CN211208258U

CN211208258U - Electrochemical device

Info

Publication number: CN211208258U
Application number: CN201790001218.6U
Authority: CN
Inventors: 朴正郁; 姜石民; 黄玟泳; 赵寅熙
Original assignee: LG Innotek Co Ltd
Current assignee: LG Innotek Co Ltd
Priority date: 2016-09-13
Filing date: 2017-06-13
Publication date: 2020-08-07
Anticipated expiration: 2027-06-13
Also published as: WO2018052179A1; KR20180029794A; KR102519740B1

Abstract

The utility model relates to an electrochemical device, electrode material can realize electrochemical device and have improved electric capacity through including following carbon source, the carbon source includes crystal structure and amorphous structure, and wherein, crystal structure includes the crystal lattice, and amorphous structure includes the hole, and the interlaminar distance of crystal structure is in the within range of 0.37nm to 0.40nm to the ratio of the unit weight (g) of crystal structure and electrode material is in the within range of 0.4 to 0.91.

Description

Electrochemical device

Technical Field

The utility model relates to an electrochemical device. More particularly, the present invention relates to an electrochemical device having a large capacitance.

Background

Recently, attention to energy storage technology has been gradually increased.

As its application fields have been expanded to cellular phones, camcorders, and notebook computers, even electric vehicles, efforts to research and develop electrochemical devices have become more and more significant.

Specific examples are supercapacitors (electric double layer capacitors (ED L C)), lithium ion secondary batteries, hybrid capacitors, and the like.

Electrochemical devices are receiving attention because they are capable of being charged and discharged and have a high energy density. As the application fields expand, large capacitance and high energy density are required.

For example, a supercapacitor includes a unit cell including: an anode and a cathode immersed in a liquid electrolyte; a separator (separator) provided between the two electrodes; a gasket for preventing leakage of the liquid electrolyte and short-circuiting and insulating the electrodes; and a metal case, etc., stacking the unit cells, and combining the stacked cells with terminals of the anode and cathode. The electrode composition may include an electrode active material, a binder, and a conductive material, which are mixed to form a slurry. The slurry can be used to form a supercapacitor.

In this regard, the performance of the electrochemical device is mainly determined by the electrode active material, and the activated carbon is mainly used as the electrode active material.

However, when a commercially available electrode active material is used, there is a limit to high capacity of an electrochemical device.

SUMMERY OF THE UTILITY MODEL

Technical problem

The present invention aims to provide an electrode material having a large capacitance when the material is used for an electrochemical device.

The present invention is directed to an electrochemical device exhibiting a large capacitance.

Technical scheme

In one aspect of the present invention, there is provided an electrode material, comprising a carbon source, the carbon source comprising: a crystal portion including a lattice layer; and an amorphous portion including a hole, wherein a spacing between adjacent lattice layers in the crystalline portion is in a range of 0.37nm to 0.40nm, wherein a weight ratio of the crystalline portion to the electrode material may be in a range of 0.4 to 0.91.

In one embodiment, the weight ratio of crystal portion to electrode material is calculated by solving the following equations 1 and 2:

[ formula 1]20x +2000y ═ k

[ formula 2] x + y is 1

Wherein x represents a weight ratio of the crystalline portion to the electrode material, y represents a weight ratio of the amorphous portion to the electrode material, and k is in a range of 200 to 1200.

In one embodiment, the volume of pores having a diameter of greater than 0nm and 1nm or less corresponds to 60% to 85% of the total volume of the amorphous portion.

In one embodiment, the volume of the pores having a diameter in the range of 0.6nm to 0.9nm is in the range of 45% to 75% of the total volume of the amorphous portion.

In one embodiment, the volume of the pores having a diameter in the range of 0.75nm to 0.85nm is in the range of 15% to 23% of the total volume of the amorphous portion.

In one embodiment, the electrodesThe specific surface area of the material is 200m²G to 1200m²In the range of/g.

In one embodiment, the apparent density of the electrode material is at 0.7g/cm³To 1.5g/cm³Within the range of (1).

