KR102167164B1 - Substituted ring-type Isothiazole compounds, non-aqueous solution electrolyte agent comprising thereof and lithium secondary battery comprising the same - Google Patents

Abstract

The present invention relates to a substituted cyclic isothiazole compound, a non-aqueous electrolyte additive including the same, and a lithium secondary battery including the same. When the substituted cyclic isothiazole compound of the present invention is used as an electrolyte additive and a separator coating agent, it forms a solid SEI film on the negative electrode during initial charging of a lithium secondary battery, and prevents decomposition and oxidation of the electrolyte solution on the surface of the positive electrode during a high-temperature cycle. To improve the high temperature cycle characteristics and low temperature output characteristics. The lithium secondary battery including the substituted cyclic isothiazole compound of the present invention can be effectively used for high output such as HEV due to excellent high-temperature cycle characteristics and low-temperature output characteristics.

Description

Substituted ring-type isothiazole compounds, non-aqueous solution electrolyte agent comprising thereof and lithium secondary battery comprising the same}

The present invention relates to a substituted cyclic isothiazole compound, a non-aqueous electrolyte additive including the same, and a lithium secondary battery including the same, and more particularly, to a substituted cyclic isothiazole compound and excellent high temperature cycle characteristics including the same And a non-aqueous electrolyte additive having low-temperature output characteristics and a lithium secondary battery including the same.

The use of portable electronic devices is increasing as it becomes possible to reduce the size and weight of electronic equipment with the recent development of the high-tech electronic industry. As the need for a battery having a high energy density as a power source for such portable electronic devices is increasing, research on a lithium secondary battery is actively progressing. Lithium metal oxide is used as a positive electrode active material of a lithium secondary battery, and lithium metal, a lithium alloy, (crystalline or amorphous) carbon or carbon composite is used as the negative electrode active material. The active material is applied to the current collector with an appropriate thickness and length, or the active material itself is coated in a film shape and wound or stacked together with a separator as an insulator to form an electrode group, and then placed in a can or similar container, and then an electrolyte is injected. Manufacture a secondary battery.

The average discharge voltage of a lithium secondary battery is about 3.6 to 3.7 V, which is higher than that of other alkaline batteries, Ni-MH batteries, and Ni-Cd batteries. However, in order to produce such a high driving voltage, an electrochemically stable electrolyte composition is required in an operating voltage range of 2.5 to 4.2V. For this reason, a mixture of non-aqueous carbonate-based solvents such as ethylene carbonate, dimethyl carbonate, and diethyl carbonate is used as an electrolyte.

Meanwhile, in recent years, as HEV vehicles (Hybrid Electric Vehicles) are in the spotlight as future vehicles, there is a growing demand for a secondary battery having excellent high-temperature cycle characteristics and low-temperature output characteristics to be applied thereto.

In a lithium secondary battery, during initial charging, lithium ions from lithium metal oxide as a positive electrode move to a carbon electrode as a negative electrode and intercalate with carbon. At this time, since lithium is highly reactive, it reacts with the carbon electrode to generate Li ₂ CO ₃ , LiO, LiOH, etc. to form a film on the surface of the negative electrode. Such a film is called a solid electrolyte (SEI) film, and the SEI film formed at the beginning of charging prevents the reaction between lithium ions and a carbon negative electrode or other materials during charging and discharging. In addition, it performs the role of an ion tunnel to pass only lithium ions. This ion tunnel serves to prevent the collapse of the structure of the carbon negative electrode by solvating lithium ions and causing organic solvents of a high molecular weight electrolyte to move together with the carbon negative electrode. Therefore, in order to improve the high-temperature cycle characteristics and low-temperature output of the lithium secondary battery, a solid SEI film must be formed on the negative electrode of the lithium secondary battery.

In addition, lithium secondary batteries generally have a problem in that the surface of the anode is decomposed during high-temperature cycles or oxidation reaction of the electrolyte occurs, resulting in deterioration of high-temperature cycle characteristics, stability, and high-temperature storage characteristics.Therefore, in order to improve the high-temperature cycle characteristics of lithium secondary batteries Decomposition of the anode surface and oxidation reaction of the electrolyte must be prevented during the cycle.

In order to solve this problem, a method of adding compounds capable of forming a protective film, that is, an SEI film on the surface of a negative electrode, has been proposed in a non-aqueous electrolyte. However, while other side effects occur due to the compounds added to the electrolyte, another problem may occur in that the overall performance of the secondary battery is reduced. Therefore, development of a lithium secondary battery containing an additive capable of improving battery performance and stability while minimizing side effects is continuously required.

Japanese Patent Laid-Open Publication No. 2001-256995. US Patent Registration No. 7,033,707. Japanese Patent Laid-Open Publication No. 2003-059529.

In order to solve the above problems, the first technical problem of the present invention is a substituted cyclic isothiazole compound capable of suppressing side effects caused by metal foreign substances inside the battery while forming a stable film on the electrode surface. And it is to provide an additive for a non-aqueous electrolyte containing the same.

A second technical problem of the present invention is to provide a non-aqueous electrolyte for a lithium secondary battery comprising the additive for a non-aqueous electrolyte.

A third technical object of the present invention is to provide a separator comprising a porous polymer substrate and a separator coating agent for a secondary battery coated on at least one surface of the porous substrate.

A fourth technical object of the present invention is to provide a lithium secondary battery comprising the additive for a non-aqueous electrolyte or a separator coating agent for a secondary battery.

In an embodiment of the present invention for achieving the above object, a substituted cyclic isothiazole compound having any one chemical structure selected from the group consisting of the following Chemical Formulas 1 to 3 is provided.

