KR20220092423A - Electrolyte Solution And Secondary Battery Comprising The Same - Google Patents

Abstract

The present invention relates to a battery electrolyte and a secondary battery. The present invention has an effect of providing a secondary battery that improves charging efficiency and output due to low charging resistance, and has a long life span and excellent high-temperature capacity retention rates. The electrolyte of the present invention includes an organic solvent, lithium salt, and an electrolyte additive.

Description

Electrolyte solution and secondary battery containing same {Electrolyte Solution And Secondary Battery Comprising The Same}

The present invention relates to an electrolyte for a battery and a secondary battery including the same, and more particularly, to an electrolyte capable of improving battery charging efficiency and output, enabling long-term storage, and increasing capacity retention at high temperatures, and the same It relates to a secondary battery comprising.

Lithium secondary batteries enable smooth movement of lithium ions by putting an electrolyte between the positive and negative electrodes, and the use of electrical energy by the method in which electricity is generated or consumed by redox reactions according to insertion and desorption from the positive and negative electrodes. make it easy

On the other hand, as interest in the environment is growing, such as tightening environmental regulations around the world, interest in eco-friendly vehicles that can replace fossil fuel vehicles, which is one of the main causes of air pollution, is also increasing. Accordingly, in the domestic/foreign battery industry, the development of batteries for automobiles is being actively carried out.

In order to use a battery in a vehicle, not only the output and capacity of the battery must be significantly increased, but it is also necessary to solve the problem of improving output and increasing resistance at high and low temperatures in accordance with the usage environment such as weather changes, In consideration of being used outdoors, there is a need to develop a battery with improved long-term charging and capacity retention in various environments.

Japanese Patent Application Laid-Open No. 2008-300126 A Korean Patent Registration 10-1586199 B1

In order to solve the problems of the prior art as described above, an object of the present invention is to provide an electrolyte including an electrolyte additive of a novel composition.

Another object of the present invention is to provide a secondary battery having reduced charging resistance, improved output of the battery, improved recovery capacity at high temperature, so that long-term storage is possible, and excellent life retention rate at high temperature.

The above and other objects of the present invention can all be achieved by the present invention described below.

In order to achieve the above object, the present invention is an electrolyte comprising an organic solvent, a lithium salt and an electrolyte additive,

The electrolyte solution additive is based on 100% by weight of the total electrolyte solution

0.1 to 10% by weight of at least one compound selected from compounds represented by the following Chemical Formulas 1 to 6; and 0.1 to 10% by weight of at least one compound selected from nitrogen-based, boron-based, monocyclic, polycyclic, and silane-based compounds.

[Formula 1]

(In Formula 1, G is -O-, -OR _a -, -N(R _b )- or -R _c -N(R _d )-R _e -, -R _f (NR _g R _h )- or -R _i -; wherein R _a , R _c , R _e , R _f and R _i are independently a linear or branched alkylene group having 1 to 10 carbon atoms; R _b , R _d , R _g and R _h are independently hydrogen or a linear or branched alkyl group having 1 to 10 carbon atoms; Q ₁ and Q ₂ are independently phosphorus (P), sulfur (S) or arsenic (As); D ₁ , D ₂ , D ₃ , D ₄ , D ₅ and D ₆ are independently oxygen (=O) or one or two lone pairs of electrons; E ₁ , E ₂ , E ₃ or E ₄ is oxygen or carbon, and D ₂ , When D ₃ , D ₅ or D ₆ is oxygen, E ₁ , E ₂ , E ₃ or E ₄ attached thereto is carbon; R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ and R ₈ is independently hydrogen, a linear or branched alkyl group having 1 to 10 carbon atoms, an alkenyl group, an alkynyl group, an alkoxy group, an alkoxycarbonyl group or an alkoxyalkyl group; optionally, R ₃ and R ₄ or R ₇ and R ₈ can be joined to form a ring;

wherein n and k are independently integers from 0 to 5; wherein m and l are independently 0 or 1; At least one of n and m and at least one of k and l is non-zero.)

[Formula 2]

(In Formula 2, A ₁ and A ₂ are independently phosphorus (P) or sulfur (S), and D ₇ and D ₈ are independently oxygen (=O) or a lone pair of electrons, and the G ₁ and G ₂ is independently -O- or -CH ₂ -, wherein R ₉ and R ₁₀ are independently a linear or branched alkyl group having 1 to 20 carbon atoms, and R ₁₁ , R ₁₂ , R ₁₃ and R ₁₄ are independently It is a bond or an alkylene group having 1 to 3 carbon atoms.)

[Formula 3]

(In Formula 3, X ₁ and X ₂ are independently F, Cl, Br, or I, and E ₅ and E ₆ are independently a substituted or unsubstituted hydrocarbon group having 1 to 3 carbon atoms, wherein the substitution is =O, -CX' ₃ and -CH ₂ CX" ₃ is substituted with one or more selected from the group consisting of, wherein X' and X" are independently F, Cl, Br or I, and are included in E ₅ and E ₆ Bonds between carbons are single or double bonds.)

[Formula 4]

(In Formula 4, A is phosphorus (P), sulfur (S), or nitrogen (N), wherein R ₁₅ , R ₁₆ and R ₁₇ are independently linear or minute having 1 to 5 carbon atoms including a substituent. It is a topographical alkyl group, and the substituent is at least one selected from the group consisting of a halogen element including F, Cl, Br and I and oxygen (=O).)

[Formula 5]

(In Formula 5, R ₁₈ and R ₁₉ are independently an alkylene group having 1 to 5 carbon atoms, and E ₇ is a bond, an alkylene group having 1 to 3 carbon atoms, or a cyclic carbonyl group having 2 to 5 carbon atoms, an ether group or an ester group, wherein R ₂₀ is a substituted or unsubstituted linear or cyclic carbonate group having 2 to 5 carbon atoms, a carbonyl group, an ether group, a phosphate group, a sulfonate or a sulfate group, and the substitution is F, Cl, Br And at least one selected from the group consisting of I or substituted with an alkenyl group having 1 to 3 carbon atoms, wherein E ₈ is a bond or a saturated or unsaturated alkylene group having 1 to 3 carbon atoms, or an ether group, wherein n is 0 or 1.)

[Formula 6]

이며; 선택적으로 상기 R₂₁ 또는 R₂₂는, 독립적으로 R₂₃ 또는 R₂₄와 연결되어 이중결합 또는 고리를 만들 수 있고; 상기 n은 0 내지 3의 정수이며; 상기 *은 결합위치이다.)(In Formula 6, P and O are each phosphorus and oxygen; A is a bond or oxygen; Q is oxygen or an unshared pair of electrons; R ₂₁ , R ₂₂ , R ₂₃ and R ₂₄ are independently hydrogen and 1 to 10 carbon atoms. of a linear or branched alkyl group, alkenyl group, alkynyl group, alkoxy group, alkoxycarbonyl group, alkoxyalkyl group, fluoroalkyl group, or

is; Optionally, R ₂₁ or R ₂₂ may be independently linked to R ₂₃ or R ₂₄ to form a double bond or a ring; wherein n is an integer from 0 to 3; The * is a bonding position.)

The compound represented by Formula 1 may be at least one selected from the group consisting of compounds represented by Formulas 1-1 to 1-24.

[Formula 1-1 to 1-24]

(In Formula 1-1, A ₁ and A ₂ are each independently phosphorus or sulfur, and R ₁ ', R ₂ ', R ₃ ', and R ₄ ' are each independently hydrogen, or a substituted or unsubstituted carbon number. An alkyl group of 1 to 10, m and n are each independently an integer of 1 to 5,

In Chemical Formulas 1-2 to 1-24, a line is a bond, a point where a bond and a bond not describing a separate element meet is carbon, and the number of hydrogens satisfying the valence of the carbon is omitted.)

The compound represented by Formula 2 may be at least one selected from the group consisting of compounds represented by Formulas 2-1 to 2-4.

[Formula 2-1 to 2-4]

(In Chemical Formulas 2-1 to 2-4, a line is a bond, and when a separate element is not described, the point where the bond and the bond meet is carbon, and the number of hydrogens satisfying the valence of the carbon is omitted.)

The compound represented by Formula 3 may be at least one selected from the group consisting of compounds represented by Formulas 3-1 to 3-2 below.

[Formula 3-1 to 3-2]

(In Formulas 3-1 to 3-2, a line is a bond, and if a separate element is not described, the point where the bond and the bond meet is carbon, and the number of hydrogens satisfying the valence of the carbon is omitted.)

The compound represented by Formula 4 may be a compound represented by Formula 4a.

[Formula 4a]

(In Chemical Formula 4a, a line is a bond, and when a separate element is not described, a point where a bond and a bond meet is carbon, and the number of hydrogens satisfying the valence of the carbon is omitted.)

The compound represented by Formula 5 may be at least one selected from the group consisting of compounds represented by Formulas 5-1 to 5-52.

[Formula 5-1 to 5-52]

(In Formulas 5-1 to 5-52, a line is a bond, and when a separate element is not described, the point where the bond and the bond meet is carbon, and the number of hydrogens satisfying the valence of the carbon is omitted.)

The compound represented by Formula 6 may be at least one selected from the group consisting of compounds represented by Formulas 6-1 to 6-31 below.

[Formula 6-1 to 6-31]

(In Chemical Formulas 6-1 to 6-31, a line is a bond, and when a separate element is not described, the point where the bond and the bond meet is carbon, and the number of hydrogens satisfying the valence of the carbon is omitted.)

The electrolyte solution additive may further include one or more compounds selected from nitrogen-based, boron-based, monocyclic, polycyclic, and silane-based compounds.

The compound may include, for example, both substituted and unsubstituted forms.

The term "substitution" used in the present invention may mean that hydrogen of a functional group, atomic group, or compound is substituted with a specific substituent, and when hydrogen of a functional group, atomic group or compound is substituted with a specific substituent, it is present in the functional group, atomic group or compound One or two or more plural substituents may be present depending on the number of hydrogens to be used. In addition, when a plurality of substituents exist, each substituent may be the same as or different from each other.

Examples of the preferred substituent include an amino group substituted with 1 or 2 organic groups, a morpholin-1-yl group and a piperazin-1-yl group, a halogen, a nitro group, a cyano group, an alkyl group having 1 to 5 carbon atoms, an alkyl group having 1 to 5 carbon atoms. A ren group, a C1-C5 alkoxy group, a cycloalkyl group, etc. are mentioned.

