Compounds for electrolytes, compounds for electrolyte additives, electrolyte substances, electrolyte additives, electrolytes for secondary batteries and secondary batteries

Abstract

The present invention relates to compounds for electrolytes, compounds for electrolyte additives, electrolyte substances, electrolyte additives, electrolytes for secondary batteries, and secondary batteries, and provides an electrolyte for secondary batteries containing a novel compound or its isomer.

Description

[Technical Field]

[0001] The present invention relates to compounds for electrolytes, compounds for electrolyte additives, electrolyte substances, electrolyte additives, electrolytes for secondary batteries, and secondary batteries. [Background technology]

[0002] Lithium-ion batteries are used as power sources for portable electronic devices such as video cameras, mobile phones, and laptop computers. Rechargeable lithium-ion batteries have more than three times the energy density per unit weight compared to conventional lead-acid batteries, nickel-cadmium batteries, nickel-metal hydride batteries, and nickel-zinc batteries, and can be rapidly charged.

[0003] Because lithium secondary batteries operate at high drive voltages, highly reactive aqueous electrolytes cannot be used. Generally, organic electrolytes are used as electrolytes for lithium secondary batteries. Organic electrolytes are manufactured by dissolving lithium salts in an organic solvent. Organic solvents are preferably stable at high voltages, have high ionic conductivity and dielectric constant, and have low viscosity.

[0004] On the other hand, the voltage, lifespan, capacity, and stability of a battery can vary greatly depending on the materials used for the negative electrode, positive electrode, and electrolyte. Therefore, there is a need for lithium-ion battery electrolytes that can provide lithium-ion batteries with improved lifespan characteristics and high-temperature stability. Lithium-ion batteries are used as power sources for portable electronic devices such as video cameras, mobile phones, and laptop computers. Rechargeable lithium-ion batteries have an energy density per unit weight that is more than three times higher than conventional lead-acid batteries, nickel-cadmium batteries, nickel-metal hydride batteries, and nickel-zinc batteries, and they can be rapidly charged.

[0005] Because lithium secondary batteries operate at high drive voltages, highly reactive aqueous electrolytes cannot be used. Generally, organic electrolytes are used as electrolytes for lithium secondary batteries. Organic electrolytes are manufactured by dissolving lithium salts in an organic solvent. Organic solvents are preferably stable at high voltages, have high ionic conductivity and dielectric constant, and have low viscosity.

[0006] On the other hand, the voltage, lifespan, capacity, and stability of a battery can vary significantly depending on the materials used for the negative electrode, positive electrode, and electrolyte. Therefore, there is a need for lithium-ion battery electrolytes that can provide lithium-ion batteries with improved lifespan characteristics and high-temperature stability. [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] The object of the present invention is to provide an electrolyte for secondary batteries containing a novel compound or its isomer.

[0008] Another object of the present invention is to provide a secondary battery containing the electrolyte for secondary batteries. [Means for solving the problem]

[0009] To achieve the above objective, one aspect of the present invention provides an electrolyte for a secondary battery comprising a compound of the following chemical formula 1 or an isomer thereof. [Chemical Formula 1] [ka] In the above formula 1, [HetCy] is a compound represented by the above chemical formula 2, [Chemical Formula 2] [ka] M is Li + kaNa + , K + , Rb + , or Cs + And, Y is (FSO2)2N - , PF6 - , PO2F2 - , BF4 - , ClO4 - , (C2O4)BF2 - , HSO4 - , CF3SO3 - , (C2F5SO2)2N - , C(CF2SO2)3 - , AsF6 - , SbF6 - , AlCl4 - , NbF6 - , CF3CO2 - , (C4F9SO3) - , AlO3 - , (N(C x F 2x+1 O2)(C y F 2y+1 SO2)) - (2 ≦ x ≦ 20, 2 ≦ y ≦ 20), Cl - or I - and In Chemical Formula 2 The dotted line indicates the presence or absence of a double bond X is O, S or CR’R” n is an integer of 1 or 2 R is hydrogen, substituted or unsubstituted C 1-10 alkyl, substituted or unsubstituted C 2-10 alkenyl, substituted or unsubstituted C 2-10 alkynyl, substituted or unsubstituted C 2-10 allyl, substituted or unsubstituted C 1-12 heteroalkyl, substituted or unsubstituted C 3-12 cycloalkyl, substituted or unsubstituted C 3-12 heterocycloalkyl, substituted or unsubstituted C 1-6 acyl, substituted or unsubstituted silyl, substituted or unsubstituted sulfonyl, or -P(=G)R 1 R 2 and G is O or S R’, R”, R 1 and R 2 are each independently hydrogen, substituted or unsubstituted C 1-10 alkyl, substituted or unsubstituted C1-12 Heteroalkyl, or substituted or unsubstituted C1-C 20 It could be an alkoxy.

[0010] In one aspect of the present invention, the substituted alkyl, alkenyl, amine, acyl, alkynyl, cycloalkyl, silyl, alkoxy, heteroalkyl, and heterocycloalkyl groups may each be independently substituted with one or more substituents selected from the group consisting of alkoxy groups, alkynyloxy groups, heteroaryl groups, alkenyl groups, heterocycloalkyl groups, carbonyl groups, halogen groups, hydroxyl groups, alkenyloxy groups, carboxyl groups, carbonate groups, alkyl groups, alkynyl groups, amine groups, cycloalkyl groups, silyl groups, sulfonate groups, phosphate groups, thiophosphate groups, nitro groups, cyano groups, heteroalkyl groups, cycloalkyl groups, aryl groups, and ether groups. [Effects of the Invention]

[0011] A secondary battery containing the electrolyte additive and electrolyte for secondary batteries according to the present invention can improve the lifespan performance at room temperature. [Brief explanation of the drawing]

[0012] [Figure 1] This shows a cross-sectional view of a secondary battery containing an electrolyte and an electrolyte additive according to one embodiment of the present invention. [Figure 2] This figure shows the results of an analysis of the lifespan performance at room temperature for a secondary battery according to one embodiment of the present invention. [Figure 3] This figure shows the results of an analysis of the capacity retention performance of a secondary battery according to one embodiment of the present invention. [Figure 4] This figure shows the results of an analysis of the room-temperature resistance improvement performance of a secondary battery according to one embodiment of the present invention. [Figure 5] This figure shows the three-dimensional structure of an electrolyte additive compound according to one embodiment of the present invention, as analyzed by SC-XRD (single crystal X-ray diffraction). [Modes for carrying out the invention]