<Formula 1>

<Formula 2>

<Formula 3>

In Chemical Formulas 1 to 3

R ¹ is hydrogen, alkyl, acetyl, acetate, sulfonyl, substituted or unsubstituted C1 to C30 alkyl group, substituted or unsubstituted C2 to C30 alkenyl group, or substituted or unsubstituted C2 to C30 alkynyl group, substituted or unsubstituted A substituted C3 to C30 carbocyclic group, a substituted or unsubstituted C1 to C10 alkoxy group, a substituted or unsubstituted C6 to C30 aryl group, a substituted or unsubstituted C3 to C30 cycloalkenyl group, a substituted or unsubstituted C7 to One of a C20 arylalkyl group, a substituted or unsubstituted C1 to C10 heteroalkyl group, a substituted or unsubstituted C2 to C30 heterocyclic group, or a substituted or unsubstituted C2 to C30 heteroaryl group, or a substitution connected via a sulfone group Or an unsubstituted C1 to C4 alkyl group, a substituted or unsubstituted C1 to C4 alkynyl group, a substituted or unsubstituted C2 to C4 alkenyl group, a substituted or unsubstituted C1 to C4 alkoxy group, a substituted or unsubstituted Aryl group, substituted or unsubstituted heteroayl group, substituted or unsubstituted aryloxy group, substituted or unsubstituted heteroaryloxy group, substituted or unsubstituted C2 to C4 alkenyloxy group, substituted or unsubstituted C2 to C4 alkynyloxy group, or one of a substituted or unsubstituted amino group,

R ² is one of H, CH ₃ , CN, COHNH ₂ and COCF ₃ .

In addition, in one embodiment of the present invention, a substituted cyclic isothiazole compound having any one chemical structure selected from the group consisting of Chemical Formulas 1 to 3 is provided as an electrolyte solution additive for a secondary battery.

In addition, in one embodiment of the present invention, an electrolyte solution additive for a secondary battery; Non-aqueous organic solvent; And it provides a non-aqueous electrolyte for a secondary battery comprising a lithium salt.

In an embodiment of the present invention for achieving the above object, there is provided a separator coating agent for a secondary battery comprising at least one compound among the compounds represented by the following Chemical Formulas 1 to 3.

<Formula 1>

<Formula 2>

<Formula 3>

In Chemical Formulas 1 to 3

R ¹ is hydrogen, alkyl, acetyl, acetate, sulfonyl, substituted or unsubstituted C1 to C30 alkyl group, substituted or unsubstituted C2 to C30 alkenyl group, or substituted or unsubstituted C2 to C30 alkynyl group, substituted or unsubstituted A substituted C3 to C30 carbocyclic group, a substituted or unsubstituted C1 to C10 alkoxy group, a substituted or unsubstituted C6 to C30 aryl group, a substituted or unsubstituted C3 to C30 cycloalkenyl group, a substituted or unsubstituted C7 to One of a C20 arylalkyl group, a substituted or unsubstituted C1 to C10 heteroalkyl group, a substituted or unsubstituted C2 to C30 heterocyclic group, or a substituted or unsubstituted C2 to C30 heteroaryl group, or a substitution connected via a sulfone group Or an unsubstituted C1 to C4 alkyl group, a substituted or unsubstituted C1 to C4 alkynyl group, a substituted or unsubstituted C2 to C4 alkenyl group, a substituted or unsubstituted C1 to C4 alkoxy group, a substituted or unsubstituted Aryl group, substituted or unsubstituted heteroayl group, substituted or unsubstituted aryloxy group, substituted or unsubstituted heteroaryloxy group, substituted or unsubstituted C2 to C4 alkenyloxy group, substituted or unsubstituted C2 to C4 alkynyloxy group, or one of a substituted or unsubstituted amino group,

R ² is one of H, CH ₃ , CN, COHNH ₂ and COCF ₃ .

In addition, an embodiment of the present invention provides a separator for a secondary battery comprising a porous polymer substrate and a separator coating agent for a secondary battery coated on at least one surface of the porous polymer substrate.

In addition, in one embodiment of the present invention, a separator for a secondary battery; Non-aqueous electrolyte; Separator; A positive electrode including a positive electrode active material capable of intercalating and deintercalating lithium; And it provides a lithium secondary battery comprising a negative electrode including a negative active material capable of intercalating and deintercalating lithium.

When the substituted cyclic isothiazole compound of the present invention is used as an electrolyte additive or a separator coating agent, it forms a solid SEI film on the negative electrode during initial charging of a lithium secondary battery, and prevents decomposition and oxidation of the electrolyte solution on the surface of the positive electrode during high-temperature cycles. To improve the high temperature cycle characteristics and low temperature output characteristics.

The lithium secondary battery including the electrolyte additive or the separator coating agent of the present invention can be effectively used for high power such as HEV due to excellent high-temperature cycle characteristics and low-temperature output characteristics.

Hereinafter, the present invention will be described in detail. The terms or words used in this specification and claims should not be construed as being limited to their usual or dictionary meanings, and the inventor may appropriately define the concept of terms in order to describe his own invention in the best way. Based on the principle that the present invention should be interpreted as a meaning and concept consistent with the technical idea of the present invention.