The alkyl group may mean a monovalent aliphatic saturated hydrocarbon, and a linear alkyl group such as methyl, ethyl, propyl and butyl, and isopropyl, sec-butyl, tertbutyl) and a branched alkyl group such as neopentyl (neo-pentyl).

The alkylene group may mean a divalent aliphatic saturated hydrocarbon such as methylene, ethylene, propylene, and butylene.

The monocyclic ring system of the present description may mean a monocyclic aromatic hydrocarbon in which one ring is formed, but is not limited thereto.

The polycyclic ring system of the present description may mean a polycyclic aromatic hydrocarbon in which two or more rings are directly or indirectly bonded, but is not limited thereto.

As used herein, the term “system” may indicate a component, structure, or substance itself derived from a certain substance.

The at least one compound selected from nitrogen-based, boron-based, monocyclic, polycyclic, and silane-based compounds preferably includes at least one selected from the group consisting of compounds represented by the following Chemical Formulas 7-1 to 7-22. may be doing

[Formula 7-1 to 7-22]

(In Formulas 7-1 to 7-22, a line is a bond, a point where a bond and a bond not describing a separate element meet is carbon, and the number of hydrogens satisfying the valence of carbon is omitted, and TMS is trimethyl It refers to trimethylsilyl.)

The organic solvent is preferably ethylene carbonate (EC), diethyl carbonate (DEC), ethylmethyl carbonate (EMC), dimethyl carbonate (DMC), propylene carbonate (PC), dipropyl carbonate (DPC), butylene carbonate, It may include at least one selected from the group consisting of methylpropyl carbonate, ethylpropyl carbonate, methyl propionate (MP), ethyl propionate (EP), and propyl propionate (PP).

The lithium salt is preferably LiPF ₆ , LiBF ₄ , LiCl, LiBr, LiI, LiClO ₄ , LiB ₁₀ Cl ₁₀ , LiCF ₃ SO ₃ , LiCF ₃ CO ₂ , LiAsF ₆ , LiSbF ₆ , LiAlCl ₄ , CH ₃ SO ₃ Li, CF ₃ SO ₃ Li, (CF ₃ SO ₂ )(C ₂ F ₅ SO ₂ )NLi, (SO ₂ F) ₂ NLi, and (CF ₃ SO ₂ ) ₂ NLi at least one selected from the group consisting of can do.

The electrolyte solution additive may contain 0.6 to 2 mol% of the lithium salt based on 100 mol% of the total.

In order to achieve the above object, the present invention provides a secondary battery comprising a negative electrode, a positive electrode, and an electrolyte additive, wherein the electrolyte additive is the electrolyte additive described above.

The secondary battery may be a battery for a vehicle.

The secondary battery including the electrolyte additive according to the present invention has the effect of providing a secondary battery having low charging resistance, which can improve charging efficiency and output, and has excellent long-term life and high-temperature capacity retention.

Hereinafter, the present invention will be described in detail, but the present invention is not limited thereto.

The present inventors have been researching a secondary battery having improved output and excellent high-temperature recovery capacity and lifespan characteristics in order to manufacture a battery that can be used as an automobile battery. It was confirmed that all of the objects of the present invention can be achieved, and based on this, the present invention was completed.

electrolyte

The present invention is an electrolyte comprising an organic solvent, a lithium salt and an electrolyte additive,

The electrolyte solution additive is based on 100% by weight of the total electrolyte solution

0.1 to 10% by weight of at least one compound selected from compounds represented by the following Chemical Formulas 1 to 6; and nitrogen-based, boron-based, monocyclic, polycyclic, and silane-based electrolyte additives comprising 0.1 to 10% by weight of at least one compound selected from the group consisting of, in which case, the charging resistance is reduced to improve the output of the battery, The recovery capacity at high temperature is improved, so long-term storage is possible, and there is an excellent effect of maintaining the lifespan at high temperature.

[Formula 1]

(In Formula 1, G is -O-, -OR _a -, -N(R _b )- or -R _c -N(R _d )-R _e -, -R _f (NR _g R _h )- or -R _i -; wherein R _a , R _c , R _e , R _f and R _i are independently a linear or branched alkylene group having 1 to 10 carbon atoms; R _b , R _d , R _g and R _h are independently hydrogen or a linear or branched alkyl group having 1 to 10 carbon atoms; Q ₁ and Q ₂ are independently phosphorus (P), sulfur (S) or arsenic (As); D ₁ , D ₂ , D ₃ , D ₄ , D ₅ and D ₆ are independently oxygen (=O) or one or two lone pairs of electrons; E ₁ , E ₂ , E ₃ or E ₄ is oxygen or carbon, and D ₂ , When D ₃ , D ₅ or D ₆ is oxygen, E ₁ , E ₂ , E ₃ or E ₄ attached thereto is carbon; R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ and R ₈ is independently hydrogen, a linear or branched alkyl group having 1 to 10 carbon atoms, an alkenyl group, an alkynyl group, an alkoxy group, an alkoxycarbonyl group or an alkoxyalkyl group; optionally, R ₃ and R ₄ or R ₇ and R ₈ can be joined to form a ring;

wherein n and k are independently integers from 0 to 5; wherein m and l are independently 0 or 1; At least one of n and m and at least one of k and l is non-zero.)

[Formula 2]

(In Formula 2, A ₁ and A ₂ are independently phosphorus (P) or sulfur (S), and D ₇ and D ₈ are independently oxygen (=O) or a lone pair of electrons, and the G ₁ and G ₂ is independently -O- or -CH ₂ -, wherein R ₉ and R ₁₀ are independently a linear or branched alkyl group having 1 to 20 carbon atoms, and R ₁₁ , R ₁₂ , R ₁₃ and R ₁₄ are independently It is a bond or an alkylene group having 1 to 3 carbon atoms.)

[Formula 3]

(In Formula 3, X ₁ and X ₂ are independently F, Cl, Br, or I, and E ₅ and E ₆ are independently a substituted or unsubstituted hydrocarbon group having 1 to 3 carbon atoms, wherein the substitution is =O, -CX' ₃ and -CH ₂ CX" ₃ is substituted with one or more selected from the group consisting of, wherein X' and X" are independently F, Cl, Br or I, and are included in E ₅ and E ₆ Bonds between carbons are single or double bonds.)

[Formula 4]

(In Formula 4, A is phosphorus (P), sulfur (S), or nitrogen (N), wherein R ₁₅ , R ₁₆ and R ₁₇ are independently linear or minute having 1 to 5 carbon atoms including a substituent. It is a topographical alkyl group, and the substituent is at least one selected from the group consisting of a halogen element including F, Cl, Br and I and oxygen (=O).)

[Formula 5]

(In Formula 5, R ₁₈ and R ₁₉ are independently an alkylene group having 1 to 5 carbon atoms, and E ₇ is a bond, an alkylene group having 1 to 3 carbon atoms, or a cyclic carbonyl group having 2 to 5 carbon atoms, an ether group or an ester group, wherein R ₂₀ is a substituted or unsubstituted linear or cyclic carbonate group having 2 to 5 carbon atoms, a carbonyl group, an ether group, a phosphate group, a sulfonate or a sulfate group, and the substitution is F, Cl, Br And at least one selected from the group consisting of I or substituted with an alkenyl group having 1 to 3 carbon atoms, wherein E ₈ is a bond or a saturated or unsaturated alkylene group having 1 to 3 carbon atoms, or an ether group, wherein n is 0 or 1.)

[Formula 6]

이며; 선택적으로 상기 R₂₁ 또는 R₂₂는, 독립적으로 R₂₃ 또는 R₂₄와 연결되어 이중결합 또는 고리를 만들 수 있고; 상기 n은 0 내지 3의 정수이며; 상기 *은 결합위치이다.) (In Formula 6, P and O are each phosphorus and oxygen; A is a bond or oxygen; Q is oxygen or an unshared electron pair; R ₂₁ , R ₂₂ , R ₂₃ and R ₂₄ are independently hydrogen, carbon atoms 1 to 10 linear or branched alkyl group, alkenyl group, alkynyl group, alkoxy group, alkoxycarbonyl group, alkoxyalkyl group, fluoroalkyl or

is; Optionally, R ₂₁ or R ₂₂ may be independently linked to R ₂₃ or R ₂₄ to form a double bond or a ring; wherein n is an integer from 0 to 3; The * is a bonding position.)

The electrolyte is preferably 0.1 to 10% by weight, preferably 0.2 to 5% by weight, more preferably 0.4 to 2.0% by weight of one or more compounds selected from compounds represented by Formulas 1 to 6, based on the total weight of the electrolyte %, and most preferably 0.5 to 1.5 wt%, in this case, the compatibility with the electrolyte is excellent, so that manufacturing efficiency can be further improved, and there is an advantage in that the battery output improvement effect is more excellent.

The at least one compound selected from the compounds represented by Formulas 1 to 6 is preferably a compound represented by the following Formula 5-52, but is not limited thereto.

[Formula 5-52]

The compound represented by Formula 1 is preferably at least one selected from the group consisting of compounds represented by Formulas 1-1 to 1-24, but is not limited thereto.

[Formula 1-1 to 1-24]

(In Formula 1-1, A ₁ and A ₂ are each independently phosphorus or sulfur, and R ₁ ', R ₂ ', R ₃ ', and R ₄ ' are each independently hydrogen, or a substituted or unsubstituted carbon number. An alkyl group of 1 to 10, m and n are each independently an integer of 1 to 5,

In Chemical Formulas 1-2 to 1-24, a line is a bond, a point where a bond and a bond not describing a separate element meet is carbon, and the number of hydrogens satisfying the valence of the carbon is omitted.)

The compound represented by Formula 2 is preferably at least one selected from the group consisting of compounds represented by Formulas 2-1 to 2-4, but is not limited thereto.

[Formula 2-1 to 2-4]

(In Chemical Formulas 2-1 to 2-4, a line is a bond, and when a separate element is not described, the point where the bond and the bond meet is carbon, and the number of hydrogens satisfying the valence of the carbon is omitted.)

The compound represented by Chemical Formula 3 is preferably at least one selected from the group consisting of compounds represented by the following Chemical Formulas 3-1 to 3-2, but is not limited thereto.

[Formula 3-1 to 3-2]

,

,

(In Formulas 3-1 and 3-2, a line is a bond, and when a separate element is not described, the point where the bond and the bond meet is carbon, and the number of hydrogens satisfying the valence of the carbon is omitted. )

The compound represented by the formula (4) is preferably a compound represented by the following formula (4a), but is not limited thereto.

