KR101583525B1 - electrolytic solution for supercapacitor and supercapacitor use the same - Google Patents

Abstract

The present invention provides an electrolytic solution for a supercapacitor and a supercapacitor adopting the same. According to the present invention, the electrolytic solution for a supercapacitor comprises a silicon compound to increase potential stability so that the supercapacitor adopting the electrolytic solution has high energy with a high voltage.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrolytic solution for a super capacitor and an electrolytic solution containing the electrolytic solution for a supercapacitor and a supercapacitor containing the same,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrolyte for a supercapacitor and a supercapacitor employing the same, and more particularly to an electrolyte solution for a supercapacitor containing a silicon compound and a supercapacitor employing the same.

BACKGROUND ART [0002] Recently, due to high capacity and high power consumption of portable devices, social interest in energy storage devices is increasing day by day. At present, lithium secondary batteries reflect the trend of this society and are used in many places as portable batteries. However, the lithium secondary battery has a disadvantage in that the output density is low. As a result, a research on a supercapacitor having a high energy density and a high output density has been started.

  Supercapacitors have a higher output density than batteries, and when they are used with batteries, their life span is prolonged. Capacitors are classified into electric double layer capacitors (EDLC) using an electric double layer principle and pseudo capacitors expressing high capacitances by a pseudo capacitance generated in a current induction process (Faradaic process) There is a capacitor (pseudocapacitor).

  Electrode materials for such electrochemical capacitors can be broadly divided into activated carbon, metal oxides, and conductive polymers. Although the activated carbon system has excellent lifetime characteristics, it exhibits a relatively low storage capacity, and thus it is required to improve the charging capacity. The conductive polymer generally has a storage capacity larger than that of the carbon-based polymer, but has a disadvantage that the life of the polymer is deteriorated due to deterioration of the conductive polymer main chain. On the other hand, a capacitor made of a metal oxide exhibits a higher energy density than EDLC using activated carbon by using a high redox reaction.

  Along with the demands of such capacitors, in recent years, there has been a demand for thinning and miniaturization of super capacitors in accordance with the tendency of miniaturization and portability of precision electronic products. One of the new capacitors that can meet this demand is a super capacitor using Polymer Gel Electrolyte (PGE). Supercapacitors using PGE can solve the problems of reliability due to leakage of liquid electrolyte of supercapacitors using conventional liquid electrolytes, problems of manufacturing cost, difficulty of thinning, difficulty in high capacity, etc. Next-generation supercapacitors to be. The super capacitor using the flexible PGE can be used as a portable electronic device such as a mobile phone, a notebook, a camcorder and the like, and can easily be used as an auxiliary power source for an electric vehicle because it is easy to develop a super capacitor of a high voltage and a large capacity by lamination.

  On the other hand, the performance and safety of the super capacitor are highly dependent on the characteristics of the electrolytic solution which is a composition of the organic solvent. The organic liquid electrolyte composition employed in the supercapacitor has been prepared by mixing ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, methylpropyl carbonate, ethyl But are not limited to, ethylpropyl carbonate, methylethyl carbonate, butylene carbonate, dimethylsulfoxide, acetonitrile, dimethoxyethane, and diethoxyethane. Have been mixed in appropriate ratios and organic electrolyte compositions have been used in supercapacitors.

  Particularly, cyclic carbonates such as ethylene carbonate and propylene carbonate in the carbonate-based organic solvent have a high dielectric constant, which is advantageous in dissolving salt in the electrolyte, but has a high viscosity Therefore, a low viscosity, low dielectric constant linear carbonate such as dimethyl carbonate and diethyl carbonate are mixed at an appropriate ratio to prepare an electrolyte having a high ionic conductivity and used for a super capacitor.

  However, the electrolytic solution composition adopted for super capacitors has been limited to the manufacture of high-voltage supercapacitors by electrochemical decomposition at 4.0 V or higher. Therefore, it is very important to expand the potential window region to fabricate super-capacitors with high energy density.

Korean Patent Application No. 2007-7028652 Korean Patent Application No. 2011-7022099

The present invention provides an electrolyte for a supercapacitor which is stable even at a high voltage of 4.0 V or higher and can store high energy, and a supercapacitor employing the same.