The electrolyte additive or separator coating agent of the present invention is added to the electrolyte of a lithium secondary battery or coated on a separator in order to improve the high-temperature cycle characteristics and low-temperature output characteristics of a lithium secondary battery, and is a conventional vinylene carbonate, propane sultone ( Compared to the addition of additives such as propane sultone) and nitrile-based compounds to the electrolyte, it is structurally stable and has a wide electrochemical potential window, so it is electrochemically stable within the operating voltage range of the battery. In particular, the electrolyte additive or separator coating agent of the present invention helps to form an SEI film. Accordingly, a lithium secondary battery including such a compound has an effect of improving the discharge power of the battery, improving the room temperature lifespan, and improving the high temperature performance by suppressing the oxidation reaction of the electrolyte solution and the decomposition of the anode surface due to a high temperature cycle.

In the present invention, a substituted cyclic isothiazole compound having any one chemical structure selected from the group consisting of the following Chemical Formulas 1 to 3 is provided.

<Formula 1>

<Formula 2>

<Formula 3>

In Chemical Formulas 1 to 3

R ¹ is hydrogen, alkyl, acetyl, acetate, sulfonyl, substituted or unsubstituted C1 to C30 alkyl group, substituted or unsubstituted C2 to C30 alkenyl group, or substituted or unsubstituted C2 to C30 alkynyl group, substituted or unsubstituted A substituted C3 to C30 carbocyclic group, a substituted or unsubstituted C1 to C10 alkoxy group, a substituted or unsubstituted C6 to C30 aryl group, a substituted or unsubstituted C3 to C30 cycloalkenyl group, a substituted or unsubstituted C7 to One of a C20 arylalkyl group, a substituted or unsubstituted C1 to C10 heteroalkyl group, a substituted or unsubstituted C2 to C30 heterocyclic group, or a substituted or unsubstituted C2 to C30 heteroaryl group, or a substitution connected via a sulfone group Or an unsubstituted C1 to C4 alkyl group, a substituted or unsubstituted C1 to C4 alkynyl group, a substituted or unsubstituted C2 to C4 alkenyl group, a substituted or unsubstituted C1 to C4 alkoxy group, a substituted or unsubstituted Aryl group, substituted or unsubstituted heteroayl group, substituted or unsubstituted aryloxy group, substituted or unsubstituted heteroaryloxy group, substituted or unsubstituted C2 to C4 alkenyloxy group, substituted or unsubstituted C2 to C4 alkynyloxy group, or one of a substituted or unsubstituted amino group,

R ² is one of H, CH ₃ , CN, COHNH ₂ and COCF ₃ .

Meanwhile, Formula 1 according to an embodiment of the present invention is a substituted cyclic isothiazolidine, Formula 2 is a substituted cyclic dihydro-isothiazole, and Formula 3 is a substituted ring. It may be named as type isothiazol-3(2H)-one.

In addition, in one embodiment of the present invention, a substituted cyclic isothiazole compound having any one chemical structure selected from the group consisting of Chemical Formulas 1 to 3 is provided as an electrolyte solution additive for a secondary battery.

According to an embodiment of the present invention, Formula 1 is any one selected from the group consisting of compounds represented by the following Formulas 1-a to 1-f,

Formula 2 is any one selected from the group consisting of compounds represented by Formula 2-a to Formula 2-e,

Formula 3 may be any one selected from the group consisting of compounds represented by the following Formula 3-a to Formula 3-e.

<Formula 1-a>

<Formula 1-b>

<Formula 1-c>

<Formula 1-d>

<Formula 1-e>

<Formula 1-f>

<Formula 2-a>

<Formula 2-b>

<Formula 2-c>

<Formula 2-d>

<Formula 2-e>

<Formula 3-a>

<Formula 3-b>

<Formula 3-c>

<Formula 3-d>

<Formula 3-e>

In addition, in the present invention, an electrolyte solution additive for secondary batteries; Non-aqueous organic solvent; And it provides a non-aqueous electrolyte for a secondary battery comprising a lithium salt.

According to one embodiment of the present invention, as the non-aqueous organic solvent, conventional solvents used as non-aqueous organic solvents of lithium secondary batteries such as cyclic carbonate, linear carbonate, ester, ether, or ketone may be used, and these may be used alone. In addition, they can be used interchangeably. Among the organic solvents, in particular, carbonate-based organic solvents may be preferably used, ethylene carbonate (EC), propylene carbonate (PC), and butylene carbonate (BC) as cyclic carbonates, and dimethyl carbonate (DMC) as linear carbonates. , Diethyl carbonate (DEC), dipropyl carbonate (DPC), ethyl methyl carbonate (EMC), methylpropyl carbonate (MPC) and ethylpropyl carbonate (EPC) are representative.

According to an embodiment of the present invention, the lithium salt is LiPF ₆ , LiAsF ₆ , LiCF ₃ SO ₃ , LiN(CF ₃ SO ₂ ) ₂ , LiBF ₄ , LiBF ₆ , LiSbF ₆ , LiN(C ₂ F ₅ SO ₂ ) ₂ , LiAlO ₄ , LiAlCl ₄ , LiSO ₃ CF ₃ and LiClO ₄ Lithium salts commonly used in the electrolyte of a lithium secondary battery may be used without limitation, and these may be used alone or in combination. The content of the electrolyte solution additive is not particularly limited, but is preferably 1 to 6 parts by weight based on 100 parts by weight of the non-aqueous electrolyte. When the content of the electrolyte solution additive is less than 1 part by weight, the effect of the addition of the additive is insignificant, and when it exceeds 6 parts by weight, the internal resistance increases and gas is generated.

In addition, the present invention provides a separator coating agent for a secondary battery comprising at least one compound among the compounds represented by the following Chemical Formulas 1 to 3.