[0013] One embodiment of the present invention provides an electrolyte for a secondary battery containing the compound of formula 1 or its isomer. [Chemical Formula 1] [ka] In the above formula 1, [HetCy] is a compound represented by the above chemical formula 2, [Chemical Formula 2] [ka] M is Li + kaNa + , K + , Rb + , or Cs + And, Y is (FSO2)2N - PF6 - , PO2F2 - BF4 - ClO4 - (C2O4)BF2 - HSO4 - CF3SO3 - (C2F5SO2)2N - , C(CF2SO2)3 - AsF6 - SbF6 - AlCl4 - , NbF6 - CF3CO2 - (C4F9SO3) - AlO3 - , (N(C x F 2x+1 O2)(C y F 2y+1 SO2)) - (2≦x≦20, 2≦y≦20), Cl - or I - And, In the above formula 2, The dotted line indicates the presence or absence of a double bond. X is O, S, or CR'R". n is an integer of 1 or 2, R is hydrogen, substituted or unsubstituted C 1-10 Alkyl, substituted, or unsubstituted C 2-10 Alkenyl, substituted, or unsubstituted C 2-10 Alkynyl, substituted, or unsubstituted C 2-10 Allyl, substituted, or unsubstituted C 1-12 Heteroalkyl, substituted, or unsubstituted C 3-12 Cycloalkyl, substituted, or unsubstituted C 3-12 Heterocycloalkyl, substituted or unsubstituted C 1-6 Acyl, substituted or unsubstituted silyl, substituted or unsubstituted sulfonyl, or -P(=G)R 1 R 2 And, G is either O or S, R', R'', R 1 and R 2 Each of these is independently hydrogen, substituted or unsubstituted C 1-10 Alkyl, substituted, or unsubstituted C 1-12 Heteroalkyl, or substituted or unsubstituted C1-C 20 It could be an alkoxy.

[0014] In one embodiment of the present invention, the substituted alkyl, alkenyl, amine, acyl, alkynyl, cycloalkyl, silyl, alkoxy, heteroalkyl, and heterocycloalkyl groups may each be independently substituted with one or more substituents selected from the group consisting of alkoxy groups, alkynyloxy groups, heteroaryl groups, alkenyl groups, heterocycloalkyl groups, carbonyl groups, halogen groups, hydroxyl groups, alkenyloxy groups, carboxyl groups, carbonate groups, alkyl groups, alkynyl groups, amine groups, cycloalkyl groups, silyl groups, sulfonate groups, phosphate groups, thiophosphate groups, nitro groups, cyano groups, heteroalkyl groups, cycloalkyl groups, aryl groups, and ether groups.

[0015] In one embodiment of the present invention, the electrolyte may further contain one or more additives selected from the group consisting of unsaturated cyclic carbonates, cyclic sultones, cyclic sulfetralactones, and nitrile compounds.

[0016] In one embodiment of the present invention, the unsaturated cyclic carbonate may be selected from the group consisting of vinylene carbonate, phenyl carbonate, vinyl carbonate, and allyl carbonate.

[0017] Another embodiment of the present invention provides a lithium-ion battery containing the non-aqueous electrolyte for secondary batteries.

[0018] In one embodiment of the present invention, a secondary battery can be provided which includes an electrode assembly comprising a positive electrode, a negative electrode, and a separator separating the positive electrode and the negative electrode, a case for housing the electrode assembly, and an electrolyte housed in the case and immersed in the electrode assembly.

[0019] One embodiment of the present invention is shown in the accompanying drawings. However, the spirit of the present invention can be embodied in many other forms and should not be construed as being limited to the embodiments described herein. Rather, these embodiments are provided so as to make the present disclosure thorough and complete and will fully convey the scope of the spirit of the invention to a person of ordinary skill in the art. The same reference numerals in the drawings refer to the same components.

[0020] The terms used herein are for the purpose of describing specific embodiments only and do not limit the ideas of the invention. The singular form used herein is intended to include multiple forms, including “at least one,” unless explicitly indicated otherwise in the text. “At least one” should not be construed as limiting to the singular. As used herein, the term “and / or” includes all any combination of one or more of the listed items. The terms “include” and / or “contain” as used in the detailed description identify the presence of the described features, regions, integers, steps, operations, components, and / or ingredients, and do not exclude the presence or addition of one or more other features, regions, integers, steps, operations, components, ingredients, and / or groups thereof.

[0021] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as they would be generally understood by a person of ordinary skill in the art to which this disclosure belongs. Furthermore, it will be understood that terms defined in commonly used dictionaries should be interpreted as having the meaning consistent with their meaning in the context of the relevant art and this disclosure, and not as idealized or overly formal.

[0022] While specific embodiments are described, alternatives, modifications, variations, improvements, and substantial equivalents not currently anticipated or foreseeable may occur to the applicant or those skilled in the art. Therefore, the attached claims, which may be filed and amended, are intended to include all such alternatives, modifications, variations, improvements, and substantial equivalents.

[0023] In this invention, the term "isomer" refers to a compound or salt thereof of the present invention that has the same chemical or molecular formula but is structurally or sterically different. Such isomers include structural isomers such as tautomers, stereoisomers such as R or S isomers with asymmetric carbon centers, geometric isomers (trans, cis), and optical isomers. All of these isomers and mixtures thereof are also within the scope of this invention.

[0024] In this invention, the term "alkyl" may refer to a linear or branched chain unless otherwise specified, and the number of carbon atoms is not particularly limited but may range from 1 to 7. Specific examples of alkyl groups include, but are not limited to, methyl, ethyl, propyl, n-propyl, isopropyl, butyl, n-butyl, isobutyl, tert-butyl, sec-butyl, 1-methyl-butyl, 1-ethyl-butyl, pentyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, hexyl, n-hexyl, 1-methylpentyl, 2-methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl, heptyl, and n-heptyl.

[0025] In this specification, the term "alkenyl" may refer to an alkyl group containing one or more double bonds, whether linear or branched, unless otherwise specified. The number of carbon atoms is not particularly limited, but may range from 2 to 6. Specific examples include, but are not limited to, vinyl, 1-profenyl, isoprofenyl, 1-butenyl, 2-butenyl, 3-butenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 3-methyl-1-butenyl, and 1,3-butadienyl.

[0026] In this specification, the term "alkynyl" may refer to an alkyl group containing one or more triple bonds, whether linear or branched, unless otherwise specified. The number of carbon atoms is not particularly limited, but may range from 2 to 6. Specific examples include, but are not limited to, ethynyl, propynyl, butynyl, and pentynyl groups.

[0027] In this specification, the term "heteroalkyl" refers to an alkyl group containing one or more heteroatoms from O, N, Si, B, Se, P, and S, and the number of carbon atoms is not particularly limited, but can range from 1 to 6. Examples of heteroalkyl groups include, but are not limited to, -CH2-CH2-O-CH3, -CH2-CH2-NH-CH3, -CH2-CH2-N(CH3)-CH3, and -CH2-S-CH2-CH3.

[0028] In this specification, the term "cycloalkyl" refers to a non-aromatic carbon ring, and the number of carbon atoms is not particularly limited, but may range from 3 to 12. Examples of cycloalkyls include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, and cyclodecyl.

