KR20130101652A - Electrolyte having improved charge and discharge, and capacitor comprising the same - Google Patents

Abstract

PURPOSE: An electrolyte and a capacitor using the same are provided to be used for a super capacitor by increasing a withstand voltage characteristic, thereby being used for various industry fields. CONSTITUTION: An electrolyte includes a compound which is selected one among chemical formulas of 12. A high effective charging/discharging characteristic of the electrolyte is improved.

Description

Electrolyte having improved high rate charge and discharge characteristics and a capacitor comprising the same {Electrolyte having improved charge and discharge, and capacitor comprising the same}

The present invention relates to an electrolyte for a capacitor having a high rate charging and discharging characteristic and a capacitor including the same, and more particularly, to prevent unnecessary overvoltage during charging and discharging of an electrochemical capacitor such as a supercapacitor, a lithium ion capacitor, and the like. It relates to an electrolyte for a capacitor and a capacitor including the same that can be improved.

In general, electrochemical energy storage devices are a key component of finished devices essential for all portable information and communication devices and electronic devices. In addition, electrochemical energy storage devices will be reliably used as high quality energy sources in the renewable energy field that can be applied to future electric vehicles and portable electronic devices.

The electrochemical capacitors of the electrochemical energy storage device may be classified into an electric double layer using an electric double layer principle and a hybrid supercapacitor using an electrochemical conversion-reduction reaction.

Here, the electric double layer capacitor is used in many fields that require high output energy characteristics, but the electric double layer capacitor has a disadvantage of being used for a small capacity. In comparison, hybrid supercapacitors are being researched as a new alternative to improve the capacity characteristics of electric double layer capacitors. In particular, the lithium ion capacitor of the hybrid supercapacitor may have an accumulation capacity of about 3 to 4 times that of the electric double layer capacitor.

The electrolytes used in high capacity capacitors are classified into aqueous electrolytes, non-aqueous electrolytes and solid electrolytes. Among them, the aqueous electrolyte has a high conductivity to reduce the internal resistance of the basic cell, but the energy density of the capacitor is low due to the low operating voltage.

On the other hand, non-aqueous electrolytes generally have a higher viscosity than aqueous electrolytes and have a conductivity of about 1/10 to 1/100 times lower. Therefore, when the non-aqueous electrolyte is used, the output resistance is worse than that of the aqueous electrolyte due to the increased internal resistance. However, in the case of the non-aqueous electrolyte, the potential difference is high, and the energy density of the capacitor which is proportional to the square of the voltage used can be greatly increased, the usable temperature range is wide, and the high pressure resistance and miniaturization can be achieved. Research is actively underway.

Li-ion capacitor is oxidized as a feature of the capacitor electrode in the positive electrode (active carbon) during charging, at which time the negative ions in the electrolyte is adsorbed on the positive electrode to maintain a stable voltage. On the other hand, when charging, the negative electrode (graphite) acts as a stable negative electrode by inserting lithium ions as in the negative electrode of the lithium secondary battery. At this time, the electrolytic salt dissolved in the electrolyte plays a role of stably maintaining the charging voltage of the lithium ion capacitor without generating an overvoltage.

In this case, when using an electrolytic salt having an electron density of anion too small in a lithium ion capacitor, an overvoltage is applied because the charging capacity cannot be properly grasped during high rate charging. On the other hand, the higher the electron density of the anion, the more strongly it is strongly adsorbed to the anode of the lithium ion capacitor during charging, the possibility of generating overvoltage during high rate discharge.

That is, when an anion having a large electron density is used as an electrolyte salt, high capacity may be realized at low rate charge and discharge. However, since these anions are strongly adsorbed with the electrode plate, it is difficult to detach them from the electrode plate. Therefore, in an electrolyte condition using an anion having a large electron density, an overvoltage is applied even at high rate discharge, resulting in a decrease in capacity.

Therefore, the development of a capacitor capable of realizing a high capacity capacitor even at a high rate by suppressing strong adsorption of anion with a large electron density is required.

In order to solve the above problems, an object of the present invention is to provide a capacitor in which the withstand voltage characteristic is increased when used in an ultra high capacity capacitor.

It is another object of the present invention to provide an electrolyte and a capacitor including the same which inhibit anion from being strongly adsorbed with an electrode even when an anion having a large electron density is used as an electrolyte salt.

