WO2021125478A1 - Electrolyte solution additive for secondary battery and electrolyte solution for secondary battery including same - Google Patents

Abstract

The present invention relates to a non-aqueous-electrolyte solution additive for a secondary battery, an electrolyte solution including same, and a secondary battery. By addition of a muconic lactone additive represented by chemical formula 1 to a non-aqueous electrolyte solution for a lithium ion secondary battery, the secondary battery including the non-aqueous electrolyte solution for a secondary battery according to the present invention has the effects of improvement in lifetime efficiency and high-temperature storage characteristic.

Description

Electrolyte additive for secondary battery and electrolyte for secondary battery comprising same

The present invention relates to an electrolyte additive for a secondary battery and an electrolyte for a secondary battery comprising the same, and more particularly, to a muconic lactone compound represented by Formula 1, which is added to a non-aqueous electrolyte for a lithium ion secondary battery to improve lifespan efficiency and It relates to an electrolyte additive for a secondary battery having an effect of improving high-temperature storage characteristics, and an electrolyte for a secondary battery comprising the same.

Recently, portable electronic devices have been widely distributed, and accordingly, these portable electronic devices are becoming thinner, smaller, and lighter. Accordingly, the secondary battery used as the power source is also small, lightweight, and capable of being charged and discharged for a long time, and efforts are being made to improve high-rate characteristics.

Secondary batteries include lead-acid batteries, nickel-cadmium (Ni-Cd) batteries, nickel-hydrogen (Ni-MH) batteries, lithium batteries, etc., depending on the material of the anode or cathode, and the unique characteristics of electrode materials. The potential and energy density are determined by Among them, lithium secondary batteries have high energy density due to the low oxidation/reduction potential and molecular weight of lithium, and thus are widely used as a driving power source for portable electronic devices such as notebook computers, camcorders, or mobile phones. However, a lithium secondary battery is a major problem in the safety degradation of the battery that occurs during continuous charging. One of the causes that can affect the stability of the battery is heat generated by the structural collapse of the positive electrode, and the battery stability according to the principle of operation of the non-aqueous electrolyte secondary battery among the secondary batteries is as follows. That is, the positive electrode active material of the non-aqueous electrolyte secondary battery is made of a lithium-containing metal oxide capable of occluding and releasing lithium and/or lithium ions. Such a positive electrode active material is thermally unstable as a large amount of lithium is released during overcharging. transformed into a structure. In this overcharged state, when the battery temperature reaches a critical temperature due to an external physical shock, for example, exposure to high temperature, oxygen is released from the cathode active material having an unstable structure, and the released oxygen causes an exothermic decomposition reaction with an electrolyte solvent and the like. In particular, since the combustion of the electrolyte solution is further accelerated by oxygen released from the positive electrode, ignition and rupture of the battery due to thermal runaway are caused by such a chain exothermic reaction. In addition, the positive transition metal deposited on the negative electrode acts as a catalyst that promotes the decomposition of the non-aqueous electrolyte, generating gas inside the battery, or interfering with the movement of lithium ions as the SEI layer of the negative electrode proceeds with charge/discharge. Due to the problem, the battery performance and efficiency are significantly reduced.

Therefore, in order to solve the above problems, Japanese Patent Application Laid-Open No. 2013-157305 discloses an electrolyte solution containing a compound having two isocyanate groups, and Korean Patent No. 10-0412522 discloses di-t-butylsilylbis (trifluoromethane sulfonate), trimethylsilylmethanesulfonate, trimethylsilyl benzenesulfonate, trimethylsilyl trifluoromethanesulfonate, triethylsilyl trifluoromethanesulfonate, etc. have been proposed, but still There is a need for research on electrolytes having excellent lifespan characteristics and storage characteristics at high temperatures.

Currently, there is a demand for the development of additives capable of improving the lifespan characteristics and storage characteristics of secondary batteries at high temperatures.

Accordingly, as a result of intensive efforts to solve the above problems, the present inventors confirmed that when the muconic lactone compound of Formula 1 is added to the non-aqueous electrolyte solution, the lifespan and storage characteristics at high temperature can be improved and completed the present invention did it

An object of the present invention is to provide a non-aqueous electrolyte additive for a secondary battery having excellent lifespan and high-temperature storage characteristics, and an electrolyte comprising the same.

Another object of the present invention is to provide a secondary battery having excellent lifespan and high temperature storage characteristics.

In order to achieve the above object, there is provided a muconic lactone compound represented by Formula 1.

[Formula 1]

In Formula 1, R ¹ and R ² are each independently a hydrogen atom, a halogen atom, an alkyl having 1 to 9 carbon atoms, an alkenyl having 2 to 9 carbon atoms, an alkoxy group having 1 to 9 carbon atoms, or an alkylfluoride having 1 to 9 carbon atoms, , R ³ is a heteroatom of oxygen, sulfur, nitrogen or phosphorus.

The present invention also comprises the steps of (a) reacting a compound of Formula 3 with trans-3-hexenedioic acid of Formula 4 with an alkali metal bicarbonate of Formula 4 to obtain a compound of Formula 5; (b) reacting a compound of Formula 5 with a compound of Formula 6 to obtain a compound of Formula 7; (c) reacting a compound of Formula 7 with I ₂ to obtain a compound of Formula 8; and (d) subjecting the compound of Formula 8 to a ring closure reaction to obtain the compound of Formula 2 and silver iodide.

[Formula 2]

[Formula 3]

[Formula 4]

In Formula 4, M is Na or K.

[Formula 5]

[Formula 6]

[Formula 7]

[Formula 8]

The present invention also provides (A) a lithium salt; (B) a non-aqueous organic solvent; And (C) provides a non-aqueous electrolyte for a secondary battery comprising a muconic lactone compound represented by Formula 1.

The present invention also provides a secondary battery comprising a positive electrode, a negative electrode, and the non-aqueous electrolyte.