[0029] In this specification, the term "heterocycloalkyl" refers to a cycloalkyl compound containing one or more heterogeneous elements from O, N, Si, B, Se, P, and S, and is not particularly limited in terms of the number of carbon atoms, but may range from 3 to 12. Examples of heterocycloalkyl compounds include, but are not limited to, epoxy, tetrahydrofuranyl, tetrahydropyranyl, tetrahydrothiophenyl, and tetrahydropyrrolyl.

[0030] In this specification, the term "allyl" refers to a substituent containing the atomic group CH2=CHCH2-, and includes, but is not limited to, 1-methylallyl, 1,1-dimethylallyl, 2-methylallyl, 1-phenylallyl, 2-phenylallyl, 3-phenylallyl, 3,3-diphenylallyl, and 1,2-dimethylallyl groups.

[0031] In this specification, the term "heteroaryl" refers to an aryl compound containing one or more of the following heteroatoms: O, N, Si, B, Se, P, and S. The number of carbon atoms is not particularly limited, but can range from 5 to 20. Examples of heteroaryl groups include, but are not limited to, xanthene, thioxanthen, thiophene group, furan group, pyrrole group, imidazole group, thiazole group, oxazole group, oxadiazole group, triazole group, pyridyl group, bipyridyl group, pyrimidyl group, triazine group, acridyl group, pyridazine group, pyrazinyl group, quinoline group, quinazoline group, quinoxalinyl group, phthalazinyl group, pyridopyrimidinyl group, pyridopyradinyl group, pyrazinopyradinyl group, isoquinoline group, indole group, carbazole group, benzoxazole group, benzimidazole group, benzothiazole group, benzocarbazole group, benzothiophene group, dibenzothiophene group, benzofuran group, phenanthroline group, isoxazolyl group, thiadiazolyl group, phenothiazine group, and dibenzofuran group.

[0032] In this specification, the term "alkoxy" refers to an alkyl group bonded to oxygen, and oxygen can be bonded to the aforementioned alkyl group. Examples of alkoxy groups include, but are not limited to, methoxy, ethoxy, propoxy, butoxy, and pentoxy groups.

[0033] In this specification, the term "acyl" refers to the residue remaining after removing the OH group from the carboxyl group (-COOH) of a carboxylic acid, and the number of carbon atoms is not particularly limited, but may range from 1 to 6. Examples of acyls include, but are not limited to, acetyl, propionyl, malonyl, and benzoyl groups.

[0034] The term "silyl" as used herein may be represented as -SiR3, and examples of silyls may be selected from, but are not limited to, alkylsilyl groups, arylsilyl groups, alkylarylsilyl groups, and heteroarylsilyl groups. More specific examples include, but are not limited to, trimethylsilyl groups, triethylsilyl groups, t-butyldimethylsilyl groups, vinyldimethylsilyl groups, propyldimethylsilyl groups, triphenylsilyl groups, diphenylsilyl groups, and phenylsilyl groups.

[0035] In this specification, the term "sulfonyl" refers to a compound with the general formula RS(=O) having two double bonds between sulfur and oxygen. 2- It can be represented by R', and examples of sulfonyl groups include alkyl sulfonyl groups such as methyl sulfonyl group, ethyl sulfonyl group, propyl sulfonyl group, butyl sulfonyl group, trifluoromethyl sulfonyl group, perfluoroethyl sulfonyl group, perfluoropropyl sulfonyl group, and perfluorobutyl sulfonyl group, as well as aryl sulfonyl groups such as phenyl sulfonyl group, p-toluene sulfonyl group, p-fluorophenyl sulfonyl group, and pentafluorophenyl sulfonyl group, but is not limited to these.

[0036] As used herein, the term "substituted or unsubstituted" can mean being substituted or unsubstituted with one or more groups selected from the group consisting of an alkoxy group, an alkynyloxy group, a heteroaryl group, an alkenyl group, a heterocycloalkyl group, a carbonyl group, a halogen group, a hydroxy group, an alkenyloxy group, a carboxyl group, a carbonate group, an alkyl group, an alkynyl group, an amine group, a cycloalkyl group, a silyl group, a sulfonate group, a phosphate group, a thiophosphate group, a nitro group, a cyano group, a heteroalkyl group, a cycloalkyl group, an aryl group, and an ether group.

[0037] Furthermore, throughout this specification, the same symbols can have the same meaning unless otherwise specified.

[0038] The present invention relates to a compound for an electrolyte, a compound for an electrolyte additive, an electrolyte substance, an electrolyte additive, an electrolyte for a secondary battery, and a secondary battery.

[0039] One aspect of the present invention provides an electrolyte for a secondary battery containing a novel compound or an isomer thereof.

[0040] The compound may be represented by the following Chemical Formula 1. [Chemical Formula 1] [Chem.] In Chemical Formula 1, [HetCy] is a compound represented by Chemical Formula 2, [Chemical Formula 2] [Chem.] M is Li + , Na + , K + , Rb + , or Cs + and Y is (FSO2)2N - , PF6 - , PO2F2 - , BF4 - , ClO4 - , (C2O4)BF2 -HSO4 - CF3SO3 - (C2F5SO2)2N - , C(CF2SO2)3 - AsF6 - SbF6 - AlCl4 - , NbF6 - CF3CO2 - (C4F9SO3) - AlO3 - , (N(C x F 2x+1 O2)(C y F 2y+1 SO2)) - (2≦x≦20, 2≦y≦20), Cl - or I - And, In the above formula 2, The dotted line indicates the presence or absence of a double bond. X is O, S, or CR'R", n is an integer, either 1 or 2. R is hydrogen, substituted or unsubstituted C 1-10 Alkyl, substituted, or unsubstituted C 2-10 Alkenyl, substituted, or unsubstituted C 2-10 Alkynyl, substituted, or unsubstituted C 1-12 Heteroalkyl, substituted, or unsubstituted C 3-12 Cycloalkyl, substituted, or unsubstituted C 3-12 Heterocycloalkyl, substituted or unsubstituted allyl, substituted or unsubstituted acyl, substituted or unsubstituted silyl, substituted or unsubstituted sulfonyl, or -P(=G)R 1 R 2 And, G is either O or S, R', R'', R 1 and R 2 These are, independently, hydrogen, substituted or unsubstituted C 1-10 Alkyl, substituted, or unsubstituted C 1-12 Heteroalkyl, or substituted or unsubstituted C1-C 20 It could be an alkoxy.

[0041] In one embodiment of the present invention, the compound represented by chemical formula 1 is a complex compound in which heterocyclic compounds having lone pairs of electrons form a coordination bond, and can be added to an electrolyte as an additive for lithium secondary batteries. The additive of the present invention can be used as an additive for non-aqueous electrolytes and can form a stable SEI (Solid Electrolyte Interphase) film on the negative electrode surface while minimizing the increase in resistance of the lithium secondary battery. Therefore, a film is formed that suppresses the decrease in the passivation capacity of SEI at high temperatures, prevents deterioration of the negative electrode, facilitates lithium movement, and improves the lifespan at room temperature.