It is still another object of the present invention to provide a capacitor of high capacity since no overvoltage is applied even at high rate charge / discharge.

In order to achieve the above object, the present invention provides an electrolyte having improved high rate charge / discharge characteristics including a compound included in at least one of the following Chemical Formulas 1 to 12:

[Formula 1]

[Formula 2]

(3)

[Formula 4]

[Chemical Formula 5]

[Formula 6]

[Formula 7]

[Formula 8]

[Chemical Formula 9]

[Formula 10]

[Formula 11]

[Chemical Formula 12]

In another aspect, the present invention provides an electrolyte with improved high rate charge and discharge characteristics, characterized in that the compound comprises 0.5 to 70 parts by weight based on 100 parts by weight of the electrolyte.

In another aspect, the present invention provides an electrolyte with improved high rate charge and discharge characteristics, including the compound, an electrolytic salt and a non-aqueous organic solvent.

In addition, the present invention, the electrolytic salt is LiPF ₆ , LiBF ₄ , LiTFSI, LiSbF ₆ , LiAsF ₆ , LiClO ₄ , LiCF ₃ SO ₃ , Li (CF ₃ SO ₂ ) ₂ N, LiC ₄ F ₉ SO ₃ , LiSbF ₆ , LiAlO ₄ , LiAlCl ₄ , LiN (C _x F _{2x +1} SO ₂ ) (C _y F _{2y +1} SO ₂ ) (where x, y is a natural number), LiCl, LiI, characterized in that the mixture of at least one It provides an electrolyte with improved high rate charge and discharge characteristics.

In the present invention, the non-aqueous organic solvent is ethylene carbonate (EC), propylene carbonate (PC), dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), 1,2 -Dimethoxyethene (DME), γ-butyrolactone (BL), tetrahydrofuran (THF), 1,3-dioxolane (DOL), diethylether (DEE), methyl formate (MF) It provides an improved electrolyte with high rate charging and discharging characteristics, characterized in that at least one mixture of methyl propionate (MP), sulfolane (S), dimethyl sulfoxide (DMSO) and acetonitrile (AN).

In another aspect, the present invention provides a capacitor comprising the electrolyte.

In another aspect, the present invention provides a capacitor, characterized in that the capacitor is manufactured by the electrode coating process, the pressure reduction impregnation process, the battery assembly process, the electrolyte injection process and the initial charging process.

The electrolyte according to the present invention has excellent conductivity, and when used in an ultra high capacity capacitor, the breakdown voltage characteristic can be greatly increased.

In addition, the electrolyte according to the present invention can be used in a wide range of industrial fields from small electronic devices to large automotive applications due to low gas generation even at high temperatures.

In addition, in the case of manufacturing a capacitor using the electrolyte according to the present invention, even if an anion having a large electron density is used as the electrolyte salt, there is an effect of suppressing the strong adsorption of the anion with the electrode.

In addition, the capacitor according to the present invention does not take an overvoltage even at high rate charging and discharging, so that a capacitor having a high capacity can be realized.

The terms " about ", " substantially ", etc. used to the extent that they are used herein are intended to be taken to mean an approximation to or in the numerical value of the manufacturing and material tolerances inherent in the meanings mentioned, Accurate or absolute numbers are used to help prevent unauthorized exploitation by unauthorized intruders of the referenced disclosure.

The present inventors have developed an organic solvent having a relatively low polarity which can prevent the capacity decrease from occurring under electrolyte conditions using an anion having a large electron density, and when added to an electrolyte of an electrochemical capacitor such as a lithium ion capacitor, the electron density is high. The present invention has been completed by focusing on the fact that large anions are prevented from being strongly adsorbed with the electrode, thereby realizing a high capacity capacitor even at a high rate.

The present invention is characterized by consisting of an electrolyte comprising a compound selected from one or more of the following Chemical Formulas 1 to 12 and a capacitor comprising the same.

[Formula 1]

When n is smaller than 1 in Chemical Formula 1, the boiling point is low, so that it may be volatilized in the adsorption process, and thus, practical application is difficult. If the value is larger than 8, the electron density of the compound is too low. You can't keep it stable.

[Formula 2]

When n is less than 1 in Formula 2, the boiling point is low, so that it may be volatilized in the adsorption process, and thus practical application is difficult. When the value is larger than 8, the electron density of the compound is too low. You can't keep it stable.

