Phosphazene derivatives, compositions and their use in electrochemical devices

Abstract

To provide an electrolyte additive with high electrochemical stability, a low addition amount, and an ability to improve safety of a lithium-ion battery in a good cycle state, without an increase in complexity of a production process.SOLUTION: The present disclosure provides a phosphazene derivative of the structure in formula (I), and an additive comprising the phosphazene derivative.SELECTED DRAWING: Figure 1A

Description

Technical Field

[0001] The present invention relates to a composition used in an electrochemical device, and particularly to a phosphazene derivative group-based additive in a composition applied to an electrochemical device.

Background Art

[0002] Currently, in equipment and devices such as electronics, energy storage, biomedicine, and electric vehicles, lithium batteries are widely applied. Therefore, the batteries used correspondingly are desired to have high energy density, high safety, and the advantages of maintaining high power storage and high discharge capacity even after long-term use. Therefore, lithium-ion batteries that meet these characteristic requirements are gradually attracting attention in the relevant academic and industrial circles.

[0003] Lithium-ion batteries have advantages such as light weight, high energy density, excellent cycle characteristics, and high output, and are gradually applied to high-output products such as power tools and electric vehicles. Based on the considerations of safety and cost required for the battery as the power source of an electric vehicle, the selection of solid electrolytes, colloidal electrolytes, and flame-retardant electrolytes has become the focus of improving the safety of lithium-ion batteries. However, although solid / colloidal electrolyte materials can solve the risk of electrolyte leakage, the impedance of their interface layer is still a problem to be solved in all fields, and it is not a product technology that can be commercialized in a short time. Therefore, the selection of an appropriate flame-retardant electrolyte is currently one of the directions that manufacturers are interested in.

[0004] One literature (Journal of Power Source, Volume 119-121, 1 June 2003, Pages 383-387) discloses that flame retardants containing organic phosphate compounds such as triphenyl phosphate (TPP) and tributyl phosphate (TBP) provide excellent thermal safety for lithium-ion batteries in a fully charged state. However, the molecular groups of most phosphorus-containing compounds are large, and the addition of excessive phosphorus-containing compounds increases the viscosity of the lithium-ion electrolyte, decreases the ionic conductivity, and has a great adverse impact on the rate performance of lithium-ion batteries. Another literature (Journal of Power Source, Volume 278, 15 March 2015, Pages 190-196) discloses a highly efficient flame retardant additive (ethoxy) pentafluorocyclotriphosphazene (also referred to as N3P3F5OCH2CH3, PFPN), which has been synthesized and is used as a safety protection additive for rechargeable lithium batteries. The PFPN additive is considered to be one of the most effective flame retardant additives in all literature reports so far. Through charge and discharge tests, the PFPN additive showed good electrochemical compatibility with the graphite anode and LiCoO2 cathode. At the same time, the incorporated PFPN additive can significantly improve the cycle performance at a high cut-off voltage of 4.5V for the LiCoO2 electrode, showing promising applicability for high-voltage lithium-ion batteries.

[0005] However, although the fluorine-containing phosphazene-based PFPN additive has a better effect than conventional phosphate ester-based flame retardants, its market price is too high, which affects the willingness of battery manufacturers to introduce it. Therefore, providing an electrolyte additive with a low price, a simple manufacturing process, and the ability to significantly improve battery safety is a problem that needs to be solved in the industry at present.

Summary of the Invention

Problems to be Solved by the Invention

[0006] In view of the various drawbacks of the above-described prior art, the present invention provides an electrolyte additive that can improve the safety of a lithium-ion battery with high electrochemical stability, a small addition amount, and a good cycle state without increasing the complexity of the manufacturing process.

Means for Solving the Problems

[0007] To achieve the above object, the present invention provides a phosphazene derivative having a structure of formula (I).

[0008]

Chemical formula

[0009]

Chemical formula

[0010]

Chemical formula

[0011] In one specific embodiment of the phosphazene derivative of the present invention, n is 3, and R1 to R2 are groups represented by the formula (I-1), A is -R3-O-R4, and R3 is a C1-C8 alkylene n group, R4 is a C1-C8 alkyl group, p is 0 or 1, B is a C1-C8 alkoxy group, and q is 0 or 1, and 0 < p + q ≤ 2.

[0012] In one specific embodiment of the phosphazene derivative of the present invention, when the R1 to R2 are selected from the groups represented by the formula (I-1), the phosphazene derivative is one selected from the group consisting of the following compounds (1-1) to (1-4).