[Formula 4a]

(In Chemical Formula 4a, a line is a bond, and when a separate element is not described, a point where a bond and a bond meet is carbon, and the number of hydrogens satisfying the valence of the carbon is omitted.)

The compound represented by Formula 5 is preferably at least one selected from the group consisting of compounds represented by Formulas 5-1 to 5-52, but is not limited thereto.

[Formula 5-1 to 5-52]

(In Formulas 5-1 to 5-52, a line is a bond, and when a separate element is not described, the point where the bond and the bond meet is carbon, and the number of hydrogens satisfying the valence of the carbon is omitted.)

The compound represented by Chemical Formula 6 is preferably at least one selected from the group consisting of compounds represented by the following Chemical Formulas 6-1 to 6-31, but is not limited thereto.

[Formula 6-1 to 6-31]

(In Chemical Formulas 6-1 to 6-31, a line is a bond, and when a separate element is not described, the point where the bond and the bond meet is carbon, and the number of hydrogens satisfying the valence of the carbon is omitted.)

In Chemical Formula 1, when n, k, m, or l is 0, the corresponding unit, that is, the group in parentheses, disappears and means a bond. For example, when n, the number of units, is 0, and the number of units, m, is 1, E ₁ is a compound directly bonded to the double bond carbon in which R ₃ is substituted.

In the present description, the alkylene group refers to a divalent hydrocarbon group, and as a specific example, the propylene group refers to -CH ₂ CH ₂ CH ₂ - or -CH ₂ CH(CH ₃ )-.

In the present description, the alkenyl group refers to a monovalent hydrocarbon group including a carbon-carbon double bond, and as a specific example, the n-butenyl group refers to CH ₂ =CHCH ₂ CH ₂ —.

In the present description, the alkynyl group refers to a monovalent hydrocarbon group including a carbon-carbon triple bond, and as a specific example, the 1-butynyl group refers to CHCCH ₂ CH ₂ —.

The R _a , R _c , _{Re , R f and} R _i are preferably independently a linear or branched alkylene group having 1 to 3 carbon atoms, and in this case, the charging efficiency and output are improved due to the low charging resistance of the secondary battery. and long-term lifespan and high-temperature capacity retention rate are excellent.

The R _b , R _d , R _g and R _h are preferably independently hydrogen or a linear alkyl group having 1 to 3 carbon atoms, and in this case, the charging resistance of the secondary battery is low, so that the charging efficiency and output can be improved, and long-term It has an excellent effect of lifespan and high temperature capacity retention rate.

The Q ₁ and Q ₂ are preferably phosphorus (P) independently, and in this case, the charging resistance of the secondary battery is low, so that the charging efficiency and output can be improved, and the long-term lifespan and high-temperature capacity retention rate are excellent.

R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ and R ₈ are preferably independently hydrogen, a linear or branched alkyl group having 1 to 5 carbon atoms, an alkenyl group, an alkynyl group, An alkoxy group, an alkoxycarbonyl group, or an alkoxyalkyl group, more preferably independently hydrogen, a linear or branched alkyl group having 1 to 3 carbon atoms, an alkenyl group, an alkynyl group, an alkoxy group, an alkoxycarbonyl group or an alkoxyalkyl group, in this case the secondary battery Charging efficiency and output can be improved because the charging resistance of

The R ₃ and R ₄ or R ₇ and R ₈ are preferably combined to form an aromatic ring, more preferably a benzene ring, and in this case, the charging resistance of the secondary battery is low, so that the charging efficiency and output are reduced. can be improved, and long life and high temperature capacity retention are excellent. Here, the benzene ring means that it is formed as shown in Chemical Formula 5 below.

The n and k are preferably independently integers of 0 to 3, more preferably independently integers of 1 to 3, and still more preferably 2 or 3, in which case the charging efficiency of the secondary battery is low due to the low charging resistance. and output can be improved, and long-term life and high-temperature capacity retention rates are excellent.

The m and l are preferably independently 1, and in this case, the charging resistance of the secondary battery is low, so that the charging efficiency and output can be improved, and the long-term lifespan and high temperature capacity retention rate are excellent.

The compound represented by Formula 1 is preferably symmetrical with respect to G, and in this case, as a symmetrical cyclic structure, electron flow in the molecule is stabilized, and through this, molecular rigidity is increased to improve battery performance. There is a big advantage.

The compound represented by Formula 1 is preferably at least one selected from the group consisting of compounds represented by Formulas 1-1 to 1-24, and more preferably represented by Formulas 1-15 to 1-24 It is at least one selected from the group consisting of compounds that become

[Formula 1-1 to 1-24]

(In Formula 1-1, A ₁ and A ₂ are each independently phosphorus or sulfur, and R ₁ ', R ₂ ', R ₃ ', and R ₄ ' are each independently hydrogen, or a substituted or unsubstituted carbon number. An alkyl group of 1 to 10, m and n are each independently an integer of 1 to 5,

In Formulas 1-2 to 1-24, a line is a bond, and when a separate element is not described, the point where the bond and the bond meet is carbon, and the number of hydrogens satisfying the valence of the carbon is omitted.)

_In Formula _1-1 , A1 and A2 are each independently phosphorus or sulfur, and R1', R2', R3' and R4' are each independently hydrogen or a substituted or unsubstituted C1-C10 alkyl group. , and m and n are each independently an integer of 1 to 5.

When the electrolyte additive represented by Formula 1-1 is added to the electrolyte of a secondary battery, electrons are localized toward the O element due to the electronegativity difference between the P or S element and the O element directly connected thereto. Accordingly, the P or S element becomes an electron-poor (e-poor, δ+) state and an oxidation reaction is induced in an electrolyte containing lithium ions, thereby forming a stable film on the electrode, specifically, the cathode. At this time, it is possible to prevent the decomposition of the electrolyte due to the stability of the film, and thereby cycle characteristics can be improved. There is an excellent effect of greatly improving.

In addition, since the increase in resistance is prevented, charging efficiency and output are improved, and gas generation due to a chemical reaction inside the battery is also suppressed, so that the safety of the battery can be improved. In addition, the capacity retention is improved by preventing the structural collapse of the electrode active material of the positive electrode and the negative electrode at a high temperature, thereby extending the lifespan.

_In Formula _1-1 , A1 and A2 are each independently phosphorus or sulfur, and in view of the above-described effect, phosphorus having a larger electronegativity difference with element O is more preferable.

Wherein R ₁ ', R ₂ ', R ₃ ' and R ₄ ' are each independently hydrogen or a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, preferably hydrogen or a methyl group, more preferably hydrogen. have.

The m and d are each independently an integer of 1 to 5, preferably 1 to 3, and more preferably 1 or 2. When R ₁ ', R ₂ ', R ₃ ', and R ₄ ' are each hydrogen, and m and n are 1 or 2, it is most preferable in terms of the stability improvement effect due to the simplification of the molecular structure.

In Chemical Formula _1-1 , A1 and _A2 , _m and n may each independently be the same as or different from each other, A1 and A2 are the same elements, and _m =n is satisfied so that chemistry of the electrolyte additive compound When the structure is symmetrical, the electron flow in the molecule is stabilized as a symmetrical cyclic structure, and through this, molecular rigidity is increased and the battery performance improvement effect is further improved, but it is not limited thereto, Even in the asymmetric structure, the above-described effects of the present invention can be exhibited.

The compound represented by Formula 1-1 may be preferably a compound represented by Formula 1a below.

[Formula 1a]

When the electrolyte additive is a pyrophosphate having a symmetrical cyclic structure like the compound represented by Formula 1a, it is preferable because electron flow stability due to the symmetrical cyclic structure and the stabilization effect according to the simplification of the molecular structure are maximized. Therefore, when it is added as an electrolyte for a secondary battery, the battery output is improved by lowering the charging resistance of the battery, the charge recovery capacity is increased at high temperature, and the life efficiency is excellent, so it is preferable as an electrolyte additive for a battery.

[Formula 2]

(In Formula 2, A ₁ and A ₂ are independently phosphorus (P) or sulfur (S), and D ₇ and D ₈ are independently oxygen (=O) or a lone pair of electrons, and the G ₁ and G ₂ is independently -O- or -CH ₂ -, wherein R ₉ and R ₁₀ are independently a linear or branched alkyl group having 1 to 20 carbon atoms, and R ₁₁ , R ₁₂ , R ₁₃ and R ₁₄ are independently It is a bond or an alkylene group having 1 to 3 carbon atoms.)

In Formula 2, the alkylene group refers to a divalent hydrocarbon group, and specifically, the propylene group refers to -CH ₂ CH ₂ CH ₂ - or -CH ₂ CH(CH ₃ )-.

A ₁ and A ₂ are preferably independently phosphorus (P), and in this case, the charging resistance of the secondary battery is low, so that the charging efficiency and output can be improved, and the long-term lifespan and high-temperature capacity retention rate are excellent.

When D ₇ and D ₈ are oxygen (=O), G ₁ and G ₂ are preferably —CH ₂ —, and when D ₇ and D ₈ are a lone pair of electrons, G ₁ and G ₂ are preferably is -O-, and in this case, the charging resistance of the secondary battery is low, so that the charging efficiency and output can be improved, and long-term lifespan and high-temperature capacity retention rate are excellent.

R ₉ and R ₁₀ are preferably independently a linear or branched alkyl group having 1 to 18 carbon atoms, more preferably independently a linear alkyl group having 1 to 18 carbon atoms, in this case, the charging efficiency of the secondary battery is low due to the low charging resistance and output can be improved, and long-term life and high-temperature capacity retention rates are excellent.

The R ₁₁ , R ₁₂ , R ₁₃ and R ₁₄ are preferably independently a bond or —CH ₂ —, and in this case, the charging resistance of the secondary battery is low, so that the charging efficiency and output can be improved, and a long lifespan and excellent high temperature capacity retention rate.

The compound represented by Formula 2 is preferably a symmetrical structure, and in this case, as a structure including a symmetrical ring, the electron flow in the molecule is stabilized. There is a big advantage.

The compound represented by Formula 2 is preferably at least one selected from the group consisting of compounds represented by Formulas 2-1 to 2-4, and in this case, charging efficiency and output are improved due to low charging resistance of the secondary battery. It has the advantages of excellent long-term lifespan and high-temperature capacity retention rate.