(3)

In the formula (3), when R is smaller than C2, the boiling point is low, so that it may be volatilized in the adsorption process, and thus practical application is difficult. When the value is larger than C8, the electron density of the compound is too low. You can't keep it stable.

[Formula 4]

In Formula 4, when R is smaller than C2, the boiling point is low, so that it may be volatilized in the adsorption process, and thus, practical application is difficult. In the case of larger than C8, the electron density of the compound is too low. You can't keep it stable.

[Chemical Formula 5]

In formula (5), when R1 and R2 are smaller than C1, practical application occurs because of deterioration of battery performance by -OH group, and when C1 is larger than C6, the electron density of the compound is too low, so the capacitor is charged. The voltage of the electrode cannot be kept stable.

[Formula 6]

In Formula 6, when R is smaller than C2, practical application occurs because of deterioration of battery performance due to -OH group, and when C is larger than C10, the electron density of the compound is too low. It can't keep the voltage stable.

[Formula 7]

In the formula (7), when R1, R2 is smaller than C2, it is difficult to apply practically because it leads to deterioration of battery performance by -OH group, and when larger than C10, the electron density of the compound is too low, so the capacitor during charging The voltage of the electrode cannot be kept stable.

[Formula 8]

In Formula 8, when R is greater than C7, the electron density of the compound is too low, and thus the voltage of the capacitor electrode cannot be stably maintained during charging.

[Chemical Formula 9]

In Formula 9, when R is greater than C7, the electron density of the compound is too low, and thus the voltage of the capacitor electrode cannot be stably maintained during charging.

[Formula 10]

When n is less than 1 in Formula 10, it is difficult to apply practically because it causes deterioration of battery performance by -OH group, and when greater than 30, the size of the compound is too large, so that the nanopore of the capacitor electrode As the compound becomes difficult to be impregnated, it is difficult to expect the effect of keeping the voltage of the capacitor electrode stable during charging.

[Formula 11]

When n is less than 1 in Formula 11, it is difficult to apply practically because of deterioration of battery performance due to -OH group, and when larger than 30, the size of the compound is too large. As the compound becomes difficult to be impregnated, it is difficult to expect the effect of keeping the voltage of the capacitor electrode stable during charging.

[Chemical Formula 12]

Chemical Formulas 1 to 12 are monomers or polymers, and the electrolyte including the chemical formulas may prevent a high electron density anion from being strongly adsorbed with the electrode, thereby realizing a capacitor having a high capacity even at a high rate.

More specifically, the compounds containing Formulas 1 to 12 have an acryl group at one end thereof, and thus have a structure that is easily polymerized by simple heating conditions in a battery. In addition, the other terminal consists of CN, NCO, F, Cl, etc. with high electron density. Therefore, the nano-size pores (pore) may play a role that can further improve the moving speed of the anion and cation.

The compound preferably contains 0.5 to 70 parts by weight based on 100 parts by weight of the electrolyte.

Within the above range, when charging and discharging the capacitor electrode, the negative ions increase the adsorption and desorption rate to the nano pores of the activated carbon electrode, thereby improving the high rate characteristic of the capacitor. When the compound is used in an amount less than 0.5 parts by weight, it is difficult to expect a great effect in improving the desorption rate of the anion having a high cell density, and when the amount is larger than 70 parts by weight for the anion having a low electron density It is difficult to expect a useful effect because it can cause a decrease in dose.

The electrolyte according to the present invention can be utilized in electrochemical capacitors such as supercapacitors, lithium ion capacitors, and the like, when the capacitor is prepared, the at least one compound selected from Chemical Formulas 1 to 12, an electrolytic salt, and a non-aqueous system It may consist of an organic solvent.

In addition, the electrolytic salts that may be used in the production of lithium ion capacitors include LiPF ₆ , LiBF ₄ , LiTFSI, LiSbF ₆ , LiAsF ₆ , LiClO ₄ , LiCF ₃ SO ₃ , Li (CF ₃ SO ₂ ) ₂ N, LiC ₄ F ₉ SO ₃ , LiSbF ₆ , LiAlO ₄ , LiAlCl ₄ , LiN (C _x F _{2x +1} SO ₂ ) (C _y F _{2y +1} SO ₂ ) (where x and y are natural numbers), LiCl, LiI, etc. It can be used as an electrolyte for lithium ion capacitors by mixing at least one group.

