KR20190007904A - Novel bicyclic boron derivatives compounds, method for preparing the same and electrolyte for secondary battery comprising the same - Google Patents

Abstract

The present invention relates to a novel bicyclic boron derivative compound, a method for preparing the same, an electrolyte addition agent for a secondary battery comprising the same, and an electrolyte. According to the present invention, the electrolyte addition agent for a secondary battery can improve output characteristics of a battery, storage characteristics at high temperature, and high voltage characteristics to secure an enough current amount required for rapid acceleration start when being used for an electric vehicle. Moreover, performance of a battery is maintained for a long period of time at high temperature, and further, an excellent capacity maintaining rate is provided in high voltage compared to operating voltage of a conventional battery to improve a capacity in each unit volume which the battery has. Therefore, the electrolyte addition agent can be helpfully used in a secondary battery for an electric vehicle.

Description

TECHNICAL FIELD [0001] The present invention relates to a novel bicyclic boron derivative compound, a process for producing the same, and an electrolyte for a secondary battery comprising the same. BACKGROUND ART [0002]

The present invention relates to a novel bicyclic boron derivative compound, a process for producing the same, an electrolyte additive for a secondary battery comprising the same, and an electrolyte solution.

In recent decades, mankind has actively pursued research on next-generation transportation methods through alternative energy sources to prevent environmental pollution.

In particular, secondary batteries using lithium ions have been used as power sources for smart phones and small electronic devices as an electric energy source capable of charging and discharging. Furthermore, the development of an electric vehicle using a large amount of small secondary batteries or a middle- or large-sized secondary battery as a main power source has attracted attention as a next-generation transportation means to replace petroleum fuel.

In recent years, demand for electric vehicles has been continuously increasing worldwide. Efforts are being made to establish social systems, device infrastructure, new policies, and unify usage standards. In addition, research and investment on battery technology are continuously being carried out, and research and development on autonomous vehicles and electric buses based on secondary batteries have become active.

As mentioned above, secondary batteries have various uses such as electric vehicles, smart phones, and small electronic devices, and various battery characteristics are required depending on kinds of products, sizes, and usage conditions.

Particularly, in the case of an electric vehicle using a secondary battery, it is a greatest challenge to reach a desired traveling speed in a short time and to enable long-distance operation by charging once. However, there remains a problem of developing a high capacity battery capable of maintaining the performance of an automobile battery at a low temperature and a high temperature according to a driving environment, and discharging for a long time by a single charge.

In the field of secondary battery research, research on secondary battery additives and / or secondary battery electrolytes to improve storage characteristics at a high temperature, that is, improvement of capacity retention rate and capacity of a battery per unit volume is being continued.

For example, WO2015 / 065093 and European Patent No. 2,211,401 disclose an electrolyte comprising a fluoroborate (or phosphate) derivative comprising lithium oxalate phosphate (or borate) or a sulphone or sulfate structure . Furthermore, U.S. Published Patent Application No. 2015-0037690 discloses a high capacity characteristic of a battery using an electrolyte solution containing lithium oxalato borate and a difluoroborate salt, and improvement of high voltage stability of the anode. In addition, U.S. Patent No. 6,783,896 discloses that various derivatives of lithium borate are incorporated in an electrolyte solution to improve heat resistance and electrolyte hydrolysis resistance, and to improve lifetime characteristics, thereby increasing battery shelf life. In addition, WO2010 / 137571 discloses that when an additive containing lithium oxalate phosphate or a cyclic sulfate structure is added to an electrolytic solution to keep the battery at a high temperature, the resistance inside the battery is prevented from increasing when the battery is used at a low temperature Thereby improving the output of the battery. In addition, WO2015 / 093885 discloses a secondary battery comprising a boron derivative structure having a cyclic boron derivative structure, which is capable of maintaining the charge / discharge speed and lifetime characteristics, while maintaining capacity retention characteristics at high temperature and low temperature, It is possible to improve swelling. Korean Patent Laid-Open Publication No. 2014-0142556 discloses structures having a diborane structure, and discloses that a secondary battery electrolyte containing the same has excellent high-temperature stability, low-temperature discharge capacity, and long life characteristics.