The present invention provides an electrolyte for a supercapacitor that is stable even at a high voltage and can store high energy, and the electrolytic solution for a supercapacitor of the present invention comprises

Electrolyte salts;

Non-aqueous organic solvent; And

And a silicone compound represented by the following formula (1).

[Chemical Formula 1]

(In the formula 1,

R ₁ to R ₃ are independently of each other hydrogen or (C 1 -C 10) alkyl;

또는

이며;A is (C6-C12) aryl,

or

;

R ₁₁ to R ₁₃ and R ₁₅ to R ₁₈ independently from each other are hydrogen or (C 1 -C 10) alkyl;

Wherein R < ₁₄ > is hydrogen, (C1-C4) alkyl or a mixture thereof;

o and p are each independently an integer of 1 to 10;

r is an integer from 2 to 5;

m and n are each independently an integer of 1 to 10.)

The silicone compound represented by Formula 1 used as an electrolyte additive for a supercapacitor of the present invention has both hydrophilicity and hydrophobicity in the compound so that the silicone compound of the present invention is arranged in the electrode and the electrolyte interface in a polar non- The shrunken capacitor employing the electrolyte for the super capacitor of the present invention as an additive is stable at a high voltage and has a very high energy storage capacity by providing excellent voltage stability.

In the formula (1) of the present invention, R ₁ to R ₃ may independently be (C ₁ -C 5) alkyl.

Preferably, R ₁ to R ₃ may independently be (C ₁ -C 5) alkyl, and R ₁₁ to R ₁₂ and R ₁₅ to R ₁₈ may be hydrogen.

The silicon compound according to an embodiment of the present invention may be contained in an amount of 1 to 15% by weight based on the total weight of the electrolytic solution.

The electrolyte salt according to an embodiment of the present invention may be one or two or more ionic liquids represented by the following formula (2).

(2)

X ⁺ Y ^-

[Formula 2]

X ^{< + &} gt ^; is an imidazolium ion, a piperidinium ion, a pyridinium ion, a pyrrolidium ion, an ammonium ion, a phosphonium ion or a sulfonium ion; Y ^- is _{(CF 3 SO 2) 2 N} -, (C 2 F 5 SO 2) 2 N -, (FSO 2) 2 N -, BF 4 -, PF 6 -, AlCl 4 -, NO 3 -, halogen _{^{-, CH 3 CO 2 -,}} CF 3 CO 2 -, C 3 F 7 CO 2 -, CH 3 SO 4 -, CF 3 SO 3 -, (CF 3 SO 2) N -, (CN) 2 N -, SbF ₆ ^-, MePhSO ₃ ^- (wherein R is alkyl of ^{C1-C5.) -, (} CF 3 SO 2) 3 C - or (oR) ₂ PO _2.

The electrolyte salt according to an embodiment of the present invention may be contained at a concentration of 0.1 to 5 mol.

The viscosity of the electrolyte according to an embodiment of the present invention may be 0.5 to 1 x 10 < ⁶ > cSt.

The non-aqueous organic solvent according to an embodiment of the present invention may be a linear carbonate solvent, a cyclic carbonate solvent, a linear ester solvent, a cyclic ester solvent, or a mixture thereof.

The present invention also provides a supercapacitor comprising a positive electrode, a negative electrode, and an electrolyte solution for a capacitor of the present invention.

The electrolyte for a supercapacitor of the present invention comprises a silicone compound represented by the above formula (1) having both hydrophilic and hydrophobic groups, and such a silicone compound is arranged in an electrode-electrolyte interface in a polar non-aqueous organic solvent and has excellent voltage stability .

Therefore, the electrolyte for a supercapacitor of the present invention maintains very stable charge / discharge characteristics even at 4.0 V or higher.

In addition, the electrolyte for a supercapacitor of the present invention has an excellent heat resistance by the silicone compound represented by the above formula (1), thereby increasing the boiling point of the non-aqueous organic solvent at a high temperature to have high temperature stability and long life.

 In addition, the silicone compound represented by Formula 1 of the present invention is economical because it is cost-effective and can cost-effectively be reduced.