[0013]

Chemical formula

[0014]

Chemical formula

[0015] The present invention further provides a composition for use in an electrochemical device, the composition comprising an electrolyte, a non-aqueous solvent and an additive, the additive comprising the phosphazene derivative of the present invention.

[0016] In one specific embodiment of the composition of the present invention, in the phosphazene derivative having the structure of the formula (I), n is 3, and R1 to R2 are groups represented by the formula (I-1), A is -R3-O-R4, and R3 is a C1-C8 alkylene n group, R4 is a C1-C8 alkyl group, p is 0 or 1, B is a C1-C8 alkoxy group, and q is 0 or 1, and 0 < p + q ≤ 2.

[0017] In one specific embodiment of the composition of the present invention, when R1 to R2 are selected from the groups represented by the formula (I-1), the phosphazene derivative is one selected from the group consisting of the following compounds (1-1) to (1-4).

[0018]

Chemical formula

[0019]

Chemical formula

[0020] In one specific embodiment of the composition of the present invention, with respect to the total weight of the composition, the content of the electrolyte is 9.95 to 19.95% by weight.

[0021] In one specific embodiment of the composition of the present invention, with respect to the total weight of the composition, the content of the additive is 0.05 to 20.0% by weight.

[0022] In one specific embodiment of the composition of the present invention, the electrolyte contains at least one selected from the group consisting of lithium hexafluorophosphate (LiPF6), lithium fluoroborate (LiBF4), lithium bis(trifluoromethanesulfonyl)imide (LiN(CF3SO2)2), and lithium trifluoromethanesulfonate (LiCF3SO3).

[0023] In one specific embodiment of the composition of the present invention, the non-aqueous solvent contains at least one selected from the group consisting of carbonates, furans, ethers, thioethers, and nitriles.

[0024] In one specific embodiment of the composition of the present invention, the non-aqueous solvent contains at least one selected from the group consisting of ether-based polymers, polymethacrylate-based polymers, polyacrylate-based polymers, and fluorine-based polymers.

[0025] The present invention further provides an electrochemical device including a positive electrode, a negative electrode, and the composition according to the present invention disposed between the positive electrode and the negative electrode.

[0026] In one specific embodiment of the electrochemical device of the present invention, it is a lithium-ion secondary battery.

Effects of the Invention

[0027] As described above, the composition used in the electrochemical device of the present invention contains a novel phosphazene derivative-based additive, and the use of this additive can improve the defect that the safety of conventional lithium-ion batteries is not preferable.

Brief Description of the Drawings

[0028]

Figure 1A - 1D

[0029]

Figure 2A - 2E

[0030]

Figure 3A - 3E

[0031]

Figure 4A - 4B

Best Mode for Carrying Out the Invention

[0032] Hereinafter, embodiments of the present invention will be described with reference to specific examples, and those skilled in the art can easily understand the advantages and effects of the present invention from the disclosure of this specification. The present invention can be implemented or applied in other different embodiments, and various modifications and changes can be made to the details of each item in this specification based on different viewpoints and applications without departing from the gist disclosed by the present invention. Also, all ranges and values in this specification are inclusive and can be combined. Any numerical value or point within the range described in this specification, for example, any integer, can be used as the minimum value or the maximum value to derive sub-ranges and the like.

[0033] In one specific embodiment, the present invention provides a phosphazene derivative having the structure of formula (I).

[0034]

Chemical Formula

[0035]

Chemical Formula

[0036]

Chemical Formula

[0037] In one specific embodiment, the range of the number of carbon atoms of the present invention can be expanded from the lower limit value to the upper limit value. For example, C1-C8 means that the number of carbon atoms is 1, 2, 3, 4, 5, 6, 7, or 8.

[0038] In some embodiments, the compound, which is a phosphazene derivative having the structure of formula (I) of the present invention, is selected from Table 1, but is not limited thereto.

[0039]

Table 1

[0040] In another specific embodiment, the phosphazene derivative having the structure of formula (I) of the present invention is preferably the following compound.

[0041]

Chemical formula

[0042] In another specific embodiment, the present invention provides a composition for use in an electrochemical device containing the phosphazene derivative-based additive of the present invention, and also provides an electrochemical device having more preferable safety by the use of the additive. In one specific example, the composition of the present invention contains an electrolyte, a non-aqueous solvent, and an additive, and the additive contains a phosphazene derivative having the structure of formula (I) of the present invention.