The non-aqueous electrolyte according to the present invention has an effect of improving lifespan and high-temperature storage characteristics by using a muconic lactone compound additive, which is a compound represented by Formula 1.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In general, the nomenclature used herein is those well known and commonly used in the art.

In the present invention, it was confirmed that the lifespan and high-temperature storage characteristics of the secondary battery were significantly improved by adding the muconic lactone additive, which is a compound represented by Formula 1, to the non-aqueous electrolyte of the secondary battery.

Accordingly, the present invention, in one aspect, relates to a muconic lactone compound represented by the formula (1).

[Formula 1]

In Formula 1, R ¹ and R ² are each independently a hydrogen atom, a halogen atom, an alkyl having 1 to 9 carbon atoms, an alkenyl having 2 to 9 carbon atoms, an alkoxy group having 1 to 9 carbon atoms, or an alkylfluoride having 1 to 9 carbon atoms, , R ³ is a heteroatom of oxygen, sulfur, nitrogen or phosphorus.

In another aspect, the present invention comprises the steps of (a) reacting a compound of Formula 3 with trans-3-hexenedioic acid of Formula 4 with an alkali metal bicarbonate of Formula 4 to obtain a compound of Formula 5; (b) reacting a compound of Formula 5 with a compound of Formula 6 to obtain a compound of Formula 7; (c) reacting a compound of Formula 7 with I ₂ to obtain a compound of Formula 8; and (d) subjecting the compound of Formula 8 to a ring closure reaction to obtain the compound of Formula 2 and silver iodide.

[Formula 2]

[Formula 3]

[Formula 4]

In Formula 4, M is Na or K.

[Formula 5]

[Formula 6]

[Formula 7]

[Formula 8]

The present invention in another aspect (A) a lithium salt; (B) a non-aqueous organic solvent; And (C) relates to a non-aqueous electrolyte solution for a secondary battery comprising a muconic lactone compound represented by the formula (1).

The present invention also relates to a secondary battery comprising a positive electrode, a negative electrode, and the non-aqueous electrolyte.

Hereinafter, the present invention will be described in detail.

mukonic lactone

The compound according to the present invention is a muconic lactone compound represented by Formula 1.

[Formula 1]

In Formula 1, R ¹ and R ² are each independently a hydrogen atom, a halogen atom, an alkyl having 1 to 9 carbon atoms, an alkenyl having 2 to 9 carbon atoms, an alkoxy group having 1 to 9 carbon atoms, or an alkylfluoride having 1 to 9 carbon atoms, , R ³ is a heteroatom of oxygen, sulfur, nitrogen or phosphorus.

The muconic lactone compound of Formula 1 is tetrahydrofuro[3,2-b]furan-2,5-dione (tetrahydrofuro[3,2-b]furan-2,5-dione) to be.

In the present invention, preferably, R ¹ and R ² in Formula 1 are each independently a hydrogen atom, a halogen atom, an alkyl having 1 to 9 carbon atoms, an alkenyl having 2 to 9 carbon atoms, or an alkoxy group having 1 to 9 carbon atoms, R ³ may be oxygen. More preferably, it may be a compound represented by the formula (2).

[Formula 2]

As an embodiment of the present invention, the muconic lactone compound represented by Chemical Formula 2 may be prepared by the following method.

(a) reacting a compound of Formula 3 with trans-3-hexenedioic acid of a compound of Formula 4 with alkali metal bicarbonate to obtain a compound of Formula 5;

(b) reacting a compound of Formula 5 with a compound of Formula 6 to obtain a compound of Formula 7;

(c) reacting a compound of Formula 7 with I ₂ to obtain a compound of Formula 8; and

(d) subjecting the compound of Formula 8 to a ring closure reaction to obtain the compound of Formula 2 and silver iodide.

[Formula 2]

[Formula 3]

[Formula 4]

In Formula 4, M is Na or K.

[Formula 5]

[Formula 6]

[Formula 7]

[Formula 8]

Steps (a) to (d) in the method for preparing the muconic lactone compound represented by Formula 2 of the present invention can be carried out at room temperature and pressure, and is shown in Scheme 1.

[Scheme 1]

The non-aqueous electrolyte for a secondary battery according to the present invention includes (A) a lithium salt; (B) a non-aqueous organic solvent; and (C) a muconic lactone compound represented by Formula 1.

In the present invention, each component contained in the electrolyte solution for a secondary battery will be described in detail.

(A) lithium salt

The electrolyte for a secondary battery according to the present invention contains a lithium salt as a solute of the electrolyte. The lithium salt is not limited, but LiPF ₆ , LiBF ₄ , LiSbF ₆ , LiAsF ₆ , LiClO ₄ , LiN(C ₂ F ₅ SO ₂ ) ₂ , LiN(CF ₃ SO ₂ ) ₂ , CF ₃ SO ₃ Li, LiC(CF ₃ SO ₂ ) _{3 ,} LiCl, LiI, LiSCN, LiB(C ₂ O ₄ ) _{2 ,} LiF ₂ BC ₂ O ₄ , LiPF ₄ (C ₂ O ₄ ), LiPF ₂ (C ₂ O ₄ ) ₂ , It may be one or a mixture of two or more selected from the group consisting of LiP(C ₂ O ₄ ) ₃ and LiPO ₂ F _{2 , preferably lithium hexafluorophosphate (LiPF 6} ). The concentration of the lithium salt is preferably used within the range of 0.1M to 2.0M, more preferably from 0.7M to 1.6M, and when it is less than 0.1M, the conductivity of the electrolyte is lowered so that it is fast between the positive and negative electrodes of the secondary battery. The performance of the electrolyte for transferring ions at a rate is poor, and when it exceeds 2.0M, the viscosity of the electrolyte increases and the mobility of lithium ions is reduced. These lithium salts act as a source of lithium ions in the battery to enable the operation of a basic lithium secondary battery.