[0042] The compound represented by chemical formula 1 of the present invention, [HetCy], is a substituted or unsubstituted heterocyclic compound, and may be represented by chemical formula 2. The compound represented by chemical formula 2 of the present invention is a heterocyclic compound having a lone pair of electrons, and a double bond may or may not be formed in the CC bond within the ring.

[0043] The substituted alkyl, alkenyl, alkynyl, alkoxy, heteroalkyl, cycloalkyl, silyl, heterocycloalkyl, allyl, acyl, silyl, and sulfonyl groups of the present invention may each be independently substituted with one or more substituents selected from the group consisting of alkoxy groups, alkynyloxy groups, heteroaryl groups, alkenyl, heterocycloalkyl groups, carbonyl groups, halogen groups, hydroxyl groups, alkenyloxy groups, carboxyl groups, carbonate groups, alkyl groups, alkynyl groups, amine groups, cycloalkyl groups, silyl groups, sulfonate groups, phosphate groups, thiophosphate groups, nitro groups, cyano groups, heteroalkyl groups, cycloalkyl groups, aryl groups, and ether groups. For example, the substituted alkoxy group may be substituted with an alkenyl group, alkynyl group, amine group, cycloalkyl group, carbonyl group, or silyl group; the substituted heterocycloalkyl group may be substituted with a carbonyl group; and the substituted carboxyl group may be substituted with a heteroaryl group, alkenyl group, heterocycloalkyl group, heterocycloalkyl group substituted with a carbonyl group, or halogen group.

[0044] In the compound represented by chemical formula 1 of the present invention, M is a metal cation, more specifically an alkali metal, Li + kaNa + , K + , Rb + or Cs + It may be, preferably Li + kaNa + or Cs + And more preferably Li + - It is possible.

[0045] Y is an anion, (FSO2)2N - PF6 - , PO2F2 - BF4 - ClO4 - (C2O4)BF2 - HSO4 - CF3SO3 - (C2F5SO2)2N - , C(CF2SO2)3 - AsF6 - SbF6 - AlCl4 - , NbF6 - CF3CO2 - (C4F9SO3) - AlO3 - , (N(C x F 2x+1 O2)(C y F 2y+1 SO2)) - (2≦x≦20, 2≦y≦20), Cl - or I - It may be (FSO2)2N, preferably (FSO2)2N - , PO2F2 - BF4 - (C2O4)BF2 - CF3SO3 - (C4F9SO3) - Or (C2F5SO2)2N - That's fine.

[0046] In one embodiment of the present invention, the compound represented by chemical formula 2 may be any one of the compounds represented by the following chemical formulas 2-1 to 2-5. [Chemical Formula 2-1] [ka] [Chemical Formula 2-2] [ka] [Chemical Formula 2-3] [ka] [Chemical Formula 2-4] [ka] [Chemical Formula 2-5] [ka] X and R are the same as defined in formula 2 above.

[0047] Compounds containing the compounds represented by the chemical formulas 2-1 to 2-5 can improve room-temperature life and resistance performance as electrolyte additives for secondary batteries according to the present invention.

[0048] The molar ratio of HetCy:M:Y in the compound represented by the chemical formula 1 of the present invention may be 1:1:1 to 3:1:1. Preferably, the compound may be composed of a molar ratio of 1:1:1.

[0049] The electrolyte for the secondary battery of the present invention contains the compound represented by the chemical formula 1 as an additive, and may further contain additional additives. For example, it may further contain one or more additives selected from the group consisting of unsaturated cyclic carbonates, cyclic sultones, cyclic sulfetralactones, and nitrile compounds, but is not limited to these.

[0050] The unsaturated cyclic carbonate of the present invention is a cyclic carbonate having carbon-carbon unsaturated bonds, such as carbon-carbon double bonds or carbon-carbon triple bonds, and is not particularly limited; any unsaturated cyclic carbonate can be used.

[0051] As the additional additive of the present invention, the unsaturated cyclic carbonate can be one or more selected from the group consisting of vinylene carbonate, phenyl carbonate, vinyl carbonate, and allyl carbonate. As the vinylene carbonates, one or more can be selected from vinylene carbonate, methyl vinylene carbonate, 4,5-dimethyl vinylene carbonate, phenyl vinylene carbonate, 4,5-diphenyl vinylene carbonate, vinyl vinylene carbonate, 4,5-vinyl vinylene carbonate, allyl vinylene carbonate, and 4,5-diallyl vinylene carbonate.

[0052] As an additional additive to the present invention, cyclic sultones can be added. In one embodiment, 1,3-propanesultone, 1-fluoro-1,3-propanesultone, 2-fluoro-1,3-propanesultone, 3-fluoro-1,3-propanesultone, 1,4-butanesultone, methylenemethanedisulfonate, and ethylenemethanedisulfonate are preferred in terms of improving storage properties, and at least one selected from the group consisting of 1,3-propanesultone, 1-fluoro-1,3-propanesultone, 2-fluoro-1,3-propanesultone, and 3-fluoro-1,3-propanesultone can be added.

[0053] As a specific embodiment of the present invention, the compound represented by chemical formula 1 may include at least one compound or isomer selected from the group represented by the following chemical formula: [ka] [ka] [ka] [ka] [ka] [ka] [ka] [ka]

[0054] Furthermore, the compounds of the present invention may have a chiral carbon center and therefore may exist in the form of R or S isomers, racemic compounds, individual enantiomers or mixtures, individual diastereoisomers or mixtures, and all such stereoisomers and mixtures thereof may fall within the scope of the present invention.

[0055] The electrolyte compound may be present in an amount of about 0.1% by weight or more based on the total weight of the entire electrolyte, but is not limited to this amount, and an appropriate amount can be used as needed within the range of the above content.

[0056] If the content of the compound in the total electrolyte is too high, the excess gas may cause the battery to swell, which could reduce its lifespan.

[0057] From this perspective, the content of the electrolyte compound is based on the total weight of the electrolyte and is 0.01-10% by weight, 0.01-9% by weight, 0.01-8% by weight, 0.01-7% by weight, 0.01-6% by weight, 0.01-5% by weight, 0.01-4% by weight, 0.01-3% by weight, 0.01-2% by weight, 0.01-1% by weight, 0.1-10% by weight, 0.1-9% by weight, 0.1-8% by weight, 0.1-7% by weight, 0.1-6% by weight, 0.1-5% by weight, and 0. The amount may be 1-4% by weight, 0.1-3% by weight, 0.1-2% by weight, 0.1-1% by weight, 1-10% by weight, 1-9% by weight, 1-8% by weight, 1-7% by weight, 1-6% by weight, 1-5% by weight, 1-4% by weight, 1-3% by weight, 1-2% by weight, 5-10% by weight, 5-9% by weight, 5-8% by weight, 5-7% by weight, or 5-6% by weight, as long as it functions as an overcharge protection agent without degrading the lifespan characteristics.