[0043] [Chemical formula] (In the formula, n is an integer from 3 to 6, and R1 to R2 are independently selected from groups represented by formula (I-1) or formula (I-2).)

[0044] [Chemical formula] (In the formula, A is -R3-O-R4, -R3-CH 3-m (OR4) m , -CH 3-m (OR4) m or

[0045] [Chemical formula] wherein R3 is a C1-C8 alkylene group which is unsubstituted or substituted with a C1-C8 alkyl group, R4 is a C1-C8 alkyl group, R5 is a C1-C3 alkyl n group, R6 is a C1-C3 alkylene group, R7 is a C1-C3 alkyl group, x is 1 or 2, m is 2 or 3, p is the number of A bonded to carbon in the linked benzene ring, and p is an integer from 0 to 3, ren B is a C1-C8 alkoxy group or a C1-C8 alkyl group, and q is an integer from 0 to 3, and 0 < p + q ≤ 5.)

[0046] In one specific embodiment, the range of the number of carbon atoms of the present invention can be expanded from the lower limit value to the upper limit value. For example, C1-C8 means that the number of carbon atoms is 1, 2, 3, 4, 5, 6, 7, or 8.

[0047] In one specific embodiment, the compound which is a phosphazene derivative having the structure of formula (I) contained in the additive in the composition of the present invention is selected from Table 1 above, but is not limited thereto.

[0048] ​In another specific embodiment, the phosphazene derivative having the structure of formula (I) contained in the additive in the composition of the present invention is preferably the following compound.

[0049]

Chemical formula

[0050] In the composition of the present invention, the content of each component can be changed according to actual applications and is not limited to the content described in this specification.

[0051] In one specific embodiment, based on the total weight of the composition, the content of the electrolyte in the composition of the present invention is about 9.95 to 19.95% by weight, for example, 9.95, 10.0, 11.0, 12.0, 13.0, 14.0, 15.0, 16.0, 17.0, 18.0, 19.0 or 19.95% by weight.

[0052] In one specific embodiment, based on the total weight of the composition, the content of the additive in the composition of the present invention is about 0.05 to 20.0% by weight, for example, 0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0, 11.0, 12.0, 13.0, 14.0, 15.0, 16.0, 17.0, 18.0, 19.0 or 20.0% by weight.

[0053] In the composition of the present invention, the content of the non-aqueous solvent can be changed according to the change in the content of other components in the composition. The total content of the non-aqueous solvent and other components in the composition may be 100% by weight, that is, one use of the non-aqueous solvent is to supplement until the composition reaches 100% by weight. In one specific embodiment, the content of the non-aqueous solvent in the composition of the present invention is about 65.0 to 90.0% by weight, for example, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89 or 90% by weight. In one specific embodiment, the content of the non-aqueous solvent in the composition of the present invention is about 80.0 to 90.0% by weight.

[0054] The electrolyte applied to the present invention is commonly used in the art. In one specific embodiment of the composition of the present invention, the electrolyte comprises at least one selected from the group consisting of lithium hexafluorophosphate (LiPF6), lithium tetrafluoroborate (LiBF4), lithium bis(trifluoromethanesulfonyl)imide (LiN(CF3SO2)2), and lithium trifluoromethanesulfonate (LiCF3SO3).

[0055] In the non-aqueous solvent in the composition of the present invention, its form may be liquid, non-liquid, for example, solid or gel-like, but is not limited thereto.

[0056] In the aspect of the liquid non-aqueous solvent, those commonly used in the art can be selected. For example, it is at least one selected from the group consisting of carbonates (such as ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, or methylethyl carbonate), furans (such as tetrahydrofuran), ethers (such as diethyl ether), thioethers (such as methyl-sulfolane), and nitriles (such as acetonitrile, propionitrile). In one specific embodiment of the composition of the present invention, the non-aqueous solvent includes at least one selected from the group consisting of carbonates, furans, ethers, thioethers, and nitriles.

[0057] In the aspect of the non-liquid non-aqueous solvent, the material may be a polymer compound. For example, it may be at least one selected from the group consisting of ether-based polymers (such as polyethyleneoxide or its cross-linked product), polymethacrylate-based polymers, polyacrylate-based polymers, and fluorine-based polymers (such as polyvinylidene fluoride (PVDF) and vinylidene fluoride-hexafluoro propylene copolymer). In one specific embodiment of the composition of the present invention, the non-aqueous solvent includes at least one selected from the group consisting of ether-based polymers, polymethacrylate-based polymers, polyacrylate-based polymers, and fluorine-based polymers.