<Formula 1>

<Formula 2>

<Formula 3>

In Chemical Formulas 1 to 3

R ¹ is hydrogen, alkyl, acetyl, acetate, sulfonyl, substituted or unsubstituted C1 to C30 alkyl group, substituted or unsubstituted C2 to C30 alkenyl group, or substituted or unsubstituted C2 to C30 alkynyl group, substituted or unsubstituted A substituted C3 to C30 carbocyclic group, a substituted or unsubstituted C1 to C10 alkoxy group, a substituted or unsubstituted C6 to C30 aryl group, a substituted or unsubstituted C3 to C30 cycloalkenyl group, a substituted or unsubstituted C7 to One of a C20 arylalkyl group, a substituted or unsubstituted C1 to C10 heteroalkyl group, a substituted or unsubstituted C2 to C30 heterocyclic group, or a substituted or unsubstituted C2 to C30 heteroaryl group, or a substitution connected via a sulfone group Or an unsubstituted C1 to C4 alkyl group, a substituted or unsubstituted C1 to C4 alkynyl group, a substituted or unsubstituted C2 to C4 alkenyl group, a substituted or unsubstituted C1 to C4 alkoxy group, a substituted or unsubstituted Aryl group, substituted or unsubstituted heteroayl group, substituted or unsubstituted aryloxy group, substituted or unsubstituted heteroaryloxy group, substituted or unsubstituted C2 to C4 alkenyloxy group, substituted or unsubstituted C2 to C4 alkynyloxy group, or one of a substituted or unsubstituted amino group,

R ² is one of H, CH ₃ , CN, COHNH ₂ and COCF ₃ .

According to an embodiment of the present invention, Formula 1 is any one selected from the group consisting of compounds represented by the following Formulas 1-a to 1-f,

Formula 2 is any one selected from the group consisting of compounds represented by Formula 2-a to Formula 2-e,

Formula 3 may be any one selected from the group consisting of compounds represented by the following Formula 3-a to Formula 3-e.

<Formula 1-a>

<Formula 1-b>

<Formula 1-c>

<Formula 1-d>

<Formula 1-e>

<Formula 1-f>

<Formula 2-a>

<Formula 2-b>

<Formula 2-c>

<Formula 2-d>

<Formula 2-e>

<Formula 3-a>

<Formula 3-b>

<Formula 3-c>

<Formula 3-d>

<Formula 3-e>

In addition, the present invention provides a separator for a secondary battery comprising a porous polymer substrate and a separator coating agent for a secondary battery represented by any one of Chemical Formulas 1 to 3 coated on at least one surface of the porous polymer substrate.

According to one embodiment of the present invention, a known method such as dip-coating and spray coating may be used as a method of applying a coating agent to the separator.

According to an embodiment of the present invention, the porous substrate has a thickness of 5 to 30 μm, a pore size of 0.01 to 50 μm, a porosity of 10 to 90%, and the porous polymer substrate is polyethylene; Polypropylene; Polybutylene; Polypentene; Polyhexene; Polyoctene; One or more copolymers of ethylene, propylene, butene, pentene, 4-methylpentene, hexene, and octene are representative, and these may be used alone or in combination.

According to an embodiment of the present invention, it is preferable that a porous coating layer including at least one particle of inorganic particles and organic particles and a binder polymer is formed on at least one surface of the porous polymer substrate, and ion permeability and short-circuiting by the formation of the porous coating layer There is an effect of improving the stability of the battery against the back.

In addition, in the present invention, a non-aqueous electrolyte for secondary batteries; Separator; A positive electrode including a positive electrode active material capable of intercalating and deintercalating lithium; And it provides a lithium secondary battery comprising a negative electrode including a negative active material capable of intercalating and deintercalating lithium.

According to one embodiment of the present invention, as the positive and negative active materials, conventional active materials used as positive and negative active materials of lithium secondary batteries may be used without limitation, and as a representative negative active material, crystalline carbon, amorphous carbon, or carbon composite A carbon-based negative active material such as may be used alone or in combination, and lithium metal oxide may be used as the positive active material. Among the lithium metal oxides, lithium-manganese-based oxides containing manganese, lithium-nickel-manganese-based oxides, lithium-manganese-cobalt-based oxides, lithium-nickel-manganese-cobalt-based oxides, and the like may be preferably used.

In addition, the lithium secondary battery of the present invention may be manufactured and used in any of a lithium ion battery, a lithium ion polymer battery, and a lithium polymer battery.

Hereinafter, implementation examples and examples of the present application will be described in detail so that those with general knowledge in the technical field to which the present application pertains can be easily implemented, as shown in the accompanying drawings. In particular, the technical idea of the present invention and its core configuration and operation are not limited by this. In addition, the content of the present invention may be implemented in various different types of equipment, and is not limited to the implementation examples and examples described herein. Therefore, the embodiments described in the present specification are only the most preferred embodiments of the present invention, and do not represent all the technical spirit of the present invention, and various equivalents and modifications that can replace them at the time of application It should be understood that there may be.

< Manufacturing example : Preparation of compounds of formula a to formula c>

The following Formula 1-a to 1-f compounds, which are specific examples of the substituted cyclic isothiazolidine compound of Formula 1 according to an embodiment of the present invention, may be prepared according to Scheme A below, and specific preparation The method is as follows.

