Method for manufacturing electrode for supercapacitor

Abstract

The present invention provides, in one embodiment, a method for manufacturing an electrode for a supercapacitor, comprising the steps of: preparing, in a slurry state, an electrode composition containing a carbon material; drying the electrode composition so as to form an electrode solid, pulverizing the electrode solid, and then vacuum drying same, thereby preparing an electrode composite; pressing the electrode composite, thereby forming an electrode composite film; and arranging the electrode composite film on an electrode current collector and pressing same.

Description

Method for manufacturing electrodes of supercapacitors

[0001] The present disclosure relates to a method for manufacturing an electrode of a supercapacitor, and more specifically, to a method for manufacturing an electrode of a supercapacitor having high electrode density and high power density and excellent capacity characteristics.

[0002]

[0003] Recently, electric double layer capacitors (EDLCs), also known as super capacitors, are being considered for application to various systems for efficient energy management, such as electric vehicles (EVs), energy storage systems (ESSs), and renewable energy.

[0004] In particular, supercapacitors can supplement batteries used as the main power source for electric vehicle operation by providing high-power energy required for rapid acceleration of electric vehicles and recovering energy generated instantaneously, thereby enabling commercial operation of electric vehicles.

[0005] Supercapacitors must store enough energy to provide the energy required for driving, and to effectively manage the cost, volume, and weight associated with this, supercapacitors must have very high power density per volume and weight, long life, and low cost.

[0006] Additionally, supercapacitors are increasingly being used as electronic components in the electronics industry due to their performance and characteristics.

[0007] As the power consumption of semiconductors such as complementary metal oxide semiconductors (CMOS) commonly used in various electronic equipment or devices has been minimized, supercapacitors with a capacitance of 1 Farad are attracting attention as memory backup applications because they can replace nickel-cadmium or lithium batteries and provide backup power for several months.

[0008] Compared with conventional electrolytic capacitors, polymer capacitors, tantalum capacitors, etc., supercapacitors use porous activated carbon series electrodes to form a large effective surface area, and store energy in an electric double layer formed at the interface between the electrolyte and the electrode, thereby providing a high volumetric capacitance density (about 10 to 100 times that of conventional capacitors).

[0009] In these supercapacitors, continuous efforts are being made to provide supercapacitors with higher electrode density, superior electrostatic capacity, and high power density.

[0010] [Prior Art Literature]

[0011] [Patent Document]

[0012] (Patent Document 1) Republic of Korea Patent Publication No. 10-2021-0149993 (December 10, 2021)

[0013] One of the objects of the present invention is to provide a method for manufacturing an electrode of a supercapacitor to provide a supercapacitor having high electrode density, excellent electrostatic capacity and high power density.

[0014]

[0015] The present invention provides, as one embodiment, a method for manufacturing an electrode of a supercapacitor, comprising the steps of: preparing an electrode composition in a slurry state including a carbon material; drying the electrode composition to form an electrode solid, pulverizing the electrode solid, and vacuum drying the same to manufacture an electrode composite; pressing the electrode composite to form an electrode composite film; and placing and pressing the electrode composite film on an electrode current collector.

[0016]

[0017] The present invention can provide a method for manufacturing an electrode of a supercapacitor for providing a supercapacitor having a high electrode density, excellent electrostatic capacity and high power density as one effect.

[0018]

[0019] The present invention will be described in detail below. However, it should be noted that the present invention is not limited to the contents described herein. Those skilled in the art will be able to implement the present invention in various forms, based on the contents described herein, without departing from the technical spirit of the present invention. Such modifications should also be understood to fall within the scope of the present invention.

[0020]

[0021] A method for manufacturing an electrode of a supercapacitor according to one embodiment of the present invention may include the following steps.

[0022] (s1) A step of preparing a slurry-state electrode composition containing carbon material,

[0023] (s2) A step of drying the electrode composition to form an electrode solid, pulverizing the electrode solid, and then vacuum drying to manufacture an electrode complex.

[0024] (s3) a step of forming an electrode composite film by pressing the electrode composite, and

[0025] (s4) A step of placing the electrode composite film on the electrode collector and applying pressure.

[0026]

[0027] The type of carbon material included in the electrode composition is not particularly limited, and activated carbon, graphene, carbon nanotubes, carbon fibers, carbon fibers, or mixtures thereof may be used.

[0028]

[0029] As the carbon material, a carbon material may be used in which the pore volume of pores having a pore diameter of 17 Å or less is 30% or less of the total pore volume. In other words, the pore distribution of the carbon material may be such that the pore volume of pores having a pore diameter greater than 17 Å is more than 70% of the total pore volume. More preferably, the pore distribution of the carbon material may be such that the pore volume of pores having a pore diameter of 17 Å or less is 29% or less, 28% or less, 27% or less, 26% or less, 25% or less, or 24% or less of the total pore volume. In addition, the pore distribution of the carbon material may be such that the pore volume of pores having a pore diameter of 17 Å or less is 0% or more, 1% or more, 2% or more, 3% or more, 4% or more, or 5% or more of the total pore volume, or may be 0%. At this time, the pore distribution of the carbon material may be such that the pore volume of the pores having a pore diameter of 17Å to 500Å among the pores having a pore diameter exceeding 17Å may be 70% or more, and the average pore diameter may be 20Å to 150Å, more preferably 50Å to 100Å. By using such a carbon material, the solvent molecules of the electrolyte can be sufficiently penetrated into the pores of the carbon material.

[0030] In addition, carbon materials having a particle size distribution of 0.01 to 5 ㎛ in D10, 3.1 to 15 ㎛ in D50, and 8.1 to 50 ㎛ in D90 can be used. D10, D50, and D90 represent particle sizes corresponding to 10%, 50%, and 90%, respectively, when measuring particle size and accumulating volume from the smallest particle size, and are known units that indicate the results analyzed through a particle size analyzer, so a further detailed explanation thereof will be omitted.

[0031] A method for manufacturing a carbon material included in a composite for an electrode of a supercapacitor according to one embodiment of the present invention may include (s1) a step of carbonizing biomass to manufacture biochar, (s2) a step of pulverizing the carbonized biochar, and (s3) a step of removing impurities from the pulverized biochar.

[0032] The step of carbonizing the biomass can be performed by introducing the biomass into a heating zone with different temperature ranges.

[0033] For example, the step of carbonizing biomass may include carbonization steps of 1 to 6, wherein step 1 may be performed at a temperature of 170°C to 200°C, step 2 may be performed at a temperature of 200°C to 280°C, step 3 may be performed at a temperature of 280°C to 500°C, step 4 may be performed at a temperature of 500°C to 700°C, step 5 may be performed at a temperature of 700°C to 800°C, and step 6 may be performed at a temperature of 800°C to 1,100°C, and may be performed for a total time of 3 to 60 minutes.

[0034] The biochar formed after carbonization has a carbon content of more than 98 wt% and becomes a high-density carbon material.

[0035] At this time, a single-layer carbon material may be formed, but generally, a carbon material with a layered structure having a small number of layers, such as 1.5 layers, 2 layers, 2.5 layers, or 3 layers, is formed.

[0036] The step of crushing carbonized biochar can be performed to ensure that biochar particles of various particle sizes have a predetermined particle size. The biochar can be crushed to an average particle size of 1 μm to 100 μm, and various technologies, such as commonly used ball mills and blade mixers, can be applied without limitation to the specific method of crushing the biochar.

[0037] The step of removing impurities from the pulverized biochar may include only a single impurity removal step, but it may be preferable to include multiple impurity removal steps.

[0038] The first impurity removal step can be performed to remove metal impurities such as iron (Fe) contained in the biochar, and can be performed, for example, by passing the biochar through a magnetic track at a constant flow rate of 1 m / min to 5 m / min.

[0039] Secondary and tertiary impurity removal steps may be performed to further remove more microscopic impurities, and may be performed by sequentially immersing the biochar in an acidic aqueous solution and a basic aqueous solution.