In one aspect of the present invention, there is provided an electrochemical device comprising: a first electrode; a second electrode; and a separator disposed between the first electrode and the second electrode, wherein at least one of the first electrode and the second electrode comprises an electrode material, wherein the electrode material comprises a carbon source comprising: a crystal portion including a lattice layer; and an amorphous portion including a hole, wherein a pitch between adjacent lattice layers in the crystal portion is in a range of 0.37nm to 0.40nm, wherein a weight ratio of the crystal portion to the electrode material may be in a range of 0.4 to 0.91.

In one embodiment of the present apparatus, the weight ratio of the crystal portion to the electrode material is calculated by solving the following equations 1 and 2:

[ formula 1]20x +2000y ═ k

[ formula 2] x + y is 1

In one embodiment of the present device, the volume of the pores having a diameter of greater than 0nm and 1nm or less corresponds to 60% to 85% of the total volume of the amorphous portion.

Effect of the utility model

According to the present invention, when this material is used for an electrochemical device, the electrode material has a large capacitance.

According to the utility model discloses, electrochemical device presents big electric capacity.

Drawings

Fig. 1 is a high level view (highlevel view) of an enlarged structure of an electrode material according to one embodiment of the present invention;

fig. 2 is a schematic view of an electrochemical device according to an embodiment of the present invention;

fig. 3 shows a flow diagram of a method of manufacturing an electrode material according to an embodiment of the invention;

FIG. 4 shows a high level view for describing the change of carbon source due to heat treatment and activation treatment;

fig. 5 is a diagram of an X-ray diffraction analysis pattern of an electrode material prepared according to an embodiment of the present invention;

fig. 6 is a graph of pore distribution based on pore diameters in example 1 and comparative example 8.

Detailed Description

In the described embodiments, where each layer, film, electrode, plate or substrate, etc., is described as being formed "above" (above) or below (below) each layer, film, electrode, e.g., plate or substrate, in which case the expressions "(above … …)" and "below … …" each include being formed directly or (indirectly) by another component.

Further criteria for the phrase "adjacent to or below" individual components will be described with reference to the drawings. The dimensions of each of the elements in the figures may be exaggerated for illustrative purposes only and are not intended to indicate actual dimensions used.

Hereinafter, embodiments according to the present invention will be described in detail with reference to the accompanying drawings.

Fig. 1 is a high-level view of an enlarged structure of an electrode material according to an embodiment of the present invention. Hereinafter, fig. 1 will be referred to.

The electrode material may include a carbon source 100. The carbon source 100 may include a crystalline portion 21 and an amorphous portion 11, wherein the crystalline portion 21 includes a crystal lattice. That is, the crystal part 21 and the amorphous part 11 can be mixed in the carbon source 100 contained in the electrode material.

Carbon source 100 may include, for example, petroleum-based or coal-based pitch, coarse coke (green coke), calcined coke, and the like. However, the present invention is not limited thereto.

The amorphous portion 11 included in the carbon source 100 includes pores 12.

The pores 12 may enable the electrode material to be porous. The hole 12 in the amorphous part 11 can receive (insert) electrolyte ions 13.

The presence/absence of the holes 12 in the amorphous portion 11 and/or the diameter of each hole 12 may affect the specific surface area of the electrode material. Therefore, the presence/absence of the holes 12 and/or the diameter of each hole 12 are adjusted to improve the capacitance of the electrode material.

The electrode material may comprise at least one hole 12 in the amorphous portion 11. That is, the electrode material may include a plurality of holes 12 in the amorphous portion 11.

When the electrode material includes a plurality of pores 12, the individual pores 12 may have the same diameter or different diameters. In particular, the electrode material may comprise holes 12 having the same diameter. Alternatively, the electrode material may include holes 12 having different diameters. Alternatively, some of the holes 12 may have the same diameter, while other holes 12 may have different diameters.

As described below, the crystal part 21 in the carbon source 100 may be formed by performing heat treatment of the carbon source 100 at 650 to 900 ℃ to allow partial crystallization of the carbon source 100.

Whether the carbon source 100 contains the crystal part 21 can be checked using an X-ray diffraction (XRD) method. When the carbon source 100 includes the crystal part 21, X-rays can be diffracted from the crystal. In this regard, the intensity and diffraction angle of the diffracted X-rays may be specific to a particular material. Using the diffracted X-rays, information about the kind and amount of the crystalline substance contained in the sample can be determined.