[Formula 2-1 to 2-4]

(In Chemical Formulas 2-1 to 2-4, a line is a bond, and when a separate element is not described, the point where the bond and the bond meet is carbon, and the number of hydrogens satisfying the valence of the carbon is omitted.)

When the electrolyte solution additive represented by Formula 2 is added to the electrolyte solution of the battery, Electrons are localized towards the O element due to the electronegativity difference between the P or S element and the directly connected O element. Accordingly, the P or S element becomes an electron-poor (δ+) state and an oxidation reaction is induced in an electrolyte containing lithium ions, thereby forming a stable film on the electrode, in a specific example, the cathode. At this time, it is possible to prevent the decomposition of the electrolyte due to the stability of the film, and thereby cycle characteristics can be improved. There is an excellent effect of greatly improving. In addition, since the increase in resistance is prevented, charging efficiency and output are improved, and gas generation due to a chemical reaction inside the battery is also suppressed, so that the safety of the battery can be improved. In addition, the capacity retention is improved by preventing the structural collapse of the electrode active material of the positive electrode and the negative electrode at a high temperature, thereby extending the lifespan.

In Formula 2, A ₁ and A ₂ are each independently phosphorus or sulfur, and in view of the above-described effect, phosphorus having a greater electronegativity difference from element O is more preferable.

When the chemical structure of the compound represented by Formula 2 is symmetrical, the electron flow in the molecule is stabilized as a symmetrical cyclic structure, and through this, molecular rigidity is increased and the effect of improving battery performance is further improved. However, it is not limited thereto, and the above-described effects of the present invention can be exhibited even in an asymmetric structure.

[Formula 3]

(In Formula 3, X ₁ and X ₂ are independently F, Cl, Br, or I, and E ₅ and E ₆ are independently a substituted or unsubstituted hydrocarbon group having 1 to 3 carbon atoms, wherein the substitution is =O, -CX' ₃ and -CH ₂ CX" ₃ is substituted with one or more selected from the group consisting of, wherein X' and X" are independently F, Cl, Br or I, and are included in E ₅ and E ₆ Bonds between carbons are single or double bonds.)

In Formula 3, X ₁ , X ₂ , X' and X" are preferably independently F or Cl, more preferably F, and in this case, the charging resistance of the secondary battery is low, so that the charging efficiency and output are improved It can be, and there is an excellent effect of long-term lifespan and high-temperature capacity retention rate.

E ₅ and E ₆ are preferably independently a substituted or unsubstituted hydrocarbon group having 2 or 3 carbon atoms, wherein the substitution is preferably 1 selected from the group consisting of 1 =O and 1 to 3 -CX′ ₃ It is substituted with more than one species, and in this case, the charging resistance of the secondary battery is low, so that the charging efficiency and output can be improved, and long-term lifespan and high-temperature capacity retention rate are excellent.

In addition, when E ₅ and E ₆ do not include an =O (oxygen) substituent, the bond between the carbons of E ₅ and E ₆ may include a double bond, and in this case, the bond stability of the compound is improved This has the effect of further improving the battery life.

The compound represented by Formula 3 may preferably have a symmetrical structure with respect to the central P element, and in this case, electron flow in the molecule is stabilized, and thus molecular rigidity is increased, resulting in a large improvement in battery performance. There is an advantage.

The compound represented by Formula 3 is an anion, and preferably includes one selected from the group consisting of compounds represented by Formulas 3-1 to 3-2, and in this case, charging efficiency and output power due to low charging resistance of the secondary battery This can be improved, and there is an advantage that a long lifespan and a high temperature capacity retention rate are excellent.

[Formula 3-1 to 3-2]

,

,

(In Formulas 3-1 to 3-2, a line is a bond, and if a separate element is not described, the point where the bond and the bond meet is carbon, and the number of hydrogens satisfying the valence of the carbon is omitted.)

When the electrolyte solution additive represented by Formula 3 is added to the electrolyte solution of the battery, The electronegativity difference between the P element and the directly connected O element causes the electrons to be localized towards the O element. Accordingly, the P element becomes in an e-poor (δ+) state and an oxidation reaction is induced in an electrolyte containing lithium ions, thereby forming a stable film on the electrode, in a specific example, the cathode. At this time, it is possible to prevent the decomposition of the electrolyte due to the stability of the film, and thereby cycle characteristics can be improved. There is an excellent effect of greatly improving. In addition, since the increase in resistance is prevented, charging efficiency and output are improved, and gas generation due to a chemical reaction inside the battery is also suppressed, so that the safety of the battery can be improved. In addition, the capacity retention is improved by preventing the structural collapse of the electrode active material of the positive electrode and the negative electrode at a high temperature, thereby extending the lifespan.

When the chemical structure of the compound represented by Formula 3 is symmetrical, the electron flow in the molecule is stabilized as a symmetrical cyclic structure, and through this, molecular rigidity is increased and the effect of improving battery performance is further improved. However, it is not limited thereto, and the above-described effects of the present invention can be exhibited even in an asymmetric structure.

[Formula 4]

(In Formula 4, A is phosphorus (P), sulfur (S), or nitrogen (N), wherein R ₁₅ , R ₁₆ and R ₁₇ are independently linear or minute having 1 to 5 carbon atoms including a substituent. It is a topographical alkyl group, and the substituent is at least one selected from the group consisting of a halogen element including F, Cl, Br and I and oxygen (=O).)

In Chemical Formula 4, A is preferably phosphorus (P), and in this case, the charging resistance of the secondary battery is low, so that the charging efficiency and output can be improved, and the long-term lifespan and high-temperature capacity retention rate are excellent.

R ₁₅ , R ₁₆ and R ₁₇ are preferably independently a linear alkyl group having 1 to 3 carbon atoms including a substituent, and in this case, the charging resistance of the secondary battery is low, so that charging efficiency and output can be improved, long life and There is an excellent effect of high temperature capacity retention rate. In addition, the substituent is preferably at least one selected from the group consisting of F and oxygen (=O), and in this case, the effect of improving the charging efficiency and output of the secondary battery, and improving the long-term life and high-temperature capacity retention rate is more excellent. have.

In the compound represented by Formula 4, R ₁₅ , R ₁₆ and R ₁₇ are preferably the same as each other. In this case, the electron flow in the molecule is stabilized, and through this, molecular rigidity is increased, thereby improving battery performance. There is a greater advantage.

The compound represented by Formula 4 may preferably include a compound represented by Formula 4a below, and in this case, charging efficiency and output may be improved due to low charging resistance of the secondary battery, and long-term lifespan and high-temperature capacity retention rate may be improved. There are excellent advantages.

[Formula 4a]

(In Chemical Formula 4a, a line is a bond, and when a separate element is not described, a point where a bond and a bond meet is carbon, and the number of hydrogens satisfying the valence of the carbon is omitted.)

When the electrolyte solution additive represented by Chemical Formula 4 is added to the electrolyte solution of a battery, electrons are localized toward the O element due to the electronegativity difference between the P, S, or N element and the directly connected O element. Accordingly, the P, S, or N element becomes an electron-poor (δ+) state, and an oxidation reaction is induced in an electrolyte containing lithium ions, forming a stable film on the electrode, in a specific example, the cathode. do. At this time, it is possible to prevent the decomposition of the electrolyte due to the stability of the film, and thereby cycle characteristics can be improved. There is an excellent effect of greatly improving. In addition, since the increase in resistance is prevented, charging efficiency and output are improved, and gas generation due to a chemical reaction inside the battery is also suppressed, so that the safety of the battery can be improved. In addition, the capacity retention is improved by preventing the structural collapse of the electrode active material of the positive electrode and the negative electrode at a high temperature, thereby extending the lifespan.

[Formula 5]

(In Formula 5, R ₁₈ and R ₁₉ are independently an alkylene group having 1 to 5 carbon atoms, and E ₇ is a bond, an alkylene group having 1 to 3 carbon atoms, or a cyclic carbonyl group having 2 to 5 carbon atoms, an ether group or an ester group, wherein R ₂₀ is a substituted or unsubstituted linear or cyclic carbonate group having 2 to 5 carbon atoms, a carbonyl group, an ether group, a phosphate group, a sulfonate or a sulfate group, and the substitution is F, Cl, Br And at least one selected from the group consisting of I or substituted with an alkenyl group having 1 to 3 carbon atoms, wherein E ₈ is a bond or a saturated or unsaturated alkylene group having 1 to 3 carbon atoms, or an ether group, wherein n is 0 or 1.)

In Formula 5, the alkylene group refers to a divalent hydrocarbon group, and specifically, the propylene group refers to -CH ₂ CH ₂ CH ₂ - or -CH ₂ CH(CH ₃ )-.

In the present description, the alkenyl group refers to a monovalent hydrocarbon group including a carbon-carbon double bond, and as a specific example, the n-butenyl group refers to CH ₂ =CHCH ₂ CH ₂ —.

R ₁₈ and R ₁₉ are preferably independently an alkylene group having 1 or 2 carbon atoms, and in this case, the charging resistance of the secondary battery is low, so that the charging efficiency and output can be improved, and the long-term life and high-temperature capacity retention rate are excellent. have.

E ₇ is preferably a bond, or a cyclic carbonyl group having 2 to 3 carbon atoms, an ether group, or an ester group. and excellent high temperature capacity retention rate.

R ₂₀ is preferably a substituted or unsubstituted linear or cyclic carbonate group having 2 to 3 carbon atoms, a carbonyl group, an ether group, a phosphate group or a sulfate group, and the substitution is preferably F or a vinyl group (vinyl). In this case, since the charging resistance of the secondary battery is low, charging efficiency and output can be improved, and long-term lifespan and high-temperature capacity retention rate are excellent.

E ₈ is preferably a bond or a saturated or unsaturated (if unsaturated, carbon number is 2) alkylene group having 1 to 2 carbon atoms, or an ether group, in this case, the charging efficiency of the secondary battery is low due to the low charging resistance and output can be improved, and long-term life and high-temperature capacity retention rates are excellent.

When n is 0, the phosphorus (P) atom has a lone pair of electrons instead of oxygen.

The compound represented by Formula 5 is preferably at least one selected from the group consisting of compounds represented by Formulas 5-1 to 5-52, and in this case, charging efficiency and output are improved due to low charging resistance of the secondary battery. It has the advantages of excellent long-term lifespan and high-temperature capacity retention rate.

[Formula 5-1 to 5-52]

(In Formulas 5-1 to 5-52, a line is a bond, and when a separate element is not described, the point where the bond and the bond meet is carbon, and the number of hydrogens satisfying the valence of the carbon is omitted.)