[0040] The secondary impurity removal step can be performed, for example, by immersing the biochar that has passed through the magnetic track in a 10 wt% to 50 wt% hydrochloric acid solution for 1 to 6 hours, then removing the hydrochloric acid component with distilled water in a volume of 200% to 5,000% of the 10 wt% to 50 wt% hydrochloric acid solution, filtering, and drying at a temperature of 60°C to 120°C. The type of acidic aqueous solution is not particularly limited, and various known acidic aqueous solutions other than the hydrochloric acid solution can be used.

[0041] In addition, the third impurity removal step can be performed by, for example, immersing biochar that has been washed with an acidic solution, neutralized with distilled water, and then dried in a 10 wt% to 50 wt% potassium hydroxide solution for 1 to 6 hours, then removing the potassium hydroxide component with distilled water in a volume of 200% to 5,000% of the 10 wt% to 50 wt% potassium hydroxide solution, filtering, and drying at a temperature of 60°C to 120°C. The type of alkaline aqueous solution is not particularly limited, and various known alkaline aqueous solutions other than the potassium hydroxide solution can be used.

[0042] The biochar manufactured through the above-described process exhibits characteristics similar to, yet different from, commercial graphene, and has characteristics suitable for use as an electrode material for supercapacitors.

[0043]

[0044] The activated carbon may have a particle size distribution of 4 to 4.3 ㎛ at D10, 5 to 5.5 ㎛ at D50, and 6 to 6.5 ㎛ at D90. If the particle diameter of the activated carbon is less than the aforementioned range, there may be a problem of a decrease in the specific surface area of ​​the activated carbon. This is because the pore structure inside the particle is destroyed and the surface area is offset, and as a result, after the electrode body is manufactured, the binder invasion range may become relatively wide, which may cause a phenomenon of an increase in resistance and a rapid decrease in electrostatic capacity. On the other hand, if the particle diameter of the activated carbon is more than the aforementioned range, the pores between the particles may increase during the manufacture of the electrode body, which may increase the possibility of cracks, lower the strength of the electrode, and increase the porosity, which may cause a problem of a decrease in the density of the electrode.

[0045]

[0046] The activated carbon may be at least one of, but is not limited to, coconut shell-based carbonized activated carbon, phenol resin-based carbonized activated carbon, and coke pitch-based carbonized activated carbon. The coconut shell-based carbonized activated carbon may have a specific surface area of ​​1,500 to 3,000 m2 / g and a particle size distribution of 3 to 5 μm at D10, 5 to 9 μm at D50, and 9 to 15 μm at D90. The phenol resin-based carbonized activated carbon may have a specific surface area of ​​1,500 to 3,000 m2 / g and a particle size distribution of 5 to 9 μm at D10, 10 to 11 μm at D50, and 11 to 15 μm at D90. The coke pitch-based carbonized activated carbon may have a specific surface area of ​​1,500 to 3,000 m2 / g and a particle size distribution of 5 to 9 μm at D10, 10 to 11 μm at D50, and 11 to 15 μm at D90.

[0047]

[0048] The electrode current collector is not particularly limited as long as it can be used as an electrode current collector of a supercapacitor, and aluminum (Al), copper (Cu), nickel (Ni), stainless steel, titanium (Ti), chromium (Cr), manganese (Mn), iron (Fe), zinc (Zn), silver (Ag), gold (Au), platinum (Pt), or an alloy thereof can be used.

[0049]

[0050] The electrode composition may further include at least one of a conductive additive and a binder in addition to the carbon material. Preferably, the electrode composition may include all of the carbon material, the conductive additive, and the binder.

[0051]

[0052] Conductive additives can be used as additives in electrode compositions to compensate for the low electrical conductivity and high resistance of carbon materials. Examples of conductive additives include carbon blacks, such as Ketjen black, acetylene black, or Super-P, either in single or multiple forms.

[0053]

[0054] As a binder, at least one of a rubber type such as SBR (styrene butadiene rubber), an elastomer type such as BM400B, and a Teflon type binder such as polytetrafluoroethylene can be used.

[0055]

[0056] In step (s1), the electrode composition may be in a slurry state. In other words, the electrode composition may be in a state in which a carbon material is dispersed in a dispersing agent. It should be noted that the slurry electrode composition may further include at least one of a carbon material and a conductive additive. From this perspective, step (s1) may include the following steps.

[0057] (a1) Step of preparing carbon material, conductive additive and binder,

[0058] (a2) a step of preparing a conductive additive slurry by mixing the conductive additive with a dispersing agent including a dispersing medium, and

[0059] (a3) A step of mixing the carbon material, the conductive additive slurry, and the binder.

[0060]

[0061] However, the dispersing agent may be mixed first with the carbon material or binder rather than the conductive additive. Alternatively, the dispersing agent may be mixed simultaneously with two or more of the carbon material, the conductive additive, and the binder.

[0062]

[0063] The description of each of the carbon material, conductive additive, and binder prepared in the step of preparing the carbon material, conductive additive, and binder is as described above.

[0064]

[0065] The step of preparing a conductive additive slurry by mixing a conductive additive with a dispersing agent containing a dispersing medium can be performed by adding the dispersing agent containing the dispersing medium to the conductive additive and performing dispersion stirring using a planetary mixer, a roll mixer, a pigment mixer, or the like. The dispersing agent can be added in an amount of 45 to 60 wt% to 40 to 55 wt% of the conductive additive.

[0066]

[0067] When using an aqueous binder as a dispersion medium, distilled water, isopropyl alcohol, ethanol, or ethyl acetate can be used alone, or distilled water can be mixed with one or two other dispersion mediums. In addition, when using an organic binder such as polyvinylidene fluoride (PVDF), N-methyl-pyrrolidone (NMP) can be used alone as a dispersion medium.

[0068]

[0069] In order to improve dispersibility, the dispersing agent may further include a dispersing agent such as carboxymethylcellulose in addition to the dispersion medium. The dispersing agent may be mixed in a ratio of 0.1 to 1.0 wt% based on the total weight of the dispersing agent. For example, the step of preparing a conductive additive slurry may be performed by mixing a dispersion medium and a dispersing agent to prepare a dispersing agent, adding the prepared dispersing agent to the conductive additive, and then performing dispersion stirring. As a more specific example, the conductive additive slurry may be prepared by mixing carboxymethylcellulose in a composition of 0.1 to 1.0 wt% in a dispersion medium such as distilled water, soft water, or higher alcohol to prepare a dispersing agent, and then adding 45 to 60 wt% of the prepared dispersing agent to 40 to 55 wt% of the conductive additive, and then performing dispersion stirring.

[0070]

[0071] In the step of mixing the carbon material, conductive additive slurry, and binder, the carbon material, conductive additive slurry, and binder may be mixed all at once, or may be mixed sequentially. For example, the electrode composition may be prepared by adding the conductive additive slurry to the carbon material and mixing them, then adding the binder to the mixture of the carbon material and conductive additive slurry and mixing them. The mixing may be performed by dispersing and stirring using a planetary mixer, a roll mixer, a pigment mixer, or the like.

[0072]

[0073] At this time, the content of the carbon material, conductive additive slurry, and binder in the electrode composition may be 70 to 85 wt%: 5 to 25 wt%: 4.6 to 5.8 wt% based on the total weight of the electrode composition. By mixing the carbon material, conductive additive slurry, and binder in such a ratio, a more uniform dispersion effect can be achieved. In addition, as the binder, a first binder and a second binder, which are different types of binders, may be mixed and used, and in this case, the content of the first binder and the second binder may be 0.1 to 0.5 wt%: 4.5 to 5.3 wt% based on the total weight of the electrode composition. The first binder may be a rubber-based SBR (styrene butadiene rubber) binder or an elastomer-based BM400B binder, and the second binder may be a Teflon-based polytetrafluoroethylene binder, and may be a binder that is introduced later. For example, the electrode composition can be manufactured in a semi-solid state by mixing 15 to 25 wt% of a conductive additive slurry with 70 to 80 wt% of a carbon material, performing primary dispersion stirring using a planetary mixer, a roll mixer, a pigment mixer, etc., then adding the manufactured primary slurry and 0.1 to 0.5 wt% of a rubber-based SBR (styrene butadiene rubber) or an elastomer-based BM400B binder to a stirrer, performing secondary dispersion stirring, and then adding 4.5 to 5.3 wt% of a Teflon-based polytetrafluoroethylene binder into the stirrer, and performing a third dispersion stirring.