(B) non-aqueous organic solvent

The electrolyte for a secondary battery according to the present invention includes a non-aqueous organic solvent. The non-aqueous organic solvent may be a cyclic carbonate, a chain carbonate, or a mixture of a cyclic carbonate and a chain carbonate, and the cyclic carbonate is ethylene carbonate (EC), propylene carbonate, PC), butylene carbonate (butylene carbonate, BC), vinylene carbonate (VC), γ-butyrolactone (γ-butyrolactone) and mixtures thereof It may be one or more carbonates selected from the group consisting of, The chain carbonate is dimethyl carbonate (DMC), diethyl carbonate (DEC), dipropyl carbonate (DPC), methylpropyl carbonate (methylpropyl carbonate, MPC), ethylpropyl carbonate (ethylpropyl carbonate) , EPC), ethylmethyl carbonate (EMC), and may be one or more carbonates selected from the group consisting of mixtures thereof. In the electrolyte solution according to an embodiment of the present invention, when the non-aqueous organic solvent is a mixed solvent of a cyclic carbonate-based solvent and a chain-type carbonate-based solvent, the mixing volume ratio of the chain-type carbonate-based solvent: the cyclic carbonate-based solvent is 1: It may be 1 to 9:1, and preferably, it may be used by mixing in a volume ratio of 1.5:1 to 4:1.

(C) mukonic lactone compound

The compound according to the present invention is a muconic lactone compound represented by Formula 1.

[Formula 1]

In Formula 1, R ¹ and R ² are each independently a hydrogen atom, a halogen atom, an alkyl having 1 to 9 carbon atoms, an alkenyl having 2 to 9 carbon atoms, an alkoxy group having 1 to 9 carbon atoms, or an alkylfluoride having 1 to 9 carbon atoms, , R ³ is a heteroatom of oxygen, sulfur, nitrogen or phosphorus.

The muconic lactone compound of Formula 1 is tetrahydrofuro[3,2-b]furan-2,5-dione (tetrahydrofuro[3,2-b]furan-2,5-dione) to be.

In the present invention, preferably, R ¹ and R ² in Formula 1 are each independently a hydrogen atom, a halogen atom, an alkyl having 1 to 9 carbon atoms, an alkenyl having 2 to 9 carbon atoms, or an alkoxy group having 1 to 9 carbon atoms, R ³ may be oxygen. More preferably, it may be a compound represented by the formula (2).

[Formula 2]

In the present invention, the content of the muconic lactone compound additive represented by Formula 1 is 0.01 to 10% by weight, preferably 0.01 to 5% by weight, more preferably 0.01 to 3% by weight based on the non-aqueous electrolyte. If it is less than 0.01% by weight, there is a problem in that high-temperature battery characteristics are lowered, and when it exceeds 10% by weight, there is a problem in that the ionic conductivity is lowered.

(D) high temperature performance enhancing additives

The electrolyte for a secondary battery according to the present invention includes 1,3-propane sultone, 1-propene 1,3-sultone, and ethylene sulfate ( = 1,3,2-dioxathiolane 2,2-dioxide (1,3,2-dioxathiolane 2,2-dioxide), 1,4-butane sultone, 1,3- 1,3-propanediol cyclic sulfate, [4,4'-bi-(1,3,2-dioxathiolane)] 2,2,2',2'-tetraoxide ([4 ,4'-bi-(1,3,2-dioxathiolane)] 2,2,2',2'-tetraoxide) and 2,4,8,10-tetraoxa-3,9-dithiaspiro [5.5] One or more high-temperature performance enhancing additives selected from the group consisting of undecane (2,4,8,10-tetraoxa-3,9-dithiaspiro[5.5]undecane) may be further included. 1,3-propane sultone, 1-propene 1,3-sultone, ethylene sulfate (= 1,3,2-dioxathiolane 2,2-dioxide), 1,4-butane sultone, 1 used in the present invention ,3-propanediol cyclic sulfate, [4,4'-bi-(1,3,2-dioxathiolane)] 2,2,2',2'-tetraoxide and 2,4,8,10- Tetraoxa-3,9-dithispiro[5.5]undecane has a structure represented by Chemical Formulas 9 to 15, respectively.

[Formula 9]

[Formula 10]

[Formula 11]

[Formula 12]

[Formula 13]

[Formula 14]

[Formula 15]

By adding the high-temperature performance-improving additive as described above, high-temperature performance characteristics can be improved.

In the present invention, the content of the high-temperature performance improving additive may be added in an amount of 0.01 to 10% by weight, preferably 0.01 to 5% by weight, more preferably 0.1 to 3% by weight, and less than 0.01% by weight based on the electrolyte. In this case, there is a problem in that the effect of improving the high temperature performance is weak, and when it exceeds 10 wt%, there is a problem in that the internal resistance of the battery is increased.

(E) power-enhancing additives

The electrolyte for a secondary battery according to the present invention is bis(triethylsilyl) sulfate, bis(trimethylsilyl) sulfate, trimethylsilyl ethenesulfonate, and triethylsilyl. At least one output improving additive selected from the group consisting of ethenesulfonate (triethylsilyl ethenesulfonate) may be further included. Bis(triethylsilyl) sulfate, bis(trimethylsilyl) sulfate, trimethylsilyl ethenesulfonate and triethylsilyl ethenesulfonate used in the present invention have structures represented by Chemical Formulas 16 to 19, respectively.

[Formula 16]

[Formula 17]

[Formula 18]

[Formula 19]

Output characteristics may be improved by adding the above-described output enhancing additive.

In the present invention, the content of the output enhancing additive may be added in an amount of 0.01 to 10% by weight, preferably 0.01 to 5% by weight, more preferably 0.1 to 3% by weight based on the electrolyte, and when it is less than 0.01% by weight There is a problem in that the output improvement effect is weak, and when it exceeds 10% by weight, there is a problem in that the ionic conductivity is lowered and the internal resistance of the battery is increased.