Among the compounds represented by Chemical Formula 5, the compound in which n is 1 is preferably at least one selected from the group consisting of compounds represented by Chemical Formulas 5-1 to 5-51, and in this case, the secondary battery has a low charging resistance to charge Efficiency and output can be improved, and long life and high temperature capacity retention are excellent.

When the electrolyte solution additive represented by Formula 5 is added to the electrolyte solution of the battery, The electronegativity difference between the P element and the directly connected O element causes the electrons to be localized towards the O element. Accordingly, the P element becomes in an e-poor (δ+) state and an oxidation reaction is induced in an electrolyte containing lithium ions to form a stable film on the electrode, in a specific example, the cathode. At this time, it is possible to prevent the decomposition of the electrolyte due to the stability of the film, and thereby cycle characteristics can be improved. There is an excellent effect of greatly improving. In addition, since the increase in resistance is prevented, charging efficiency and output are improved, and gas generation due to a chemical reaction inside the battery is also suppressed, so that the safety of the battery can be improved. In addition, the capacity retention rate is improved by preventing the structural collapse of the electrode active material of the positive electrode and the negative electrode at a high temperature, thereby extending the lifespan.

[Formula 6]

이며; 선택적으로 상기 R₂₁ 또는 R₂₂는, 독립적으로 R₂₃ 또는 R₂₄와 연결되어 이중결합 또는 고리를 만들 수 있고; 상기 n은 0 내지 3의 정수이며; 상기 *은 결합위치이다.)(In Formula 6, P and O are each phosphorus and oxygen; A is a bond or oxygen; Q is oxygen or an unshared pair of electrons; R ₂₁ , R ₂₂ , R ₂₃ and R ₂₄ are independently hydrogen and 1 to 10 carbon atoms. of a linear or branched alkyl group, alkenyl group, alkynyl group, alkoxy group, alkoxycarbonyl group, alkoxyalkyl group, fluoroalkyl group, or

is; Optionally, R ₂₁ or R ₂₂ may be independently linked to R ₂₃ or R ₂₄ to form a double bond or a ring; wherein n is an integer from 0 to 3; The * is a bonding position.)

In Formula 6, the ring may be preferably an aromatic or aliphatic ring, and n may be preferably 1 or 2, and the fluoroalkyl is preferably a fluoroalkyl group. from 8 to 8 substituted alkyl.

In the compound in which the group represented by Formula 6 is substituted, various groups may be bonded to the * position of the group represented by Formula 1 as needed, for example, a linear or branched alkyl group having 1 to 10 carbon atoms, an alkenyl group , alkynyl group, alkoxy group, hydroxyl group, alkoxycarbonyl group, alkoxyalkyl group, fluoroalkyl, cyano group, alkylcyano group, alkylsilyl, amide, imidazole, thiophene, ether, thioether, alkylsulfonyl, sulfonyl group phonylalkyl, cycloalkylsulfonyl, cyclosulfonylalkyl, alkylsulfoxide or phosphorus fluoride, and the like. Here, the group named as the completed compound means that hydrogen or some atomic groups of the group are substituted at the * position with the group represented by Formula 6 above.

The compound in which the group represented by Formula 6 is substituted is preferably at least one selected from the group consisting of compounds represented by Formulas 6-1 to 6-31, and more preferably Formula 6-15 or Formula 6 It is a compound represented by -31, and in this case, the charging resistance of the secondary battery is low, so that the charging efficiency and output can be improved, and there is an advantage in that a long lifespan and a high temperature capacity retention rate are excellent.

[Formula 6-1 to 6-31]

(In Chemical Formulas 6-1 to 6-31, a line is a bond, and when a separate element is not described, the point where the bond and the bond meet is carbon, and the number of hydrogens satisfying the valence of the carbon is omitted.)

When the electrolyte solution additive represented by Formulas 6-1 to 6-31 is added to the electrolyte solution of a secondary battery, electrons are localized toward the O element due to a difference in electronegativity between the P or S element and the O element directly connected thereto. Accordingly, the P or S element becomes an electron-poor (δ+) state and an oxidation reaction is induced in an electrolyte containing lithium ions, thereby forming a stable film on the electrode, specifically, the cathode. At this time, it is possible to prevent the decomposition of the electrolyte due to the stability of the film, and thereby cycle characteristics can be improved. There is an excellent effect of greatly improving. In addition, since the increase in resistance is prevented, charging efficiency and output are improved, and gas generation due to a chemical reaction inside the battery is also suppressed, so that the safety of the battery can be improved. In addition, the capacity retention is improved by preventing the structural collapse of the electrode active material of the positive electrode and the negative electrode at a high temperature, thereby extending the lifespan.

One or more compounds selected from the compounds represented by Formulas 1 to 6 may be included in an amount of 0.1 to 10% by weight, preferably 0.2 to 5% by weight, more preferably 0.4 to 10% by weight based on 100% by weight of the total electrolyte. 2.0% by weight, most preferably 0.5 to 1.5% by weight. Within the above range, the effect of improving the charging efficiency and high temperature life of the battery may be the most excellent.

The at least one compound selected from the nitrogen-based, boron-based, monocyclic, polycyclic, and silane-based compounds may be preferably at least one selected from the group consisting of compounds represented by the following Chemical Formulas 7-1 to 7-22, but , but is not limited thereto. In this case, since the charging resistance of the secondary battery is low, charging efficiency and output may be improved, and there is an advantage in that a long lifespan and a high temperature capacity retention rate are excellent.

[Formula 7-1 to 7-22]

The electrolyte may be added to the electrolyte of the battery to form a stable film on the electrode. At this time, it is possible to prevent the decomposition of the electrolyte additive due to the stability of the film, and thereby cycle characteristics can be improved. There is an excellent effect of greatly improving high-temperature storage properties. In addition, since the increase in resistance is prevented, charging efficiency and output are improved, and gas generation due to a chemical reaction inside the battery is also suppressed, so that the safety of the battery can be improved. In addition, the capacity retention is improved by preventing the structural collapse of the electrode active material of the positive electrode and the negative electrode at a high temperature, thereby extending the lifespan.

In addition, the present invention is an electrolyte solution additive comprising an organic solvent and/or lithium salt in 0.1 to 10% by weight of at least one selected from the compounds represented by Formulas 1 to 6 and 0.1 to 10% by weight of the compound represented by Formula 7 provides

The organic solvent is preferably ethylene carbonate (EC), diethyl carbonate (DEC), ethylmethyl carbonate (EMC), dimethyl carbonate (DMC), propylene carbonate (PC), dipropyl carbonate (DPC), butylene carbonate, It may include one or more selected from the group consisting of methylpropyl carbonate, ethylpropyl carbonate, methyl propionate (MP), ethyl propionate (EP) and propyl propionate (PP), preferably two types. The above may be included, and in this case, it is easy to control the ionic conductivity, viscosity, etc. of the electrolyte additive, so that the effect of improving battery performance is more excellent.

The organic solvent is a specific example by mixing an organic solvent of high dielectric constant having high ionic conductivity and a low-viscosity organic solvent that can be adjusted so that the viscosity of the solvent has an appropriate viscosity to be applied to the battery so as to increase the charging and discharging performance of the battery. It can be used as a mixed solvent, and more specifically, EC and/or PC can be used as an example of the organic solvent of high dielectric constant, and as an example of the low-viscosity organic solvent, from the group consisting of EMC, DMC and DEC One or more selected types may be used.

The high dielectric constant and low viscosity organic solvent is preferably mixed in a volume ratio of 2:8 to 8:2. More specifically, it may be a ternary mixed solvent of EC and/or PC and EMC and DEC, and a ratio of EC and/or PC:EMC:DEC may be 1:3 to 5:2 to 4.

When the organic solvent contains moisture, lithium ions in the electrolyte additive may be hydrolyzed, and therefore, moisture in the organic solvent is preferably controlled to 150 ppm or less, preferably 100 ppm or less.

The electrolyte additive may include at least one selected from the group consisting of LiPF ₆ and LiFSI, for example, as a lithium salt, and may preferably include LiPF ₆ , in which case lithium ions are smoothly supplied to the battery. It has the advantage of excellent performance.

The electrolyte additive is, for example, a lithium salt LiF ₄ , LiCl, LiBr, LiI, LiClO ₄ , LiB ₁₀ Cl ₁₀ , LiCF ₃ SO ₃ , LiCF ₃ CO ₂ , LiAsF ₆ , LiSbF ₆ , LiAlCl ₄ , CH ₃ SO ₃ Li , CF ₃ SO ₃ Li, (SO ₂ F) ₂ NLi and (CF ₃ SO ₂ ) ₂ NLi may further include one or more selected from the group consisting of, in this case, lithium ions may be more smoothly supplied .

When the lithium salt is dissolved in the electrolyte solution additive, the lithium salt functions as a source of lithium ions in the lithium secondary battery, and may promote movement of lithium ions between the positive electrode and the negative electrode. Accordingly, the lithium salt is preferably contained in a concentration of about 0.6 mol% to 2 mol% of the electrolyte additive. If the concentration of the lithium salt is less than 0.6 mol%, the conductivity of the electrolyte solution additive may be lowered, and thus the electrolyte solution additive performance may be deteriorated. Considering the conductivity of the electrolyte additive and the mobility of lithium ions, the lithium salt may be included in the electrolyte additive in an amount of preferably 0.7 mol% to 1.6 mol%, more preferably 0.8 mol% to 1.5 mol%. .

The electrolyte additive of the present invention, for example, in addition to the electrolyte additive containing the compound represented by the above-mentioned formula, can be generally used in electrolyte additives for the purpose of improving battery life characteristics, suppressing reduction in battery capacity, improving battery discharge capacity, etc. It may further include an additive.