[0074]

[0075] In step (s2), drying the electrode composition to form an electrode solid can be performed to remove moisture from the outer and inner surfaces of the manufactured electrode composition, and can be performed at a temperature of, for example, 60°C to 150°C. Within the above temperature range, a favorable effect can be obtained in forming a composite film having excellent mechanical strength and uniform density across electrode portions. If the temperature is lower than the above temperature range, the mechanical strength may be excellent, but the density across electrode portions may not be uniform, and if the temperature is higher than the above temperature range, a negative effect may be generated in which a composite film having uniform density across electrode portions but low mechanical strength is formed. At this time, moisture on the surface of the electrode composition may be completely removed, but some of it may not be completely removed and may remain. Thereafter, when the electrode solid is pulverized, the electrode solid is pulverized into a powder or granule state. The pulverization can be performed using a blade mixer, etc. Subsequent vacuum drying of the electrode solid can be performed to remove moisture inside the pores, and can be performed at a temperature of, for example, 150°C to 200°C.

[0076]

[0077] (s3) In step (s3), the pressing of the vacuum-dried powder or granule-state electrode composite may be performed using a heating roll press, etc. The pressing may be performed once alone, or may be performed multiple times, such as twice or three times. Among these, it may be preferable to press the electrode composite three times. The first pressing may be performed by maintaining the roll surface temperature of the heating roll press at 40°C to 120°C, while putting the powder or granule-state electrode composite between rolls and pressing it to form an electrode composite film having a thickness of 170 to 200 μm. The second pressing may be performed by maintaining the roll surface temperature of the heating roll press at 40°C to 120°C, while putting the first press-formed electrode composite film between rolls and pressing it to form an electrode composite film having a thickness of 80 to 120 μm. The third pressurization may be performed by placing the second press-formed electrode composite film between rolls and pressurizing it while maintaining the roll surface temperature of the heating roll press at room temperature of 25℃, thereby pressurizing and forming an electrode composite film having a thickness of 50 to 80㎛. The final pressurization, for example, the third roll pressurization, may be performed at room temperature to minimize the thickness variation of the electrode composite film.

[0078]

[0079] In step (s4), the electrode current collector combined with the electrode composite film may have a conductive layer on at least one side, and in this respect, step (s4) may include the following steps.

[0080] (b1) a step of manufacturing a conductive layer paste,

[0081] (b2) a step of manufacturing an electrode current collector having a conductive layer by coating the conductive layer paste on a metal foil and drying it;

[0082] (b3) a step of vacuum drying the electrode current collector having the conductive layer, and

[0083] (b4) A step of placing an electrode composite film on an electrode current collector having the conductive layer so as to face the conductive layer and applying pressure.

[0084]

[0085] The conductive layer paste is intended to bond the electrode composite film to the electrode current collector, and includes a carbon material having excellent electrical conductivity and a conductive additive, and may further include a binder. The conductive layer paste may be prepared, for example, by mixing a carbon material and a conductive additive slurry (a mixture of a conductive additive and a dispersing agent), performing primary dispersion stirring using a planetary mixer, a roll mixer, a pigment mixer, etc., and then adding a binder to the primary slurry thus prepared and performing secondary dispersion stirring. At this time, the carbon material, the conductive additive slurry, and the binder may be mixed in a ratio of 1 to 20 wt%: 70 to 90 wt%: 5 to 10 wt%. By mixing the carbon material, the conductive additive slurry, and the binder in such a ratio, a more uniform dispersion effect can be achieved. The carbon material and conductive additive slurry may be the same as those described above in the description of the electrode composition, and a detailed description thereof will be omitted. The binder may also be the same as those described above in the description of the electrode composition, and for example, rubber-based SBR (styrene butadiene rubber) or elastomer-based BM400B may be used. The viscosity of the manufactured conductive layer paste may be 10,000 to 100,000 cP, and the sheet resistance may be 0.5 Ω / cm3 to 5.0 Ω / cm3.

[0086]

[0087] In the step of manufacturing an electrode current collector having a conductive layer by coating a conductive layer paste on a metal foil and drying it, the coating can be performed by a known method such as a doctor blade, a comma roll, gravure, or spray coating. The conductive layer paste can be coated on one or both sides of the metal foil. The coating thickness during coating can be adjusted so that the thickness of the conductive layer formed after drying is 1 to 10 μm, and can be coated to a thickness of, for example, 10 to 50 μm. The metal foil can be an aluminum foil or an etched aluminum foil, and the thickness of the metal foil can be, but is not limited to, 5 to 50 μm. The drying can be performed at a temperature of, for example, 40°C to 120°C.

[0088]

[0089] The step of vacuum drying the electrode current collector having the conductive layer can be performed to remove moisture, and can be performed at a temperature of, for example, 150°C to 200°C.

[0090]

[0091] In the step of arranging the electrode composite film on the electrode current collector having the conductive layer so as to face the conductive layer and applying pressure, the pressing may be performed using a heating roll press or the like. For example, the step may be performed by arranging the electrode composite film on one or both sides of an aluminum current collector having a conductive layer on one or both sides, and applying pressure once while maintaining the roll surface temperature of the heating roll press at 40°C to 120°C. The thickness of the electrode after pressing may be 85% or more of the total thickness of the thickness of the electrode composite film before pressing and the thickness of the electrode current collector having the conductive layer. Here, the electrode means that the current collector having the electrode conductive layer and the composite film are combined by pressing. If the thickness of the electrode after pressing is less than the above range, it is difficult for the electrolyte to penetrate into the pores, which may cause a loss of electrical performance of the supercapacitor, and the expansion rate of the electrode increases during charge and discharge of the supercapacitor, which increases the possibility of cracking in the separator.

[0092]

[0093] Meanwhile, in the wet coating method of coating a slurry-state electrode composition on the surface of a metal current collector such as aluminum, drying occurs together with the coating, so when the slurry dries, migration occurs in which the binder contained in the slurry intensively floats to the upper surface of the electrode as the vaporized dispersion solvent moves, which increases the resistance of the electrode surface. In addition, since the moisture inside the electrode must be removed while it is wound in a roll shape during the manufacturing process, there is a problem in that the moisture that has penetrated into the pores inside the winding (core) cannot be completely removed. On the other hand, in the present invention, since the electrode solid content in the powder or granule state is directly vacuum-dried, even the moisture inside the pores can be removed, and since migration does not occur, it is possible to prevent a decline in electrical performance and an increase in internal pressure due to the decomposition of moisture that occurs during long-term use of the supercapacitor.

[0094]

[0095] In addition, by press-molding the electrode composite manufactured in powder form using a roll press, the density of the electrode can be controlled, and by controlling the thickness of the electrode through a simple operation of the roll press, the electrostatic capacity can be controlled. In addition, by performing a pressurizing process using a roll heated to a temperature of 40℃ to 120℃ on the current collector having the conductive layer and the electrode composite film, the pores of the electrode material are sufficiently sealed, and furthermore, the carbon material and the conductive additive are sufficiently sealed to each other, resulting in close contact, and as the density of particles per unit volume increases, the contact resistance can be reduced. This can ultimately lead to the effect of reducing the internal resistance of the supercapacitor.

[0096]

[0097] In addition, the electrode of the supercapacitor manufactured by the method for manufacturing the supercapacitor electrode according to the present invention can have a high electrode density and a low electrode surface resistance. Accordingly, the supercapacitor electrode according to the present invention can be formed with a thinner thickness compared to other electrodes having the same electrostatic capacity, and can exhibit a high output density due to the high electrostatic capacity and low resistance characteristics due to the high electrode density compared to other electrodes having the same thickness or volume.