<Formula 1-a>

<Formula 1-b>

<Formula 1-c>

<Formula 1-d>

<Formula 1-e>

<Formula 1-f>

<Reaction Scheme A>

S-(3-((( benzyloxy )carbonyl)amino) propyl ) ethanethioate ( 2) of synthesis

Benzyl N-allylcarbamate (1) (13.9 g, 0.069 mol) was dissolved in 70 ml of toluene, and thioacetic acid (15.7 g, 0.21 mol) and AIBN (catalyst amount) were added at room temperature. After adding, reflux for 3 hours. When the reaction is complete, make it weakly basic with a saturated aqueous NaHCO ₃ solution, extracted three times with ethyl acetate (EtOAc), washed with brine, and dried the organic layer with anhydrous magnesium sulfate (MgSO ₄ ) and removed the solvent under reduced pressure, 18.2 g (98%) of thioacetate compound (2) was obtained.

LC/MS [M+H] = 268

Benzyl (3- mercaptopropyl ) carbamate ( 3) of synthesis

Thioacetate compound (2) (18.2 g, 0.068 mol) was dissolved in methanol (MeOH) (100 ml), concentrated hydrochloric acid (conc. HCl) (6.5 ml) was added at room temperature, and then refluxed for 16 hours. When the reaction is complete, make it weakly basic with saturated NaHCO ₃ aqueous solution at 0°C, extract three times with ethyl acetate (EtOAc), wipe with brine, and dry the organic layer with anhydrous magnesium sulfate (MgSO ₄ ) and remove the solvent under reduced pressure. After removal, 12.4 g (81%) of a thiol compound (3) was obtained.

LC/MS [M+H] = 226

(Benzyl (3-( methylthio ) propyl ) carbamate )2 ( 4) of synthesis

Thiol (thiol) compound (3) (12.4 g, 0.055 mol) was dissolved in ethyl acetate (EtOAc) (100 ml) and H ₂ O ₂ aqueous solution (30%, 6.2 g, 0.055 mol) and NaI (0.08 g, 0.55 mol) ) Is added at room temperature and then reacted at the same temperature for 1 hour. When the reaction was completed, saturated Na ₂ S ₂ O ₃ aqueous solution was added, extracted 3 times with ethyl acetate (EtOAc), washed with brine, and the organic layer was dried over anhydrous magnesium sulfate (MgSO ₄ ) and the solvent was removed under reduced pressure. , 9.2 g (75%) of disulfide compound (4) was obtained.

LC/MS [M+H] = 449

Benzyl isothiazolidine -2- carboxylate ( 5) of synthesis

Disulfide compound (4) (2.5 g, 5.6 mmol) was dissolved in CH ₂ Cl ₂ (70 ml), and Br ₂ (0.94 g, 5.85 mmol) and pyridine (6.7 g, 0.085 mol) were dissolved in -78 After slowly adding dropwise at °C, the mixture is reacted at 0 °C for 1 hour. After the reaction was completed, saturated Na ₂ S ₂ O ₃ aqueous solution was added, extracted 3 times with CH ₂ Cl ₂ and washed with brine, and the organic layer was dried over anhydrous sodium sulfate (Na ₂ SO ₄ ) and the solvent was removed under reduced pressure. , 2.5 g (97%) of a sulfenamide compound (5) was obtained.

LC/MS [M+H] = 224

Benzyl (E)-1-( cyanoimino )- 1λ4 - isothiazolidine -2- carboxylate ( 6) of synthesis

Sulfenamide compound (5) (2.57 g, 11.5 mmol) was dissolved in methanol (MeOH) (50 ml) and tBuOCl (1.5 g, 13.8 mmol) and sodium cyanamide (0.88 g, 13.8 mmol) ) Is slowly added dropwise at 0° C., and then reacted at the same temperature for 1 hour. When the reaction was completed, saturated NaHCO ₃ solution was added, extracted three times with ethyl acetate (EtOAc), washed with brine, and the organic layer was dried over anhydrous sodium sulfate (Na ₂ SO ₄ ), and the solvent was removed under reduced pressure, followed by column chromatography. Purified through column chromatography to obtain a sulfilamidine compound (6) 1.5 g (46%).

LC/MS [M+H] = 264

Benzyl 1-( cyanoimino )- 1λ6 - isothiazolidine -2- carboxylate 1-oxide ( 7) of synthesis

Sulfilamidine compound (6) (1.8 g, 6.9 mmol) was dissolved in ethyl acetate (EtOAc) (45 ml) and NaOCl (ca. 10%, 41 g) and Bu ₄ NBr (0.1 g, 0.27 mmol) Was slowly added dropwise at 0° C., and reacted at the same temperature for 1 hour. When the reaction was completed, saturated NaHCO ₃ solution was added, extracted three times with ethyl acetate (EtOAc), washed with brine, and the organic layer was dried over anhydrous sodium sulfate (Na ₂ SO ₄ ), and the solvent was removed under reduced pressure, followed by column chromatography. Purification was carried out through column chromatography to obtain 1.5 g (72%) of a sulfonimidamide compound (7).

LC/MS [M+H] = 280

One- Imino - 1λ6 - isothiazolidine 1-oxide ( 8) of synthesis

Sulfonimide amide (sulfonimidamide) compound (7) (2.5 g, 9.1 mmol) was dissolved in H ₂ SO ₄ aqueous solution (50%, 10 ml), and refluxed at 110° C. for 1 hour. When the reaction is complete, make it weakly basic with saturated aqueous NaHCO ₃ solution at 0 °C, extract 3 times with ethyl acetate (EtOAc), wipe with brine, and dry the organic layer with anhydrous sodium sulfate (Na ₂ SO ₄ ) and use a solvent under reduced pressure. By removing, 0.87 g (80%) of compound (8) of formula a was obtained.