[0058] The composition of the present invention can be obtained by dissolving the above electrolyte and the phosphazene-based derivative group additive of the present invention in the above liquid non-aqueous solvent, or by dissolving the electrolyte and the phosphazene-based derivative group additive of the present invention in the liquid non-aqueous solvent respectively and then mixing them. When the non-aqueous solvent to be used is in a solid state, an organic solvent (for example, alkanes, ketones, aldehydes, alcohols, ethers, benzene, toluene, xylene, kerosene or a combination thereof) is used in advance, and the electrolyte, the phosphazene-based derivative group additive of the present invention and the solid non-aqueous solvent are dissolved and uniformly mixed, and then heated to evaporate the organic solvent to obtain the composition of the present invention.

[0059] In another specific embodiment, the present invention can obtain an electrochemical device different from the conventional electrochemical device by applying the above composition to the electrochemical device. That is, the present invention also provides an electrochemical device including a positive electrode, a negative electrode, and the composition according to the present invention disposed between the positive electrode and the negative electrode.

[0060] In one specific example, the electrochemical device of the present invention is a lithium ion secondary battery.

Examples

[0061] Hereinafter, various properties and effects of the present invention will be described in detail by way of examples. These detailed examples are only for explaining the properties of the present invention, and the present invention is not limited to those exemplified by specific examples.

[0062] Production Example 1 1. Production of the compound of Formula 1-1: The compound of formula 1-1 of the present invention can be produced from the following synthetic scheme 1. Specifically, hexachlorocyclotriphosphazene (1 g, 2.87 mmol, 1 eq) and acetone (20 mL) were mixed to form solution a, and 4-(2-methoxyethyl)phenol (3.94 g, 25.9 mmol, 9 eq) and acetone (60 mL) were mixed to form solution b. Then, K2CO3 (3.58 g, 25.9 mmol, 9 eq) was added to solution b to form solution c. Solution c was added to solution a, and the mixture was condensed and refluxed in an oil bath at 70 °C for 4 days. After the reaction was completed, the solid was filtered off, and the solvent was removed by distillation under reduced pressure to obtain a crude product. The crude product was repeatedly washed with methanol and water and then freeze-dried to obtain the compound of formula 1-1 in powder form. The NMR spectrum of the compound of formula 1-1 is shown in Figure 1A. <Synthetic Scheme 1>

[0063]

Chemical Formula

[0064] 2. Preparation of the Composition Used in the Electrochemical Device Ethylene carbonate (EC) was dissolved in diethyl carbonate (DEC) or dimethyl carbonate (DMC) at an equal weight ratio and mixed to obtain a mixed solution of EC:DEC:DMC (1:1:1) or EC:DEC (1:1). Next, after calculating the weight molar concentration, 11.8 wt% LiPF6 electrolyte was added to the mixed solution. Finally, 5 wt% or 7 wt% of an additive (the compound of formula 1-1 produced by the above method) was added by weight, stirred and uniformly mixed to prepare a composition used in the electrochemical device.

[0065] Production Examples 2 to 4 Preparation of Compounds of Formula 1-2 to 1-4: 4-(2-Methoxyethyl)phenol was used to prepare Compounds of Formula 1-2, 1-3, and 1-4, respectively, in the same production method as the Compound of Formula 1-1 in Production Example 1, except that it was changed to vanillyl butyl ether, vanillyl ethyl ether, and hydroquinone monomethyl ether (4-methoxyphenol). The NMR spectra of Compounds of Formula 1-2 to 1-4 are shown in Figures 1B to 1D, respectively.

[0066] Example 1: Flame Retardancy Test of Electrolyte A flame retardancy test was conducted using the Compound of Formula 1-1 obtained in Production Example 1 in the electrolyte, and the test method is as follows. 1. The Compound of Formula 1-1 and the commercially available flame retardant PFPN (pentafluoroethoxycyclotriphosphazene) were dissolved in a commercially available electrolyte (EC:DEC = 1:1, 1M LiPF6) in amounts of 0 and 5% by weight, respectively, to prepare the electrolyte to be measured. 2. 10 ml of the electrolyte to be measured was placed in a 20 ml sample bottle. A glass cloth with a length of 4 cm and a width of 1 cm was completely immersed in the electrolyte for 10 seconds and then taken out, and one end of the glass cloth was fixed to a test tube stand with a double clip. 3. A fixed ignition source (derived from a commercially available butane lighter) was brought into contact with the unfixed end of the glass cloth relative to the fixed end for 3 seconds and then removed, and the combustion phenomenon was continuously observed until the flame completely disappeared, and the combustion time was recorded. This time is calculated as the time from when the ignition source is removed until the fire completely disappears (self-extinguishing time). Test Results: The results of the flame retardancy test are summarized in Table 2 below. From the results of the addition concentration and self-extinguishing time, the Compound of Formula 1-1 has the effect of surely improving the flame retardancy of the electrolyte, and when the usage amount is 5%, the effect is shown to be superior to that of the commercially available flame retardant PFPN.