[0098]

[0099] Hereinafter, the present invention will be described in more detail through examples.

[0100] Meanwhile, the following examples are merely intended to illustrate the present invention and do not represent all of the technical ideas of the present invention. Therefore, it should be understood that there may be various equivalents and modified examples that can replace the following examples at the time of filing this application.

[0101]

[0102] Manufacturing example: Manufacturing of carbon materials

[0103] In the following examples and some comparative examples, carbon materials manufactured according to the manufacturing examples were used as described below. The carbon materials manufactured according to the manufacturing examples were manufactured as biochar formed by carbonizing oak as biomass according to the steps (s1) to (s3) described above. At this time, in step (s1), all of the carbonization steps 1 to 6 described above were performed, in step (s2), the biochar was pulverized with a ball mill, and in step (s3), all of the first to third impurity removal steps described above were performed.

[0104] In the carbon material manufactured according to the manufacturing example, the pore volume of pores having a pore diameter of 17 Å or less was measured to be 23.39% of the total pore volume.

[0105] In addition, the specific surface area of ​​the carbon material manufactured according to the manufacturing example was 62.55 m2 / g, and the particle size distribution was 3.4 μm at D10, 5.9 μm at D50, and 9.1 μm at D90.

[0106]

[0107] Example 1

[0108] A dispersing agent was prepared with a composition of distilled water and 0.2 wt% of carboxymethylcellulose (the amount of the dispersing agent is such that the proportion of carboxymethylcellulose is 0.2 wt% based on the total mass of the powdered conductive additive, powdered carbon material, activated carbon, and binder), and the prepared dispersing agent was added to 10 wt% of the powdered conductive additive super-P, followed by dispersion stirring using a planetary mixer to prepare a conductive additive slurry.

[0109] The pore volume of pores with a pore diameter of 17Å or less in the manufactured conductive additive slurry is 23.39% of the total pore volume, and the powdered carbon material manufactured according to the manufacturing example having a particle size distribution of 3.4㎛ at D10, 5.9㎛ at D50, and 9.1㎛ at D90 and the mixed powder of coconut shell-based carbonized activated carbon (YP-50) having a specific surface area of ​​1,500㎡ / g and a particle size distribution of 3㎛ at D10, 7㎛ at D50, and 15㎛ at D90 were added, and dispersion stirring was performed using a planetary mixer to prepare a solid slurry. At this time, the powdered carbon material and the activated carbon were added in a weight ratio of 8:2 (carbon material: activated carbon) and 85 wt% based on the total weight of the electrode composition to prepare a solid slurry.

[0110] The manufactured solid slurry of 95.2 wt% and SBR binder of 0.3 wt% were placed in a stirrer and subjected to secondary dispersion stirring, then mixed with polytetrafluoroethylene binder of 4.5 wt% and subjected to a third dispersion stirring, thereby producing a semi-solid electrode composition.

[0111] The manufactured electrode composition was dried at a temperature of 100°C, and the electrode solid from which moisture had been removed was ground into granules using a blade mixer. Next, the granule-like electrode solid was vacuum-dried at a temperature of 150°C to manufacture an electrode composite.

[0112] While maintaining the roll surface temperature of the heating roll press at 80°C, the manufactured electrode composite was placed between the rolls and subjected to a first press molding to a thickness of 180 to 190 μm. Next, while maintaining the roll surface temperature of the heating roll press at 40°C, the first press molded electrode composite film was subjected to a second press molding to a thickness of 100 to 110 μm. Thereafter, while maintaining the roll surface temperature of the heating roll press at room temperature of 25°C, the second press molded electrode composite film was subjected to a third press molding to a thickness of 60 μm, thereby producing an electrode composite film.

[0113] According to the manufacturing example, 13 wt% of carbon material powder was prepared, and 80 wt% of the conductive additive slurry prepared as described above was mixed, and after the first dispersion stirring was performed with a planetary mixer, the prepared first slurry and 7 wt% of SBR binder were added to the stirrer, and the second dispersion stirring was performed, thereby preparing a conductive layer paste having a viscosity of 60,000 cP. The prepared conductive layer paste was coated on one side of an 18 μm aluminum foil using a doctor blade to a thickness of 15 μm, dried at a temperature of 100°C to form a conductive layer having a thickness of 4 μm, and then vacuum-dried at a temperature of 150°C to remove moisture. The prepared electrode composite film was placed on an aluminum current collector having a conductive layer, and pressurized once while maintaining the roll surface temperature of a heating roll press at 80°C.

[0114] The total thickness of the electrode of the completed supercapacitor after roll pressing was 78 μm, and the electrode density was 1.17 g / cm3. The specific capacity was calculated as 56 μm, excluding the thickness of the electrode current collector having the conductive layer, 22 μm from the total thickness of the electrode of the supercapacitor, 78 μm.

[0115]

[0116] Example 2

[0117] A dispersing agent was prepared with a composition of distilled water and 0.2 wt% of carboxymethylcellulose, and the prepared dispersing agent was added to 9.5 wt% of powdered conductive additive super-P (the amount of the dispersing agent is such that the ratio of carboxymethylcellulose is 0.2 wt% based on the total mass of the powdered conductive additive, powdered carbon material, activated carbon, and binder), and then dispersion stirring was performed using a planetary mixer to prepare a conductive additive slurry.

[0118] In the manufactured conductive additive slurry, the pore volume of pores with a pore diameter of 17Å or less is 23.39% of the total pore volume, and the powdered carbon material manufactured according to the manufacturing example having a particle size distribution of 3.5㎛ at D10, 13㎛ at D50, and 39㎛ at D90 and the mixed powder of phenol resin-based carbonized activated carbon (MSP-20) having a specific surface area of ​​1,750㎡ / g and a particle size distribution of 5㎛ at D10, 11㎛ at D50, and 15㎛ at D90 were added, and dispersion stirring was performed using a planetary mixer to prepare a solid slurry. At this time, the powdered carbon material and the activated carbon were added in a weight ratio of 8:2 (carbon material:activated carbon) and 84.5 wt% based on the total weight of the electrode composition to prepare a solid slurry.

[0119] The manufactured solid slurry of 94.2 wt% and SBR binder of 0.5 wt% were placed in a stirrer and subjected to secondary dispersion stirring, then mixed with polytetrafluoroethylene binder of 5.3 wt% and subjected to a third dispersion stirring, thereby producing a semi-solid electrode composition.

[0120] The manufactured electrode composition was dried at a temperature of 100°C, and the electrode solid from which moisture had been removed was ground into granules using a blade mixer. Next, the granule-like electrode solid was vacuum-dried at a temperature of 150°C to manufacture an electrode composite.

[0121] While maintaining the roll surface temperature of the heating roll press at 70°C, the manufactured electrode composite was placed between the rolls and subjected to a first pressure molding to a thickness of 180 to 190 μm. Next, while maintaining the roll surface temperature of the heating roll press at 40°C, the first pressure molded electrode composite film was subjected to a second pressure molding to a thickness of 80 to 90 μm. Thereafter, while maintaining the roll surface temperature of the heating roll press at room temperature of 25°C, the second pressure molded electrode composite film was subjected to a third pressure molding to a thickness of 60 to 65 μm, thereby producing an electrode composite film.

[0122] According to the manufacturing example, 13 wt% of carbon material powder was prepared, and 80 wt% of the conductive additive slurry prepared as described above was mixed, and after the first dispersion stirring was performed with a planetary mixer, the prepared first slurry and 7 wt% of SBR binder were added to the stirrer, and the second dispersion stirring was performed, thereby preparing a conductive layer paste having a viscosity of 60,000 cP. The prepared conductive layer paste was coated on one side of an 18 μm aluminum foil using a doctor blade to a thickness of 15 μm, dried at a temperature of 100°C to form a conductive layer having a thickness of 4 μm, and then vacuum-dried at a temperature of 150°C to remove moisture. The prepared electrode composite film was placed on an aluminum current collector having a conductive layer, and pressurized once while maintaining the roll surface temperature of a heating roll press at 80°C.