However, the rechargeable battery technology has not yet sufficiently implemented the stable performance required by consumers for extreme situations or sudden environmental changes. In particular, it has a disadvantage in that it can not fully manifest the characteristics of a secondary battery as a main power source of an automobile in the field of electric automobile industry where high output characteristics and stable capacity maintenance characteristics at high temperature are required. Therefore, it is essential to develop a secondary battery electrolyte capable of maintaining excellent performance in high output characteristics, storage characteristics, and high voltage characteristics under any extreme conditions and / or rapidly changing environmental conditions.

Accordingly, the present inventors have continued to carry out studies to improve the output characteristics, storage characteristics, and high-voltage characteristics of the secondary battery to develop additives that can improve the characteristics of the secondary battery and apply it to an electrolyte for a secondary battery Thereby completing the invention.

WO2015 / 065093 European Patent No. 2,211,401 U.S. Published Patent Application No. 2015-0037690 U.S. Patent No. 6,783,896 WO2010 / 137571 WO2015 / 093885 Korean Patent Publication No. 2014-0142556

Accordingly, an object of the present invention is to provide a novel dibasic boron derivative compound contained in an electrolyte solution for a secondary battery to improve the output characteristics of the battery, a method for producing the same, an electrolyte additive for a secondary battery comprising the same, and an electrolyte solution.

In order to achieve the above object, the present invention provides a compound having the structure of the following formula:

[Chemical Formula 1]

In Formula 1,

Q and A are each independently selected from the group consisting of carbonyl, glyoxal, thionyl, sulfuryl, difluoroboron, tetrafluorophosphorane, hydroxyboron or hydroxyphosphonyl,

Wherein the hydroxyl group of the hydroxyboron and the hydroxyphosphonyl is selected from the group consisting of C _1-10 alkyl, C _1-10 alkoxy, C _6-10 aryl, C _6-10 aryloxy, C _2-10 alkenyl, C _1-3 (O) OR ₁ , -C (O) R ₂ , -Si (R ₃ ) ₃ , -SO ₃ H, trifluoroalkyl, hydrogen or a halogen atom,

Wherein R ₁ , R ₂ and R ₃ are each independently selected from the group consisting of C _1-6 alkyl, C _6-10 aryl, C _1-6 alkoxy, acetyloxy, mono-haloacetyloxy, di- ≪ / RTI > oxy, and the like.

Further, in order to accomplish the above other objects, the present invention provides a process for producing a polyimide film comprising at least one selected from the group consisting of oxalic acid, sulfur dioxide, concentrated sulfuric acid, and dimethyl carbonate; And a step of reacting tetrakis (dimethylamino) diboron in a solvent of hexane or toluene.

According to another aspect of the present invention, there is provided an electrolyte solution for a secondary battery comprising an electrolyte additive for a secondary battery represented by Formula 1, a non-aqueous solvent, and a lithium salt.

In order to achieve the above-mentioned further object, the present invention provides a secondary battery comprising the electrolyte for the secondary battery.

The electrolyte additive for a secondary battery comprising the compound according to the present invention can improve the output characteristics of the battery, the storage characteristics at high temperature and the high voltage characteristics, and when the battery is used in an electric vehicle battery, sufficient amount of current can do. Further, since the capacity per unit volume of the battery can be improved by maintaining the performance of the battery for a long time at a high temperature as well as having an excellent capacity retention ratio at a voltage higher than the operating voltage of the existing battery, the battery can be advantageously used for an electric vehicle secondary battery have.

Hereinafter, the present invention will be described in detail.

The present invention provides compounds having the structure of Formula 1:

[Chemical Formula 1]

In Formula 1,

Q and A are each independently selected from the group consisting of carbonyl, glyoxal, thionyl, sulfuryl, difluoroboron, tetrafluorophosphorane, hydroxyboron or hydroxyphosphonyl,

Wherein the hydroxyl group of the hydroxyboron and the hydroxyphosphonyl is selected from the group consisting of C _1-10 alkyl, C _1-10 alkoxy, C _6-10 aryl, C _6-10 aryloxy, C _2-10 alkenyl, C _1-3 (O) OR ₁ , -C (O) R ₂ , -Si (R ₃ ) ₃ , -SO ₃ H, trifluoroalkyl, hydrogen or a halogen atom,

Wherein R ₁ , R ₂ and R ₃ are each independently selected from the group consisting of C _1-6 alkyl, C _6-10 aryl, C _1-6 alkoxy, acetyloxy, mono-haloacetyloxy, di- ≪ / RTI > oxy, and the like.