LC/MS [M+H] = 121

One- Imino -2-methyl- 1λ6 - isothiazolidine 1-oxide ( 9) of synthesis

Compound (8) (0.95 g, 7.88 mmol) of formula a was dissolved in THF (30 ml), and DIAD (1.7 g, 7.88 mmol) and PPh ₃ (7.88 mmol) were slowly added dropwise at 0° C. for 16 hours at room temperature. React. When the reaction is complete, make it weakly basic with saturated NaHCO ₃ aqueous solution at 0 °C, extract 3 times with ethyl acetate (EtOAc), wash with brine, and dry the organic layer with anhydrous sodium sulfate (Na ₂ SO ₄ ) and reduce pressure. The solvent was removed under, and purified through column chromatography to obtain 0.7 g (66%) of compound (9) of formula b.

LC/MS [M+H] = 135

2-Methyl-1-( methylimino )- 1λ6 - isothiazolidine 1-oxide ( Of 10) synthesis

Compound (9) (1 g, 7.45 mmol) of formula b, formaldehyde (5 ml), and formic acid (5 ml) were refluxed at 150° C. for 72 hours. When the reaction is complete, make it weakly basic with saturated NaHCO ₃ aqueous solution, extracted three times with ethyl acetate (EtOAc), washed with brine, and then dried the organic layer with anhydrous sodium sulfate (Na ₂ SO ₄ ) and removed the solvent under reduced pressure. , Purified through column chromatography to obtain 0.77 g (70%) of compound (10) of formula c.

LC/MS [M+H] = 149

N-(1- oxido - λ6 - isothiazolidin -One- ylidene ) cyanamide ( 11) of synthesis

*Sulfonimidamide compound (7) (8.5 g, 30.4 mmol), Et ₃ N (3.08 g, 30.4 mmol), Et ₃ Si (10.6 g, 91.3 mmol) and Pd(OAc) ₂ (0.7 g , 3 mmol) is dissolved in CH2Cl2 and stirred at room temperature for 1 hour. When the reaction is complete, make it weakly basic with a saturated aqueous NaHCO ₃ solution, extracted three times with ethyl acetate (EtOAc), washed with brine, and dried the organic layer with anhydrous sodium sulfate (Na ₂ SO ₄ ) and removed the solvent under reduced pressure. , Purified through column chromatography to obtain 2.6 g (59%) of compound (11).

LC/MS [M+H] = 146

N-(2-methyl-1- oxido - λ6 - isothiazolidin -One- ylidene ) cyanamide ( 12) of synthesis

Compound (11) (0.57 g, 3.94 mmol) was dissolved in THF (30 ml), DIAD (1.7 g, 7.88 mmol) and PPh ₃ (7.88 mmol) were slowly added dropwise at 0 °C, and reacted at room temperature for 16 hours. When the reaction is complete, make it weakly basic with saturated NaHCO ₃ aqueous solution at 0 °C, extract 3 times with ethyl acetate (EtOAc), wash with brine, and dry the organic layer with anhydrous sodium sulfate (Na ₂ SO ₄ ) and reduce pressure. The solvent was removed under, and purified through column chromatography to obtain 0.4 g (66%) of compound (12).

LC/MS [M+H] = 160

2,2,2- Trifluoro -N-(2-methyl-1- oxido -1l6- isothiazolidin -1-ylidene)acetamide ( 13) of synthesis

Compound (12) (1 mmol) and TFAA (3 mmol) are dissolved in CH2Cl2 (18 ml) and reacted at room temperature. After confirming that the starting material disappears on TLC, make it weakly basic with a saturated aqueous NaHCO ₃ solution at 0 °C, extract 3 times with ethyl acetate (EtOAc) and wipe with brine, and then wash the organic layer with anhydrous sodium sulfate (Na ₂ SO ₄ ) dried over, the solvent was removed under reduced pressure, and purified by column chromatography to obtain compound (13).

LC/MS [M+H] = 231

One- Imino -2-methyl- λ6 - isothiazolidine 1-oxide ( 14) of synthesis

Compound (13) (1 mmol) and K2CO3 (5 mmol) are dissolved in MeOH (7 ml) and reacted at room temperature. After confirming that the starting material disappears on TLC, make it weakly basic with a saturated aqueous NaHCO ₃ solution at 0 °C, extract 3 times with ethyl acetate (EtOAc) and wipe with brine, and then wash the organic layer with anhydrous sodium sulfate (Na ₂ SO ₄ ) dried over, the solvent was removed under reduced pressure, and purified by column chromatography to obtain compound (14).

LC/MS [M+H] = 135

1-(2-Methyl-1- oxido -1l6- isothiazolidin -One- ylidene )urea ( 15) of synthesis

Compound (11) and TfOH are dissolved in CH3CN, and reacted at room temperature for 18 hours. When the reaction is complete, make it weakly basic with saturated NaHCO ₃ aqueous solution at 0 °C, extract 3 times with ethyl acetate (EtOAc), wipe with brine, and dry the organic layer with anhydrous sodium sulfate (Na ₂ SO ₄ ). The solvent was removed under reduced pressure, and purified through column chromatography to obtain compound (15).

LC/MS [M+H] = 178

A substituted cyclic dihydro-isothiazole of Formula 2 and a substituted cyclic isothiazole-3(2H)-one of Formula 3 according to an embodiment of the present invention (isothiazol-3(2H) -one) The compound of a specific example of the compound may be prepared by the same reaction as in Scheme A with the compound prepared by Scheme B and Scheme C below, and specific Scheme B and Scheme C are as follows.