[0123] The total thickness of the electrode of the completed supercapacitor after roll pressing was 80 μm, and the electrode density was 1.23 g / cm3. The specific capacity was calculated as 58 μm, excluding the thickness of the electrode current collector having the conductive layer, 22 μm from the total thickness of the electrode of the supercapacitor of 80 μm.

[0124]

[0125] Example 3

[0126] A dispersing agent was prepared with a composition of distilled water and 0.2 wt% of carboxymethylcellulose, and the prepared dispersing agent was added to 9 wt% of powdered conductive additive super-P (the amount of the dispersing agent is such that the ratio of carboxymethylcellulose is 0.2 wt% based on the total mass of the powdered conductive additive, powdered carbon material, activated carbon, and binder), and then dispersion stirring was performed using a planetary mixer to prepare a conductive additive slurry.

[0127] The pore volume of pores having a pore diameter of 17Å or less is 23.39% of the total pore volume in the manufactured conductive additive slurry, and the powdered carbon material manufactured according to the manufacturing example having a particle size distribution of 3.5㎛ at D10, 13㎛ at D50, and 39㎛ at D90 and the mixed powder of coke pitch-based carbonized activated carbon (CEP-21KS) having a specific surface area of ​​1,850㎡ / g and a particle size distribution of 5㎛ at D10, 10㎛ at D50, and 15㎛ at D90 were added, and dispersion stirring was performed using a planetary mixer to prepare a solid slurry. At this time, the powdered carbon material and the activated carbon were added in a weight ratio of 8:2 (carbon material:activated carbon) and 85 wt% based on the total weight of the electrode composition to prepare a solid slurry.

[0128] The manufactured solid slurry of 90 wt% and SBR binder of 0.5 wt% were added to a stirrer and subjected to secondary dispersion stirring, then mixed with polytetrafluoroethylene binder of 5.3 wt% and subjected to a third dispersion stirring, thereby producing a semi-solid electrode composition.

[0129] The manufactured electrode composition was dried at a temperature of 100°C, and the electrode solid from which moisture had been removed was ground into granules using a blade mixer. Next, the granule-like electrode solid was vacuum-dried at a temperature of 150°C to manufacture an electrode composite.

[0130] While maintaining the roll surface temperature of the heating roll press at 90°C, the manufactured electrode composite was placed between the rolls and subjected to a first pressure molding to a thickness of 180 to 190 μm. Next, while maintaining the roll surface temperature of the heating roll press at 60°C, the first pressure molded electrode composite film was subjected to a second pressure molding to a thickness of 100 to 110 μm. Thereafter, while maintaining the roll surface temperature of the heating roll press at room temperature of 25°C, the second pressure molded electrode composite film was subjected to a third pressure molding to a thickness of 60 to 65 μm, thereby producing an electrode composite film.

[0131] According to the manufacturing example, 13 wt% of carbon material powder was prepared, and 80 wt% of the conductive additive slurry prepared as described above was mixed, and after the first dispersion stirring was performed with a planetary mixer, the prepared first slurry and 7 wt% of SBR binder were added to the stirrer, and the second dispersion stirring was performed, thereby preparing a conductive layer paste having a viscosity of 60,000 cP. The prepared conductive layer paste was coated on one side of an 18 μm aluminum foil using a doctor blade to a thickness of 15 μm, dried at a temperature of 100°C to form a conductive layer having a thickness of 4 μm, and then vacuum-dried at a temperature of 150°C to remove moisture. The prepared electrode composite film was placed on an aluminum current collector having a conductive layer, and pressurized once while maintaining the roll surface temperature of a heating roll press at 80°C.

[0132] The total thickness of the electrode of the completed supercapacitor after roll pressing was 75 μm, and the electrode density was 1.31 g / cm3. The specific capacity was calculated as 53 μm, excluding the thickness of the electrode current collector having the conductive layer, 22 μm from the total thickness of the electrode of the supercapacitor, 75 μm.

[0133]

[0134] Comparative Example 1

[0135] The pore volume of pores having a pore diameter of 17 Å or less is 23.39% of the total pore volume, and the powdered carbon material manufactured according to the manufacturing example having a particle size distribution of 3.4 ㎛ at D10, 5.9 ㎛ at D50, and 9.1 ㎛ at D90 and coconut shell-based carbonized activated carbon (YP-50) having a specific surface area of ​​1,500 ㎡ / g and a particle size distribution of 3 ㎛ at D10, 7 ㎛ at D50, and 15 ㎛ at D90, and 85.0 wt% of the mixed powder in a weight ratio of 8:2 (carbon material:activated carbon) and 10.0 wt% of the conductive modifier Super P were mixed and placed in a container, and a solution of 0.2 wt% of carboxymethyl cellulose as a dispersing aid dissolved in distilled water was added thereto in the same volume as the activated carbon, and then the activated carbon was first dispersed using a dispersion stirrer to form a slurry. It was manufactured in a state of

[0136] PTFE 4.5 wt% and SBR 0.3 wt% as binders were added to the primary dispersion slurry, and the electrode material was mixed by dispersion stirring.

[0137] Afterwards, a small amount of distilled water was added as a dispersing medium and stirred at low speed until a solid state with a viscosity of 20,000 cp was obtained, thereby obtaining a conductive solid electrode slurry. At this time, when the solid state reached one monomer, the addition of the dispersing medium was stopped.

[0138] A conductive solid electrode slurry was coated to a thickness of 120 μm on a cross-section of a 20 μm thick aluminum etching foil, dried, and then a compression molding process was performed in a roll press heated to 80°C to produce a sheet-shaped electrode having a thickness of 60 μm and an electrode density of 0.79 g / cm3.

[0139]

[0140] Comparative Example 2

[0141] The pore volume of pores having a pore diameter of 17Å or less is 23.39% of the total pore volume, and the powdered carbon material manufactured according to the manufacturing example having a particle size distribution of 3.5㎛ at D10, 13㎛ at D50, and 39㎛ at D90 and the phenol resin-based carbonized activated carbon (MSP-20) having a specific surface area of ​​1,750㎡ / g and a particle size distribution of 5㎛ at D10, 11㎛ at D50, and 15㎛ at D90 are mixed at a weight ratio of 8:2 (carbon material:activated carbon) and 9.5 wt% of the conductive modifier Super P are mixed and placed in a container, and a solution of 0.2 wt% of carboxymethyl cellulose as a dispersing aid dissolved in distilled water is added thereto in the same volume as the activated carbon, and then the activated carbon is first dispersed using a dispersion stirrer to form a slurry. It was manufactured in a state of

[0142] 5.3 wt% of PTFE as a binder and 0.5 wt% of BM400B were added to the primary dispersion slurry, and the electrode material was mixed and composed by dispersion stirring.

[0143] Afterwards, a small amount of distilled water was added as a dispersing medium and stirred at low speed until a solid state with a viscosity of 20,000 cp was obtained, thereby obtaining a conductive solid electrode slurry. At this time, when the solid state reached one monomer, the addition of the dispersing medium was stopped.

[0144] A conductive solid electrode slurry was coated to a thickness of 120 μm on a cross-section of a 20 μm thick aluminum etching foil, dried, and then a compression molding process was performed in a roll press heated to 80°C to produce a sheet-shaped electrode having a thickness of 60 μm and an electrode density of 0.86 g / cm3.

[0145]

[0146] Comparative Example 3

[0147] The pore volume of pores having a pore diameter of 17 Å or less is 23.39% of the total pore volume, and the powdered carbon material manufactured according to the manufacturing example having a particle size distribution of 3.5 ㎛ at D10, 13 ㎛ at D50, and 39 ㎛ at D90 and the coke pitch-based carbonized activated carbon (CEP-21KS) having a specific surface area of ​​1,850 ㎡ / g and a particle size distribution of 5 ㎛ at D10, 10 ㎛ at D50, and 15 ㎛ at D90 are mixed in a weight ratio of 8:2 (carbon material:activated carbon) and 9.0 wt% of the conductive modifier Super P are mixed and placed in a container, and a solution of 0.2 wt% of carboxymethyl cellulose as a dispersing aid dissolved in distilled water is added thereto in the same volume as the activated carbon, and then the activated carbon is first dispersed using a dispersion stirrer to form a slurry. It was manufactured.