[0058] On the other hand, in one embodiment, the electrolyte for the secondary battery may further contain a lithium salt and an organic solvent.

[0059] The concentration of the lithium salt in the electrolyte may be approximately 0.01 to 2.0 M, but is not necessarily limited to this range, and an appropriate concentration can be used as needed. Further improved battery characteristics can be obtained within the aforementioned concentration range.

[0060] The lithium salt used in the electrolyte is not particularly limited, and any lithium salt that can be used in the art is acceptable. For example, LiPF6, LiBF4, LiSbF6, LiAsF6, LiClO4, LiCF3SO3, Li(CF3SO2)2N, LiC4F9SO3, LiAlO2, LiAlCl4, LiC2F6NO4S2, LiB(C2O4)2, LiN(C x F 2x+1 SO2)(C y F 2y+1 You may use one or more integers selected from the group consisting of SO2)(x and y are one or more independent integers), LLiCl, and LiI.

[0061] The organic solvent may include one or more selected from the group consisting of dialkyl carbonates, cyclic carbonates, linear or cyclic esters, linear or cyclic amides, aliphatic nitriles, linear or cyclic ethers, and derivatives thereof.

[0062] Specifically, the organic solvent may include, but is not limited to, one or more selected from the group consisting of dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), methyl propyl carbonate, ethyl propyl carbonate, diethyl carbonate (DEC), dipropyl carbonate, propylene carbonate (PC), ethylene carbonate (EC), fluoroethylene carbonate (FEC), butylene carbonate, ethyl propionate (EP), ethyl butyrate, acetonitrile (AN), succinone nitrile (SN), dimethyl sulfoxide, dimethylformamide, dimethylacetamide, γ-valerolactone, γ-butyrolactone, and tetrahydrofuran. Any organic solvent that can be used as an organic electrolyte in the art is acceptable.

[0063] Another aspect of the present invention provides a secondary battery comprising the electrolyte for the secondary battery.

[0064] The secondary battery includes an electrode assembly comprising a positive electrode, a negative electrode, and a separator that separates the positive electrode and the negative electrode. A case for housing the electrode assembly, and The case may contain the electrolyte for the secondary battery, which is housed within the case and immersed in the electrode assembly.

[0065] The aforementioned secondary battery is not particularly limited in form and includes, but is not limited to, lithium-ion batteries, lithium-ion polymer batteries, lithium-sulfur batteries, lithium-air batteries, etc.

[0066] For example, if the secondary battery is a lithium-ion battery, it can be manufactured by the following method.

[0067] First, the positive electrode is prepared.

[0068] For example, a positive electrode active material composition is prepared by mixing a positive electrode active material, a conductive material, a binder, and a solvent. A positive electrode plate is manufactured by directly coating the positive electrode active material composition onto a metal current collector. Alternatively, the positive electrode active material composition can be cast onto a separate support, and then the film peeled off the support is laminated onto the metal current collector to manufacture a positive electrode plate. The positive electrode is not limited to the forms listed above, and may be in forms other than those described above.

[0069] The positive electrode active material is a lithium-containing metal oxide, and any of those commonly used in the art can be used without limitation. For example, one or more composite oxides of lithium with metals selected from cobalt, manganese, nickel, and combinations thereof can be used, and a specific example is Li a A 1-b B b D2 (wherein the above formula, 0.90 ≤ a ≤ 1.8 and 0 ≤ b ≤ 0.5), Li a E 1-b B b O 2-c D c (In the above formula, 0.90 ≤ a ≤ 1.8, 0 ≤ b ≤ 0.5, and 0 ≤ c ≤ 0.05), LiE 2-b B b O 4-c D c (In the above formula, 0≦b≦0.5 and 0≦c≦0.05), Li a Ni 1-b-c Co b B c D α (In the above formula, 0.90 ≤ a ≤ 1.8, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05, and 0 < α ≤ 2), Li a Ni 1-b-c Co b B c O 2-α F α (In the above formula, 0.90 ≤ a ≤ 1.8, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05, and 0 < α < 2), Li a Ni 1-b-c Cob B c O 2-α F2 (In the above formula, 0.90 ≤ a ≤ 1.8, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05, and 0 < α < 2), Li a Ni 1-b-c Mn b B c D α (In the above formula, 0.90 ≤ a ≤ 1.8, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05, and 0 < α ≤ 2), Li a Ni 1-b-c Mn b B c O 2-α F α (In the above formula, 0.90 ≤ a ≤ 1.8, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05, and 0 < α < 2), Li a Ni 1-b-c Mn b B c O 2-α F2 (In the above formula, 0.90 ≤ a ≤ 1.8, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05, and 0 < α < 2), Li a Ni b E c G d O2 (in the above formula, 0.90 ≤ a ≤ 1.8, 0 ≤ b ≤ 0.9, 0 ≤ c ≤ 0.5, 0.001 ≤ d ≤ 0.1), Li a Ni b Co c Mn d G e O2 (In the above formula, 0.90 ≤ a ≤ 1.8, 0 ≤ b ≤ 0.9, 0 ≤ c ≤ 0.5, 0 ≤ d ≤ 0.5, 0.001 ≤ e ≤ 0.1), Li a NiG b O2 (In the above formula, 0.90 ≤ a ≤ 1.8 and 0.001 ≤ b ≤ 0.1), Li a CoG b O2 (In the above formula, 0.90 ≤ a ≤ 1.8 and 0.001 ≤ b ≤ 0.1), Li a MnG b O2 (In the above formula, 0.90 ≤ a ≤ 1.8 and 0.001 ≤ b ≤ 0.1), Li a Mn2G bO4 (where 0.90 ≤ a ≤ 1.8 and 0.001 ≤ b ≤ 0.1 in the above formula), QO2, QS2, LiQS2, V2O5, LiV2O5, LiIO2, LiNiVO4, Li (3-F) J2(PO4)3(0≦f≦2), Li (3ーF) Compounds represented by either the chemical formula Fe2(PO4)3 (0≦f≦2) or LiFePO4 can be used.

[0070] In the above chemical formula, A is Ni, Co, Mn, or a combination thereof; B is Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, rare earth elements, or a combination thereof; D is O, F, S, P, or a combination thereof; E is CO, Mn, or a combination thereof; F is F, S, P, or a combination thereof; G is Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V, or a combination thereof; Q is Ti, Mo, Mn, or a combination thereof; I is Cr, V, Fe, Sc, Y, or a combination thereof; and J is V, Cr, Mn, Co, Ni, Cu, or a combination thereof.

[0071] For example, LiCoO2, LiMn x O 2x (x=1, 2), LiNi 1-x Mn x O 2x (0 <x<1)、LiNi 1-x-y Co x Mn y Examples include O2 (0 ≤ x ≤ 0.5, 0 ≤ y ≤ 0.5) and LiFePO4.