Accordingly, the supercapacitor including the electrolytic solution for a shrunken capacitor of the present invention has high energy storage characteristics with excellent stability.

FIG. 1 shows voltage-current curves obtained by measuring the electrolytes of Examples 2 to 5 and Comparative Examples 2 to 3 by linear sweep voltammetry.
FIG. 2 shows the ionic conductivity according to the concentration of TEABF ₄ in the electrolyte of Example 6. FIG.

The present invention provides an electrolyte for a supercapacitor and a supercapacitor containing the same, wherein the electrolyte solution for a supercapacitor of the present invention comprises

Electrolyte salts;

Non-aqueous organic solvent; And

And a silicone compound represented by the following formula (1).

[Chemical Formula 1]

(In the formula 1,

R ₁ to R ₃ are independently of each other hydrogen or (C 1 -C 10) alkyl;

또는

이며;A is (C6-C12) aryl,

or

;

R ₁₁ to R ₁₃ and R ₁₅ to R ₁₈ independently from each other are hydrogen or (C 1 -C 10) alkyl;

Wherein R < ₁₄ > is hydrogen, (C1-C4) alkyl or a mixture thereof;

o and p are each independently an integer of 1 to 10;

r is an integer from 2 to 5;

m and n are each independently an integer of 1 to 10.)

The silicone compound represented by Formula 1 used as an electrolyte additive for a supercapacitor of the present invention has both hydrophilicity and hydrophobicity in the compound so that the silicone compound of the present invention is arranged in the electrode and the electrolyte interface in a polar non- The shrunken capacitor adopting the electrolyte of the present invention as an additive by providing the excellent voltage stability is stable at a high voltage and has a very high energy storage capacity.

That is, the silicone compound contained in the electrolytic solution for a supercapacitor of the present invention is a colorless and odorless liquid that does not volatilize for a long time even at a high temperature of 250 DEG C and is not oxidized by heat, . In addition, the silicone compound represented by the above formula (1) of the present invention has a low fluidity without being frozen to below -50 캜 and is excellent in cold resistance which does not freeze even at a low temperature and maintains a high ion conductivity even at a temperature below -20 캜. The characteristics of the super capacitor employing the electrolytic solution can be improved. That is, it is possible to realize a supercapacitor which exhibits very excellent performance from low temperature to high temperature.

  Further, since the silicone compound of the present invention shows little change in viscosity over a wide temperature range from a low temperature to a high temperature, the electrolyte containing the same exhibits a high ionic conductivity from a low temperature to a high temperature. %, It is very stable in chemistry, and it has excellent stability because there is no side reaction with current collector (aluminum, copper), active material, organic solvent, salt and so on. In other words, the electrolytic solution for a supercapacitor of the present invention includes a silicon compound having the above-described characteristics, and thus has excellent stability and energy storage characteristics.

As a result, the electrolyte for a supercapacitor of the present invention has excellent cold resistance, heat resistance, oxidation resistance stability, electrical characteristics and stability at low temperature and high temperature as well as at room temperature.

 In addition, the silicone compound has a property of being very well mixed with a carbonate-based solvent used as an electrolyte of a supercapacitor, and thus has the advantage that it can be easily applied to a supercapacitor electrolyte.

In the formula (1) of the present invention, R ₁ to R ₃ may independently be (C ₁ -C 5) alkyl.

Preferably, R ₁ to R ₃ may independently be (C ₁ -C 5) alkyl, and R ₁₁ to R ₁₂ and R ₁₅ to R ₁₈ may be hydrogen.

More specifically, the silicone compound of the present invention may be a poly (dimethylsiloxane-co-siloxane-g-acrylate) (PDMS-A) or poly (dimethylsiloxane-co- .

The silicone compound according to an embodiment of the present invention may be contained in an amount of 1 to 15% by weight based on the total weight of the electrolytic solution, more preferably 1 to 5% by weight in view of high ionic conductivity.