[0067] [Table 2]

[0068] Example 2: Cycle Life Test of LiFePO4 Coin Cells 1. Battery Assembly: Using LiFePO4 as the positive electrode, a lithium metal sheet as the negative electrode, a commercially available separator film (CelgardR 2325), and an electrolyte (1M LiPF6 in EC / DEC (1:1)), a coin cell was constructed and tested. 2. 1C Cycle Life Test: To the electrolyte of the assembled battery, the compound of Formula 1-1 was added at 0% (as the control group), 5%, 10%, 15%, and 20% without addition respectively. At an environmental temperature of 25 °C, (1) it was charged to 4.0 V at a constant current of 1C, and then (2) it was discharged to 2.5 V under the discharge condition of a constant current of 1C. The above steps (1) and (2) were repeated to charge and discharge the battery, and the deterioration status of the battery capacity in the first 250 cycles (charge and discharge test device: Acutech Systems BAT-750B) was recorded. The test results, as shown in Figures 2A to 2E, revealed that regardless of the presence or absence of the addition of the compound of Formula 1-1 or the ratio of the addition amount, there was no significant effect on the cycle life of the battery within 250 cycles. The following Table 3 records the battery capacity of the first 5 cycles and the last 5 cycles in the cycle test with different addition ratios of the compound of Formula 1-1, as well as the battery capacity retention rate.

[0069]

Table 3

[0070] Example 3: Rate Charge and Discharge Test Regarding the coin cells assembled in Example 2 above, the following were added to the electrolytes thereof: 0% (as a control group) without adding the compound of Formula 1-1, or 5%, 10%, 15%, and 20% respectively. Charge-discharge tests (charge-discharge test apparatus: Acutech Systems BAT-750B) were conducted at different rates of 0.1C, 0.2C, 0.3C, 0.5C, and 1C at an environmental temperature of 25°C. As shown in FIGS. 3A to 3E, the test results revealed that there were no significant differences in the specific capacity at the same charge-discharge rate regardless of the presence or absence of the addition of the compound of Formula 1-1 or the ratio of the added amount. Table 4 below exemplarily records the discharge specific capacities at 0.1C and 1C rates for different addition ratios of the compound of Formula 1-1.

[0071]

Table 4

[0072] Example 4: Performance Test and Nail Penetration Test of NMC622 Ternary System Battery The laminated cells in this test used a battery with a cathode: LiNi0.6Mn0.2Co0.2O2 / anode: artificial graphite (also simply referred to as "NMC622 ternary system battery"), and the design of the battery is shown as follows in Table 5.

[0073]

Table 5

[0074] The laminated cell with 7% by weight of the compound of Formula 1-1 added was used as the test group, and the one without any flame retardant added was used as the control group. A battery performance test (analysis equipment: Keysight 34972A LXI) was carried out using a charge and discharge device (CT-4008T-5V6A-S1, NEWARE), and a nail penetration test was also carried out. The equipment for the nail penetration test is a customized product. In this equipment, steel nails and a control device are additionally installed in a metal box, a temperature and voltage monitor is installed outside, and a detection circuit is provided inside the equipment. The nail penetration test meets the regulations for the nail diameter and nail penetration speed in standards such as IEC60086-4:2000, UL1642-2007, and UL2054. The process of the battery performance test is shown as in Table 6 below, and the parameters of the nail penetration test are shown as in Table 7 below.