[0072] Of course, compounds having a coating layer on their surface can also be used, or the compound and a compound having a coating layer can be mixed and used. This coating layer may include coating element compounds of oxide, hydroxide, oxyhydroxy, oxycarbonate, or hydroxycarbonate of the coating element. The compounds constituting these coating layers may be amorphous or crystalline. As coating elements included in the coating layer, Mg, Al, Co, K, Na, Ca, Si, Ti, V, Sn, Ge, Ga, B, As, Zr, or mixtures thereof can be used. Any coating method can be used for the coating layer formation step, as long as the compound is coated with these elements in a way that does not adversely affect the physical properties of the positive electrode active material (e.g., spray coating, immersion method, etc.). Since this is something that people engaged in this field will understand well, a detailed explanation will be omitted.

[0073] The conductive material can be carbon black, graphite fine particles, etc., but is not limited to these; any conductive material that can be used in the relevant technical field can be used.

[0074] As the binder, vinylidene fluoride / hexafluoropropylene copolymer, polyvinylidene fluoride (PVDF), polyacrylonitrile, polymethyl methacrylate, polytetrafluoroethylene and mixtures thereof, or styrene-butadiene rubber polymers can be used, but are not limited to these; any binder that can be used in the art can be used.

[0075] As the aforementioned solvent, N-methylpyrrolidone, acetone, water, etc., can be used, but the solvent is not limited to these, and any solvent that can be used in the art can be used.

[0076] The content of the positive electrode active material, conductive material, binder, and solvent is at levels typically used in lithium-ion batteries. Depending on the application and configuration of the lithium-ion battery, one or more of the conductive material, binder, and solvent may be omitted.

[0077] Next, the negative electrode is prepared.

[0078] For example, a negative electrode active material composition is prepared by mixing a negative electrode active material, a conductive material, a binder, and a solvent. The negative electrode plate is manufactured by directly coating and drying the negative electrode active material composition onto a metal current collector. Alternatively, the negative electrode active material composition can be cast onto a separate support, and then the film peeled off the support is laminated onto a metal current collector to manufacture the negative electrode plate.

[0079] The negative electrode active material can be any material that can be used as a negative electrode active material for lithium-ion batteries in the art. For example, it may include one or more selected from the group consisting of lithium metal, metals alloyable with lithium, transition metal oxides, non-transition metal oxides, and carbon-based materials.

[0080] For example, the metals alloyable with lithium may be Si, Sn, Al, Ge, Pb, Bi, Sb, Si-Y alloys (where Y is an alkali metal, alkaline earth metal, group 13 element, group 14 element, transition metal, rare earth element, or a combination thereof, and not Si), Sn-Y alloys (where Y is an alkali metal, alkaline earth metal, group 13 element, group 14 element, transition metal, rare earth element, or a combination thereof, and not Sn), etc. The element Y may be 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, Ti, Ge, P, As, Sb, Bi, S, Se, Te, Po, or a combination thereof.

[0081] For example, the transition metal oxide can be lithium titanate, vanadium oxide, lithium vanadium oxide, etc.

[0082] For example, the non-transition metal oxide is SnO2, SiO x (0 < x < 3), etc.

[0083] The carbon-based material can be crystalline carbon, amorphous carbon, or a mixture thereof. The crystalline carbon may be graphite such as amorphous, plate-like, flaky, spherical or fibrous natural graphite or artificial graphite, and the amorphous carbon may be soft carbon (low-temperature fired carbon) or hard carbon, mesophase pitch carbide, calcined coke, etc.

[0084] In the negative electrode active material composition, the same conductive material and binder as those in the case of the positive electrode active material composition can be used.

[0085] The contents of the negative electrode active material, conductive material, binder and solvent are at levels commonly used in lithium ion batteries. Depending on the use and configuration of the lithium ion battery, one or more of the conductive material, binder and solvent can be omitted.

[0086] Next, a separator for separating the positive electrode and the negative electrode is prepared.

[0087] Any separator commonly used in lithium-ion batteries can be used. A separator with low resistance to electrolyte ion movement while possessing excellent electrolyte moisture absorption capacity can be used. For example, it may be a nonwoven or woven fabric selected from glass fiber, polyester, Teflon®, polyethylene, polypropylene, polytetrafluoroethylene (PTFE), or a combination thereof. For example, a rollable separator such as polyethylene or polypropylene can be used in lithium-ion batteries, while a separator with excellent organic electrolyte impregnation capacity can be used in lithium-ion polymer batteries. For example, the separator can be manufactured according to the following method.

[0088] A separator composition is prepared by mixing a polymer resin, a filler, and a solvent. The separator composition can be directly coated onto the electrode and dried to form a separator. Alternatively, the separator composition may be cast onto a support and dried, and then the separator film peeled off the support may be laminated onto the electrode to form a separator.

[0089] The polymer resin used in the manufacture of the separator is not particularly limited, and all substances used as binders for electrode plates can be used. For example, vinylidene fluoride / hexafluoropropylene copolymer, polyvinylidene fluoride (PVDF), polyacrylonitrile, polymethyl methacrylate, or mixtures thereof can be used.

[0090] Next, prepare the electrolyte solution for the secondary battery as described above.

[0091] As shown in Figure 1, the secondary battery 1 includes a positive electrode 40, a negative electrode 60, and a separator 50. The positive electrode 40, negative electrode 60, and separator 50 are wound up or folded and housed in cases 10 and 80. Subsequently, electrolyte is injected into cases 10 and 80 to complete the secondary battery 1.

[0092] The aforementioned case can have various forms depending on the application and design standards of the secondary battery, and can be formed to have various sizes and shapes, such as rectangular, thin-film, and button-shaped.

[0093] For example, the secondary battery may be a button-type battery. Specifically, the secondary battery may be a lithium-ion battery.

[0094] An electrode assembly can be formed by placing a separator between the positive electrode and the negative electrode. After stacking the electrode assembly in a bicell structure, it is impregnated with an electrolyte, and the resulting product is placed in a pouch and sealed to complete a lithium-ion polymer battery.

[0095] Furthermore, multiple electrode assemblies can be stacked to form a battery pack, which can then be used in all devices requiring high capacity and high output. For example, it can be used in laptop computers, smartphones, electric vehicles, and the like.

[0096] The present invention will be described in detail below using manufacturing examples, embodiments, and experimental examples.

[0097] However, the manufacturing examples, embodiments, and experimental examples described later are merely illustrative of one aspect of the present invention, and the present invention is not limited thereto.

[0098] Examples <Synthesis Example 1> Synthesis of Compound 1 [ka] <Compound 1> 2-Oxazolidinone (5 g, 0.057 mol) and LiPO2F2 (6.20 g, 0.057 mol) were dissolved in acetone (35 ml) and stirred at room temperature for 18 hours. The precipitated compound 1 was filtered to obtain 11 g (yield: 98%), and this was used. 1 H-NMR, 13 C-NMR, 19 F-NMR and 31 Confirmed by P-NMR.