(F) salt type additive

The electrolyte for a secondary battery according to the present invention is lithium difluorophosphate, lithium-bis (oxalato) borate, lithium bis (fluorosulfonyl) imide (lithium bis ( One selected from the group consisting of fluorosulfonyl)imide), lithium difluoro(oxalato)borate, and lithium difluoro bis(oxalato) phosphate. The above additives may be further included. Lithium difluorophosphate, lithium-bis(oxalato)borate, lithium bis(fluorosulfonyl)imide, lithium difluoro(oxalato)borate, lithium difluorobis(oxalato) used in the present invention The phosphates have structures represented by Formulas 20 to 24, respectively.

[Formula 20]

[Formula 21]

[Formula 22]

[Formula 23]

[Formula 24]

By adding the salt-type additive as described above, high-temperature performance and output characteristics can be improved at the same time.

In the present invention, the content of the salt-type additive may be added in an amount of 0.01 to 10% by weight, preferably 0.01 to 5% by weight, more preferably 0.1 to 3% by weight, based on the electrolyte, and when it is less than 0.01% by weight There is a problem in that the effect of improving high temperature performance and output is weak, and when it exceeds 10% by weight, there is a problem in that the ionic conductivity is lowered and the internal resistance of the battery is increased.

The electrolyte of the lithium ion secondary battery of the present invention usually maintains stable characteristics in a temperature range of -20 to 50 °C. The electrolyte solution of the present invention may be applied to a lithium ion secondary battery, a lithium ion polymer battery, and the like.

A positive electrode material for a lithium secondary battery in the present invention include _{LiCoO 2, LiNiO 2, LiMnO 2} , LiMn 2 O 4, or _{LiNi 1 -x- y Co x M y} O 2 (0≤x≤1, 0≤y≤1 , 0≤x+y≤1, M is a lithium metal oxide such as Al, Sr, Mg, La, etc.), and as a negative electrode material, crystalline or amorphous carbon, carbon composite, lithium metal, or lithium alloy use The active material is applied to the current collector of a thin plate with an appropriate thickness and length, or the active material itself is applied in the form of a film and wound or laminated together with a separator, which is an insulator, to make an electrode group, and then placed in a can or similar container, followed by trialkyl A lithium ion secondary battery is prepared by injecting a non-aqueous electrolyte containing silyl sulfate and a phosphite-based stabilizer. As the separator, a resin such as polyethylene or polypropylene may be used.

Hereinafter, the present invention will be described in more detail through examples. These examples are only for illustrating the present invention, and it will be apparent to those skilled in the art that the scope of the present invention is not limited by these examples.

[Example]

Example 1

_{LiNi 0} as a positive electrode active material _{. 8} Co _{0 . 1} Mn _{0 . 1} , polyvinylidene fluoride (PVdF) as a binder, and carbon black as a conductive material were mixed in a weight ratio of 95.6:2.2:2.2, and then dispersed in N-methyl-2-pyrrolidone to prepare a positive electrode slurry. The slurry was coated on an aluminum foil having a thickness of 20 μm, dried and rolled to prepare a positive electrode.

A negative active material slurry was prepared by mixing natural graphite as an anode active material, acetylene black as a conductive material, and polyvinylidene fluoride (PVdF) as a binder in a weight ratio of 85:8:7 and dispersing it in N-methyl-2-pyrrolidone. did. This slurry was coated on a copper foil having a thickness of 15 μm, dried and rolled to prepare a negative electrode.

A thickness of 20 μm between the prepared electrodes Film made of polyethylene (PE) The separator was stacked, wound and compressed to construct a cell using a pouch having a thickness of 6 mm x 35 mm x 60 mm, and the following non-aqueous electrolyte was injected to prepare a lithium secondary battery.

_{1.0M LiPF 6} was added to a non-aqueous organic solvent in which ethylene carbonate (EC) and ethylmethyl carbonate (EMC) were mixed in 3:7 (v/v), and 0.25 wt% of muconic lactone of Formula 2 was added. An electrolyte solution for a secondary battery was prepared.

Example 2

A secondary battery was prepared in the same manner as in Example 1, except that 0.5 wt% was added instead of 0.25 wt% of the muconic lactone of Formula 2 in the electrolyte solution for a secondary battery.

Example 3

A secondary battery was prepared in the same manner as in Example 1, except that 1% by weight of the muconic lactone of Formula 2 was added instead of 0.25% by weight in the electrolyte solution for a secondary battery.

Example 4

A secondary battery was manufactured in the same manner as in Example 1, except that 2 wt% of 1,3-propane sultone was additionally added to the electrolyte solution for a secondary battery.

Example 5

A secondary battery was manufactured in the same manner as in Example 1, except that 2 wt% of 1-propene 1,3-sultone was additionally added to the electrolyte solution for a secondary battery.

Example 6

A secondary battery was manufactured in the same manner as in Example 1, except that 2 wt% of ethylene sulfate (1,3,2-dioxathiolane 2,2-dioxide) was additionally added in the electrolyte solution for a secondary battery.

Example 7

A secondary battery was manufactured in the same manner as in Example 1, except that 2 wt% of 1,4-butane sultone was additionally added to the electrolyte solution for a secondary battery.

Example 8

A secondary battery was manufactured in the same manner as in Example 1, except that 2 wt% of 1,3-propanediol cyclic sulfate was additionally added to the electrolyte solution for a secondary battery.

Example 9

Except for additionally adding 2 wt% of [4,4'-by-(1,3,2-dioxathiolane)] 2,2,2',2'-tetraoxide in the electrolyte solution for secondary batteries of Example 1 and a secondary battery was manufactured in the same manner.

Example 10

A secondary battery was manufactured in the same manner as in Example 1, except that 2,4,8,10-tetraoxa-3,9-dithispiro[5.5]undecane 2 wt% was additionally added in the electrolyte solution for a secondary battery of Example 1 did.

Example 11

A secondary battery was manufactured in the same manner as in Example 1, except that 1 wt% of bis(triethylsilyl) sulfate was additionally added to the electrolyte solution for a secondary battery of Example 1.