[0075]

Table 6

[0076]

Table 7

[0077] The results of the battery performance test and the nail penetration test are shown in Table 8, Figures 4A and 4B below. In the nail penetration test, it was observed that the test group with the compound of Formula 1-1 added had no ignition or smoke, and maintained the surface temperature at 30°C without significant increase, and the battery voltage did not change significantly. In contrast, the control group without any additive was observed to catch fire, burn, emit smoke, and the surface temperature increased rapidly, and the voltage dropped to 0V. The voltage change and temperature change in the nail penetration test of the test group and the control group are shown as in Figures 4A and 4B respectively. From the above results, it was clearly shown that the electrolyte prepared with the compound of Formula 1-1 of the present invention has improved results in the battery nail penetration safety test compared to the electrolyte without any additive.

[0078]

Table 8

[0079] From the above embodiments, when the phosphazene derivative of the present invention is used as an additive for the electrolyte of a lithium secondary battery, it not only has no significant effect on the performance of the battery, but also achieves an effect superior to that of the commercially available flame retardant PFPN in making the electrolyte flame retardant, and it has been clarified that the safety when the battery is damaged by an external force can be significantly improved. Therefore, the phosphazene derivative of the present invention is an innovative substance that is actually significantly effective and widely applicable.

Claims

1. A phosphazene derivative having the structure of formula (I). 【Chemical 1】 (wherein n is an integer of 3 to 6, and R １ ~R ２ is independently a group represented by formula (I-1).) [Chemical Formula 2] (wherein, A is -R ３ -O-R ４ , -R ３ -CH ３－ｍ (OR ４ ) ｍ -CH ３－ｍ (OR ４ ) ｍ or 【Chemical Formula 3】 and R ３ is unsubstituted or C １ -C ８ an alkylene group substituted with an alkyl group, R １ -C ８ is an alkylene group, R ４ is C １ -C ８ an alkyl group, R ５ is C １ -C ３ is an alkylene group, R ６ is C １ -C ３ is an alkylene group, R ７ is C １ -C ３ is an alkyl group, x is 1 or 2, m is 2 or 3, p is the number of A bonded to carbon in the linked benzene ring, and p is an integer from 1 to 3. B is C １ -C ８ an alkoxy group or C １ -C ８ is an alkyl group, and q is an integer from 0 to 3, and 0 < p + q ≤ 5.)

2. R １ ~R ２ is a group represented by formula (I-1), A is -R ３ -O-R ４ , and R ３ is C １ -C ８ an alkylene group, and R ４ is C １ -C ８ is an alkyl group, p is 1, and B is C １ -C ８ is an alkoxy group, q is 0 or 1, and 0 < p + q ≤ 2. The phosphazene derivative according to claim 1.

3. The phosphazene derivative according to claim 2, which is one selected from the group consisting of the following compounds (1-1) to (1-3). 【Chemical Formula 4】

4. A composition for use in an electrochemical device, comprising an electrolyte, a non-aqueous solvent, and an additive, wherein the additive comprises the phosphazene derivative according to claim 1.

5. R １ to R ２ is a group represented by the formula (I-1), A is -R ３ -O-R ４ and R ３ is C １ -C ８ an alkylene group, R ４ is C １ -C ８ an alkyl group, p is 1, B is C １ -C ８ an alkoxy group, and q is 0 or 1, and 0 < p + q ≦ 2. The composition according to claim 4.

6. The composition according to claim 5, which is one selected from the group consisting of the following compounds (1-1) to (1-3). 【Chemical Formula 5】 【Chemical Formula 6】

7. The composition according to claim 4, wherein the content of the electrolyte is 9.95 to 19.95% by weight based on the total weight of the composition.

8. The composition according to claim 4, wherein the content of the additive is 0.05 to 20.0% by weight based on the total weight of the composition.

9. The electrolyte is lithium hexafluorophosphate (LiPF ６ ), lithium fluoroborate (LiBF ４ ), lithium bis(trifluoromethanesulfonyl)imide (LiN(CF ３ SO ２ ), ２ ), and lithium trifluoromethanesulfonate (LiCF ３ SO ３ ), and the composition according to claim 4, comprising at least one selected from the group consisting of these substances.

10. The composition according to claim 4, wherein the non-aqueous solvent comprises at least one selected from the group consisting of carbonates, furans, ethers, thioethers, and nitriles.

11. The composition according to claim 4, wherein the non-aqueous solvent comprises at least one selected from the group consisting of ether-based polymers, polymethacrylate-based polymers, polyacrylate-based polymers, and fluorine-based polymers.

12. An electrochemical device comprising a positive electrode, a negative electrode, and the composition according to claim 4 disposed between the positive electrode and the negative electrode.

13. The electrochemical device according to claim 12, which is a lithium-ion secondary battery.

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