The electrode material as the carbon source 100 may include a crystal portion 21 in addition to the hole 12 in the amorphous portion 11. Therefore, the crystal part 21 can function as a moving path for the electrolyte ions 13 to move easily, thereby reducing the resistance and improving the conductivity. In addition, the capacitance can be significantly improved.

In this regard, the spacing d between adjacent lattice layers in the crystal portion may be in the range of 0.37nm to 0.40 nm.

As described below, the spacing d between adjacent lattice layers in the crystal portion can be adjusted by adjusting the activation temperature and/or the content ratio between the carbon source and the activator.

When the spacing d between adjacent lattice layers in the crystal section is less than 0.37nm, the electrolyte ions 13 may not enter and exist between the adjacent lattice layers. When the spacing d between adjacent lattice layers in the crystal section exceeds 0.40nm, van der Waals force may not act between adjacent lattice layers, thereby not allowing crystallization of the material. Therefore, when the spacing d between adjacent lattice layers in the crystal section is not in the above range, the capacitance (F/cc) may decrease.

The spacing d between adjacent lattice layers in the crystal section can be measured using techniques well known to those skilled in the art. The spacing d between adjacent lattice layers in the crystal portion can be measured using, for example, an X-ray diffraction analysis method, a TEM (Transmission electron microscope) photograph, or the like. However, the present invention is not limited thereto.

The weight ratio of the crystal part 21 to the electrode material may be in the range of 0.4 to 0.91.

Depending on the type of the carbon source 100 contained in the electrode material, the specific surface area of the electrode material when the carbon source 100 contains only the crystalline portion 21 may be different from the specific surface area of the electrode material when the carbon source 100 contains only the amorphous portion 11. Therefore, in order to improve the capacitance of the electrode material, the weight ratio of the crystal part 21 to the electrode material and the weight ratio of the amorphous part 11 to the electrode material may be specified.

The weight ratio of the crystal part 21 to the electrode material can be calculated by solving the following equations 1 and 2:

[ formula 1]20x +2000y ═ k

[ formula 2] x + y is 1

Where x represents the weight ratio of the crystal portion 21 to the electrode material, y represents the weight ratio of the amorphous portion 11 to the electrode material, and k represents a specific surface area in the range of 200 to 1200.

Further, as described below, the weight ratio of the crystal part 21 to the electrode material can be adjusted by the heat treatment temperature of the carbon source 100.

Since the carbon source 100 may include the amorphous portion 11 and the crystal portion 21, the capacitance of the electrode material may be improved taking into consideration all characteristics of the amorphous portion 11 and the crystal portion 21 contributing to the capacitance.

In one embodiment, the capacitance of the electrode material may be improved by adjusting the percentage of holes 12 having a predetermined diameter in the amorphous portion 11.

The percentage of the pores 12 having a predetermined diameter in the amorphous portion 11 and the predetermined diameter of the pores 12 may be measured using a BET (BRUNAUER EMMETT TE LL) method.

In one embodiment, the holes 12 may have diameters of various sizes.

Specifically, the pores 12 may have a diameter greater than 0nm and 1nm or less. The volume of the pores 12 having a diameter of greater than 0nm and 1nm or less may be 60% to 85% of the total volume of the amorphous portion 11.

When the volume of the hole 12 having a diameter of more than 0nm and 1nm or less is less than 60% of the total volume of the amorphous portion 11 or more than 85% of the total volume of the amorphous portion 11, the capacitance of the electrode material may be reduced. Therefore, the electrical characteristics of the electrode material may deteriorate, and accordingly, the electrical characteristics of the electrochemical device 10 may deteriorate.

In one embodiment, the volume of the pores 12 having a diameter in the range of 0.6nm to 0.9nm may be in the range of 45% to 75% of the total volume of the amorphous portion 11. When the volume of the hole 12 having a diameter in the range of 0.6nm to 0.9nm is in the range of 45% to 75% of the total volume of the amorphous portion 11, the capacitance of the electrode material can be improved.

In another embodiment, the volume of the pores 12 having a diameter in the range of 0.75nm to 0.85nm may be in the range of 15% to 23% of the total volume of the amorphous portion 11. When the volume of the hole 12 having a diameter in the range of 0.75nm to 0.85nm is in the range of 15% to 23% of the total volume of the amorphous portion 11, the capacitance of the electrode material can be improved.