The electrolyte salt according to an embodiment of the present invention may be an ionic liquid with ionic salts or molten salts composed of a cation and an anion. That is, an ionic liquid such as salt, which is composed of a cation and a nonmetal anion, is generally referred to as an ionic liquid, which is present as a liquid at a temperature of 100 ° C or less, unlike melting at a high temperature of 800 ° C or higher. Particularly, an ionic liquid present as a liquid at room temperature is referred to as a room temperature ionic liquid (RTIL). Ionic liquids are nonvolatile, non-toxic, non-flammable, and have excellent thermal stability and ionic conductivity. In addition, it has a unique polarity, which dissolves inorganic and organic metal compounds and exists as a liquid in a wide temperature range, and is applied to a wide range of chemical fields such as catalysts, separation, and electrochemistry.

The electrolyte salt according to an embodiment of the present invention may be one or two or more ionic liquids represented by the following formula (2).

(2)

X ⁺ Y ^-

[Formula 2]

X ^{< + &} gt ^; is an imidazolium ion, a piperidinium ion, a pyridinium ion, a pyrrolidium ion, an ammonium ion, a phosphonium ion or a sulfonium ion; Y ^- is _{(CF 3 SO 2) 2 N} -, (C 2 F 5 SO 2) 2 N -, (FSO 2) 2 N -, BF 4 -, PF 6 -, AlCl 4 -, NO 3 -, halogen _{^{-, CH 3 CO 2 -,}} CF 3 CO 2 -, C 3 F 7 CO 2 -, CH 3 SO 4 -, CF 3 SO 3 -, (CF 3 SO 2) N -, (CN) 2 N -, SbF ₆ ^-, MePhSO ₃ ^- (wherein R is alkyl of ^{C1-C5.) -, (} CF 3 SO 2) 3 C - or (oR) ₂ PO _2.

Preferably, the electrolyte salt according to an embodiment of the present invention may be represented by the following formula (3).

(3)

(3)

R ₂₁ to R ₂₃ independently from each other are (C 1 -C 5) alkyl;

Y ^- is _{(CF 3 SO 2) 2 N} -, (C 2 F 5 SO 2) 2 N -, (FSO 2) 2 N -, BF 4 -, PF 6 -, AlCl 4 -, NO 3 -, halogen _{^{-, CH 3 CO 2 -,}} CF 3 CO 2 -, C 3 F 7 CO 2 -, CH 3 SO 4 -, CF 3 SO 3 -, (CF 3 SO 2) N -, (CN) 2 N -, SbF ₆ ^-, MePhSO ₃ ^- (wherein R is alkyl of ^{C1-C5.) -, (} CF 3 SO 2) 3 C - or (oR) ₂ PO _2.

Specifically, the anion of the electrolyte salt according to an embodiment of the present invention may be bis (perfluoroethylsulfonyl) imide, bis (trifluoromethylsulfonyl) imide, tris (trifluoromethylsulfonylmethide) , Trifluoromethanesulfonimide, trifluoromethylsulfonimide, trifluoromethylsulfonate, tris (pentafluoroethyl) trifluorophosphate, bis (trifluoromethylsulfonyl) imide, tetrafluoro Or a hexafluorophosphate, and the electrolyte salt may be contained at a concentration of 0.1 to 5 mol (mol / L).

Preferably, the electrolytic solution of the supercapacitor of the present invention is a silicone compound wherein R ₁ to R ₃ are independently (C ₁ -C 5) alkyl and R ₁₁ to R ₁₂ and R ₁₅ to R ₁₈ are hydrogen, It is possible to manufacture a supercapacitor which has higher ionic conductivity and higher stability than that of the combination of 1 to 5 wt% and an electrolyte salt of 0.5 to 2 moles of the ionic liquid represented by the above formula (3).

The viscosity of the electrolyte according to an embodiment of the present invention may be 0.5 to 1 x 10 ⁶ cSt at room temperature (20 ° C). If the viscosity is 1 x 10 ⁶ cSt or more, the viscosity of the silicone compound increases to cause a decrease in ion conductivity And if it has a value of 0.5 cSt or less, it is difficult to suppress the volatility of the organic solvent, which may lower the stability of the electrolyte solution.