,

,

,

,

,

,

,

,

또는

일 수 있다. Specifically, the compound having the structure of Formula 1 may be a bicyclic boron derivative, Q and A are each independently

,

,

,

,

,

,

,

,

or

Lt; / RTI >

,

,

,

,

,

,

,

,

또는

일 수 있으나, 이에 한정되는 것은 아니다.More specifically, Q and A may be equal to each other. More specifically, in Formula 1,

,

,

,

,

,

,

,

,

or

But is not limited thereto.

The present invention includes at least one selected from the group consisting of oxalic acid, sulfur dioxide, concentrated sulfuric acid, and dimethyl carbonate; And a step of reacting tetrakis (dimethylamino) diboron in a solvent of hexane or toluene.

Specifically, the compound of formula (1) may be prepared by a process comprising the following steps (1) to (4).

Step of the above production method (1) hexane or toluene solvent, oxalic acid, sulfur dioxide, concentrated sulfuric acid, or dimethyl carbonate, and tetrakis (dimethylamino) mixed to react the diboron, a temperature under a N ₂ environment, (2) 40 Maintaining the temperature at the temperature of the step (2) for 24 hours, and then lowering the temperature to room temperature; and (4) subjecting the solvent to distillation under reduced pressure , Followed by recrystallization from dichloromethane and hexane and vacuum drying.

Furthermore, the present invention can provide an electrolyte additive for a secondary battery having the structure of Formula 1 above.

The electrolyte additive for a secondary battery comprising the bicyclic boron derivative of Formula 1 can improve the output characteristics, high-temperature storage characteristics, and high-voltage characteristics of a battery, particularly a secondary battery.

Also, the present invention provides an electrolyte solution for a secondary battery comprising an electrolyte additive for a secondary battery represented by Formula 1, a non-aqueous solvent, and a lithium salt.

The electrolyte additive for the secondary battery represented by Formula 1 is as described above.

It is preferable that the non-aqueous solvent has a high solubility in the lithium salt and the electrolyte additive. For example, propyl propionate, ethylene carbonate, propylene carbonate, ethylmethyl carbonate, dimethyl carbonate, gamma-butyrolactone, butyrolactone, diethyl carbonate, etc. may be used singly or in combination. Specifically, linear carbonates such as ethyl methyl carbonate, dimethyl carbonate, and diethyl carbonate; And cyclic carbonates such as propylene carbonate and ethylene carbonate; Or a mixture of propionate-based solvents such as propyl propionate can be used.

The non-aqueous solvent is desirably dehydrated, and specifically, the moisture concentration in the non-aqueous solvent may be 300 ppm or less. If the moisture concentration of the nonaqueous solvent is within the above range, the electrolyte salt can be prevented from being decomposed to optimize the performance of the electrolyte. Hydrolysis of the electrolyte additive for the secondary battery can also be prevented.

The lithium salt is used for improving the ion conductivity of the electrolytic solution. For example, the lithium salt may be used alone or in combination of _two or more of LiClO ₄ , LiCF ₃ SO ₃ , LiPF ₆ , LiBF ₄ , LiFSi, LiTFSi, LiAsF ₆ , LiN (CF ₃ SO ₂ ) Or may be used in combination.

The concentration (content) of the lithium salt in the electrolytic solution may be 0.3 M to 10.0 M (mol / liter), specifically 0.7 M to 2.5 M. By including the lithium salt in the above content range, the lithium ion conductivity of the electrolytic solution can be improved to an appropriate level.

The electrolyte additive may be added in an amount of 0.01 to 30 wt%, 0.01 to 20 wt%, 0.01 to 15 wt%, 0.01 to 10 wt%, 0.04 to 20 wt%, 0.04 to 15 wt%, 0.04 to 10 wt% 0.05 to 10% by weight, 0.01 to 6% by weight, 0.05 to 6% by weight, 0.05 to 3% by weight, 0.04 to 1.2% by weight or 0.8 to 1.2% by weight. By including the additive in the above content range, the resistance can be suppressed and the output characteristics can be improved, and the storage characteristics of the secondary battery including the electrolyte can be suitably maintained. In addition, it is possible to secure the effect of improving the high-voltage characteristics of the electrolytic solution, and also it is possible to reduce the solubility of the additive in the electrolytic solution, thereby reducing the manufacturing cost of the secondary battery.

The electrolyte for a secondary battery of the present invention can be produced by mixing and stirring a non-aqueous solvent, a lithium salt, and an electrolyte additive for the secondary battery.