The commercial additive is preferably vinylene carbonate (VC), fluoroethylene carbonate (FEC), vinylethylene carbonate (VEC), ethyl propionate (Ethyl propionate), propyl propionate ( Propyl propionate), bisdifluorophosphanyloxyethane (1,2-bis((difluorophosphaneyl)oxy)ethane), fluoromethyldioxaphospholane (2-fluoro-4methyl-[1,3,2]-dioxaphospholane) ), difluoro pentyloxy phosphane (Difluoro (pentyloxy) phosphane), hexane tricarbonitrile (1,3,6-hexanetricarbonitrile, HTCN), succinonitrile (succinonitrile, SN), adiponitrile (adiponitrile, AN), 4-tolunitrile, Lithium bis(oxalato)borate (LiBOB), Lithium difluoro (oxalate) borate, LiDFOB ), lithium tetrafluoroborate (LiBF4), tris(trimethylsilyl)borate, triisopropyl borate, trimethoxyboroxine, lithium tetrafluoro Oxalatophosphate (Lithium tetrafluro(oxalato) Phosphate), lithium difluorobisoxalatophosphate (Lithium DiFluro(bisoxalato) Phosphate), lithium difluorophosphate (lithium difluorophosphate), tristrimethylsillyphosphite (Tris (Tris) trimethylsilyl) Phosphite), tripropagyl phosphate (Tripropagyl pho) sphate), triphenyl phosphate, tetraoxadithiaspiro5,5-undecane3,3,9,9-tetraoxide (2,4,8,10-Tetraoxa-3,9-dithiaspiro [5.5 ]undecane, 3,3,9,9-tetraoxide), dimethyl sulfate, ethylene dimethanesulfonate, lithium bis(fluorosulfonyl)imide, LiFSI), ethylene sulfate, 1,3-propene sultone (1-propene-1,3-sultone, 1,3-propane sultone), propylene sulfate (1,3- propylene sulfate), butane sultone (1,4-Butane sultone), sulfolene, biphenyl (biphenayl), cyclohexyl benzene, 4-fluorotoluene (4-fluorotoluene), fluorobenzene ( Fluoro benzene), 2-fluorobiphenyl (2-fluoro-biphenyl) and 3-fluorobiphenyl (3-fluoro-biphenyl) may be at least one selected from the group consisting of.

The commercially available additives may be used alone or in combination of two or more of them. As an example, the commercial additive may be fluoroethylene carbonate, 1,3-propanesultone, 1,3-propensultone or ethyl sulfuric acid alone, or fluoroethylene carbonate and 1,3-propanesultone It may be desirable to use a combination, but is not limited thereto.

The commercial additive may be included in an amount of 0.01 to 20 wt%, preferably 0.1 to 10 wt%, based on the total weight of the electrolyte additive.

The electrolyte additive may include at least one selected from the group consisting of LiPF ₆ and LiFSI, for example, as a lithium salt, and may preferably include LiPF ₆ , in which case lithium ions are smoothly supplied to the battery. It has the advantage of excellent performance.

The electrolyte additive is, for example, a lithium salt LiF ₄ , LiCl, LiBr, LiI, LiClO ₄ , LiB ₁₀ Cl ₁₀ , LiCF ₃ SO ₃ , LiCF ₃ CO ₂ , LiAsF ₆ , LiSbF ₆ , LiAlCl ₄ , CH ₃ SO ₃ Li , CF ₃ SO ₃ Li, (SO ₂ F) ₂ NLi and (CF ₃ SO ₂ ) ₂ NLi may further include one or more selected from the group consisting of, in this case, the supply of lithium ions may be smoother .

When the lithium salt is dissolved in the electrolyte solution additive, the lithium salt functions as a source of lithium ions in the lithium secondary battery, and may promote movement of lithium ions between the positive electrode and the negative electrode. Accordingly, the lithium salt is preferably contained in a concentration of about 0.6 mol% to 2 mol% of the electrolyte additive. If the concentration of the lithium salt is less than 0.6 mol%, the conductivity of the electrolyte solution additive may be lowered, and thus the electrolyte solution additive performance may be deteriorated. Considering the conductivity of the electrolyte additive and the mobility of lithium ions, the lithium salt may be included in the electrolyte additive in an amount of preferably 0.7 mol% to 1.6 mol%, more preferably 0.8 mol% to 1.5 mol%. .

secondary battery

A secondary battery comprising the negative electrode, the positive electrode, the separator interposed between the negative electrode and the positive electrode, and the electrolyte solution additive of the present invention is provided.

The positive electrode may be prepared by, for example, preparing a composition for forming a positive electrode active material layer by mixing a positive electrode active material, a binder, and optionally a conductive material, and then applying it to a positive electrode current collector such as aluminum foil.

The positive active material may be, for example, a conventional high-nickel positive active material used in lithium secondary batteries, a lithium nickel manganese cobalt oxide (NCM) positive active material, or a lithium iron phosphorus oxide (LFP) positive active material, preferably of the formula Li [ NixCo _1-xy Mn _y ]O ₂ (here, 0<x<0.5, 0<y<0.5) may be a lithium composite metal oxide in the form, a specific example may be LiNiMnCoO ₂ , but is not limited thereto.

Variables x and y of the formula Li[NixCo _1-xy Mn _y ]O ₂ of the lithium composite metal oxide are, for example, 0.0001<x<0.5, 0.0001<y<0.5, or 0.001<x<0.3, 0.001<y<0.3 can be

As another example of the positive active material, a compound capable of reversible intercalation and de-intercalation of lithium (a lithiated intercalation compound) may be used.

LiCoO ₂ , LiMnO ₂ , LiMn ₂ O ₄ , LiNiO ₂ , LiNi _x Mn _(1-x) O ₂ (provided that 0<x<1), and LiM1 _x M2 _y O ₂ (provided that 0≤x≤1, 0≤y≤1, 0≤x+y≤1, M1 and M2 are each independently any one selected from the group consisting of Al, Sr, Mg and La ), preferably at least one selected from the group consisting of.

The negative electrode may be prepared by, for example, mixing a negative electrode active material, a binder, and optionally a conductive agent to prepare a composition for forming the negative electrode active material layer, and then applying it to a negative electrode current collector such as copper foil.

As the anode active material, for example, a compound capable of reversible intercalation and deintercalation of lithium may be used.

Specific examples of the negative active material may be a carbonaceous material such as a Si-based negative active material, artificial graphite, natural graphite, graphitized carbon fiber, or amorphous carbon.

In addition, in addition to the carbonaceous material, a metal compound capable of alloying with lithium, or a composite including a metal compound and a carbonaceous material may be used as the negative electrode active material, and may be graphite, for example.

As the metal alloyable with lithium, for example, at least one of Si, Al, Sn, Pb, Zn, Bi, In, Mg, Ga, Cd, Si alloy, Sn alloy, or Al alloy may be used.

In addition, a metal lithium thin film may be used as the negative electrode active material.

As the negative active material, in view of high stability, any one or more selected from the group consisting of crystalline carbon, amorphous carbon, carbon composite material, lithium metal, and an alloy containing lithium may be used.

In the secondary battery of the present invention, by adding an electrolyte solution additive containing the compound represented by the above formula, the battery charging resistance, output characteristics, and capacity at a high temperature of 60° C. or higher measured by the HPPC (Hybrid Pulse Power Characterization) method compared to the related art There is an effect that the effect of improving battery characteristics such as recovery characteristics and lifespan characteristics is further improved.

As a specific example, in the secondary battery of the present invention, the HPPC charging resistance value measured at 60° C. may be 500 mΩ or less, preferably 200 mΩ or less, more preferably 60 mΩ or less, and most preferably 55 mΩ or less.

In addition, the secondary battery may have a recovery capacity of 600 mAh or more at 60° C., preferably 605 mAh or more, more preferably 630 mAh or more, and most preferably 650 mAh or more .

The lifetime maintenance efficiency at 45° C. of the secondary battery may be 80% or more, preferably 85% or more, and more preferably 87% or more .

In this description, the HPPC charging resistance value can be measured by a method specified in the document “Battery test manual for plug-in hybrid electric vehicles,” (2010, Idaho National Laboratory for the U.S. Department of Energy.) It is an important index indicating the output characteristics of the battery. In addition, the charging resistance is a resistance value measured during charging of the battery, and as the charging resistance is lower, energy loss is small, the charging speed may be increased, and the output of the battery may be improved. The secondary battery of the present invention has a low HPPC charging resistance value as described above, and thus has excellent charging speed and output, and is suitable for use as, for example, an automobile battery.

In the present description, the recovery capacity represents the capacity preservation characteristics of a battery left for a long time, and the discharged electric capacity when the battery left for a long time is discharged to the end-of-discharge voltage, and the discharged battery is recharged and discharged again to the end-of-discharge voltage By measuring the discharged electric capacity when will be. The higher the recovery capacity, the smaller the amount of natural discharge due to battery preservation (storage), which means that the battery can be stored for a long time. This is a very important characteristic in a battery. When the compound of the present invention is added to the electrolyte solution for a battery, the recovery capacity is improved compared to when only the conventional additive is used, so that it can be stored for a longer period of time with a single charge.

Therefore, when the battery of the present invention is used as a battery for an electric vehicle, output improvement, which becomes important depending on the size of the vehicle, and climate change, low temperature and Performance improvement at high temperature can be achieved, thereby exhibiting excellent performance as an automobile battery.

Accordingly, when the electrolyte additive according to the embodiments of the present invention is applied to a secondary battery, charging resistance, output, recovery capacity, and lifespan efficiency are improved, and thus it can be seen that it is suitable for use as a secondary battery for automobiles.

Hereinafter, preferred examples are presented to help the understanding of the present invention, but the following examples are merely illustrative of the present invention, and it will be apparent to those skilled in the art that various changes and modifications are possible within the scope and spirit of the present invention, It goes without saying that such variations and modifications fall within the scope of the appended claims.

[Synthesis Example]

Synthesis Example 1: Preparation of 1,3,2-Dioxaphospholan-2-yl diethyl phosphite

2.38 g (17.2 mmol) of diethyl phosphite was added to 50 ml of a three-necked flask prepared for drying, and 5 ml of benzene was added dropwise. While stirring, 1.75 g (17.2 mmol) of triethylamine was slowly added dropwise. While maintaining the reaction temperature at 0° C., 2.18 g (17.2 mmol) of ethylene chlorophosphite was slowly added dropwise over 30 minutes. After completion of the dropwise addition, the mixture was stirred at 0° C. for 30 minutes, and the resulting triethylamine salt was filtered off. The filtrate was subjected to vacuum distillation to obtain the desired product, 1,3,2-dioxaphosphoran-2-yl diethyl phosphite, in 2,1 g, yield of 55%. The obtained product was confirmed to correspond to the structure of Formula 1-24 by 1H NMR as follows.