The non-aqueous organic solvent according to an embodiment of the present invention may be a linear carbonate solvent, a cyclic carbonate solvent, a linear ester solvent, a cyclic ester solvent, or a mixture thereof, but may be a linear carbonate solvent, a cyclic carbonate- Solvent or a mixed solvent thereof, and it is most preferable to use a mixture of a linear carbonate-based solvent and a cyclic carbonate-based solvent. The cyclic carbonate solvent has a large polarity, which can sufficiently dissociate the ions, but has a disadvantage in that the viscosity is large and the ion conductivity is low. Therefore, the characteristics of the supercapacitor can be optimized by mixing a linear carbonate solvent having a low polarity but a low viscosity in the cyclic carbonate solvent.

The linear carbonate solvent may be selected from the group consisting of dimethyl carbonate (DMC), diethyl carbonate (DEC), dipropyl carbonate (DPC), ethyl propyl carbonate (EPC), ethyl methyl carbonate (EMC) and methyl propyl carbonate And the cyclic carbonate solvent is selected from the group consisting of ethylene carbonate (EC), propylene carbonate (PC), 1,2-butylene carbonate (BC), 2,3-butylene carbonate, 1,2- Terephthalene carbonate, terephthalene carbonate, tilene carbonate, 2,3-pentylene carbonate, vinylene carbonate (VC), vinylethylene carbonate and fluoroethylene carbonate, and the linear ester solvent is methyl propionate, ethyl propionate Propionate, propyl acetate, butyl acetate, and ethyl acetate. Mixture, and the cyclic ester-based solvent may be alone or a mixture of two or more selected from the group consisting of a lactone with the lactone, caprolactone and ballet as gamma -butyrolactone.

In the electrolytic solution for a supercapacitor according to an embodiment of the present invention, the non-aqueous organic solvent is a mixed solvent of a linear carbonate solvent and a cyclic carbonate solvent, wherein the volume ratio of the linear carbonate solvent: cyclic carbonate solvent is 1 to 9 : 1, preferably in a volume ratio of 2: 8 to 8: 2, from the viewpoints of life characteristics and storage characteristics of the battery.

The present invention also provides a supercapacitor comprising a positive electrode, a negative electrode, and an electrolyte solution for a capacitor of the present invention.

The supercapacitor of the present invention is an electrochemical capacitor, which is equipped with an electrode, a current collector and a separator as basic components, and optionally includes a case, a gasket, and the like which are commonly used in a capacitor. The electrolytic solution is impregnated into the electrode and the separator in a glove box or the like in an argon gas atmosphere.

The electrolytic solution of the present invention is suitable for an electric double layer capacitor (one using a polarized electrode, for example, activated carbon or the like) among electrochemical capacitors. The basic structure of the electric double layer capacitor is formed by sandwiching a separator between two polarizable electrodes and impregnating an electrolytic solution.

In the electric double-layer capacitor of the present invention, it is preferable that at least one of the positive electrode and the negative electrode be a polarizable electrode, and the following electrodes can be used as the polarizable electrode and the non-polarizable electrode.

As the polarizable electrode, a polarizable electrode composed mainly of activated carbon may be used, but preferably includes a non-activated carbon having a large specific surface area and a conductive agent such as carbon black for imparting electron conductivity. The polarizable electrode can be formed by various methods. For example, a polarizable electrode comprising activated carbon and carbon black can be formed by mixing activated carbon powder, carbon black and a phenolic resin, and pressing and molding in an inert gas atmosphere and a steam atmosphere after press molding. Preferably, the polarizable electrode is bonded to the current collector with a conductive adhesive or the like.

The active carbon powder, the carbon black and the binder may be kneaded in the presence of alcohol to form a sheet, followed by drying to obtain a polarized electrode. As this binder, for example, polytetrafluoroethylene is used. It is also possible to make a slurry by mixing activated carbon powder, carbon black, a binder and a solvent, coating the slurry on a metal foil of the current collector, and drying it to obtain a polarized electrode integrated with the current collector. Although a polarizable electrode mainly composed of activated carbon may be used for the anode to form an electric double layer capacitor, it is possible to use a structure using a nonpolar polar electrode on one side, for example, a positive electrode mainly composed of a battery active material such as a metal oxide, A positive electrode made of a carbon material capable of reversibly intercalating and deintercalating lithium ions or a negative electrode made of a lithium metal or a lithium alloy and a polarized electrode made mainly of activated carbon are combined with each other The configuration is also possible.