[0099] The synthesized compound 1 underwent three-dimensional structural analysis using SC-XRD, and its structure is shown in Figure 1. The SC-XRD analysis data is shown in Table 3 below.

[0100] The structure of the compound was confirmed by SC-XRD analysis.

[0101] 1 H-NMR (400MHz, DMSO-d6) δ7.49(s, 1H), 4.30-4.26(m, 2H), 3.46-3.42(m, 2H) 13 C-NMR (400MHz, DMSO-d6) δ160.1, 64.6, 40.4 19 F-NMR (400MHz, DMSO-d6) δ -77.93, -80.44 31 P-NMR (400MHz, DMSO-d6) δ -10.57, -16.41, -22.24

[0102] <Synthesis Example 2> Synthesis of Compound 2 [ka] 2-Cyazolidinone (5 g, 0.048 mol) and LiPO2F2 (5.23 g, 0.048 mol) were dissolved in acetone (35 ml) and stirred at room temperature for 18 hours. The precipitated compound 2 was filtered to obtain 8 g (yield: 78%), and this was used. 1 H-NMR, 13 C-NMR, 19 F-NMR and 31 Confirmed by P-NMR.

[0103] 1 H-NMR (400MHz, DMSO-d6) δ8.00(s, 1H), 3.49-3.46(m, 2H), 3.39-3.35(m, 2H) 13 C-NMR (400MHz, DMSO-d6) δ174.3, 43.3,29.9 19 F-NMR (400MHz, DMSO-d6) δ -77.93, -80.44 31P-NMR (400MHz, DMSO-d6)δ -10.63, -16.46, -22.30

[0104] <Manufacturing Example 1> Manufacturing of Electrolyte Solution <Comparative Example 1> 1.15 M LiPF6 was dissolved in a solvent prepared by mixing ethylene carbonate (EC), ethyl methyl carbonate (EMC), and dimethyl carbonate (DMC) in a volume ratio of 20:40:40. This was designated as Comparative Example 1.

[0105] <Comparative Example 2> An electrolyte was prepared by adding vinylene carbonate (VC) at a concentration of 1% by weight relative to 100% by weight of the organic electrolyte to the electrolyte produced in the aforementioned electrolyte preparation method.

[0106] <Comparative Example 3> An electrolyte was prepared by adding lithium difluorophosphate (LiPO2F2) at a concentration of 0.5% by weight relative to 100% by weight of the organic electrolyte to the electrolyte prepared in Comparative Example 1.

[0107] <Comparative Example 4> An electrolyte was prepared by adding 0.022% by weight of 2-oxazolidone and 0.029% by weight of lithium difluorophosphate (LiPO2F2) to the electrolyte prepared in Comparative Example 1.

[0108] <Example 1> The electrolyte produced in the aforementioned electrolyte production process was prepared by adding the synthesized compound 1 at a concentration of 0.5% by weight relative to 100% by weight of the organic electrolyte.

[0109] <Example 2> The electrolyte produced in the aforementioned electrolyte production process was prepared by adding the synthesized compound 1 at a concentration of 1.0% by weight relative to 100% by weight of the organic electrolyte.

[0110] <Example 3> The synthesized compound 2 was added to the electrolyte produced in the aforementioned electrolyte production process at a concentration of 0.5% by weight relative to 100% by weight of the organic electrolyte to produce the electrolyte.

[0111] <Example 4> The synthesized compound 2 was added to the electrolyte produced in the aforementioned electrolyte production process at a concentration of 1.0% by weight relative to 100% by weight of the organic electrolyte to produce the electrolyte.

[0112] <Manufacturing Example 2> Battery Manufacturing A slurry of 96% by weight artificial graphite (S360-L2-H Tiangin BTR New energy technology Co.,Ltd.), 1% by weight SuperP (TIMCAL), 1.5% by weight styrene-butadiene rubber (SBR) binder (ZEON), and 1.5% by weight carboxymethylcellulose (CMC, Sigma-Aldrich) was mixed, then added to distilled water and stirred for 60 minutes using a mechanical stirrer to produce a negative electrode active material slurry. The slurry was coated onto a 30 μm thick copper current collector to a thickness of approximately 60 μm using a doctor blade, dried in a hot air dryer at 100°C for 1 hour, dried again under vacuum conditions for 8 hours, and then rolled (roll pressed) to produce a negative electrode plate.

[0113] LiRing 0.6 Mn 0.2 Co 0.2 A cathode active material slurry was prepared by mixing 2% by weight of superP(TIMCAL) and 2% by weight of polyvinylidene fluoride (PVdF, Sigma-Aldrich) as O296 wt% conductive material, adding the mixture to N-methyl-2-pyrrolidone solvent, and stirring for 30 minutes using a mechanical stirrer. The slurry was then coated to a thickness of 60 μm onto a 20 μm thick aluminum current collector using a doctor blade, dried in a 100°C hot air dryer for 1 hour, dried again under vacuum conditions for 8 hours, and then rolled (roll pressed) to produce a cathode plate.

[0114] A lithium battery was manufactured using 14 μm thick polypropylene as the separator and the organic electrolytes prepared in Examples 1-4 and 1-4, respectively, as the electrolyte.

[0115] <Experimental Example 1> Evaluation of lifespan performance at room temperature A lithium secondary battery was charged at 25°C under constant current / constant voltage (CC / CV) conditions to 4.2V at a rate of 1.0C. Then, while maintaining 4.2V in constant voltage mode, it was cut off at a rate of 0.05C, and finally discharged to 2.7V at a rate of 1.0C. The charge / discharge conditions were repeated 100 times for analysis. The results are shown in Table 1 and Figure 2.

[0116] Referring to Figure 2 and Table 1, it was found that when compounds 1 and 2 synthesized in the present invention are used to produce electrolytes for secondary batteries, they have a higher capacity retention rate after 100 charge-discharge cycles at room temperature compared to Comparative Examples 1 and 2. [Table 1]

[0117] <Experimental Example 2> Evaluation of resistance improvement performance at room temperature After charging the batteries manufactured according to the manufacturing example to 4.2V at 1C and discharging them to SOC50, the initial DC-IR was measured by discharging each of the four C-rates (0.5, 1, 2, and 3C) for 10 seconds. After charging to 4.2V at 1C and performing 200 charge-discharge cycles at room temperature, the DC-IR was measured again in the same manner as the initial DC-IR measurement method, and the ratio to the initial DC-IR was expressed as a percentage. The results are shown in Figures 3 and 4 and Table 2.