1H NMR (CDCl ₃ , 400 MHz) δ = 4.18 (m, 2H), 4.05 (m, 2H), 3.85 (m, 4H), 1.24 (m. 6H)

Synthesis Example 2: Preparation of 2-((Trimethylsilyl)oxy)-1,3,2-dioxaphospholane

5g (55.4mmol) of trimethylsilanol was added to 100ml of a 3-neck flask prepared for drying, and 50ml of diethyl ether and 6.1g (60.0mmol) of triethylamine were added dropwise as solvents. While maintaining the reaction temperature at -10 °C, 5.8 g (46.1 mmol) of 2-chloro-1,3,2-dioxaphosphorane was slowly added dropwise. The reaction time was stirred for 10 hours, and the triethylamine salt was removed by filtration at room temperature. The filtrate was subjected to vacuum distillation to obtain the desired product, 2-((trimethylsilyl)oxy)-1,3,2-dioxaphosphorane, 4.9 g, in a yield of 60%. The obtained product was confirmed to have a structure of Formula 6-31 by 1H NMR as follows.

1H NMR (CDCl ₃ , 400 MHz) δ = 4.12 (m, 2H), 3.92 (m, 2H), 0.18 (s. 9H)

[Example: Preparation of electrolyte solution for batteries]

Example 1

As the organic solvent, a carbonate-based mixed solvent having a volume ratio of EC:EMC:DEC = 3:4:3 is used, and as an electrolyte additive in a solution containing LiPF ₆ as a lithium salt at a concentration of 1.15M, the following formula 1a 0.5 wt% of a compound represented by (Bisethylene pyrophosphate) was added to prepare an electrolyte for a battery.

[Formula 1a]

Example 2

As the organic solvent, a carbonate-based mixed solvent having a volume ratio of EC:EMC:DEC = 3:4:3 is used, and in a solution containing LiPF ₆ as a lithium salt at a concentration of 1.15M, represented by Formula 1a 0.5 wt% of the compound and 1 wt% of the compound represented by the following Chemical Formula 7-14 were added to prepare an electrolyte for a battery.

[Formula 7-14]

Example 3

In Example 2, a compound represented by the following formula 7-15 in place of the compound represented by the formula 7-14 while adding 0.3% by weight of the compound represented by the following formula 2-2 instead of the compound represented by the formula 1a It was carried out in the same manner as in Example 2, except that

[Formula 2-2]

[Formula 7-15]

Example 4

In Example 2, 0.8 wt% of the compound represented by the following formula 3-1 was added instead of the compound represented by the formula 1a, and the compound represented by the following formula 7-8 instead of the compound represented by the formula 7-14 It was carried out in the same manner as in Example 2, except that

[Formula 3-1]

[Formula 7-8]

Example 5

Example 2 was carried out in the same manner as in Example 2, except that 1.0 wt % of the compound represented by the following formula 4a was added instead of the compound represented by the formula 1a.

[Formula 4a]

Examples 6 to 8

In Example 2, a compound represented by the following formula 5-52 was added in place of the compound represented by the formula 1a in Example 2, and 0.5 wt%, 1.0 wt%, 2.0 wt%, respectively, were used in Example 2 and The same was carried out.

[Formula 5-52]

Examples 9 to 10

The same as in Example 1, except that the compound represented by Formula 1-24 prepared in Synthesis Example 1 was added instead of the compound added in Example 1, and the content thereof was 0.5 wt% and 1 wt%, respectively was carried out.

Examples 11 to 12

The compound represented by Formula 6-31 prepared in Synthesis Example 2 was added instead of the compound added in Example 1, and the same as in Example 1, except that 0.5 wt% and 1 wt% of the compound were used, respectively. was carried out.

Comparative Example 1

Example 2 was carried out in the same manner as in Example 2, except that the compound represented by Formula 1a was not added.

Comparative Example 2

It was carried out in the same manner as in Example 1, except that 0.5 wt% of cyclic ethylene phosphate having an asymmetric structure was added instead of the compound represented by Formula 1a added in Example 1.

For reference, the components and contents of the electrolyte additive used in Examples 1 to 12 and Comparative Examples 1 to 2 are briefly summarized in Table 1 below for better understanding.

manufacture of batteries

Li (Ni _0.5 Co _0.2 Mn _0.3 )O ₂ 92 wt% as a positive active material, 4 wt% of carbon black as a conductive agent, and 4 wt% of polyvinylidene fluoride (PVdF) as a binder N-methyl- as a solvent It was added to 2-pyrrolidone (NMP) to prepare a positive electrode mixture slurry. The positive electrode mixture slurry was coated on an aluminum (Al) thin film as a positive electrode current collector having a thickness of about 20 μm, dried to prepare a positive electrode, and then a positive electrode was manufactured by performing a roll press.

Carbon powder as an anode active material, PVdF as a binder, and carbon black as a conductive agent in 96 wt%, 3 wt%, and 1 wt%, respectively, were added to NMP as a solvent to prepare an anode mixture slurry. The negative electrode mixture slurry was applied to a 10 μm-thick copper (Cu) thin film as a negative electrode current collector, dried to prepare a negative electrode, and then roll press was performed to prepare a negative electrode.

After preparing a pouch-type battery in a conventional manner with a separator consisting of three layers of polypropylene/polyethylene/polypropylene (PP/PE/PP) for the positive and negative electrodes prepared as described above, Examples 1 to 12 and Comparative Examples Preparation of the lithium secondary battery was completed by injecting the electrolyte solution prepared in steps 1 and 2.

test example

In order to evaluate the performance of each secondary battery prepared above, the performance was measured by the following method, and the results are shown in Table 1 below.

[HPPC charging resistance evaluation]

It was measured by the method prescribed in the document “Battery test manual for plug-in hybrid electric vehicles,” (2010, Idaho National Laboratory for the U.S. Department of Energy.).

At high temperature (60℃), the measured voltage value, the charge/discharge current value corresponding to the C-rate, the current change amount (∆I), the discharge voltage change amount (∆V), the charge voltage change amount (∆V), the discharge resistance, the charge resistance was measured, and the charge/discharge current for each C-rate was briefly flowed for a certain period of time, and the resistance value was calculated using the slope value obtained from the amount of change in current and voltage.

[High temperature recovery capacity evaluation]

The charging conditions were a constant current of 1.0C and a voltage of 4.2V until the charging current became 1/10C. Discharge conditions were measured after charging and discharging by discharging to 3.0V with a constant current of 1.0C, and then the discharge capacity was measured.

After charging under the same charging and discharging conditions, it was stored in a thermostat at 60° C. for 4 weeks, and then discharged to a discharge voltage of 3V at a high temperature of 60° C., and the remaining capacity was measured. After three times under the same charge and discharge conditions, the recovery capacity was measured and the average value thereof was calculated.

[High temperature life evaluation]

The secondary battery was charged with a constant current at 45° C. at a current of 1C rate until the voltage reached 4.20V (vs. Li), and then cut-off at a current of 0.05C rate while maintaining 4.20V in the constant voltage mode. did Then, it was discharged at a constant current of 1C rate until the voltage reached 3.0V (vs. Li) during discharge (1st cycle). The above cycle was repeated 300 times to calculate the average value thereof.

division Chemical formula of additives Additive content
(weight%) additional additives
chemical formula Additional additive content
(weight%) HPPC
charging resistance
(mΩ) After high temperature storage
recovery capacity
(mAh) High temperature
Life Efficiency
(%) Example 1 1a 0.5 - - 51.1 663.3 88.3 Example 2 1a 0.5 7-14 1.0 52.1 661.1 88.5 Example 3 2-2 0.3 7-15 1.0 51.8 666.3 88.1 Example 4 3-1 0.8 7-8 1.0 51.3 659.6 88.8 Example 5 4a 1.0 7-14 1.0 52.8 656.5 87.9 Example 6 5-52 0.5 7-14 1.0 52.1 671.6 88.1 Example 7 5-52 1.0 7-14 1.0 52.1 651.0 88.1 Example 8 5-52 2.0 7-14 1.0 52.1 685.3 88.1 Example 9 1-24 0.5 - - 50 685.5 89 Example 10 1-24 1.0 - - 48 683.1 90 Example 11 6-31 0.5 - - 48.2 693.2 90 Example 12 6-31 1.0 - - 46 696.5 91 Comparative Example 1 - - 7-14 1.0 113.7 598.1 71.2 Comparative Example 2 Cyclic Ethylene Phosphate 0.5 - - 98.3 601.1 75.4

As shown in Table 1 above, in the case of the secondary batteries including the electrolyte additives of Examples 1 to 12 according to the present invention, the charging resistance value was 46 to 52.8 mΩ, and the battery performance was excellent, while the electrolyte additive according to the present invention was used. Comparative Example 1 without including VC alone had a high charge resistance value of 113.7 mΩ, indicating poor battery performance, and Comparative Example 2 using asymmetric cyclic ethylene phosphate alone without including the electrolyte additive according to the present invention showed a high charging resistance value of 98.3 mΩ, indicating that the battery performance was also poor, and it was confirmed that the charging resistance value at a high temperature of 60 ° C. This indicates that the output of the battery is improved by the electrolyte additive according to the present invention.

As shown in Table 1 above, in the case of the secondary battery including the electrolyte additive of Examples 1 to 12 according to the present invention, the high temperature recovery capacity is 651.0 to 696.5 mAh, whereas the comparison outside the range of the electrolyte additive according to the present invention In the case of Examples 1 and 2, 598,1 mAh and 601.1 mAh, respectively, were found to have a maximum difference of 98.4 mAh compared to the embodiment of the present invention. This means that the recovery capacity at a high temperature of 60° C. is improved by the electrolyte additive according to the present invention, and thus, the effect of improving the recovery capacity efficiency of the battery during long-term storage in a high temperature environment by the electrolyte additive according to the present invention It can be confirmed that there is

In addition, as a result of the evaluation of high temperature life efficiency, the secondary batteries using the electrolyte additives of Examples 1 to 12 according to the present invention were 87.9% to 91%, whereas Comparative Examples 1 and 2 outside the range of the electrolyte additive according to the present invention In the case of 71.2% and 75.4%, it can be seen that the maximum is 27.8%p (% points) lower than the embodiment of the present invention. This means that by using the electrolyte additive according to the present invention, the capacity retention rate of the battery is improved while repeating 300 cycles at a high temperature of 45° C. compared to when only the conventional electrolyte additive is used, and thus the electrolyte additive of the present invention is used in a high-temperature environment. It can be seen that the cycle characteristics and life efficiency of the battery are improved.