Alternatively, carbonaceous materials such as carbon black, graphite, expanded graphite, porous carbon, carbon nanotube, carbon nanohorn, and Ketjen black may be used instead of or in combination with activated carbon. As the non-polar electrode, it is preferable to use a carbon material mainly containing a carbon material capable of reversibly intercalating and deintercalating lithium ions, and storing lithium ions in the carbon material. In this case, a lithium salt is used for the electrolyte. According to the electric double-layer capacitor having this structure, a withstand voltage exceeding 4 V is obtained.

The solvent to be used in the production of the slurry in the production of the electrode is preferably one which dissolves the binder and may be selected from the group consisting of N-methylpyrrolidone, dimethylformamide, toluene, xylene, isophorone, methyl ethyl ketone, Ethyl acetate, methyl acetate, dimethyl phthalate, ethanol, methanol, butanol or water is appropriately selected.

Examples of the activated carbon used for the polarized electrode include phenol resin-based activated carbon, coconut shell-based activated carbon, and petroleum coke-based activated carbon. Among them, petroleum coke-based activated carbon or phenol resin-based activated carbon is preferably used because a large capacity can be obtained. The activation treatment of activated carbon includes steam activation treatment, melt KOH activation treatment and the like. In view of obtaining a larger capacity, it is preferable to use activated carbon by the melt KOH activation treatment method.

Preferred conductive agents for use in the polarizable electrode include carbon black, ketjen black, acetylene black, natural graphite, artificial graphite, metal fibers, conductive titanium oxide, and ruthenium oxide. The amount of the conductive agent such as carbon black to be used for the polarized electrode is preferably 1 to 50% by weight based on the total amount of the conductive agent and the active carbon, so that good conductivity (low internal resistance) is obtained and, .

As the activated carbon used for the polarized electrode, it is preferable to use an activated carbon having an average particle diameter of 20 占 퐉 or less and a specific surface area of 1,500 to 3,000 m2 / g so that an electric double layer capacitor having a large capacity and low internal resistance can be obtained. Preferred examples of the carbon material for constituting the electrode mainly composed of the carbon material capable of reversibly intercalating and deintercalating lithium ions include natural graphite, artificial graphite, graphitized meso carbon microspheres, graphitized whiskers, , A fired product of furfuryl alcohol resin or a fired product of novolak resin.

The current collector may be chemically or electrochemically corrosion resistant. As the collector of the polarized electrode mainly composed of activated carbon, stainless steel, aluminum, titanium or tantalum can be preferably used. Of these, stainless steel or aluminum is a particularly preferable material in both aspects of the characteristics and price of the obtained electric double-layer capacitor. Stainless steel, copper or nickel is preferably used as the collector of the electrode mainly composed of the carbon material capable of reversibly intercalating and deintercalating lithium ions.

In order to previously store lithium ions in a carbon material capable of reversibly intercalating and deintercalating lithium ions, there are (1) a method of mixing powdery lithium with a carbon material capable of reversibly intercalating and deintercalating lithium ions , (2) a lithium foil is placed on an electrode formed of a carbon material capable of reversibly intercalating and deintercalating lithium ions and a binder, and this electrode is immersed in an electrolytic solution in which a lithium salt is dissolved in a state of being in electrical contact with the electrode A method of ionizing lithium to introduce lithium ions into the carbon material, (3) a method in which an electrode formed of a carbon material capable of reversibly intercalating and deintercalating lithium ions and a binder is placed on the negative side, and lithium metal is placed on the positive side In a state in which lithium is ionized in a carbon material electrochemically by flowing a current through a non-aqueous electrolytic solution containing a lithium salt as an electrolyte There are ways to.

 As electric double layer capacitors, a wound type electric double layer capacitor, a laminate type electric double layer capacitor, a coin type electric double layer capacitor, and the like are generally known, and the electric double layer capacitor of the present invention can be also of these types.