Furthermore, in one embodiment, the specific surface area of the electrode material may affect its capacitance. In particular, in general, when the specific surface area is large, the energy storage efficiency can be improved. However, when the specific surface area is outside the given limit, the electrode material has a lower density so that its capacitance (F/cc) is reduced.

The lower heat treatment temperature of the carbon source 100 may result in an increase in the weight ratio of the amorphous portion 11 to the electrode material, and thus an increase in the specific surface area of the electrode material. In contrast, a higher heat treatment temperature of the carbon source 100 may result in an increase in the weight ratio of the crystal part 11 to the electrode material, and thus a decrease in the specific surface area of the electrode material.

The specific surface area of the electrode material may vary depending on the type of the carbon source 100 contained in the electrode material.

In addition, the specific surface area of the electrode material may vary depending on the ratio of the crystal part 21 to the electrode material and the ratio of the amorphous part 11 to the electrode material.

When the weight ratio of the crystal part 21 to the electrode material is less than 0.4, the specific surface area of the electrode material may be small, and thus the capacitance of the electrode material may be reduced. In contrast, when the weight ratio of the crystal part 21 to the electrode material is greater than 0.91, the specific surface area of the electrode material may be excessively large, and thus the capacitance of the electrode material may be reduced.

In one embodiment, the specific surface area of the electrode material may be 200m²G to 1200m²In the range of/g. When the specific surface area of the electrode material is 200m²G to 1200m²In the range of/g, electrolyte ions can easily flow between the lattice layers or into the pores 12 in the amorphous portion, thereby improving the capacitance of the electrode material.

The BET (BRUNAUER EMMETT TE LL) method may be used to measure the specific surface area.

As used herein, the term "apparent density" refers to the mass per unit volume. The apparent density may affect the capacitance of the electrode material. In particular, when the apparent density is very large, the capacitance may decrease. When the apparent density is very small, the energy storage efficiency may be deteriorated.

In one embodiment, the apparent density of the electrode material may be at 0.7g/cm³To 1.5g/cm³Within the range of (1). When the apparent density of the electrode material is 0.7g/cm³To 1.5g/cm³In the above range, the capacitance of the electrode material can be advantageously increased.

In another embodiment, the apparent density of the electrode material may be at 0.9g/cm³To 1.3g/cm³Within the range of (1). When the electrodeThe apparent density of the material is 0.9g/cm³To 1.3g/cm³Can advantageously and significantly increase the capacitance of the electrode material.

The electrode material of the present invention may include a carbon source 100, and the carbon source 100 may include a crystal portion 21 including a lattice layer and an amorphous portion 11 including a hole 12, wherein an interval d between adjacent lattice layers in the crystal portion may be in a range of 0.37nm to 0.40nm, and a weight ratio of the crystal portion to the electrode material may be in a range of 0.4 to 0.91. Therefore, the electrode material can have a greatly improved capacitance.

Fig. 2 is a schematic view of an electrochemical device 10 according to an embodiment of the present invention.

The electrochemical device 10 may be configured to allow conversion between electrical energy and chemical energy. In one example, the electrochemical device 10 may be implemented as a supercapacitor, a secondary battery, or the like. However, the present invention is not limited thereto. Hereinafter, for the purpose of describing the present invention, the electrochemical device 10 may be exemplified as a supercapacitor. Reference will be made to fig. 2.

The electrochemical device 10 of the present invention is made of the above electrode material.

The electrochemical device 10 may include a first electrode 2, a second electrode 4, and a separator 3 disposed between the first electrode 2 and the second electrode 4.

At least one of the first electrode 2 and the second electrode 4 in the electrochemical device 10 may be made of the above-described electrode material. Therefore, details about the electrode material, which may be repeated, may be omitted.

The electrode material for at least one of the first electrode 2 and the second electrode 4 in the electrochemical device 10 may include the carbon source 100, and the carbon source 100 may include a crystal portion 21 including a lattice layer and an amorphous portion 11 including holes 12, wherein a spacing d between adjacent lattice layers in the crystal portion may be in a range of 0.37nm to 0.40nm, and a weight ratio of the crystal portion to the electrode material may be in a range of 0.4 to 0.91.

Therefore, the electrode material is contained in at least one of the first electrode 2 and the second electrode 4 as an electrode-forming composition, and the electrode material can function as an electrode active material.