The electrolyte for the secondary battery may further include additives as long as it can improve the output characteristics, storage characteristics and the like of the secondary battery. Examples of the electrolyte include lithium difluoro (oxalato) borate (LiDFOB), lithium bis Lithium bis (oxalato) borate, LiB (C ₂ O ₄ ) ₂ , LiBOB), fluoro ethylene carbonate (FEC), vinylene carbonate (VC), vinyl ethylene carbonate ethylene carbonate (VEC), divinyl sulfone, ethylene sulfite, propylene sulfite, diallyl sulfonate, ethane sultone, propane sulphonate, butane sultone, ethene sultone, ethylene sulfate, butene sulton, lithium difluorophosphate (LiDFP), lithium Selected from the group consisting of lithium difluoro bis (oxalato) phosphate (LiDFOP), lithium tetrafluoro oxalato phosphate (LiTFOP), and propene sultone (PRS) And may further comprise at least one additive.

The secondary battery battery of the present invention can be manufactured by injecting the above-described electrolyte for a secondary battery of the present invention into an electrode assembly including a cathode, a cathode and a separator therebetween. The secondary battery of the present invention includes all kinds of secondary batteries, and specifically, it may be a lithium ion battery, a lithium ion polymer battery, or a lithium polymer battery.

The positive electrode includes a positive electrode active material capable of reversibly intercalating and deintercalating lithium ions. Examples of the positive electrode active material include at least one selected from the group consisting of cobalt, manganese, iron, aluminum and nickel; Or a lithium composite metal oxide may be used. The employment ratio between the metals can be varied and the elements selected from the group consisting of K, Na, Ca, Sn, V, Ge, Ga, B, As, Zr, Cr, Sr, V and rare- .

The negative electrode includes a negative electrode active material capable of intercalating and deintercalating lithium ions. Examples of the negative electrode active material include crystalline or amorphous carbon; Carbon composite anode active material (thermally decomposed carbon, coke, graphite); Burned organic polymer compounds; Carbon fiber; Tin oxide compounds; Lithium metal; Or a lithium alloy may be used. Examples of the amorphous carbon include hard carbon, coke, mesocarbon microbead (MCMB) calcined at 1,500 ° C or lower, and mesophase pitch-based carbon fiber (MPCF). have. Examples of the crystalline carbon include graphite-based materials, and specific examples thereof include natural graphite, artificial graphite, graphitized coke, graphitized MCMB, and graphitized MPCF. Among the lithium alloys, silicon, titanium, zinc, bismuth, cadmium, antimony, lead, tin, gallium or indium may be used as other elements constituting the alloy with lithium. The separation membrane is a polyolefin-based polymer membrane such as polypropylene or polyethylene or a multiple membrane thereof for preventing a short circuit between the anode and the cathode. Microporous film; web; And a nonwoven fabric may be used.

The electrolyte additive for a secondary battery of the present invention can improve the output characteristics of a battery, storage characteristics at high temperatures and high voltage characteristics, and when used in a battery for an electric vehicle, sufficient amount of current can be secured at the time of rapid acceleration. In addition, not only the performance of the battery is maintained for a long time at a high temperature but also the excellent capacity retention ratio is maintained at a voltage higher than the operating voltage of the conventional battery, thereby improving the capacity per unit volume of the battery. have.

Hereinafter, the present invention will be described in more detail by way of specific examples and comparative examples. The following examples are intended to further illustrate the present invention and are not intended to limit the scope of the present invention.

[ Synthetic example ]

Synthetic example  One. Morbid type  Preparation of boron ester (compound of formula 2)

3.6 g of oxalic acid (40 mmol) and 3.96 g of tetrakis (dimethylamino) diboron (20 mmol) were dissolved in 20 ml of hexane using a 100 ml round bottom flask, the temperature was raised to 50 ℃ under a N ₂ environment. After the reaction was carried out at 50 ° C for 24 hours, the temperature was lowered to room temperature. The solvent was removed by distillation under reduced pressure, and recrystallization from dichloromethane and hexane yielded 2.1 g of a compound represented by the following formula (2) (bicyclic boron ester).