In addition, the non-aqueous organic solvent is ethylene carbonate (EC), propylene carbonate (PC), dimethyl carbonate (DMC), diethyl carbonate (DEC), ethylmethyl carbonate (EMC), 1,2-dimethoxy Ethene (DME), γ-butyrolactone (BL), tetrahydrofuran (THF), 1,3-dioxolane (DOL), diethylether (DEE), methyl formate (MF), methylpro Pioneate (MP), sulfolane (S), dimethyl sulfoxide (DMSO) and acetonitrile (AN), etc. can be used as an electrolyte by mixing at least one.

When the capacitor is manufactured using the electrolyte as described above, even if an anion having a large electron density is used as the electrolyte salt, there is an effect of suppressing the strong adsorption of the anion with the electrode. Therefore, overvoltage is not applied even at high rate charging and discharging, so that a capacitor having a high capacity can be realized.

On the other hand, the capacitor according to the present invention provides a capacitor including the positive electrode, the negative electrode, the separator and the electrolyte described above.

The electrode mixture of the positive electrode includes a positive electrode active material, a conductive material and a binder, and the electrode mixture of the negative electrode includes a negative electrode active material, a conductive material and a binder.

The cathode active material may be any carbon material having a double layer capacity, and may be used in the group consisting of activated carbon, natural fiber, amorphous carbon, fullerene, nanotube, graphene, and the like. Although it is not limited to the kind, it is preferable to use activated carbon with a large specific surface area and cheap.

As the negative electrode active material, any carbon material capable of adsorption and desorption with lithium ions may be used, and for example, natural graphite, artificial graphite, mixed mesocarbon, mixed carbon fiber, cocos, carbon material heat treated, etc. , Hard carbon, soft carbon and the like can be used.

Specifically as the conductive material, graphite, carbon black, acetylene black, Ketjen black, or the like can be used.

As the binder, polyethylene, polypropylene, polyethylene terephthalate, aromatic polyamide, cellulose, styrene-butadiene rubber, or the like may be used, and the material is not particularly limited as long as it is a stable material for electrolyte.

In addition, the separator is located between the positive electrode and the negative electrode to prevent a short circuit caused by the contact between the two electrode plate active material and to hold and maintain the electrolyte solution required for the battery reaction. The separator is not particularly limited as long as it is insulating and can penetrate the nonaqueous electrolyte. Specific examples thereof include polyethylene, vinylon, polyamide, polypropylene, polyvinyl chloride, polyethylene, and other porous materials having pores or pores.

On the other hand, optionally, the capacitor may be manufactured including an electrode coating process, a pressure reduction impregnation process, a battery assembly process, an electrolyte injection process, and an initial charging process.

The electrode coating process may apply a material to assist the movement of ions to be free from the anode and the cathode of the capacitor electrode to the nano-sized pores (pore).

The material is applied to the compound containing at least one in the group consisting of Formula 1 to Formula 12 described above.

Next, the coated negative electrode and the positive electrode undergo a reduced pressure impregnation process.

The pressure reduction impregnation process is preferably carried out under reduced pressure and temperature within a range in which the material (compound containing at least one in the group consisting of Chemical Formulas 1 to 12) applied to the positive electrode and the negative electrode does not volatilize under a reduced pressure. The decompression time is appropriate as long as the applied materials are impregnated between the nanopores. The reduced pressure, temperature and time can be appropriately adjusted because the structure is different according to the formulas (1) to (12). That is, it carries out by adjusting pressure_reduction | reduced_pressure, temperature, and time in the range which does not volatilize.

In the battery assembly process, a battery type is manufactured using a positive electrode, a negative electrode, and a separator. In this case, the shape of the battery is not particularly limited, and may be manufactured in all battery types such as pouch type, rectangular type, cylindrical type as well as stacking type and winding type batteries.

Meanwhile, the reduced pressure impregnation and the battery assembly may be performed in a reversed order. That is, after assembling the battery using the positive electrode, the negative electrode, and the separator, the positive electrode and the negative electrode may be impregnated under reduced pressure.

Next, an electrolyte injection process is performed, and the electrolyte injection process is a process of injecting an electrolyte including a compound including at least one of Formulas 1 to 12 into the assembled battery.