The weight ratio of the crystal portion 21 to the electrode material can be calculated by solving the following equations 1 and 2 for the electrochemical device 10. :

[ formula 1]20x +2000y ═ k

[ formula 2] x + y is 1

Where x represents the weight ratio of the crystal portion 21 to the electrode material, y represents the weight ratio of the amorphous portion 11 to the electrode material, and k represents a range of 200 to 1200.

In one embodiment, among the pores 12 included in the electrochemical device 10, the volume of the pores 12 having a diameter greater than 0nm and equal to or less than 1nm may correspond to 60% to 85% of the total volume of the amorphous portion 11.

In another embodiment, for the pores contained in the electrochemical device 10, the volume of the pores 12 having a diameter in the range of 0.6nm to 0.9nm may be in the range of 45% to 75% of the total volume of the amorphous portion 11.

In another embodiment, the volume of the pores 12 having a diameter in the range of 0.75nm to 0.85nm may be in the range of 15% to 23% of the total volume of the amorphous portion 11.

The electrode material in the electrochemical device 10 may have a thickness of 200m²G to 1200m²Specific surface area in the range of/g.

The electrode material in the electrochemical device 10 may have a thickness of 0.7g/cm³To 1.5g/cm³Apparent density in the range of (a).

In one example, the first electrode 2 may be an anode and the second electrode 4 may be a cathode.

The separator 3 may be disposed between the first electrode 2 and the second electrode 4. Specifically, the separator 3 may be disposed between the first electrode 2 and the second electrode 4, and in contact with the first electrode 2 and the second electrode 4. One surface and the other surface of the separator 3 may be in direct contact and disposed on the first electrode 2 and the second electrode 4.

The first electrode 2, the second electrode 4 and the separator 3 may be impregnated with a liquid electrolyte.

In one embodiment, the liquid electrolyte may be implemented as a non-aqueous liquid electrolyte.

Specifically, when a non-aqueous liquid electrolyte is used, the electrolyte cation may include TEA⁺、TEMA⁺、 Li⁺、EMIM⁺、Na⁺Etc., the electrolyte anion may comprise BF₄ ^-、PF₆ ^-、TFSI^-、FSI^-Alternatively, the liquid electrolyte solvent may be an organic liquid electrolyte, specifically, ACN, PC, GB L, DMK, or the like.

The concentration of the liquid electrolyte may vary depending on the type of solvent and electrolyte ions 13.

The electrochemical device 10 may include at least two partitions as necessary.

In one embodiment, when the electrochemical device 10 includes a plurality of partitions, another partition 1 may be disposed on an upper portion of the first electrode 2 in addition to the partition 3 disposed between the first electrode 2 and the second electrode 4.

In one embodiment, at least one of the first electrode 2 and the second electrode 4 may be formed by rolling an electrode composition comprising an electrode material on a base substrate.

In one embodiment, the first electrode 2 and/or the second electrode 4 may be formed by coating an electrode composition including an electrode material on a base substrate.

In another embodiment, the first electrode 2 and/or the second electrode 4 may be formed by forming an electrode composition comprising an electrode material into a sheet and attaching the sheet to a base substrate and performing a drying operation. However, the formation of the first electrode 2 and/or the second electrode 4 may not be limited thereto.

The base substrate may contain a conductive material, and an example of the conductive material may be a metal or the like. Specifically, the metal may be copper, aluminum, or the like. However, the present invention is not limited thereto.

The base substrate may be implemented as a thin film.

The electrode composition may include a binder and a conductive material in addition to the electrode material. Optionally, the electrode composition may also comprise a solvent. The binder, the conductive material, and the electrode material (optionally a solvent) may be mixed to form a slurry, which may be coated on the electrochemical device 10.

The binder may allow for the binding ability of the electrode composition. As an example, the binder may include carboxymethyl cellulose (CMC), polyvinyl pyrrolidone (PVP), styrene-butadiene rubber (SBR), polyvinylidene fluoride (PVDF), Polyethylene (PE), polypropylene (PP), polyvinyl alcohol (PVA), and the like. The binder may be implemented as at least one selected from the above-listed substances. The present invention is not limited thereto.

In one embodiment, the binder may comprise 1 wt% to 45 wt% of the total weight of the electrode composition.