For example, a wound type electric double-layer capacitor is manufactured by winding a positive electrode and a negative electrode including a laminate (electrode) of a current collector and an electrode layer through a separator to manufacture a winding element, And filled with an electrolytic solution, preferably a nonaqueous electrolytic solution, and then sealed with a sealing member made of a rubber and sealed.

As the separator, conventionally known materials and constitutions may be used in the present invention. Examples thereof include a polyethylene porous film, a polypropylene fiber, a glass fiber, and a nonwoven fabric of cellulose fibers.

A laminate type electric double layer capacitor in which a sheet-like positive electrode and a negative electrode are laminated via an electrolytic solution and a separator by a known method, or a coin type in which a positive electrode and a negative electrode are formed in a coin shape with an electrolytic solution and a separator interposed therebetween, Electric double layer capacitor.

In addition, the electrolytic solution of the present invention is useful not only for an electric double layer capacitor but also for electrolytic solution of an electrochemical device having various electrolytic solutions. Examples of the electrochemical device include a lithium secondary battery, a radical battery, a solar cell (particularly a dye sensitized solar cell), a fuel cell, various electrochemical sensors, an electrochromic device, an electrochemical switching device, an aluminum electrolytic capacitor, a tantalum electrolytic capacitor, And a lithium secondary battery is particularly suitable. In addition, it can be used as an ion conductor of an antistatic coating material.

[Example 1]

5% by weight of poly [dimethylsiloxane-co- (siloxane-g-acrylate)] represented by the following formula in a mixture of ethylene carbonate: dimethyl carbonate (EC: DMC) = 1: 1, viscosity: 0.65 cSt ) Was added to prepare an electrolyte solution for a supercapacitor. Voltage stability was measured with a linear sweep voltammetry (PGstat 100, Eco Chemie) at a scanning rate of 10 mV / s and stable to about 4.5 V Respectively.

[Comparative Example 1]

The electrolyte was prepared in the same manner as in Example 1 except that the silicone compound was not added in Example 1, and the voltage stability was measured by a linear sweep voltammetry at a scanning rate of 10 mV / s. As a result, 4.0 V or less.

[Examples 2 to 5 and Comparative Examples 2 to 3]

]), EC는 ethylene carbonate, PC는 propylene carbonate, EMC는 ethylmethyl carbonate, DEC는 diethyl carbonate, VC는 vinylene carbonate, FEC는 fluoroethylene carbonate, DMC는 dimethyl carbonate이다.](EC / DMC = 1: 1 by volume) and liquid electrolyte B (EC / PC / EMC / DEC / VC / FEC = 20: 5: 55: 20: 1 was added to prepare an electrolyte solution for a supercapacitor. The types and amounts of the added silicon compounds were shown in Table 1 and the results of voltage stability measurements are shown in Table 1 and Figure 1. [PDMS-EO (poly [dimethylsiloxane-co- (siloxane-g-ethylene oxide ),

]), EC is ethylene carbonate, PC is propylene carbonate, EMC is ethylmethyl carbonate, DEC is diethyl carbonate, VC is vinylene carbonate, FEC is fluoroethylene carbonate, and DMC is dimethyl carbonate.

Electrolyte Amount of silicon compound added 2 Example 2 Liquid electrolyte A PDMS-A (1 wt%) 2 Example 3 Liquid electrolyte A PDMS-A (2 wt%) 3 Example 4 Liquid electrolyte A PDMS-A (3 wt%) 4 Example 5 Liquid electrolyte B PDMS-EO (5 wt%) 6 Comparative Example 2 Liquid electrolyte A 0 wt% One Comparative Example 3 Liquid electrolyte B 0 wt% 5

FIG. 1 shows the voltage-current curves measured with a linear sweep voltammetry at a scanning rate of 10 mV / s for the electrolytes of Examples 2 to 5 and Comparative Examples 2 to 3. FIG.

  As shown in FIG. 1, it can be seen that all silicon compounds added are stable at 4.0 V or higher. The high oxidation currents at high potentials are attributed to the oxidation / decomposition of the electrolyte. In the case of the electrolyte solution containing the silicon compound in the liquid electrolyte, the current value is lower than that of the liquid electrolyte. This indicates that the oxidation of the electrolyte is reduced And it can be interpreted that the stability of the electrolytic solution is increased by the addition of the silicon compound. The addition of the silicone compound greatly improves the dislocation stability because the hydrophilic group of the silicone compound contributes to the enhancement of the ionic conductivity by improving the affinity with the organic solvent and the dissociation degree of the salt, The interfacial stability of the polymer is improved.