<Reaction Scheme B>

Using 2,5-dihydroisothiazole (CAS 24919-10-6) as a starting material, except that benzyl isothiazole-2(5H)-carboxylate was synthesized, and in the following chemistry, 2-a to 2 A compound represented by -e was synthesized.

<Formula 2-a>

<Formula 2-b>

<Formula 2-c>

<Formula 2-d>

<Formula 2-e>

<Reaction Scheme C>

Using 3(2H)-Isothiazolone (CAS 1003-07-2) as a starting material, except that benzyl 3-oxoisothiazole-2(3H)-carboxylate was synthesized, Scheme A and the following formulas 3-a to 3- A compound represented by e was synthesized.

<Formula 3-a>

<Formula 3-b>

<Formula 3-c>

<Formula 3-d>

<Formula 3-e>

Various substituents of R ¹ in the cyclic structure of the substituted cyclic isothiazole according to an embodiment of the present invention can be obtained by a conventional amine substitution reaction based on the following scheme D, and the specific scheme D is as follows: Same as

<Reaction Scheme D>

Examples of specific compounds that can be prepared by reactions according to Scheme A to Scheme D according to an embodiment of the present invention are summarized and described in Tables 1 to 3 below. Tables 1 to 3 are specific examples of compounds corresponding to Chemical Formulas 1 to 3, respectively.

<Experimental Example>

Manufacture of anode

LiCoO ₂ (B&M, HVC-16C) as a cathode active material, PVdF (polyvinylidene fluoride) (Kureha, KF9700) as a binder, and carbon black (Denka, FX35) as a conductive material in a ratio of 97.5:1.2:1.3 And NMP as a solvent to prepare a 75% solid content slurry. The prepared slurry was dried on an Al foil having a thickness of 12 μm and coated to a coating amount of 507 mg/25 cm 2, and the porosity was rolled to a level of 19.7% to prepare a positive electrode.

Preparation of cathode

Artificial graphite (Shanshan, QCG-X) as a negative electrode active material, CMC (carboxylmethylcellulose) (Daicel, 2200) as a dispersant, SBR/Acrylate emulsion (Zeon, BM-L301) as a binder, carbon black as a conductive material (Imerys) Graphite & Carbon, Super C65) was mixed in a ratio of 96:1.0:2.5:0.5, and a 40% solid content slurry using water as a solvent was prepared. The prepared slurry was dried on 8 μm thick Cu foil and coated to a coating amount of 256 mg/25 cm 2, and the porosity was rolled to a level of 27.5% to prepare a negative electrode.

Preparation of separator

A polyolefin separator (W Scope, WL11C) having a thickness of 11 μm and a porosity of 40% was prepared.

Preparation of electrolyte

Ethylene carbonate (EC), propylene carbonate (PC), and propylene propionate (PP) were prepared in a volume ratio of 3:1:6 as a solvent, and LiPF6 was added at a concentration of 1.2M as a salt.

In Examples 1 to 12, 0.5 wt% of vinylene carbonate, 3.0 wt% of propane sultone, and 0.2 wt% of each additive were used. In Comparative Example 1, 0.5 wt% of vinylene carbonate and 3.0 wt% of propane sultone were used, and in Comparative Example 2, 0.7 wt% of vinylene carbonate and 3.0 wt% of propane sultone were used.

Battery manufacturing

With the above materials, the cathode/separator/anode/separator are stacked in an 11-layer stack in order, inserted into a pouch (DNP, D-EL30H(3)), inject 6.035g of electrolyte, sealed, and pressurized from the outside of the pouch to prevent detachment. I did. After activation was performed by charging to 65% of the design capacity at a charging rate of 0.2C, the battery was completed through a process of removing gas generated from the battery (degassing).

Dose evaluation

The capacity was measured by charging CC/CV (0.1C, 4.4V, 1/20C cut) and discharging CC (0.1C, 3.0V cut) at room temperature based on the design capacity of 3550mAh.

Resistance property evaluation

Based on the design capacity of 3550mAh, the discharge rate was measured at room temperature by varying the discharge rate of 0.2C and 1.5C, and the resistance characteristics were evaluated as 2.0C capacity compared to 0.2C capacity.

Life characteristics evaluation

CC/CV charging (0.7C, 4.4V, 1/20C cut) and CC discharging (0.7C, 3.0V cut) were repeated 500 times at room temperature, and then the lifespan characteristics were evaluated with the capacity at 500 times compared to the one capacity .

Additive type Additive content
(wt%) Capacity (mAh) Resistance characteristics
(% 2.0C/0.2C) Life characteristics
(% 500th/1st) Example 1 VC+PS+Formula 1a 0.5+3.0+0.2 3552 85.2 91.0 Example 2 VC+PS+Formula 1b 0.5+3.0+0.2 3551 86.3 90.1 Example 3 VC+PS+Formula 1c 0.5+3.0+0.2 3550 84.4 91.3 Example 4 VC+PS+Formula 1d 0.5+3.0+0.2 3551 85.3 89.9 Example 5 VC+PS+Formula 1e 0.5+3.0+0.2 3553 85.6 91.0 Example 6 VC+PS+Formula 1f 0.5+3.0+0.2 3552 85.7 90.9 Example 7 VC+PS+Formula 2a 0.5+3.0+0.2 3550 85.2 90.8 Example 8 VC+PS+Formula 2b 0.5+3.0+0.2 3551 85.1 89.8 Example 9 VC+PS+Formula 2d 0.5+3.0+0.2 3554 85.2 90.1 Example 10 VC + PS + Chemical Formula 3a 0.5+3.0+0.2 3553 85.7 90.5 Example 11 VC + PS + Chemical Formula 3b 0.5+3.0+0.2 3551 85.7 90.3 Example 12 VC+PS+ chemical formula 3d 0.5+3.0+0.2 3550 85.3 90.2 Comparative Example 1 VC+PS 0.5+3.0 3550 80.0 85.2 Comparative Example 2 VC+PS 0.7+3.0 3553 79.4 84.4

VC: vinylene carbonate, PS: propane sultone

As can be seen from Table 4, the additives of Examples 1 to 12 according to an embodiment of the present invention have a battery capacity of almost as compared to Comparative Examples 1 and 2 of vinylene carbonate and propane sultone, which are conventional additives. While the same, it shows more improved results in resistance characteristics and life characteristics.