The conductive material may allow for the conductive capability of the electrode composition. As an example, the conductive material may include carbon black, graphene, Carbon Nanotubes (CNTs), Carbon Nanofibers (CNFs), and the like. The conductive material may be implemented as at least one selected from the above-listed substances. The present invention is not limited thereto.

In one embodiment, the conductive material may comprise 1 wt% to 45 wt% of the total weight of the electrode composition.

The electrode composition may further include a solvent, if necessary. As an example, the solvent may include water or an organic solvent, etc. The present invention is not limited thereto.

In one embodiment, the solvent may comprise 10 wt% to 97 wt% of the total weight of the electrode composition.

In one embodiment, leads 6 and 7 may be connected to the first electrode 2 and the second electrode 4, respectively. The first electrode 2, the second electrode 4, and the separator 3 may be accommodated in a case 5.

In one embodiment, the housing 5 may comprise a conductive material, and examples of the conductive material may comprise a metal or the like. Specifically, the metal may be aluminum or the like. However, the present invention is not limited thereto.

Fig. 3 shows a flow chart of a method of manufacturing an electrode material according to an embodiment of the invention. Fig. 4 shows a high-level view for describing the change of the carbon source due to the activation process. Hereinafter, referring to fig. 3 and 4, a method of manufacturing an electrode material according to an embodiment of the present invention will be described.

First, the carbon source 100 may be heat-treated at 650 ℃ to 900 ℃.

When the heat treatment temperature is less than 650 deg.c, the crystal portion 21 may not be formed in the carbon source 100. When the heat treatment temperature is higher than 900 ℃, the amorphous portion 11 may not be formed in the carbon source 100 and thus only the crystal portion 21 may exist, thereby failing to realize a large capacitance. That is, the carbon source 100 may be heat-treated at 650 to 900 ℃ so that both the amorphous portion 11 and the crystalline portion 21 can be formed in the carbon source 100.

In one embodiment, the heat treatment temperature may be in the range of 650 ℃ to 850 ℃.

The weight ratio of the crystal part 21 to the electrode material can be adjusted by adjusting the heat treatment temperature of the carbon source 100.

The weight ratio of the crystal part 21 to the electrode material may vary depending on the heat treatment temperature of the carbon source 100. The proportion of the crystal portions 21 can influence the specific surface area of the electrode material and thus the capacitance of the electrode material.

When the heat treatment temperature of the carbon source 100 is low, the ratio of the amorphous portion 11 is high, and the specific surface area of the electrode material is increased. In contrast, when the heat treatment temperature of the carbon source 100 is higher, the proportion of the crystal part 12 is higher, so that the specific surface area of the electrode material is reduced.

In the present invention, the carbon source 100 may be heat-treated at 650 to 900 ℃, so that the electrode material may contain the crystal part 21, and further, the weight ratio of the crystal part 21 to the electrode material may be in the range of 0.4 to 0.91 to improve the capacitance of the electrode material.

The duration of the heat treatment may depend on the size of the reaction bath.

The heat treatment may be performed in an inert gas atmosphere. As an example, the inert gas may include helium, argon, nitrogen, and the like. The inert gas may be implemented as at least one selected from the gases listed above. The present invention is not limited thereto.

Subsequently, the heat-treated carbon source 100 may be subjected to an activation treatment using an alkali-containing material at a temperature of 800 ℃ to 1000 ℃.

During the activation process, the amorphous portion 11 may be broken to form the pores 12, and/or the spacing between adjacent lattice layers in the crystal portion 21 may be larger (see fig. 4) to increase the specific surface area of the carbon source.

When the activation treatment temperature is less than 800 ℃ or more than 1000 ℃, the spacing between adjacent lattice layers in the crystal section 21 in the carbon source 100 may deviate from the range of 0.37nm to 0.40nm, so that a large capacitance cannot be realized.

Further, when the activation treatment temperature is out of the range of 800 ℃ to 1000 ℃, it may be difficult or impossible to adjust the proportion of the pores 12 having a predetermined diameter. Therefore, the volume of the pores 12 having a diameter of greater than 0nm and 1nm or less may be out of the range of 60% to 85% of the total volume of the amorphous portion 11. In this regard, the electrode material and the electrochemical device 10 including the electrode material may not have a large capacitance.