In addition, in the case of secondary batteries using the electrolyte additives of Examples 2 to 8 according to the present invention, which further include a nitrogen-based, boron-based, monocyclic, polycyclic or silane-based system, improved cycle characteristics and improved cycle characteristics within an appropriate amount range and It can be seen that, at the same time, when it is combined with phosphate, it has an effect of improving resistance properties and high temperature life performance.

Therefore, when the electrolyte additive according to the embodiments of the present invention, and the electrolyte containing the same, are applied to a secondary battery, the charging resistance, output, recovery capacity and life efficiency are improved, and it is found that it is suitable for use as a secondary battery for automobiles. can

Claims (15)

As an electrolyte comprising an organic solvent, a lithium salt and an electrolyte additive,
The electrolyte solution additive is based on 100 wt% of the total electrolyte solution
0.1 to 10% by weight of at least one compound selected from compounds represented by the following Chemical Formulas 1 to 6; and at least one compound selected from nitrogen-based, boron-based, monocyclic, polycyclic and silane-based compounds. Electrolyte, characterized in that it comprises 0.1 to 10% by weight.
[Formula 1]

(In Formula 1, G is -O-, -OR _a -, -N(R _b )- or -R _c -N(R _d )-R _e -, -R _f (NR _g R _h )- or -R _i -; wherein R _a , R _c , R _e , R _f and R _i are independently a linear or branched alkylene group having 1 to 10 carbon atoms; R _b , R _d , R _g and R _h are independently hydrogen or a linear or branched alkyl group having 1 to 10 carbon atoms; Q ₁ and Q ₂ are independently phosphorus (P), sulfur (S) or arsenic (As); D ₁ , D ₂ , D ₃ , D ₄ , D ₅ and D ₆ are independently oxygen (=O) or one or two lone pairs of electrons; E ₁ , E ₂ , E ₃ or E ₄ is oxygen or carbon, and D ₂ , When D ₃ , D ₅ or D ₆ is oxygen, E ₁ , E ₂ , E ₃ or E ₄ attached thereto is carbon; R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ and R ₈ is independently hydrogen, a linear or branched alkyl group having 1 to 10 carbon atoms, an alkenyl group, an alkynyl group, an alkoxy group, an alkoxycarbonyl group or an alkoxyalkyl group; optionally, R ₃ and R ₄ or R ₇ and R ₈ may be combined to form a ring; n and k are independently integers from 0 to 5; m and l are independently 0 or 1; and at least one of n and m and k and l is 0 not this.)
[Formula 2]

(In Formula 2, A ₁ and A ₂ are independently phosphorus (P) or sulfur (S), and D ₇ and D ₈ are independently oxygen (=O) or a lone pair of electrons, and the G ₁ and G ₂ is independently -O- or -CH ₂ -, wherein R ₉ and R ₁₀ are independently a linear or branched alkyl group having 1 to 20 carbon atoms, and R ₁₁ , R ₁₂ , R ₁₃ and R ₁₄ are independently It is a bond or an alkylene group having 1 to 3 carbon atoms.)
[Formula 3]

(In Formula 3, X ₁ and X ₂ are independently F, Cl, Br, or I, and E ₅ and E ₆ are independently a substituted or unsubstituted hydrocarbon group having 1 to 3 carbon atoms, wherein the substitution is =O, -CX' ₃ and -CH ₂ CX" ₃ is substituted with one or more selected from the group consisting of, wherein X' and X" are independently F, Cl, Br or I, and are included in E ₅ and E ₆ Bonds between carbons are single or double bonds.)
[Formula 4]

(In Formula 4, A is phosphorus (P), sulfur (S), or nitrogen (N), wherein R ₁₅ , R ₁₆ and R ₁₇ are independently linear or minute having 1 to 5 carbon atoms including a substituent. It is a topographical alkyl group, and the substituent is at least one selected from the group consisting of a halogen element including F, Cl, Br and I and oxygen (=O).)
[Formula 5]

(In Formula 5, R ₁₈ and R ₁₉ are independently an alkylene group having 1 to 5 carbon atoms, and E ₇ is a bond, an alkylene group having 1 to 3 carbon atoms, or a cyclic carbonyl group having 2 to 5 carbon atoms, an ether group or an ester group, wherein R ₂₀ is a substituted or unsubstituted linear or cyclic carbonate group having 2 to 5 carbon atoms, a carbonyl group, an ether group, a phosphate group, a sulfonate or a sulfate group, and the substitution is F, Cl, Br And at least one selected from the group consisting of I or refers to being substituted with an alkenyl group having 1 to 3 carbon atoms, wherein E ₈ is a bond or a saturated or unsaturated alkylene group having 1 to 3 carbon atoms, or an ether group, wherein n is 0 or 1.)
[Formula 6]

(In Formula 6, P and O are each phosphorus and oxygen; A is a bond or oxygen; Q is oxygen or an unshared electron pair; R ₂₁ , R ₂₂ , R ₂₃ and R ₂₄ are independently hydrogen and 1 to 10 carbon atoms. of a linear or branched alkyl group, alkenyl group, alkynyl group, alkoxy group, alkoxycarbonyl group, alkoxyalkyl group, fluoroalkyl or

is; Optionally, R ₂₁ or R ₂₂ may be independently linked to R ₂₃ or R ₂₄ to form a double bond or a ring; wherein n is an integer from 0 to 3; The * is a bonding position.) According to claim 1,
The electrolyte solution, the electrolyte, characterized in that it comprises 0.1 to 10% by weight of one or more compounds selected from the compounds represented by the formulas 1 to 6 based on the total weight of the electrolyte. According to claim 1,
The at least one compound selected from the compounds represented by Formulas 1 to 6 is an electrolyte solution, characterized in that it is a compound represented by the following Formula 5-52.
[Formula 5-52]

According to claim 1,
The compound represented by the formula (1) is an electrolyte solution, characterized in that at least one selected from the group consisting of compounds represented by the following formulas 1-1 to 1-24.
[Formula 1-1 to 1-24]

(In Formula 1-1, A ₁ and A ₂ are each independently phosphorus or sulfur, and R ₁ ', R ₂ ', R ₃ ', and R ₄ ' are each independently hydrogen, or a substituted or unsubstituted carbon number. an alkyl group of 1 to 10, and m and n are each independently an integer of 1 to 5,
In Chemical Formulas 1-2 to 1-24, a line is a bond, a point where a bond and a bond not describing a separate element meet is carbon, and the number of hydrogens satisfying the valence of the carbon is omitted.) According to claim 1,
The compound represented by Formula 2 is an electrolyte solution that is at least one selected from the group consisting of compounds represented by the following Formulas 2-1 to 2-4.
[Formula 2-1 to 2-4]

(In Chemical Formulas 2-1 to 2-4, a line is a bond, and when a separate element is not described, the point where the bond and the bond meet is carbon, and the number of hydrogens satisfying the valence of the carbon is omitted.) According to claim 1,
The compound represented by Formula 3 is an electrolyte solution, characterized in that at least one selected from the group consisting of compounds represented by the following Formulas 3-1 to 3-2.
[Formula 3-1 to 3-2]

,

(In Formulas 3-1 to 3-2, a line is a bond, and if a separate element is not described, the point where the bond and the bond meet is carbon, and the number of hydrogens satisfying the valence of the carbon is omitted.) According to claim 1,
The compound represented by the formula (4) is an electrolyte solution, characterized in that the compound represented by the following formula (4a).
[Formula 4a]

(In Chemical Formula 4a, a line is a bond, and when a separate element is not described, a point where a bond and a bond meet is carbon, and the number of hydrogens satisfying the valence of the carbon is omitted.) According to claim 1,
The compound represented by Formula 5 is an electrolyte solution, characterized in that at least one selected from the group consisting of compounds represented by Formulas 5-1 to 5-52.
[Formula 5-1 to 5-52]

(In Formulas 5-1 to 5-52, a line is a bond, and when a separate element is not described, the point where the bond and the bond meet is carbon, and the number of hydrogens satisfying the valence of the carbon is omitted.) According to claim 1,
The compound represented by Formula 6 is an electrolyte solution, characterized in that at least one selected from the group consisting of compounds represented by the following Formulas 6-1 to 6-31.
[Formula 6-1 to 6-31]

(In Chemical Formulas 6-1 to 6-31, a line is a bond, and when a separate element is not described, the point where the bond and the bond meet is carbon, and the number of hydrogens satisfying the valence of the carbon is omitted.) According to claim 1,
The at least one compound selected from nitrogen-based, boron-based, monocyclic, polycyclic, and silane-based compounds comprises at least one selected from the group consisting of compounds represented by the following Chemical Formulas 7-1 to 7-22 electrolyte with
[Formula 7-1 to 7-22]

(In Formulas 7-1 to 7-22, a line is a bond, a point where a bond and a bond not describing a separate element meet is carbon, and the number of hydrogens satisfying the valence of carbon is omitted, and TMS is trimethyl It refers to trimethylsilyl.) According to claim 1,
The organic solvent is ethylene carbonate (EC), diethyl carbonate (DEC), ethylmethyl carbonate (EMC), dimethyl carbonate (DMC), propylene carbonate (PC), dipropyl carbonate (DPC), butylene carbonate, methylpropyl carbonate , ethyl propyl carbonate, methyl propionate (MP), ethyl propionate (EP) and propyl propionate (PP) characterized in that it comprises at least one selected from the group consisting of. According to claim 1,
The lithium salt is LiPF ₆ , LiBF ₄ , LiCl, LiBr, LiI, LiClO ₄ , LiB ₁₀ Cl ₁₀ , LiCF ₃ SO ₃ , LiCF ₃ CO ₂ , LiAsF ₆ , LiSbF ₆ , LiAlCl ₄ , CH ₃ SO ₃ Li, CF ₃ SO ₃ Li, (CF ₃ SO ₂ )(C ₂ F ₅ SO ₂ )NLi, (SO ₂ F) ₂ NLi and (CF ₃ SO ₂ ) ₂ NLi(LiFSi) includes at least one selected from the group consisting of Electrolyte, characterized in that. 13. The method of claim 12,
The electrolyte solution additive, characterized in that it comprises 0.6 to 2 mol% of the lithium salt based on 100 mol% of the total. A secondary battery comprising a negative electrode, a positive electrode, and an electrolyte additive, comprising:
The electrolyte solution additive is a secondary battery, characterized in that the electrolyte solution additive of any one of claims 1 to 13. 15. The method of claim 14,
The secondary battery is a lithium secondary battery, characterized in that the battery for automobiles.