After injecting the electrolyte, the capacitor may be completed through an initial charging process.

Capacitors prepared through such a manufacturing process are easily inserted and detached from cations and anions during charging or discharging at the nano-sized pores of the electrodes, thereby improving high-rate charging and discharging efficiency.

Hereinafter, embodiments of the present invention will be described in detail.

Example  One

The preparation of the electrolyte was performed by mixing an organic solvent obtained by mixing ethylene carbonate (EC): diethyl carbonate (DEC) in a volume ratio of 30:70 and compound 2-Isocyanatoethyl methacrylate having n 1 in formula 1 in 0.5M LiBF ₄ . Was prepared. The compound was added in 1 part by weight based on 100 parts by weight of the electrolyte.

In the manufacture of the capacitor, 2-Isocyanatoethyl methacrylate was applied to the positive electrode and the negative electrode and subjected to reduced pressure impregnation so as to freely move ions in the nano-sized pores in the positive electrode and the negative electrode. After carrying out the pressure reduction impregnation, the activated carbon and the lithium metal were cut to an appropriate size, and a separator made of a porous polyethylene film was inserted therebetween to prepare an electrode assembly. After inserting the electrode assembly into the pouch, the portion except the electrolyte injection hole was fused, and the electrolyte prepared above was injected into the injection hole to complete the capacitor.

Example  2 to 5

In the same manner as in Example 1, but the compound is 5 parts by weight (Example 2), 25 parts by weight (Example 3), 50 parts by weight (Example 4) and 70 parts by weight (100 parts by weight of the electrolyte) Example 5) was added.

Example  6

The preparation of the electrolyte was carried out by mixing an organic solvent in which ethylene carbonate (EC): diethyl carbonate (DEC) was mixed in a volume ratio of 30:70 and a compound Ethylene glycol methyl ether methacrylate consisting of n in Formula 11 in 0.5M LiBF ₄ . An electrolyte was prepared. The compound was added in 1 part by weight based on 100 parts by weight of the electrolyte.

In the manufacture of the capacitor, Ethylene glycol methyl ether methacrylate was applied to the positive electrode and the negative electrode in order to free the movement of ions in the nano-sized pores on the positive electrode and the negative electrode, and subjected to reduced pressure impregnation. After carrying out the pressure reduction impregnation, the activated carbon and the lithium metal were cut to an appropriate size, and a separator made of a porous polyethylene film was inserted therebetween to prepare an electrode assembly. After inserting the electrode assembly into the pouch, the portion except the electrolyte injection hole was fused, and the electrolyte prepared above was injected into the injection hole to complete the capacitor.

Example  7 to 10

In the same manner as in Example 6, but the compound is 5 parts by weight (Example 7), 25 parts by weight (Example 8), 50 parts by weight (Example 9) and 70 parts by weight (100 parts by weight of the electrolyte) Example 10) was added.

Example  11

The preparation of the electrolyte was prepared by mixing an organic solvent in which ethylene carbonate (EC): diethyl carbonate (DEC) was mixed in a volume ratio of 30:70 and a compound Hexyl methacrylate having n 6 in Formula 3 in 0.5M LiBF ₄ . It was. The compound was added in 1 part by weight based on 100 parts by weight of the electrolyte.

In the manufacture of the capacitor, Hexyl methacrylate was applied to the positive electrode and the negative electrode and subjected to reduced pressure impregnation so as to freely move ions in the nano-sized pores in the positive electrode and the negative electrode. After carrying out the pressure reduction impregnation, the activated carbon and the lithium metal were cut to an appropriate size, and a separator made of a porous polyethylene film was inserted therebetween to prepare an electrode assembly. After inserting the electrode assembly into the pouch, the portion except the electrolyte injection hole was fused, and the electrolyte prepared above was injected into the injection hole to complete the capacitor.

Example  12 to 15

In the same manner as in Example 6, but the compound is 5 parts by weight (Example 12), 25 parts by weight (Example 13), 50 parts by weight (Example 14) and 70 parts by weight (based on 100 parts by weight of the electrolyte) Example 15) was added.

Comparative example  One

In preparing the electrolyte, an electrolyte was prepared by mixing an organic solvent and 0.5 M LiBF ₄ mixed with ethylene carbonate (EC): diethyl carbonate (DEC) in a volume ratio of 30:70.