Example 12

A secondary battery was manufactured in the same manner as in Example 1, except that 1 wt% of bis(trimethylsilyl) sulfate was additionally added to the electrolyte solution for a secondary battery of Example 1.

Example 13

A secondary battery was manufactured in the same manner as in Example 1, except that 1 wt% of trimethylsilyl ethenesulfonate was additionally added to the electrolyte solution for a secondary battery.

Example 14

A secondary battery was manufactured in the same manner as in Example 1, except that 1 wt% of triethylsilyl ethenesulfonate was additionally added to the electrolyte solution for a secondary battery.

Example 15

A secondary battery was prepared in the same manner as in Example 1, except that 1 wt% of lithium difluorophosphate was additionally added to the electrolyte solution for a secondary battery.

Example 16

A secondary battery was prepared in the same manner as in Example 1, except that 1 wt% of lithium-bis(oxalato)borate was additionally added to the electrolyte solution for a secondary battery of Example 1.

Example 17

A secondary battery was prepared in the same manner as in Example 1, except that 1 wt% of lithium bis(fluorosulfonyl)imide was additionally added to the electrolyte solution for a secondary battery.

Example 18

A secondary battery was manufactured in the same manner as in Example 1, except that 1 wt% of lithium difluoro(oxalato)borate was additionally added to the electrolyte solution for a secondary battery of Example 1.

Example 19

A secondary battery was prepared in the same manner as in Example 1, except that 1 wt% of lithium difluorobis(oxalato)phosphate was additionally added to the electrolyte solution for a secondary battery.

Comparative Example 1

A secondary battery was manufactured in the same manner as in Example 1, except that the muconic lactone of Formula 2 was not added to the electrolyte solution for a secondary battery.

Comparative Example 2

A secondary battery was prepared in the same manner as in Comparative Example 1, except that 0.25 wt% of vinylene carbonate (VC) was additionally added to the electrolyte for a secondary battery.

Comparative Example 3

A secondary battery was manufactured in the same manner as in Comparative Example 1, except that 0.5 wt% of vinylene carbonate was additionally added to the electrolyte for a secondary battery.

Comparative Example 4

A secondary battery was manufactured in the same manner as in Comparative Example 1, except that 1 wt% of vinylene carbonate was additionally added to the electrolyte for secondary battery.

Comparative Example 5

A secondary battery was prepared in the same manner as in Comparative Example 1, except that 1,3-propane sultone 1 wt% was additionally added to the secondary battery electrolyte.

Comparative Example 6

A secondary battery was manufactured in the same manner as in Comparative Example 1, except that 1 wt% of 1-propene 1,3-sultone was additionally added to the electrolyte solution for a secondary battery.

Comparative Example 7

A secondary battery was manufactured in the same manner as in Comparative Example 1, except that 1% by weight of ethylene sulfate (1,3,2-dioxathiolane 2,2-dioxide) was additionally added to the electrolyte solution for a secondary battery.

Comparative Example 8

A secondary battery was manufactured in the same manner as in Comparative Example 1, except that 1,4-butane sultone was additionally added in an amount of 1 wt% in the electrolyte solution for a secondary battery.

Comparative Example 9

A secondary battery was manufactured in the same manner as in Comparative Example 1, except that 1 wt% of 1,3-propanediol cyclic sulfate was additionally added to the electrolyte solution for a secondary battery.

Comparative Example 10

[4,4'-by-(1,3,2-dioxathiolane)] 2,2,2',2'-tetraoxide in the electrolyte for secondary battery of Comparative Example 1 except for additionally adding 1% by weight and a secondary battery was manufactured in the same manner.

Comparative Example 11

[4,4'-by-(1,3,2-dioxathiolane)] 2,2,2',2'-tetraoxide in the electrolyte for secondary battery of Comparative Example 1 except for additionally adding 1% by weight and a secondary battery was manufactured in the same manner.

Comparative Example 12

A secondary battery was manufactured in the same manner as in Comparative Example 1, except that 1 wt% of bis(triethylsilyl) sulfate was additionally added to the electrolyte solution for a secondary battery.

Comparative Example 13

A secondary battery was manufactured in the same manner as in Comparative Example 1, except that 1 wt% of bis(trimethylsilyl) sulfate was additionally added to the electrolyte solution for a secondary battery.

Comparative Example 14

A secondary battery was manufactured in the same manner as in Comparative Example 1, except that 1 wt% of trimethylsilyl ethenesulfonate was additionally added to the electrolyte solution for a secondary battery.

Comparative Example 15

A secondary battery was manufactured in the same manner as in Comparative Example 1, except that 1 wt% of triethylsilyl ethenesulfonate was additionally added to the electrolyte solution for a secondary battery.

Comparative Example 16

A secondary battery was prepared in the same manner as in Comparative Example 1, except that 1 wt% of lithium difluorophosphate was additionally added to the electrolyte solution for a secondary battery.

Comparative Example 17

A secondary battery was prepared in the same manner as in Comparative Example 1, except that 1 wt% of lithium-bis(oxalato)borate was additionally added to the electrolyte solution for a secondary battery.

Comparative Example 18

A secondary battery was manufactured in the same manner as in Comparative Example 1, except that 1 wt% of lithium bis(fluorosulfonyl)imide was additionally added to the electrolyte solution for a secondary battery.

Comparative Example 19

A secondary battery was prepared in the same manner as in Comparative Example 1, except that 1 wt % of lithium difluoro (oxalato) borate was additionally added to the electrolyte solution for a secondary battery.

Comparative Example 20

A secondary battery was prepared in the same manner as in Comparative Example 1, except that 1 wt% of lithium difluorobis(oxalato)phosphate was additionally added to the electrolyte solution for a secondary battery.

The electrolyte compositions of Examples 1 to 19 and Comparative Examples 1 to 20 are shown in Table 1.