[0148] 5.3 wt% PTFE and 0.5 wt% SBR as binders were added to the primary dispersion slurry, and the electrode material was mixed by dispersion stirring.

[0149] Afterwards, a small amount of distilled water was added as a dispersing medium and stirred at low speed until a solid state with a viscosity of 20,000 cp was obtained, thereby obtaining a conductive solid electrode slurry. At this time, when the solid state reached one monomer, the addition of the dispersing medium was stopped.

[0150] A conductive solid electrode slurry was coated to a thickness of 120 μm on a cross-section of a 20 μm thick aluminum etching foil, dried, and then a compression molding process was performed in a roll press heated to 80°C to produce a sheet-shaped electrode having a thickness of 60 μm and an electrode density of 0.78 g / cm3.

[0151]

[0152] Test Example 1: Manufacturing and Evaluation of a Supercapacitor

[0153] The electrodes according to Examples 1, 2, and 3 and Comparative Examples 1, 2, and 3 were processed with a punch to produce coin-shaped electrodes with a diameter of 16 mm. Next, an insulating gasket made of polypropylene (PP) was placed between the metal cases of the positive and negative electrodes, each made of SUS metal, to prevent short circuits due to contact between metal cases of different polarities and leakage of the liquid electrolyte present inside the unit cell. Then, a certain amount of a 0.1 N concentration organic electrolyte containing acetonitrile as a solvent and tetraethylammonium tetrafluoroborate (TEABF4) as a solute was impregnated onto the surfaces of the electrodes located inside the metal cases of the positive and negative electrodes, and a separator made of a porous nonwoven fabric was placed between the electrodes to prevent short circuits due to contact between electrodes of different polarities. After that, in order to implement effective airtightness, the outermost edge of the lower metal case, which is the part that is directly crimped, the outermost edge of the gasket that is in close contact with the outermost edge of the lower metal case, and the outermost edge of the upper metal case that is in close contact with the inner edge of the outermost edge of the gasket were crimped while pressing from the outermost edge of the lower metal case to the cell center using a crimping mold, thereby manufacturing a unit cell.

[0154] For each supercapacitor including the electrode manufactured according to the examples and comparative examples, a test was conducted under the conditions that the charging voltage was 2.7 V, the charging current was the same as the discharge current, the charging time was 1 hour after the charging voltage reached 2.7 V, and the discharge current was 1 mA. At this time, the electrode surface resistance, electrode resistivity, leakage current (LC), and alternating current resistance (ESR) were measured. AC ), electrostatic resistance (ESR) DC ), electrostatic capacity (CAP) and specific capacity were measured, and the results are shown in Table 1 below.

[0155] Item Electrode Density Electrode Surface Resistance LCESR AC ESR DC CAP Capacity Unit (g / cm3)(Ω / sqm)(㎃)(Ω)(Ω)(F)(F / cm3)Example 11.1750.20.111.165.90.2511.10Example 21.2354.30.321.207.40.3515.01Example 31.3149.20.341.232.30.3817.83Comparative Example 11.0779.30.191.337.90.239.54Comparative Example 21.1172.10.441.358.50.2912.03Comparative Example 31.1971.00.411.356.80.3213.27

[0156] Example 4

[0157] A dispersing agent was prepared with a composition of distilled water and 0.5 wt% of carboxymethylcellulose (the amount of the dispersing agent is such that the proportion of carboxymethylcellulose becomes 0.5 wt% based on the total mass of the powdered conductive additive, powdered activated carbon, and binder), and the prepared dispersing agent was added to 5 wt% of the powdered conductive additive super-P, followed by dispersion stirring using a planetary mixer to prepare a conductive additive slurry.

[0158] Amorphous coconut shell-based carbonized activated carbon powder (YP-50, specific surface area 1,344 m2 / g, pore distribution: 86% of the total pore volume of pores with a diameter of 17 Å or less) was added to the prepared conductive additive slurry, and dispersion stirring was performed using a planetary mixer to prepare a solid slurry. At this time, the powdered activated carbon was added in an amount of 90 wt% based on the total weight of the electrode composition to prepare a solid slurry.

[0159] The manufactured solid slurry of 95.5 wt% and SBR binder of 1.0 wt% were placed in a stirrer and subjected to secondary dispersion stirring, then mixed with polytetrafluoroethylene binder of 3.5 wt% and subjected to a third dispersion stirring, thereby producing a semi-solid electrode composition.

[0160] The manufactured electrode composition was dried at a temperature of 100°C, and the electrode solid from which moisture had been removed was ground into granules using a blade mixer. Next, the granule-like electrode solid was vacuum-dried at a temperature of 150°C to manufacture an electrode composite.

[0161] While maintaining the roll surface temperature of the heating roll press at 80°C, the manufactured electrode composite was placed between the rolls and subjected to a first press molding to a thickness of 180 to 190 μm. Next, while maintaining the roll surface temperature of the heating roll press at 40°C, the first press molded electrode composite film was subjected to a second press molding to a thickness of 100 to 110 μm. Thereafter, while maintaining the roll surface temperature of the heating roll press at room temperature of 25°C, the second press molded electrode composite film was subjected to a third press molding to a thickness of 60 μm, thereby producing an electrode composite film.

[0162] According to the manufacturing example, 13 wt% of carbon material powder was prepared, and 80 wt% of the conductive additive slurry prepared as described above was mixed, and after the first dispersion stirring was performed with a planetary mixer, the prepared first slurry and 7 wt% of SBR binder were added to the stirrer, and the second dispersion stirring was performed, thereby preparing a conductive layer paste having a viscosity of 60,000 cP. The prepared conductive layer paste was coated on one side of an 18 μm aluminum foil using a doctor blade to a thickness of 15 μm, dried at a temperature of 100°C to form a conductive layer having a thickness of 4 μm, and then vacuum-dried at a temperature of 150°C to remove moisture. The prepared electrode composite film was placed on an aluminum current collector having a conductive layer, and pressurized once while maintaining the roll surface temperature of a heating roll press at 80°C.

[0163] The total thickness of the electrode of the completed supercapacitor after roll pressing was 75 μm, and the electrode density was 0.73 g / cm3. The specific capacity was calculated as 53 μm, excluding the 22 μm thickness of the electrode current collector having the conductive layer from the total thickness of the 75 μm electrode of the supercapacitor.

[0164]

[0165] Example 5

[0166] A dispersing agent was prepared by mixing distilled water and 0.5 wt% of carboxymethylcellulose, and adding 5 wt% of the powdered conductive additive super-P (the amount of the dispersing agent is such that the proportion of carboxymethylcellulose becomes 0.5 wt% based on the total mass of the powdered conductive additive, powdered activated carbon, and binder) to the prepared dispersing agent, followed by dispersion stirring using a planetary mixer to prepare a conductive additive slurry.

[0167] Amorphous coke pitch-based carbonized activated carbon powder (CEP-21KS, specific surface area 2,000㎡ / g, pore distribution: pore volume of pores with a diameter of 17Å or less is 72% of the total pore volume) was added to the manufactured conductive additive slurry, and dispersion stirring was performed using a planetary mixer to prepare a solid slurry. At this time, the powdered activated carbon was added in an amount of 95.5 wt% based on the total weight of the electrode composition, thereby preparing a solid slurry.

[0168] The manufactured solid slurry of 90 wt% and SBR binder of 1.0 wt% were added to a stirrer and subjected to secondary dispersion stirring, then mixed with polytetrafluoroethylene binder of 3.5 wt% and subjected to a third dispersion stirring, thereby producing a semi-solid electrode composition.