Capacitors were manufactured by conventional methods known in the art, in which activated carbon and lithium metal were cut to a suitable size, and a separator made of a porous polyethylene film was inserted therebetween to prepare an electrode assembly. After inserting the electrode assembly into the pouch, the portion except the electrolyte injection hole was fused, and the prepared electrolyte was injected into the injection hole to complete the capacitor.

Discharge capacities were measured after charging 0.2C, 1C, 2C, 5C, and 10C using the capacitors prepared in Examples and Comparative Examples. The measured results are shown in Table 1 below.

division compound
Compound content Discharge capacity (mAh / g) 0.2C 1C 2C 5C 10C Example 1 2-Isocyanatoethyl methacrylate One 78 76 65 52 45 Example 2 5 76 74 63 54 50 Example 3 25 77 73 70 61 51 Example 4 50 70 66 61 45 27 Example 5 70 23 22 20 18 15 Example 6 Ethylene glycol methyl ether methacrylate One 77 76 63 53 46 Example 7 5 65 57 50 45 41 Example 8 25 55 48 37 33 31 Example 9 50 41 39 27 13 11 Example 10 70 17 18 13 12 8 Example 11 Hexyl methacrylate One 74 65 60 54 42 Example 12 5 62 55 46 33 21 Example 13 25 45 42 35 32 15 Example 14 50 21 20 17 15 8 Example 15 70 15 14 10 8 7 Comparative Example 1 - - 69 55 39 26 3

As a result, when the capacitor was prepared using the electrolyte containing the compound according to the present invention, it was confirmed that the discharge capacity was superior to that of Comparative Example 1. In particular, in the case of high rate charging and discharging, the discharge capacity of Comparative Example 1 was significantly reduced, whereas in Examples 1 to 15, it was confirmed that the reduction of the discharge capacity was not large.

Through this, even when charging and discharging at a high rate, the overvoltage is not applied, and it can be confirmed that there is an effect that can improve the performance of the capacitor which requires a high rate characteristic.

The present invention described above is not limited to the above-described embodiments, and various substitutions, modifications, and changes can be made without departing from the technical spirit of the present invention. It will be obvious to him.

Claims (7)

An electrolyte having improved high rate charging / discharging characteristics including a compound included in at least one of the following Chemical Formulas 1 to 12:
[Formula 1]

(2)

(3)

[Chemical Formula 4]

[Chemical Formula 5]

[Chemical Formula 6]

(7)

[Chemical Formula 8]

[Chemical Formula 9]

[Formula 10]

(11)

[Chemical Formula 12]

The method of claim 1,
The compound is improved electrolyte with high rate charge and discharge characteristics, characterized in that it comprises 0.5 to 70 parts by weight based on 100 parts by weight of the electrolyte. The method of claim 1,
The electrolyte is an electrolyte having improved high-rate charging and discharging characteristics including the compound, an electrolytic salt, and a non-aqueous organic solvent. The method of claim 3,
The electrolytic salt is LiPF ₆ , LiBF ₄ , LiTFSI, LiSbF ₆ , LiAsF ₆ , LiClO ₄ , LiCF ₃ SO ₃ , Li (CF ₃ SO ₂ ) ₂ N, LiC ₄ F ₉ SO ₃ , LiSbF ₆ , LiAlO ₄ , LiAlCl ₄ , LiN (C _x F _{2x + 1} SO ₂ ) (C _y F _{2y +1} SO ₂ ) (where x, y is a natural number), high rate insect characterized in that the mixture of one or more from the group consisting of LiCl, LiI Electrolyte with improved discharge characteristics. The method of claim 3,
The non-aqueous organic solvent is ethylene carbonate (EC), propylene carbonate (PC), dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), 1,2-dimethoxy Ten (DME), γ-butyrolactone (BL), tetrahydrofuran (THF), 1,3-dioxolane (DOL), diethylether (DEE), methyl formate (MF), methylpropio Nate (MP), sulfolane (S), dimethyl sulfoxide (DMSO) and acetonitrile (AN) in the group consisting of at least one mixed electrolyte, characterized in that the high rate charge and discharge characteristics improved. A capacitor comprising the electrolyte according to any one of claims 1 to 5. The method according to claim 6,
The capacitor is a capacitor, characterized in that produced by the electrode coating process, pressure reduction impregnation process, battery assembly process, electrolyte injection process and initial charging process.