 (en)

Priority Applications (5)

Application Number Priority Date Filing Date Title
US16/477,348 US10950895B2 (en) 2017-11-03 2018-11-01 Electrolyte for lithium secondary battery and lithium secondary battery including the same
JP2020502292A JP7027628B2 (en) 2017-11-03 2018-11-01 Electrolytes for lithium secondary batteries and lithium secondary batteries containing them
PL18874455.1T PL3561936T3 (en) 2017-11-03 2018-11-01 Electrolyte for lithium secondary battery and lithium secondary battery including the same
EP18874455.1A EP3561936B1 (en) 2017-11-03 2018-11-01 Electrolyte for lithium secondary battery and lithium secondary battery including the same
CN201880007159.2A CN110178258B (en) 2017-11-03 2018-11-01 Electrolyte for lithium secondary battery and lithium secondary battery comprising the same

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
KR10-2017-0146223 2017-11-03
KR20170146223 2017-11-03
KR10-2018-0132195 2018-10-31
KR1020180132195A KR102227811B1 (en) 2017-11-03 2018-10-31 Electrolyte for lithium secondary battery and lithium secondary battery comprising the same

Publications (1)

Publication Number Publication Date
WO2019088733A1 true WO2019088733A1 (en) 2019-05-09

Family

ID=66332390

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/KR2018/013181 WO2019088733A1 (en) 2017-11-03 2018-11-01 Electrolyte for lithium secondary battery and lithium secondary battery comprising same

Country Status (1)

Country Link
WO (1) WO2019088733A1 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113966557A (en) * 2019-09-03 2022-01-21 株式会社Lg新能源 Non-aqueous electrolyte and lithium secondary battery comprising the same
JP2022530431A (en) * 2019-08-30 2022-06-29 エルジー エナジー ソリューション リミテッド Electrolytes for lithium secondary batteries and lithium secondary batteries containing them

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20050019667A1 (en) * 2002-03-22 2005-01-27 Bookeun Oh Solid polymer electrolyte and method of preparation
KR20080058197A (en) * 2006-12-21 2008-06-25 주식회사 엘지화학 Gel polymer electrolyte composition, gel polymer electrolyte and electrochemical device comprising the same
JP2008288127A (en) * 2007-05-21 2008-11-27 Nitto Denko Corp Nonaqueous electrolyte solution for lithium battery
KR20130058403A (en) * 2011-11-25 2013-06-04 삼성전자주식회사 Electrolyte composition, gel polymer electrolyte and lithium battery comprising gel polymer electrolyte
KR20140066163A (en) 2011-08-12 2014-05-30 모멘티브 퍼포먼스 머티리얼즈 인크. Siloxane copolymer and solid polymer electrolyte comprising such siloxane copolymers
KR20180132195A (en) 2017-06-01 2018-12-12 삼성디스플레이 주식회사 Organic Light Emitting Display Device and Driving Method Thereof

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20050019667A1 (en) * 2002-03-22 2005-01-27 Bookeun Oh Solid polymer electrolyte and method of preparation
KR20080058197A (en) * 2006-12-21 2008-06-25 주식회사 엘지화학 Gel polymer electrolyte composition, gel polymer electrolyte and electrochemical device comprising the same
JP2008288127A (en) * 2007-05-21 2008-11-27 Nitto Denko Corp Nonaqueous electrolyte solution for lithium battery
KR20140066163A (en) 2011-08-12 2014-05-30 모멘티브 퍼포먼스 머티리얼즈 인크. Siloxane copolymer and solid polymer electrolyte comprising such siloxane copolymers
KR20130058403A (en) * 2011-11-25 2013-06-04 삼성전자주식회사 Electrolyte composition, gel polymer electrolyte and lithium battery comprising gel polymer electrolyte
KR20180132195A (en) 2017-06-01 2018-12-12 삼성디스플레이 주식회사 Organic Light Emitting Display Device and Driving Method Thereof

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
CHEMICAL ABSTRACTS, Columbus, Ohio, US; abstract no. 2589-57-3
GERBALDI, C.: "UV-curable siloxane-acrylate gel-copolymer electrolytes for lithium-based battery applications", ELECTROCHIMICA ACTA, vol. 55, 2010, XP026867412 *
See also references of EP3561936A4 *