Comparative Example/Example	Electrolyte composition (100wt%)
Comparative Example 1	Ref. One)
Comparative Example 2	Ref.+ VC 2) 0.25wt%
Comparative Example 3	Ref.+ VC 2) 0.5wt%
Comparative Example 4	Ref.+ VC 2) 1wt%
Comparative Example 5	Ref.+ A-1 3) 2wt%
Comparative Example 6	Ref.+ A-2 4) 2wt%
Comparative Example 7	Ref.+ A-3 5) 2wt%
Comparative Example 8	Ref.+ A-4 6) 2wt%
Comparative Example 9	Ref.+ A-5 7) 2wt%
Comparative Example 10	Ref.+ A-6 8) 2wt%
Comparative Example 11	Ref.+ A-7 9) 2wt%
Comparative Example 12	Ref.+ B-1 10) 1wt%
Comparative Example 13	Ref.+ B-2 11) 1wt%
Comparative Example 14	Ref.+ B-3 12) 1wt%
Comparative Example 15	Ref.+ B-4 13) 1wt%
Comparative Example 16	Ref.+ C-1 14) 1wt%
Comparative Example 17	Ref.+ C-2 15) 1wt%
Comparative Example 18	Ref.+ C-3 16) 1wt%
Comparative Example 19	Ref.+ C-4 17) 1wt%
Comparative Example 20	Ref.+ C-5 18) 1wt%
Example 1	Ref.+ Mu conic lactone 0.25wt%
Example 2	Ref.+ Mu conic lactone 0.5wt%
Example 3	Ref.+ Mu conic lactone 1wt%
Example 4	Ref.+ Mu conic lactone 0.25wt% + A-1 3) 2wt%
Example 5	Ref.+ Mu conic lactone 0.25wt% + A-2 4) 2wt%
Example 6	Ref.+ Mu conic lactone 0.25wt% + A-3 5) 2wt%
Example 7	Ref.+ Mu conic lactone 0.25wt% + A-4 6) 2wt%
Example 8	Ref.+ Mu conic lactone 0.25wt% + A-5 7) 2wt%
Example 9	Ref.+ Mu conic lactone 0.25wt% + A-6 8) 2wt%
Example 10	Ref.+ Mu conic lactone 0.25wt% + A-7 9) 2wt%
Example 11	Ref.+ Mu conic lactone 0.25wt% + B-1 10) 1wt%
Example 12	Ref.+ Mu conic lactone 0.25wt% + B-2 11) 1wt%
Example 13	Ref.+ Mu conic lactone 0.25wt% + B-3 12) 1wt%
Example 14	Ref.+ Mu conic lactone 0.25wt% + B-4 13) 1wt%
Example 15	Ref.+ Mu conic lactone 0.25wt% + C-1 14) 1wt%
Example 16	Ref.+ Mu conic lactone 0.25wt% + C-2 15) 1wt%
Example 17	Ref.+ Mu conic lactone 0.25wt% + C-3 16) 1wt%
Example 18	Ref.+ Mu conic lactone 0.25wt% + C-4 17) 1wt%
Example 19	Ref.+ Mu conic lactone 0.25wt% + C-5 18) 1wt%

1) * Note Ref.: 1.0M LiPF ₆ , EC/EMC=3/7 (v/v)

2) VC: vinyl carbonate

3) A-1: 1,3-propane sultone (1,3-propane sultone)

4) A-2: 1-propene 1,3-sultone (1-propene 1,3-sultone)

5) A-3: ethylene sulfate (1,3,2-dioxathiolane 2,2-dioxide)

6) A-4: 1,4-butane sultone (1,4-butane sultone)

7) A-5: 1,3-propanediol cyclic sulfate

8) A-6: [4,4'-bi-(1,3,2-dioxathiolane)] 2,2,2',2'-tetraoxide ([4,4'-bi-(1, 3,2-dioxathiolane)] 2,2,2',2'-tetraoxide)

9) A-7: 2,4,8,10-tetraoxa-3,9-dithiaspiro[5.5]undecane (2,4,8,10-tetraoxa-3,9-dithiaspiro[5.5]undecane)

10) B-1: bis (triethylsilyl) sulfate

11) B-2: bis (trimethylsilyl) sulfate

12) B-3: trimethylsilyl ethenesulfonate

13) B-4: triethylsilyl ethenesulfonate

14) C-1: lithium difluorophosphate

15) C-2: lithium-bis(oxalato)borate

16) C-3: lithium bis(fluorosulfonyl)imide

17) C-4: lithium difluoro (oxalato) borate

18) C-5: lithium difluoro bis(oxalato) phosphate

[Evaluation of physical properties]

1. Life evaluation

The prepared battery was charged at 1C to 4.2V and then discharged at 1C to 3V, and this process was repeated 500 times to measure the lifespan maintenance rate. Life retention was evaluated at room temperature (25°C) and high temperature (45°C).

2. High temperature storage evaluation

1) Cell thickness: After charging at 1C to 4.2V and storing at high temperature (70°C) for 7 days, the cell thickness was measured and expressed as a percentage of the initial thickness.

2) EIS: After charging at 1C to 4.2V, applying an AC signal of 10mV, changing the voltage frequency to 90000~0.05Hz, measuring the initial EIS (Electrochemical impedance spectroscopy), charging at 1C to 4.2V, and then charging at high temperature (70℃) for 7 days After storage, 1C charge to 4.2V, 1C discharge twice, and high temperature (70°C) storage in the same manner as the initial EIS measurement method, the EIS was measured and the percentage compared to the initial EIS was indicated.

3) DC-IR: After charging the prepared battery at 1C to 4.2V, discharging it to SOC50, and then discharging each of the four C-rates for 10 seconds to measure the initial direct current resistance (DC-IR), charge it to 4.2V at 1C and then high temperature Store at (70℃) for 7 days, then charge 1C to 4.2V, discharge 1C twice, store at high temperature (70℃) in the same way as the initial DC resistance measurement method, and measure DC-IR. DC-IR contrast is expressed as a percentage.