 (2)

Synthetic example  2. Morbid type  Preparation of boron ester (compound of formula 3)

3.6 g of dimethyl carbonate (40 mmol) and 3.96 g of tetrakis (dimethylamino) diboron (20 mmol) were dissolved in 40 ml of toluene using a 100 ml round bottom flask, the temperature was raised to 50 ℃ under a N ₂ environment. After the reaction was carried out at 50 DEG C for 24 hours, toluene was removed by distillation under reduced pressure and vacuum drying was conducted to obtain 2.3 g of a compound represented by the following formula (3) (bicyclic boron ester).

(3)

Synthetic example  3. Morbid type  Boron The sulfonate (compound of formula 4)  Produce

(H ₂ SO ₃ ,> 6% 40 mmol) and 3.96 g of tetrakis (dimethylamino) diboron were added to 20 ml of hexane using a 100 ml round bottom flask , 20 mmol) were dissolved, and the temperature was raised to 50 캜 under an N ₂ environment. After the reaction was carried out at 50 ° C for 24 hours, the temperature was lowered to room temperature. The solvent was removed by distillation under reduced pressure, and the residue was recrystallized from dichloromethane and hexane to obtain 1.3 g of a compound represented by the following formula (4) (bicyclic boron sulfonate).

[Chemical Formula 4]

Synthetic example  4. Morbid type  Boron The sulfonate (compound of formula 5)  Produce

(H ₂ SO ₄ ,> 98% of 40 mmol) and 3.96 g of tetrakis (dimethylamino) diboron were added to 20 ml of hexane using a 100 ml round bottom flask, 20 mmol) was dissolved, and the temperature was raised to 50 캜 under an N ₂ environment. After the reaction was carried out at 50 ° C for 24 hours, the temperature was lowered to room temperature. The solvent was removed by distillation under reduced pressure, and the residue was recrystallized from dichloromethane and hexane to obtain 1.8 g of a compound represented by the following formula (5) (bicyclic boron sulfonate).

[Chemical Formula 5]

[ Example ]

Example  One

43 g of ethylene carbonate, 59 g of ethylmethyl carbonate and 38 g of diethyl carbonate were mixed to prepare a mixed solution, and 15.2 g of LiPF ₆ was added to the mixed solution to prepare a 1.0 M LiPF ₆ electrolytic solution. Then, the electrolyte solution was added with the dibasic boron ester prepared in Synthesis Example 1 in an amount of 0.05% by weight based on the total weight of the electrolytic solution to prepare an electrolyte solution for a secondary battery.

Example  2

An electrolyte for a secondary battery was prepared in the same manner as in Example 1, except that the bicyclic boron ester prepared in Synthesis Example 1 was added in an amount of 1 wt% based on the total amount of the electrolytic solution.

Example  3

An electrolyte for a secondary battery was prepared in the same manner as in Example 1, except that the bicyclic boron ester prepared in Synthesis Example 1 was added in an amount of 3% by weight based on the total amount of the electrolytic solution.

Example  4

An electrolytic solution for a secondary battery was prepared in the same manner as in Example 1, except that the bicyclic boron ester prepared in Synthesis Example 1 was added in an amount of 6% by weight based on the total amount of the electrolytic solution.

Example  5

An electrolytic solution for a secondary battery was prepared in the same manner as in Example 1 except that the bicyclic boron ester prepared in Synthesis Example 1 was added in an amount of 9 wt% based on the total amount of the electrolytic solution.

Example  6

Except that the dibasic boron ester (compound of formula (III)) prepared in Synthesis Example 2 was used instead of the compound of formula (2) prepared in Synthesis Example 1, To prepare an electrolyte for a secondary battery.

Example  7

An electrolyte for a secondary battery was prepared in the same manner as in Example 6, except that the bicyclic boron ester prepared in Synthesis Example 2 was added in an amount of 1% by weight based on the total amount of the electrolytic solution.

Example  8

An electrolyte for a secondary battery was prepared in the same manner as in Example 6 except that the bicyclic boron ester prepared in Synthesis Example 2 was added in an amount of 3% by weight based on the total amount of the electrolytic solution.

Example  9

An electrolyte for a secondary battery was prepared in the same manner as in Example 6, except that the bicyclic boron ester prepared in Synthesis Example 2 was added in an amount of 6% by weight based on the total amount of the electrolytic solution.

Example  10

An electrolyte for a secondary battery was prepared in the same manner as in Example 6, except that the bicyclic boron ester prepared in Synthesis Example 2 was added in an amount of 9 wt% based on the total amount of the electrolytic solution.