As an example, the alkaline substance may include lithium, sodium, potassium metal, and the like. The present invention is not limited thereto.

The activation treatment may be performed in an inert gas atmosphere.

As an example, the inert gas may include helium, argon, nitrogen, and the like. The inert gas may be implemented as at least one selected from the gases listed above. The present invention is not limited thereto.

In the activation treatment, the carbon source 100 and the activator may be mixed in a ratio of 1: 0.8 to 1: the mixing ratios of 5.5 by weight were mixed with each other.

When the mixing ratio between the carbon source and the activator is less than 1: at 0.8, the carbon source may not be sufficiently activated. Thus, although the electrode material contains the crystal sections 21, the spacing between adjacent lattice layers in the crystal sections 21 may not be sufficient to allow electrolyte ions to be inserted between the adjacent lattice layers.

In contrast, when the weight ratio between the carbon source and the activator is higher than 1: 5.5, the spacing between adjacent lattice layers in the crystal section 21 may be very large. Thus, van der waals forces may not act between adjacent lattice layers, thereby not allowing crystallization of the material.

Further, when the mixing ratio between the carbon source and the activator is out of the above range, it may be difficult or impossible to adjust the proportion of the pores 12 having a predetermined diameter. Therefore, the volume of the hole 12 having a diameter greater than 0nm and 1nm or less may be out of the range of 60% to 85% of the total volume of the amorphous portion 11, thereby significantly reducing the capacitance.

After the activation treatment, in order to remove alkali-containing substances, neutralization may be performed using a neutralizing agent (e.g., hydrochloric acid \ nitric acid, etc.).

After neutralization, cleaning may be performed using a cleaning agent such as distilled water.

After cleaning, drying may be performed. The time and temperature of the drying process may vary depending on the size of the reaction bath.

The manufacturing method of the electrode material may also comprise other operations known to the person skilled in the art, as long as other operations may be suitable for the present invention.

The electrode material obtained by the above-described electrode material manufacturing method may include the carbon source 100, and the carbon source 100 may include the crystal portion 21 including the lattice layer, and the amorphous portion 11 including the hole 12, wherein the pitch d of adjacent lattice layers in the crystal portion may be in the range of 0.37nm to 0.40nm, and the weight ratio of the crystal portion to the electrode material may be in the range of 0.4 to 0.91. That is, the electrode material obtained by the above-described manufacturing method of the electrode material may have the same details as those of the electrode material described above.

Example 1

Preparation of electrode composition

Residual oil resulting from the ncc (naphta Cracking center) process is heat treated at a temperature of 350 ℃ to obtain a solid pitch with a molecular weight of 1000 to 2500. The pitch is used as a carbon source for the electrode material.

The pitch as a carbon source was heat-treated in a hot spot (hot spot) having a size of 60 Φ × 120cm at a temperature of 750 ℃ for 1 hour in an argon atmosphere.

Then, the content ratio is 1: 4 as a carbon source and a KOH activator, were subjected to an activation treatment at a temperature of 900 deg.c for 1 hour in an argon atmosphere, thereby obtaining an electrode material. Then, an electrode composition having the components and contents shown in the following table 1 was prepared:

table 1:

preparation of electrochemical devices

The above electrode composition was press-rolled on a copper-based base substrate to form an electrode sheet, and then the electrode sheet was dried to prepare a first electrode and a second electrode, and then leads were connected to the first and second electrodes, respectively.

The first separator, the first electrode, the second separator, and the second electrode are stacked to form a stacked body. Then, the stack is wound to form a wound stack. Then, the stacked body is sealed with rubber, and then the stacked body is accommodated in a case. Next, the stack was impregnated with liquid electrolyte (ACN of 1M TEABF 4) in the case. Then, the case was sealed to prepare an electrochemical device (supercapacitor) (see fig. 2).

Test 1: checking the presence/absence of a crystal part

The presence/absence of crystal portions in the electrode material prepared using example 1 was checked using an X-ray diffraction method.

Fig. 5 is a graph of an X-ray diffraction analysis pattern of the electrode material prepared using example 1.

Referring to fig. 5, when 2 θ is 25.5 °, an intensity peak occurs. The intensity peak corresponds to the crystal portion. Therefore, the X-ray diffraction analysis pattern indicated that the electrode material prepared using example 1 contained both an amorphous portion and a crystalline portion.