Claims (20)

delete delete For a secondary battery, characterized in that it is any one selected from the group consisting of compounds represented by the following formulas 1-a to 1-f, formulas 2-a to 2-e, and formulas 3-a to 3-e Electrolyte additive.
<Formula 1-a>

<Formula 1-b>

<Formula 1-c>

<Formula 1-d>

<Formula 1-e>

<Formula 1-f>

<Formula 2-a>

<Formula 2-b>

<Formula 2-c>

<Formula 2-d>

<Formula 2-e>

<Formula 3-a>

<Formula 3-b>

<Formula 3-c>

<Formula 3-d>

<Formula 3-e>

The electrolyte solution additive for secondary batteries according to claim 3;
Non-aqueous organic solvent; And
Non-aqueous electrolyte solution for secondary batteries containing a lithium salt. The method of claim 4,
The non-aqueous organic solvent is one or a mixture of two or more selected from the group consisting of cyclic carbonates, linear carbonates, esters, ethers, and ketones. The method of claim 5,
The cyclic carbonate is a non-aqueous electrolyte for a secondary battery, characterized in that any one single substance or a mixture of two or more selected from the group consisting of ethylene carbonate, propylene carbonate, and butylene carbonate. The method of claim 5,
The linear carbonate is any one selected from the group consisting of dimethyl carbonate, diethyl carbonate, dipropyl carbonate, ethyl methyl carbonate, methyl propyl carbonate and ethyl propyl carbonate. Aqueous electrolyte. The method of claim 4,
The lithium salt is LiPF ₆ , LiAsF ₆ , LiCF ₃ SO ₃ , LiN(CF ₃ SO ₂ ) ₂ , LiBF ₄ , LiBF ₆ , LiSbF ₆ , LiN(C ₂ F ₅ SO ₂ ) ₂ , LiAlO ₄ , LiAlCl ₄ , LiSO ₃ CF ₃ and LiClO ₄ Non-aqueous electrolyte for a secondary battery, characterized in that one or a mixture of two or more selected from the group consisting of. The method of claim 4,
The electrolytic solution additive is added in an amount of 1 to 6 parts by weight based on 100 parts by weight of the non-aqueous electrolytic solution. Non-aqueous electrolyte for a secondary battery according to claim 4;
Separator;
A positive electrode including a positive electrode active material capable of intercalating and deintercalating lithium; And
A lithium secondary battery comprising a negative electrode including a negative active material capable of intercalating and deintercalating lithium. delete For a secondary battery, characterized in that it is any one selected from the group consisting of compounds represented by the following formulas 1-a to 1-f, formulas 2-a to 2-e, and formulas 3-a to 3-e Separator coating agent.
<Formula 1-a>

<Formula 1-b>

<Formula 1-c>

<Formula 1-d>

<Formula 1-e>

<Formula 1-f>

<Formula 2-a>

<Formula 2-b>

<Formula 2-c>

<Formula 2-d>

<Formula 2-e>

<Formula 3-a>

<Formula 3-b>

<Formula 3-c>

<Formula 3-d>

<Formula 3-e>

Porous polymer substrate and
A separator for a secondary battery comprising the separator coating agent for a secondary battery according to claim 12 coated on at least one surface of the porous polymer substrate. The method of claim 13,
The porous polymer substrate has a thickness of 5 to 30 μm, a pore size of 0.01 to 50 μm, and a porosity of 10 to 90%. The method of claim 13,
The porous polymer substrate is polyethylene; Polypropylene; Polybutylene; Polypentene; Polyhexene; Polyoctene; A separator for a secondary battery comprising a copolymer of at least one of ethylene, propylene, butene, pentene, 4-methylpentene, hexene, and octene, or a mixture thereof. The method of claim 13,
A separator for a secondary battery, wherein a porous coating layer including at least one of inorganic particles and organic particles and a binder polymer is formed on at least one surface of the porous polymer substrate. The separator for a secondary battery according to claim 16;
Non-aqueous electrolyte;
A positive electrode including a positive electrode active material capable of intercalating and deintercalating lithium; And
A lithium secondary battery comprising a negative electrode including a negative active material capable of intercalating and deintercalating lithium. The method according to claim 10 or 17,
The negative electrode active material is a lithium secondary battery, characterized in that at least one carbon-based negative active material selected from the group consisting of crystalline carbon, amorphous carbon, and carbon composite. The method according to claim 10 or 17,
The positive electrode active material is any one or more lithium metal oxides selected from the group consisting of lithium-manganese-based oxides, lithium-nickel-manganese-based oxides, lithium-manganese-cobalt-based oxides, and lithium-nickel-manganese-cobalt-based oxides. Lithium secondary battery. The method of claim 19,
The lithium secondary battery is a lithium secondary battery, characterized in that the lithium ion battery or a lithium polymer battery.