[0169] The manufactured electrode composition was dried at a temperature of 100°C, and the electrode solid from which moisture had been removed was ground into granules using a blade mixer. Next, the granule-like electrode solid was vacuum-dried at a temperature of 150°C to manufacture an electrode composite.

[0170] While maintaining the roll surface temperature of the heating roll press at 90°C, the manufactured electrode composite was placed between the rolls and subjected to a first pressure molding to a thickness of 180 to 190 μm. Next, while maintaining the roll surface temperature of the heating roll press at 60°C, the first pressure molded electrode composite film was subjected to a second pressure molding to a thickness of 100 to 110 μm. Thereafter, while maintaining the roll surface temperature of the heating roll press at room temperature of 25°C, the second pressure molded electrode composite film was subjected to a third pressure molding to a thickness of 60 to 65 μm, thereby producing an electrode composite film.

[0171] According to the manufacturing example, 13 wt% of carbon material powder was prepared, and 80 wt% of the conductive additive slurry prepared as described above was mixed, and after the first dispersion stirring was performed with a planetary mixer, the prepared first slurry and 7 wt% of SBR binder were added to the stirrer, and the second dispersion stirring was performed, thereby preparing a conductive layer paste having a viscosity of 60,000 cP. The prepared conductive layer paste was coated on one side of an 18 μm aluminum foil using a doctor blade to a thickness of 15 μm, dried at a temperature of 100°C to form a conductive layer having a thickness of 4 μm, and then vacuum-dried at a temperature of 150°C to remove moisture. The prepared electrode composite film was placed on an aluminum current collector having a conductive layer, and pressurized once while maintaining the roll surface temperature of a heating roll press at 80°C.

[0172] The total thickness of the electrode of the completed supercapacitor after roll pressing was 75 μm, and the electrode density was 0.72 g / cm3. The specific capacity was calculated as 53 μm, excluding the thickness of the electrode current collector having the conductive layer, 22 μm from the total thickness of the electrode of the supercapacitor, 75 μm.

[0173]

[0174] Example 6

[0175] A dispersing agent was prepared with a composition of distilled water and 0.5 wt% of carboxymethylcellulose, and the prepared dispersing agent was added to 5.0 wt% of powdered conductive additive super-P (the amount of the dispersing agent is such that the proportion of carboxymethylcellulose becomes 0.5 wt% based on the total mass of the powdered conductive additive, powdered activated carbon, and binder), and then dispersion stirring was performed using a planetary mixer to prepare a conductive additive slurry.

[0176] Amorphous phenolic resin-based carbonized activated carbon powder (MSP-20, specific surface area 2,750 m2 / g, pore distribution: 82% of the total pore volume of pores with a diameter of 17 Å or less) was added to the prepared conductive additive slurry, and dispersion stirring was performed using a planetary mixer to prepare a solid slurry. At this time, the powdered activated carbon was added in an amount of 85.5 wt% based on the total weight of the electrode composition to prepare a solid slurry.

[0177] The manufactured solid slurry of 94.2 wt% and SBR binder of 1.0 wt% were placed in a stirrer and subjected to secondary dispersion stirring, then mixed with polytetrafluoroethylene binder of 3.5 wt% and subjected to a third dispersion stirring, thereby producing a semi-solid electrode composition.

[0178] The manufactured electrode composition was dried at a temperature of 100°C, and the electrode solid from which moisture had been removed was ground into granules using a blade mixer. Next, the granule-like electrode solid was vacuum-dried at a temperature of 150°C to manufacture an electrode composite.

[0179] While maintaining the roll surface temperature of the heating roll press at 70°C, the manufactured electrode composite was placed between the rolls and subjected to a first pressure molding to a thickness of 180 to 190 μm. Next, while maintaining the roll surface temperature of the heating roll press at 40°C, the first pressure molded electrode composite film was subjected to a second pressure molding to a thickness of 80 to 90 μm. Thereafter, while maintaining the roll surface temperature of the heating roll press at room temperature of 25°C, the second pressure molded electrode composite film was subjected to a third pressure molding to a thickness of 60 to 65 μm, thereby producing an electrode composite film.

[0180] According to the manufacturing example, 13 wt% of carbon material powder was prepared, and 80 wt% of the conductive additive slurry prepared as described above was mixed, and after the first dispersion stirring was performed with a planetary mixer, the prepared first slurry and 7 wt% of SBR binder were added to the stirrer, and the second dispersion stirring was performed, thereby preparing a conductive layer paste having a viscosity of 60,000 cP. The prepared conductive layer paste was coated on one side of an 18 μm aluminum foil using a doctor blade to a thickness of 15 μm, dried at a temperature of 100°C to form a conductive layer having a thickness of 4 μm, and then vacuum-dried at a temperature of 150°C to remove moisture. The prepared electrode composite film was placed on an aluminum current collector having a conductive layer, and pressurized once while maintaining the roll surface temperature of a heating roll press at 80°C.

[0181] The total thickness of the electrode of the completed supercapacitor after roll pressing was 75 μm, and the electrode density was 0.72 g / cm3. The specific capacity was calculated as 53 μm, excluding the thickness of the electrode current collector having the conductive layer, 22 μm from the total thickness of the electrode of the supercapacitor, 75 μm.

[0182]

[0183] Comparative Example 4

[0184] 90.0 wt% of amorphous coconut shell-based carbonized activated carbon (YP-50, specific surface area 1,344 m2 / g, pore distribution: 86% of the total pore volume of pores with a diameter of 17 Å or less) and 5.0 wt% of a conductivity modifier, Super P, were mixed and placed in a container. A solution of 0.5 wt% of carboxymethyl cellulose dissolved in distilled water as a dispersing aid was added thereto in the same volume as the activated carbon, and the activated carbon was first dispersed using a dispersing stirrer to prepare a slurry.

[0185] 3.5 wt% PTFE and 1.0 wt% SBR as binders were added to the primary dispersion slurry, and the electrode material was mixed by dispersion stirring.

[0186] Afterwards, a small amount of distilled water was added as a dispersing medium and stirred at low speed until a solid state with a viscosity of 20,000 cp was obtained, thereby obtaining a conductive solid electrode slurry. At this time, when the solid state reached one monomer, the addition of the dispersing medium was stopped.

[0187] A conductive solid electrode slurry was coated to a thickness of 70 μm on a cross-section of a 20 μm thick aluminum etching foil, dried, and then a compression molding process was performed in a roll press heated to 80°C to produce a sheet-shaped electrode having a thickness of 50 μm and an electrode density of 0.60 g / cm3.

[0188]

[0189] Comparative Example 5

[0190] 90.0 wt% of amorphous coke pitch-based carbonized activated carbon (CEP-21KS, specific surface area 2,000 m2 / g, pore distribution: 72% of the total pore volume of pores with a diameter of 17 Å or less) and 5.0 wt% of a conductivity modifier Super P were mixed and placed in a container. A solution of 0.5 wt% of carboxymethyl cellulose dissolved in distilled water as a dispersing aid was added thereto in the same volume as the activated carbon, and the activated carbon was first dispersed using a dispersing stirrer to prepare a slurry.

[0191] 3.5 wt% PTFE and 1.0 wt% SBR as binders were added to the primary dispersion slurry, and the electrode material was mixed by dispersion stirring.

[0192] Afterwards, a small amount of distilled water was added as a dispersing medium and stirred at low speed until a solid state with a viscosity of 20,000 cp was obtained, thereby obtaining a conductive solid electrode slurry. At this time, when the solid state reached one monomer, the addition of the dispersing medium was stopped.

[0193] A conductive solid electrode slurry was coated to a thickness of 70 μm on a cross-section of a 20 μm thick aluminum etching foil, dried, and then a compression molding process was performed in a roll press heated to 80°C to produce a sheet-shaped electrode having a thickness of 50 μm and an electrode density of 0.65 g / cm3.