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2022530431A (en) * 2019-08-30 2022-06-29 エルジー エナジー ソリューション リミテッド Electrolytes for lithium secondary batteries and lithium secondary batteries containing them
JP7278658B2 (en) 2019-08-30 2023-05-22 エルジー エナジー ソリューション リミテッド Electrolyte for lithium secondary battery and lithium secondary battery containing the same
CN113966557A (en) * 2019-09-03 2022-01-21 株式会社Lg新能源 Non-aqueous electrolyte and lithium secondary battery comprising the same
JP2022530430A (en) * 2019-09-03 2022-06-29 エルジー エナジー ソリューション リミテッド Non-aqueous electrolyte solution and lithium secondary battery containing it
JP7278657B2 (en) 2019-09-03 2023-05-22 エルジー エナジー ソリューション リミテッド Non-aqueous electrolyte and lithium secondary battery containing the same
CN113966557B (en) * 2019-09-03 2024-02-20 株式会社Lg新能源 Nonaqueous electrolyte and lithium secondary battery comprising same

Similar Documents

Publication Publication Date Title
WO2021034141A1 (en) Non-aqueous electrolyte for lithium secondary battery and lithium secondary battery comprising same
WO2018169371A2 (en) Electrolyte for lithium secondary battery and lithium secondary battery comprising same
WO2020009436A1 (en) Lithium secondary battery with improved high temperature characteristics
WO2019203622A1 (en) Electrolyte for lithium secondary battery and lithium secondary battery comprising same
WO2018106078A1 (en) Electrolyte for lithium secondary battery and lithium secondary battery comprising same
WO2019108032A1 (en) Gel polymer electrolyte composition and lithium secondary battery comprising same
WO2019135624A1 (en) Gel polymer electrolyte composition, gel polymer electrolyte prepared therefrom, and lithium secondary battery comprising same
WO2020060295A1 (en) Composition for gel polymer electrolyte, and lithium secondary battery including gel polymer electrolyte formed therefrom
WO2020096343A1 (en) Composition for gel polymer electrolyte, and lithium secondary battery comprising gel polymer electrolyte formed therefrom
WO2021025521A1 (en) Copolymer for polymer electrolyte, gel polymer electrolyte comprising same, and lithium secondary battery
WO2018044129A1 (en) Gel polymer electrolyte and lithium secondary battery including same
WO2019013501A1 (en) Non-aqueous electrolyte solution additive, non-aqueous electrolyte solution for lithium secondary battery and lithium secondary battery, comprising non-aqueous electrolyte solution additive
WO2020167021A1 (en) Electrochemical device and method for manufacturing same
WO2019093853A1 (en) Non-aqueous electrolyte for lithium secondary battery and lithium secondary battery comprising same
WO2019108031A1 (en) Composition for gel polymer electrolyte, gel polymer electrolyte prepared by means of same, and lithium secondary battery comprising same
WO2020060293A1 (en) Composition for gel polymer electrolyte and lithium secondary battery comprising gel polymer electrolyte formed therefrom
WO2021015535A1 (en) Lithium secondary battery
WO2019088733A1 (en) Electrolyte for lithium secondary battery and lithium secondary battery comprising same
WO2019039903A2 (en) Nonaqueous electrolyte for lithium secondary battery and lithium secondary battery comprising same
WO2022055307A1 (en) Precursor composition for polymer electrolyte, and gel polymer electrolyte formed therefrom
WO2019108024A1 (en) Composition for gel polymer electrolyte, gel polymer electrolyte prepared by means of same, and lithium secondary battery comprising same
WO2018080259A1 (en) Polymer electrolyte for secondary battery and secondary battery comprising same
WO2021025535A1 (en) Copolymer for polymer electrolyte, gel polymer electrolyte comprising same, and lithium secondary battery
WO2022010281A1 (en) Nonaqueous electrolyte for lithium secondary battery, and lithium secondary battery comprising same
WO2018044128A1 (en) Polymer electrolyte and lithium secondary battery including same

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 18874455

Country of ref document: EP

Kind code of ref document: A1

ENP Entry into the national phase

Ref document number: 2018874455

Country of ref document: EP

Effective date: 20190722

ENP Entry into the national phase

Ref document number: 2020502292

Country of ref document: JP

Kind code of ref document: A

NENP Non-entry into the national phase

Ref country code: DE