4) Retention capacity and recovery capacity (discharge capacity) were measured and expressed as a percentage compared to the initial discharge capacity.

Table 2 shows the cell thickness change rate, impedance increase rate, capacity retention rate, capacity recovery rate, room temperature cycle, high temperature cycle performance evaluation and charge/discharge efficiency of Examples and Comparative Examples.

	4.2V, 25℃ Cycle test	4.2V, 45℃ Cycle test	High temperature storage evaluation (70℃, 1 week)
			Cell thickness	EIS	DC-IR	retention capacity	Recovery capacity
Examples/Comparative Examples	Life Efficiency (%, 500cyc)	Life Efficiency (%, 500cyc)	rate of change (%)	rate of change (%)	rate of change (%)	Capacity retention rate (%)	Capacity recovery rate (%)
Comparative Example 1	68.4	35.4	35.1	140.5	130.2	64.2	68.7
Comparative Example 2	70.1	40.2	34.2	138.3	126.1	68.4	70.2
Comparative Example 3	72.4	43.7	32.5	134.8	112.4	70.5	71.5
Comparative Example 4	75.9	49.8	30.7	130.9	105.2	72.4	74.1
Comparative Example 5	61.3	22.7	12.7	127.7	126.7	67.2	72.7
Comparative Example 6	59.7	20.5	18.4	146.7	130.4	58.9	67.5
Comparative Example 7	63.7	30.3	13.50	151.50	124.7	66.9	72.1
Comparative Example 8	59.4	28.7	14.3	141.1	127.3	64.2	69.4
Comparative Example 9	60.8	31.2	12.5	132.3	125.3	65.8	70.8
Comparative Example 10	65.3	50.8	15.6	95.8	89.7	70.8	80.2
Comparative Example 11	73.7	62.1	13.3	60.5	52.7	79.9	86.4
Comparative Example 12	71.6	28.7	23.4	70.4	54.6	74.1	82.6
Comparative Example 13	72.1	30.1	24.6	81.6	58.1	72.4	81.6
Comparative Example 14	74.8	36.9	19.6	56.8	50.1	82.4	88.2
Comparative Example 15	73.8	31.8	21.4	62.1	52.4	79.1	86.2
Comparative Example 16	75.1	36.8	17.0	56.6	48.4	83.1	90.2
Comparative Example 17	72.0	28.6	22.8	85.7	70.5	73.9	82.4
Comparative Example 18	72.6	30.2	19.6	73.2	66.5	75.2	84.6
Comparative Example 19	73.2	32.5	17.9	60.4	53.1	80.1	89.6
Comparative Example 20	75.7	37.2	16.7	56.4	50.7	83.4	91.8
Example 1	80.1	68.8	24.3	101.7	91.6	75.6	77.4
Example 2	77.5	64.9	26.3	105.6	96.8	74.6	76.6
Example 3	76.1	60.4	28.1	110.6	98.3	73.4	75.1
Example 4	85.5	72.8	4.2	82.5	81.1	85.6	91.3
Example 5	82.5	60.2	11.3	90.7	87.8	78.7	84.3
Example 6	87.1	77.6	8.4	93.1	90.9	83.7	90.5
Example 7	81.4	74.3	9.2	87.3	86.4	81.6	87.8
Example 8	88.3	76.5	6.1	74.5	70.6	82.3	89.4
Example 9	86.4	79.5	10.70	62.60	53.8	79.7	88.4
Example 10	92.8	85.6	5.1	34.0	21.9	89.7	93.5
Example 11	87.7	81.1	14.2	50.4	34.6	84.5	89.1
Example 12	93.1	78.4	17.2	58.4	33.4	81.5	86.4
Example 13	95.0	87.4	9.0	26.8	19.8	88.4	95.1
Example 14	93.2	86.0	10.5	34.8	23.4	87.1	94.2
Example 15	95.2	87.9	7.8	27.4	20.1	90.9	97.7
Example 16	83.4	78.5	15.7	60.2	53.2	80.5	86.7
Example 17	87.8	80.2	12.9	52.8	40.6	83.9	90.4
Example 18	93.4	86.1	10.7	34.4	22.4	90.4	97.8
Example 19	95.6	88.2	7.3	24.6	19.8	91.8	98.1

As shown in Table 2, it was confirmed that the electrolyte solution of Examples of the present invention has improved high temperature life even after storage at a high temperature (70° C.) compared to Comparative Examples, and the EIS is reduced, so that high temperature storage characteristics are significantly improved.

The embodiment of the present invention has an effect of improving high temperature storage characteristics, high temperature lifespan characteristics, and high rate characteristics.

Compared to Comparative Examples 1 and 2 to 4, the electrolyte of Example 1 in which 0.25% by weight of muconic lactone was added showed excellent performance in life evaluation, and as in Examples 4 to 19, high-temperature performance-improving additives and output-improving additives were used. In addition, the battery performance was further improved.

Examples 4 to 10, in which the high-temperature performance-improving additive was additionally added, have more suppressed cell swelling after storage at a high temperature than in Example 1. Examples 11 to 14, in which the output performance improving additive was additionally added, improved output as well as EIS and DC-IR resistance after high-temperature storage compared to Example 1. In addition, Examples 15 to 19, in which a salt-type additive that improves both high temperature and output performance were additionally added, suppressed cell swelling after storage at a higher temperature than Example 1 and had excellent output performance. In addition, life efficiency and capacity retention and recovery rate after high temperature storage are also improved.

As the specific parts of the present invention have been described in detail above, it will be apparent to those of ordinary skill in the art that these specific descriptions are only preferred embodiments, and the scope of the present invention is not limited thereby. will be. Accordingly, it is intended that the substantial scope of the invention be defined by the claims and their equivalents.