[Example 6]

PDMS-A was added to the PC so that the concentration of TEABF ₄ was 0.5 mol / L, 1.0 mol / L, 1.5 mol / L and 2.0 mol / L, respectively. TEABF ₄ (tetra ethyl ammonium BF ₄ ) / PC / PDMS-A electrolyte.

The ionic conductivity of the prepared TEABF ₄ / PC / PDMS-A electrolyte was measured by impedance measurement method (PGstat 100, Eco Chemie manufactured by Autolab) in a glove box, where the water and oxygen concentrations were 0.1 ppm or less, 95.63 < 0 > C.

FIG. 2 shows the ionic conductivity of TEABF ₄ (tetra ethylammonium BF ₄ ) / PC / PDMS-A electrolyte according to the concentration of TEABF ₄ . As the concentration of TEABF _{4 in} the electrolytic solution increased, the ionic conductivity increased. As shown in FIG. 2, the ionic conductivity was about 9.0 × 10 ^-3 S / cm or more in 1M TEABF ₄ .

Therefore, the electrolyte for a supercapacitor of the present invention contains the silicone compound represented by the formula (1), and thus has high stability even at a high voltage, and has high ion storage capacity depending on the concentration of the electrolyte salt.

Claims (9)

Electrolyte salts;
Non-aqueous organic solvent; And
A silicone compound for a supercapacitor, comprising: at least one silicon compound represented by the following formula (1).
[Chemical Formula 1]

(In the formula 1,
R ₁ to R ₃ are independently of each other (C ₁ -C 5) alkyl;
A is (C6-C12) aryl,

or

;
The R < ₁₃ & R ₁₄ are independently hydrogen or (C1-C10) alkyl each other, wherein R ₁₁ to R ₁₂ and R ₁₅ to R ₁₈ is hydrogen;
o and p are each independently an integer of 1 to 10;
r is an integer from 2 to 5;
m and n are each independently an integer of 1 to 10.) delete delete The method according to claim 1,
Wherein the silicon compound is contained in an amount of 1 to 15% by weight based on the total weight of the electrolytic solution. The method according to claim 1,
Wherein the electrolyte salt further comprises one or two or more ionic liquids represented by the following general formula (2).
(2)
X ⁺ Y ^-
[Formula 2]
X ^{< + &} gt ^; is an imidazolium ion, a piperidinium ion, a pyridinium ion, a pyrrolidium ion, an ammonium ion, a phosphonium ion or a sulfonium ion; Y ^- is _{(CF 3 SO 2) 2 N} -, (C 2 F 5 SO 2) 2 N -, (FSO 2) 2 N -, BF 4 -, PF 6 -, AlCl 4 -, NO 3 -, halogen ^{_{-, CH 3 CO 2 -,}} CF 3 CO 2 -, C 3 F 7 CO 2 -, CH 3 SO 4 -, CF 3 SO 3 -, (CF 3 SO 2) N -, (CN) 2 N -, SbF ₆ ^-, MePhSO ₃ ^- (wherein R is alkyl of ^{C1-C5.) -, (} CF 3 SO 2) 3 C - or (oR) ₂ PO _2. 6. The method of claim 5,
Wherein the electrolyte salt is contained in a concentration of 0.1 to 5 moles. The method according to claim 1,
Wherein the electrolytic solution has a viscosity of 0.5 to 1 x 10 < ⁶ > cSt. The method according to claim 1,
Wherein the non-aqueous organic solvent is a linear carbonate-based solvent, a cyclic carbonate-based solvent, a linear ester-based solvent, a cyclic ester-based solvent, or a mixed solvent thereof. A supercapacitor comprising an anode, a cathode, and an electrolytic solution selected from the group consisting of the electrolytic solution selected from the group consisting of the electrolytic solution and the electrolytic solution.

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