Example  11

Except that the dibasic boron sulfonate (compound of formula (IV)) prepared in Synthesis Example 3 was used instead of the dibasic boron ester (compound of Formula 2) prepared in Synthesis Example 1, To prepare an electrolyte solution for a secondary battery.

Example  12

An electrolytic solution for a secondary battery was prepared in the same manner as in Example 11, except that the bicyclic sulfonate prepared in Synthesis Example 3 was added in an amount of 1% by weight based on the total amount of the electrolytic solution.

Example  13

An electrolytic solution for a secondary battery was prepared in the same manner as in Example 11 except that the bicyclic sulfonic acid sulfonate prepared in Synthesis Example 3 was added in an amount of 3% by weight based on the total amount of the electrolytic solution.

Example  14

An electrolytic solution for a secondary battery was prepared in the same manner as in Example 11 except that the bicyclic sulfonic acid sulfonate prepared in Synthesis Example 3 was added in an amount of 6% by weight based on the total amount of the electrolytic solution.

Example  15

An electrolytic solution for a secondary battery was prepared in the same manner as in Example 11 except that the bicyclic sulfonic acid sulfonate prepared in Synthesis Example 3 was added in an amount of 9% by weight based on the total amount of the electrolytic solution.

Example  16

The same procedure as in Example 16 was carried out except that the dibasic boron sulfonate (compound of the formula 5) prepared in the above Synthesis Example 4 was used instead of the dibasic boron ester (the compound of the formula 2) prepared in the above Synthesis Example 1 To prepare an electrolyte solution for a secondary battery.

Example  17.

An electrolyte for a secondary battery was prepared in the same manner as in Example 16, except that the bicyclic sulfonic acid sulfonate prepared in Synthesis Example 4 was added in an amount of 1% by weight based on the total amount of the electrolytic solution.

Example  18.

An electrolyte for a secondary battery was prepared in the same manner as in Example 16, except that the bicyclic sulfonic acid sulfonate prepared in Synthesis Example 4 was added in an amount of 3% by weight based on the total amount of the electrolytic solution.

Example  19.

An electrolyte for a secondary battery was prepared in the same manner as in Example 16, except that the bicyclic sulfonate prepared in Synthesis Example 4 was added in an amount of 6% by weight based on the total amount of the electrolytic solution.

Example  20.

An electrolytic solution for a secondary battery was prepared in the same manner as in Example 16 except that the bicyclic sulfonic acid sulfonate prepared in Synthesis Example 4 was added in an amount of 9% by weight based on the total amount of the electrolytic solution.

Comparative Example  One.

An electrolyte solution for a secondary battery was prepared in the same manner as in Example 1, except that the electrolyte additive was not added.

Comparative Example  2.

An electrolyte for a secondary battery was prepared in the same manner as in Example 1 except that lithium difluorophosphate was added in an amount of 0.2% by weight based on the total amount of the electrolytic solution instead of the electrolyte additive represented by the formula 2, 3, 4 or 5 .

Comparative Example  3.

Except that lithium bis oxalate borate was added in an amount of 1 wt% based on the total amount of the electrolytic solution instead of the electrolyte additive represented by the formula 2, 3, 4, or 5, to prepare an electrolyte for a secondary battery Respectively.

[ Experimental Example ]

Experimental Example  1. Impedance Measurement of Secondary Battery

A 1.3Ah pouch battery was assembled by using a cathode material in which LiNi ₅ Co ₂ Mn ₃ and LiMnO ₂ were mixed as a cathode active material in a ratio of 1: 1 (weight ratio) and an anode material using artificial graphite as an anode active material, 6 g of the electrolyte solution for each of the secondary batteries of Examples 1 to 20 and Comparative Examples 1 to 3 was injected to complete the secondary battery. Then, the impedance obtained when discharging at 3 C (C-rate) for 10 seconds while maintaining the 60% charged state voltage of the 1.3Ah pouch battery at 25 ° C was compared with that of the PNE-0505 charge / discharge device : PNE solution Co., Ltd.). After measuring the impedance of the battery, the discharge impedances of the batteries were measured in the same manner as described above after being stored for 7 days and 14 days in a 60 ° C oven. The results are shown in Table 1 below.