Claims (15)

1. Muconic lactone compound represented by Formula 1:

   [Formula 1]

   

   In Formula 1, R ¹ and R ² are each independently a hydrogen atom, a halogen atom, an alkyl having 1 to 9 carbon atoms, an alkenyl having 2 to 9 carbon atoms, an alkoxy group having 1 to 9 carbon atoms, or an alkylfluoride having 1 to 9 carbon atoms, , R ³ is a heteroatom of oxygen, sulfur, nitrogen or phosphorus.
2. The method according to claim 1, wherein R ¹ and R ² are each independently a hydrogen atom, a halogen atom, an alkyl having 1 to 9 carbon atoms, an alkenyl having 2 to 9 carbon atoms, or an alkoxy group having 1 to 9 carbon atoms, and R ³ is oxygen Muconic lactone compound, characterized in that.
3. According to claim 2, wherein the muconic lactone compound represented by Formula 2:

   [Formula 2]

   

   .
4. A method for preparing a muconic lactone compound comprising the steps of:

   (a) reacting a compound of Formula 3 with trans-3-hexenedioic acid of a compound of Formula 4 with alkali metal bicarbonate to obtain a compound of Formula 5;

   (b) reacting a compound of Formula 5 with a compound of Formula 6 to obtain a compound of Formula 7;

   (c) reacting a compound of Formula 7 with I ₂ to obtain a compound of Formula 8; and

   (d) subjecting the compound of Formula 8 to a ring closure reaction to obtain the compound of Formula 2 and silver iodide.

   [Formula 2]

   

   [Formula 3]

   

   [Formula 4]

   

   In Formula 4, M is Na or K.

   [Formula 5]

   

   [Formula 6]

   

   [Formula 7]

   

   [Formula 8]

   
5. A non-aqueous electrolyte for a secondary battery comprising:

   (A) lithium salts;

   (B) a non-aqueous organic solvent; and

   (C) a muconic lactone compound represented by Formula 1.

   [Formula 1]

   

   In Formula 1, R ¹ and R ² are each independently a hydrogen atom, a halogen atom, an alkyl having 1 to 9 carbon atoms, an alkenyl having 2 to 9 carbon atoms, an alkoxy group having 1 to 9 carbon atoms, or an alkylfluoride having 1 to 9 carbon atoms; , R ³ is a heteroatom of oxygen, sulfur, nitrogen or phosphorus.
6. 6. The method of claim 5, wherein R ¹ and R ² are each independently a hydrogen atom, a halogen atom, an alkyl having 1 to 9 carbon atoms, an alkenyl having 2 to 9 carbon atoms, or an alkoxy group having 1 to 9 carbon atoms, and R ³ is oxygen Non-aqueous electrolyte for secondary batteries, characterized in that
7. The non-aqueous electrolyte for a secondary battery according to claim 5, wherein the muconic lactone compound is represented by Chemical Formula 2:

   [Formula 2]

   

   .
8. According to claim 5, wherein the lithium salt is LiPF ₆ , LiBF ₄ , LiSbF ₆ , LiAsF ₆ , LiClO ₄ , LiN(C ₂ F ₅ SO ₂ ) ₂ , LiN(CF ₃ SO ₂ ) ₂ , CF ₃ SO ₃ Li and LiC(CF ₃ SO ₂ ) ₃ .
9. The non-aqueous electrolyte for a secondary battery according to claim 5, wherein the non-aqueous organic solvent is a cyclic carbonate, a chain carbonate, or a mixture of a cyclic carbonate and a chain carbonate.
10. 10. The method of claim 9, wherein the cyclic carbonate is at least one carbonate selected from the group consisting of ethylene carbonate, propylene carbonate, butylene carbonate, vinylene carbonate, γ-butyrolactone and mixtures thereof, and the chain carbonate is dimethyl A non-aqueous electrolyte for a secondary battery, characterized in that at least one carbonate selected from the group consisting of carbonate, diethyl carbonate, dipropyl carbonate, methylpropyl carbonate, ethylpropyl carbonate, ethylmethyl carbonate, and mixtures thereof.
11. The non-aqueous electrolyte for a secondary battery according to claim 5, wherein the content of the muconic lactone compound is 0.01 to 10% by weight based on the non-aqueous electrolyte.
12. According to claim 5, 1,3-propane sultone (1,3-propane sultone), 1-propene 1,3-sultone (1-propene 1,3-sultone), 1,3,2-dioxathiolane 2,2-dioxide (1,3,2-dioxathiolane 2,2-dioxide), 1,4-butane sultone, 1,3-propanediol cyclic sulfate (1,3-propanediol) cyclic sulfate), [4,4'-bi-(1,3,2-dioxathiolane)] 2,2,2',2'-tetraoxide ([4,4'-bi-(1,3, 2-dioxathiolane)] 2,2,2',2'-tetraoxide) and 2,4,8,10-tetraoxa-3,9-dithispiro[5.5]undecane (2,4,8,10- tetraoxa-3,9-dithiaspiro[5.5]undecane), a non-aqueous electrolyte for a secondary battery further comprising one or more high-temperature performance-improving additives selected from the group consisting of.
13. 6. The method of claim 5, wherein bis(triethylsilyl) sulfate, bis(trimethylsilyl) sulfate, trimethylsilyl ethenesulfonate and triethylsilyl ethenesulfonate A non-aqueous electrolyte for a secondary battery further comprising at least one output enhancing additive selected from the group consisting of triethylsilyl ethenesulfonate.
14. According to claim 5, lithium difluorophosphate (lithium difluorophosphate), lithium-bis (oxalato) borate (lithium-bis (oxalato) borate), lithium bis (fluorosulfonyl) imide (lithium bis (fluorosulfonyl) imide), lithium difluoro (oxalato) borate, lithium difluoro bis (oxalato) phosphate) at least one additive selected from the group consisting of A non-aqueous electrolyte for a secondary battery further comprising a.
15. A secondary battery comprising a positive electrode, a negative electrode, and the non-aqueous electrolyte of any one of claims 5 to 14.