[0118] Referring to Figures 3 and 4 and Table 2, a comparison of Example 1, an electrolyte for secondary batteries to which Compound 1 of the present invention was added, and Comparative Example 4, an electrolyte simply in which 2-oxazolidinone and lithium difluorophosphate (LiPO2F2) were mixed, confirmed that Example 1 had a 1.1% higher capacity retention rate after 200 room-temperature charge-discharge cycles than Comparative Example 4, and the effect of a resistance increase rate of 55.8% or even lower after 200 room-temperature charge-discharge cycles was confirmed. [Table 2]

[0119] <Experimental Example 3> Evaluation of High-Temperature Resistance Improvement Performance A secondary battery electrolyte additive manufactured according to the present invention was prepared in a pouch-type battery and stored for 10 weeks under conditions of 60°C. The change in the resistance increase rate was then observed. The result value was calculated based on Comparative Example 3. The results are shown in Table 3.

[0120] Referring to Table 3, it was found that Example 1, prepared using Chemical Formula 1 synthesized in the present invention, had a resistance increase rate 10.6% lower after 10 weeks than Comparative Example 3, which used lithium difluorophosphate (LiPO2F2). This confirms that the secondary battery electrolyte using the compound according to the present invention as an additive has the characteristic of reducing the resistance increase rate when the secondary battery is implemented. [Table 3]

[0121] <Experimental Example 4> Crystal Structure Analysis To analyze the structure of compound 1 of the present invention, its three-dimensional structure was analyzed by SC-XRD (single crystal X-ray diffraction). The results are shown in Figure 5 and Table 4. It was confirmed that the electrolyte additive compound 1 according to the present invention is a compound in which 2-oxazolidinone and LiPO2F2 are bonded in a way that is not a simple mixture. [Table 4]

[0122] The foregoing description of the present invention is illustrative, and a person with ordinary skill in the art will understand that the invention can be easily modified into other specific forms without altering the technical idea or essential features of the invention. Therefore, the embodiments described above should be understood to be illustrative in all respects and not limiting. For example, each component described in a single form can be implemented in a distributed manner, and similarly, components described as distributed can be implemented in a combined manner.

[0123] The scope of the present invention is defined by the claims described below, and all modifications or alterations derived from the meaning and scope of the claims and the concept of equivalents thereto should be interpreted as being included within the scope of the present invention. [Explanation of symbols]

[0124] 1: Secondary battery 10: Top Case 20: Spring 30: Spacer 40: Positive electrode 50: Separator 60: Negative electrode 70: Gasket 80: Bottom Case

Claims

1. Electrolytes for secondary batteries containing the compound represented by the following chemical formula 1, or its isomers: [Chemical Formula 1] 【Chemistry 1】 In the above formula 1 [HetCy] is a compound represented by the following chemical formula 2, [Chemical Formula 2] 【Chemistry 2】 M is Li ＋ Na ＋ _K ＋ , Rb ＋ , or Cs ＋ And, Y is (FSO ２ ), ２ N － PF ６ － PO ２ F ２ － BF ４ － ClO ４ － (C ２ O ４ )BF ２ － HSO ４ － CF ３ SO ３ － (C ２ F ５ SO ２ ) ２ N － C(CF ２ SO ２ ) ３ － AsF ６ － SbF ６ － AlCl ４ － NbF ６ － CF ３ CO ２ － (C ４ F ９ SO ３ ) － AlO ３ － (N(C ｘ F ２ｘ＋１ O ２ )(C ｙ F ２ｙ＋１ SO ２ )) － (2 ≤ x ≤ 20, 2 ≤ y ≤ 20), Cl － or I － and In the above formula 2, The dotted line indicates the presence or absence of a double bond. X is O, S or CR'R'', n is an integer of 1 or 2, R is hydrogen, substituted or unsubstituted C １－１０ Alkyl, substituted, or unsubstituted C ２－１０ Alkenyl, substituted, or unsubstituted C ２－１０ Alkynyl, substituted, or unsubstituted C ２－１０ Allyl, substituted, or unsubstituted C １－１２ Heteroalkyl-substituted or unsubstituted C ３－１２ Cycloalkyl, substituted, or unsubstituted C ３－１２ Heterocycloalkyl, substituted, or unsubstituted C １－６ Acyl, substituted or unsubstituted silyl, substituted or unsubstituted sulfonyl, or -P(=G)R １ R ２ And, G is either O or S, R', R'', R １ and R ２ These are, independently, hydrogen, substituted or unsubstituted C. １－１０ Alkyl, substituted, or unsubstituted C １－１２ Heteroalkyl, or substituted or unsubstituted C １ ~C ２０ It is an alkoxy.

2. M is Li ＋ Na ＋ or Cs ＋ And, Y is (FSO ２ ), ２ N － , PO ２ F ２ － , BF ４ － , (C ２ O ４ )BF ２ － , CF ３ SO ３ － , (C ４ F ９ SO ３ ), － or (C ２ F ５ SO ２ ), ２ N － The electrolyte for a secondary battery according to claim 1, wherein it is

3. The electrolyte for a secondary battery according to claim 1, wherein the chemical formula 2 is a compound represented by any of the following chemical formulas 2-1 to 2-5: [Chemical Formula 2-1] 【Transformation 3】 [Chemical Formula 2-2] 【Chemistry 4】 [Chemical Formula 2-3] 【Transformation 5】 [Chemical Formula 2-4] 【Transformation 6】 [Chemical Formula 2-5] 【Transformation 7】 X and R are the same as defined in formula 2 above.

4. The electrolyte for a secondary battery according to claim 1, characterized in that the molar ratio of HetCy, M, and Y is 1:1:1 to 3:1:

1.

5. The electrolyte for a secondary battery according to claim 1, further comprising one or more additives selected from the group consisting of unsaturated cyclic carbonates, cyclic sultones, cyclic sulfetralactones, and nitrile compounds.

6. The electrolyte for a secondary battery according to claim 5, wherein the unsaturated cyclic carbonate is selected from the group consisting of vinylene carbonate, phenyl carbonate, vinyl carbonate, and allyl carbonate.

7. The electrolyte for a secondary battery according to claim 1, comprising a compound selected from the following compounds, or at least one isomer thereof: 【Chemistry 8-1】 【Chemistry 8-2】 【Chemistry 8-3】 【Chemistry 8-4】 【Chemistry 8-5】 【Chemistry 8-6】 【Chemistry 8-7】 【Chemistry 8-8】

8. The electrolyte for a secondary battery according to claim 1, further comprising an organic solvent.

9. The electrolyte for a secondary battery according to claim 1, wherein the compound represented by the chemical formula 1 is provided as an electrolyte additive.

10. The electrolyte for a secondary battery according to claim 1, wherein the secondary battery is a lithium-ion battery.

11. An electrode assembly including a positive electrode, a negative electrode, and a separator for separating the positive electrode and the negative electrode. A case for housing the electrode assembly, and A secondary battery comprising an electrolyte for a secondary battery according to claim 1, which is housed in the case and immersed in the electrode assembly.

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