Impedance (mΩ) 25 ℃ (initial) After 7 days of storage at 60 ° C After 14 days of storage at 60 ° C Example 1 29 42 50 Example 2 29 36 43 Example 3 29 37 46 Example 4 30 41 48 Example 5 31 42 50 Example 6 29 41 49 Example 7 28 34 42 Example 8 29 37 47 Example 9 29 43 50 Example 10 30 44 51 Example 11 31 40 48 Example 12 30 38 42 Example 13 33 40 45 Example 14 32 49 50 Example 15 35 50 53 Example 16 33 42 49 Example 17 33 38 44 Example 18 34 40 47 Example 19 35 49 50 Example 20 36 50 51 Comparative Example 1 40 59 75 Comparative Example 2 39 47 62 Comparative Example 3 39 44 58

As shown in Table 1, in the case of the battery using the electrolyte for the secondary battery of Examples 1 to 20 including the additive of the present invention, the impedance at the time of storage after storage at a high temperature (60 ° C) Most of them are small. From this, it can be seen that the secondary battery including the electrolyte additive of the present invention improved the output characteristics of the battery due to the low resistance characteristics of the interface between the electrode and the electrolyte during the discharge process.

Experimental Example  2. Evaluation of high-temperature storage characteristics (capacity preservation characteristics) of secondary batteries

The secondary battery (1.3Ah pouch battery), which had been subjected to the cellization process in the same manner as in Experimental Example 1, was charged with 0.5 C and 4.2 V in a 65 ° C chamber in a fully charged state and discharged at 5 C and 2.7 V, respectively. After that, the discharge capacity at 500 times of charging / discharging with respect to the initial capacity was measured with a PNE-0505 charge / discharge device (manufactured by PNE Co., Ltd.). The results are shown in Table 2 below.

Relative discharge capacity (%) in high temperature cycle Early(%) Charging / discharging 500th discharge capacity (% from initial) Example 1 100 85 Example 2 100 98 Example 3 100 95 Example 4 100 93 Example 5 100 90 Example 6 100 85 Example 7 100 98 Example 8 100 95 Example 9 100 93 Example 10 100 91 Example 11 100 87 Example 12 100 98 Example 13 100 96 Example 14 100 91 Example 15 100 90 Example 16 100 83 Example 17 100 93 Example 18 100 90 Example 19 100 85 Example 20 100 82 Comparative Example 1 100 80 Comparative Example 2 100 83 Comparative Example 3 100 92

As shown in Table 2, in the batteries using the secondary battery electrolyte of Examples 1 to 20 including the additive of the present invention, it was confirmed that the discharge capacity in the high-temperature cycle was mostly excellent as compared with Comparative Examples 1 to 3 . From this, it can be seen that the secondary battery including the electrolyte additive of the present invention reduces the electrochemical deterioration reaction occurring during charging and discharging of the battery at a high temperature and maintains the ion conductivity of the electrolyte for a long time at a high temperature. It can be understood that a stable charge / discharge capacity can be realized.

Experimental Example  3. Evaluation of high voltage (4.4V) characteristics of secondary battery

A 1.3 Ah pouch battery was assembled by a conventional method using a cathode material using LiCoO ₂ as a cathode active material and an anode material using artificial graphite as a cathode active material, and the electrolyte for a secondary battery of Examples 1 to 20 and Comparative Examples 1 to 3 Were injected into the secondary battery to complete the secondary battery. Thereafter, the rechargeable battery (1.3Ah pouch battery) which had been subjected to the cellization process was charged and discharged at a rate of 0.5 C charged at 4.4 V and at 0.5 C discharged at 2.7 V in a 60 ° C chamber under full charge. The discharge capacity at 500 charge / discharge cycles with respect to the initial capacity was measured with a PNE-0505 charge / discharge device (manufactured by PNE Co., Ltd.), and the ratios are shown in Table 2 below. After that, the discharge capacity at 500 times of charging / discharging with respect to the initial capacity was measured with a PNE-0505 charge / discharge device (manufactured by PNE Co., Ltd.). The results are shown in Table 3 below.