[0194]

[0195] Comparative Example 6

[0196] 90.0 wt% of amorphous phenolic resin-based carbonized activated carbon (MSP-20, specific surface area 2,750 m2 / g, pore distribution: 82% of the total pore volume of pores with a diameter of 17 Å or less) and 5.0 wt% of a conductivity modifier, Super P, were mixed and placed in a container. A solution of 0.5 wt% carboxymethyl cellulose dissolved in distilled water as a dispersing aid was added thereto in the same volume as the activated carbon, and the activated carbon was first dispersed using a dispersing stirrer to prepare a slurry.

[0197] 3.5 wt% of PTFE as a binder and 1.0 wt% of BM400B were added to the primary dispersion slurry, and the electrode material was mixed and composed by dispersion stirring.

[0198] Afterwards, a small amount of distilled water was added as a dispersing medium and stirred at low speed until a solid state with a viscosity of 20,000 cp was obtained, thereby obtaining a conductive solid electrode slurry. At this time, when the solid state reached one monomer, the addition of the dispersing medium was stopped.

[0199] A conductive solid electrode slurry was coated to a thickness of 70 μm on a cross-section of a 20 μm thick aluminum etching foil, dried, and then a compression molding process was performed in a roll press heated to 80°C to produce a sheet-shaped electrode having a thickness of 50 μm and an electrode density of 0.66 g / cm3.

[0200]

[0201] Test Example 2: Manufacturing and Evaluation of a Supercapacitor

[0202] The electrodes according to Examples 4, 5, and 6 and Comparative Examples 4, 5, and 6 were cut to a width of 100.0 mm and a length of 100.0 mm, respectively, and aluminum terminals were ultrasonically welded to the surfaces of each electrode to adhere them.

[0203] To prevent electrical shorts between the two electrodes and to ensure smooth flow of the impregnated electrolyte, a porous non-woven fabric separator was cut to 120.0 mm in width and 120.0 mm in length between each electrode to which aluminum terminals were welded, and then placed in the center and inserted into an aluminum pouch. Then, a 0.1 N concentration organic electrolyte containing acetonitrile as a solvent and tetraethyl ammonium tetrafluoroborate (TEABF4) as a solute was impregnated onto the surfaces of the two electrodes, and the aluminum pouch was sealed by heat compression, thereby producing a pouch cell for testing.

[0204] For the manufactured supercapacitor, the charging voltage was 2.7 V, the charging current was the same as the discharge current, the charging time was 1 hour after the charging voltage reached 2.7 V, and the discharge current was 0.1 A. At this time, the electrode surface resistance, AC resistance (ESR) AC ), leakage current (LC), and electrostatic resistance (ESR) DC ), electrostatic capacity (CAP) and specific capacity were evaluated, and the results are shown in Table 2 below.

[0205] Item Electrode Density Electrode Surface Resistance LCESR AC ESR DC CAP Capacity Unit (g / cm3)(Ω / sqm)(㎃)(mΩ)(mΩ)(F)(F / cm3)Example 40.733551.822728015.915.0Example 50.723761.722026116,615.7Example 60.723601.822523016.315.4Comparative Example 40.607802.336041012.512.5Comparative Example 50.655952.329735014.514.5Comparative Example 60.665032.027432214.814.8

[0206] The output and output density of each of the examples and comparative examples are as shown in Table 3 below.

[0207] Item Output Electrode Weight Output Density Unit (W) (g) (kW / kg) Example 10.30890.02211.73 Example 20.24630.0238.58 Example 30.79240.02128.39 Example 46.510.778.41 Example 56.980.769.15 Example 67.920.7610.38 Comparative Example 10.23070.0268.94 Comparative Example 20.21440.0278.01 Comparative Example 30.26800.0299.33 Comparative Example 44.440.67.40 Comparative Example 55.200.658.01 Comparative Example 65.650.668.57

[0208] At this time, the output can be calculated with the following function.

[0209] P = V 2 / (4*ESR DC )

[0210] Here, P is power, V is voltage, and ESR DC is the DC resistance, and the unit of output is W.

[0211]

[0212] Through the examples and comparative examples, it can be seen that when manufacturing the electrode of a supercapacitor according to the present invention, a supercapacitor having a high electrode density, excellent electrostatic capacity, and high power density can be provided.

[0213]

[0214] While one embodiment of the present invention has been exemplified above, it is not intended to limit the scope of the present invention to the aforementioned embodiments. Those skilled in the art will be able to appropriately modify one embodiment of the present invention by omitting, modifying, or substituting all or part of the components of the present invention, or adding other components, without departing from the technical spirit of the present invention, by referring to this specification.

[0215]

[0216] The terms and expressions in this specification should be interpreted broadly and not in a restrictive sense. As used herein, the term "includes" does not exclude the presence or addition of one or more other components other than the mentioned components. Furthermore, as used herein, the term "to" includes upper and lower limits. For example, "1 to 10" includes the upper limit of 10 and the lower limit of 1, and can also be expressed as "1 or more and 10 or less."

[0217]

[0218] Each of the embodiments exemplarily described herein can be combined with one another, and unless contradictory, the content described in a particular embodiment can be equally applied to other embodiments even if not described in the other embodiments.

Claims

1. A step of preparing an electrode composition in a slurry state containing a carbon material; A step of drying the electrode composition to form an electrode solid, pulverizing the electrode solid, and then vacuum drying to manufacture an electrode complex; A step of forming an electrode composite film by pressing the electrode composite; and A step of placing and pressing the electrode composite film on an electrode current collector; comprising; A method for manufacturing electrodes of a supercapacitor.

2. In paragraph 1, The electrode composition further comprises at least one of a conductive additive and a binder. A method for manufacturing electrodes of a supercapacitor.

3. In paragraph 1, The step of preparing an electrode composition including the above carbon material is Step of preparing carbon material, conductive additive and binder; A step of preparing a conductive additive slurry by mixing the conductive additive with a dispersing agent including a dispersing medium; and A step of mixing the carbon material, the conductive additive slurry, and the binder; comprising; A method for manufacturing electrodes of a supercapacitor.

4. In paragraph 3, In the above electrode composition, the content ratio (by weight%) of the carbon material, conductive additive slurry, and binder is 70 to 85:5 to 25:4.6 to 5.8 based on the total weight of the electrode composition. A method for manufacturing electrodes of a supercapacitor.

5. In paragraph 1, Drying the electrode composition to form an electrode solid is performed at a temperature of 60°C to 150°C, Vacuum drying of the above electrode solid is performed at a temperature of 150°C to 200°C. A method for manufacturing electrodes of a supercapacitor.

6. In paragraph 1, In the step of forming an electrode composite film by pressing the electrode composite, the pressing is performed multiple times, and the final pressing is performed at room temperature. A method for manufacturing electrodes of a supercapacitor.

7. In paragraph 1, The step of placing the electrode composite film on the electrode current collector and pressurizing it is Step of manufacturing a conductive layer paste; A step of manufacturing an electrode current collector having a conductive layer by coating the conductive layer paste on a metal foil and drying it; A step of vacuum drying the electrode current collector having the conductive layer; and A step of arranging and pressing an electrode composite film on an electrode current collector having the conductive layer so as to face the conductive layer; comprising; A method for manufacturing electrodes of a supercapacitor.

8. In paragraph 7, The above conductive layer paste comprises carbon material, conductive additive and binder. A method for manufacturing electrodes of a supercapacitor.

9. In paragraph 7, In the step of manufacturing an electrode current collector having a conductive layer by coating the conductive layer paste on a metal foil and drying it, the drying is performed at a temperature of 40°C to 120°C. A method for manufacturing electrodes of a supercapacitor.

10. In paragraph 7, The step of vacuum drying the electrode current collector having the above conductive layer is performed at a temperature of 150°C to 200°C. A method for manufacturing electrodes of a supercapacitor.

11. In paragraph 7, In the step of arranging and pressing an electrode composite film on an electrode current collector having the conductive layer so as to face the conductive layer, the sum of the thickness of the electrode composite film after pressing and the thickness of the electrode current collector having the conductive layer is 85% or more of the sum of the thickness of the electrode composite film before pressing and the thickness of the electrode current collector having the conductive layer. A method for manufacturing electrodes of a supercapacitor.