Relative discharge amount in high voltage cycle (%) Early(%) Discharge and discharge 500th discharge amount (% of initial) Example 1 100 84 Example 2 100 96 Example 3 100 92 Example 4 100 90 Example 5 100 89 Example 6 100 84 Example 7 100 95 Example 8 100 92 Example 9 100 90 Example 10 100 85 Example 11 100 85 Example 12 100 94 Example 13 100 90 Example 14 100 85 Example 15 100 93 Example 16 100 80 Example 17 100 89 Example 18 100 83 Example 19 100 82 Example 20 100 80 Comparative Example 1 100 65 Comparative Example 2 100 70 Comparative Example 3 100 88

As shown in Table 3, in the case of the battery using the electrolyte for the secondary battery of Examples 1 to 20 including the additive of the present invention, as compared with Comparative Examples 1 to 3, the discharge capacity in the high voltage cycle was 80% And it showed stable capacity recovery. This is because by adding the electrolyte additive of the present invention to the electrolyte solution, it is possible to prevent corrosion phenomenon of the anode material occurring when the battery is charged and discharged at a high voltage, thereby maintaining the capacity characteristics of the battery for a long time under high voltage conditions, So that it can be expected to make long distance travel possible. Thus, it can be confirmed that the use of the additive of the present invention realizes a stable charge / discharge capacity even after a long charge / discharge cycle at a high voltage.

Claims (8)

1. A compound having the structure of Formula 1:
[Chemical Formula 1]

In Formula 1,
Q and A are each independently
Carbonyl, glyoxal, thionyl, sulfuryl, difluoroboron, tetrafluorophosphorane, hydroxyboron or hydroxyphosphonyl,
Wherein the hydroxyl group of the hydroxyboron and the hydroxyphosphonyl is selected from the group consisting of C _1-10 alkyl, C _1-10 alkoxy, C _6-10 aryl, C _6-10 aryloxy, C _2-10 alkenyl, C _1-3 (O) OR ₁ , -C (O) R ₂ , -Si (R ₃ ) ₃ , -SO ₃ H, trifluoroalkyl, hydrogen or a halogen atom,
Wherein R ₁ , R ₂ and R ₃ are each independently selected from the group consisting of C _1-6 alkyl, C _6-10 aryl, C _1-6 alkoxy, acetyloxy, mono-haloacetyloxy, di- ≪ / RTI > oxy, and the like. The method according to claim 1,
Q and A are each independently

,

,

,

,

,

,

,

,

or

Lt; / RTI > The method according to claim 1,
The compound having the structure of the above formula (1)

,

,

,

,

,

,

,

,

or

Lt; / RTI > At least one selected from the group consisting of oxalic acid, sulfur dioxide, concentrated sulfuric acid, and dimethyl carbonate; And tetrakis (dimethylamino) diboron in a solvent of hexane or toluene.
[Chemical Formula 1]

An electrolyte additive for a secondary battery represented by Formula 1 below;
Non-aqueous solvent; And
Electrolyte for secondary battery comprising lithium salt:
[Chemical Formula 1]

In Formula 1,
Q and A are each independently
Carbonyl, glyoxal, thionyl, sulfuryl, difluoroboron, tetrafluorophosphorane, hydroxyboron or hydroxyphosphonyl,
Wherein the hydroxyl group of the hydroxyboron and the hydroxyphosphonyl is selected from the group consisting of C _1-10 alkyl, C _1-10 alkoxy, C _6-10 aryl, C _6-10 aryloxy, C _2-10 alkenyl, C _1-3 (O) OR ₁ , -C (O) R ₂ , -Si (R ₃ ) ₃ , -SO ₃ H, trifluoroalkyl, hydrogen or a halogen atom,
Wherein R ₁ , R ₂ and R ₃ are each independently selected from the group consisting of C _1-6 alkyl, C _6-10 aryl, C _1-6 alkoxy, acetyloxy, mono-haloacetyloxy, di- ≪ / RTI > oxy, and the like. 6. The method of claim 5,
Wherein the additive is contained in an amount of 0.01 to 30% by weight based on the total amount of the electrolyte for a secondary battery. 6. The method of claim 5,
Wherein the electrolyte for the secondary battery is selected from the group consisting of lithium difluoro (oxalato) borate, lithium bis (oxalato) borate, fluoro ethylene carbonate, vinylene carbonate carbonate, vinyl ethylene carbonate, divinyl sulfone, ethylene sulfite, propylene sulfite, diallyl sulfonate, ethane sultone, Propane sultone, butane sultone, ethene sultone, ethylene sulfate, butene sulton, lithium difluorophosphate, lithium difluoroacetate, Lithium difluoro bis (oxalato) phosphate, lithium tetrafluoro oxalato phosphate and lithium tetrafluorooxalate phosphate. And at least one selected from the group consisting of propene sultone. A lithium secondary battery comprising an electrolyte solution for a secondary battery according to any one of claims 5 to 7.