And (3) testing 2: measuring capacitance based on spacing between adjacent lattice layers in a crystal section

Examples 2 to 4

An electrochemical device was prepared in the same manner as in example 1, except that the content ratio of the carbon source and the active agent was activated to 1: 0.8 to 1: 5.5.

Comparative example 1

An electrode material was prepared in the same manner as in example 1, except that the electrode material was changed in the ratio of 1: 0.5 of the mixing ratio between the carbon source and the activator.

Comparative example 2

An electrochemical device was prepared in the same manner as in example 1, except that the electrode material was changed in the ratio of 1: 6, and an activator.

In the electrode materials according to examples and comparative examples, the distances between adjacent lattice layers in the crystal portion were measured using an X-ray diffraction analysis method.

In addition, the capacitance per unit volume was measured at 0.565mA using a Hi-ED L C16 CH device (available from Human Instrument) and the results are shown in table 2 below:

TABLE 2

Referring to table 2 above, the electrode materials prepared from examples 2 to 4 include crystal portions having a spacing between adjacent lattice layers in the range of 0.37nm to 0.4 nm.

In addition, the electrode materials prepared by examples 2 to 4 showed higher capacitance than the electrode materials in comparative examples 1 and 2.

And (3) testing: capacitance measurement based on the specific weight of the crystal portion in the carbon source

Examples 5 to 11 and comparative examples 3 to 7An electrochemical device was manufactured in the same manner as in example 1, except that the carbon source was heat-treated at different temperatures in the range of 650 ℃ to 900 ℃, respectively. Specifically, comparative examples 3 and 4 were also heat-treated at a temperature close to 650 ℃ in the temperature range, and comparative examples 5 to 7 were also heat-treated at a temperature close to 900 ℃ in the temperature range.

The specific surface area of each of the electrode materials prepared by examples 5 to 11 and comparative examples 3 to 7, respectively, was measured using the BET method. The capacitance was measured in the same manner as in experimental example 2, and the results are shown in Table 3 below.

TABLE 3

Referring to table 3 above, it can be determined that the examples all contain crystal portions in the range of 0.4 to 0.91, and the proportions of the crystal portions of the comparative examples are all outside the range of the present invention.

Specifically, since the heat treatment is performed in the temperature range of 650 ℃ to 900 ℃, both the examples and the comparative examples include a crystalline portion and an amorphous portion.

On the other hand, in the temperature range, the ratio of the crystal portions of comparative examples 3 and 4 heat-treated at a high temperature was relatively high, and the amorphous portion was low, and in the temperature range, the ratio of the crystal portions of comparative examples 5 to 7 heat-treated at a low temperature was relatively low, and it was found that the amorphous portion was high.

Further, it was confirmed that the capacitance values in the examples are significantly excellent relative to the comparative examples.

Examples 12 to 14 and comparative example 8

An electrochemical device was prepared in the same manner as in example 1, except that the electrochemical device was prepared using an electrode composition having the composition and content shown in table 4 below: TABLE 4

And (4) testing: hole distribution testing

For the specific pore diameter and the pore distribution with the specific pore diameter of the materials of example 1 and comparative example 8, by using N₂BET measurement device for absorption (SURFACace AnaAnaAnanaa available from MICROMERICS)L YZER) (TRISTAR-3000)), the test results are shown in Table 5 below, with reference to the graph of FIG. 6:

TABLE 5

Referring to table 5 and fig. 6, the electrode material of example 1 includes pores, and the volume of the pores having a diameter of greater than 0nm and 1nm or less may correspond to 74.61% of the total volume of the amorphous portion 11, and thus it is understood that example 1 is within the scope of the present invention.

However, the electrode material used in comparative example 8 includes pores, but the volume of pores having a diameter of greater than 0nm and 1nm or less may correspond to 32.16% of the total volume of the amorphous portion, and thus it is understood that the electrode material is outside the scope of the present invention.

And (5) testing: measurement of apparent Density and capacitance

The apparent density and capacitance of each of the electrode materials of examples 1, 12, 13 and comparative example 8 prepared by the method were measured.

The apparent density was calculated as mass per unit volume and the capacitance was measured as capacitance per unit volume at 0.565mA using a Hi-ED L C16 CH instrument (available from HumanInstrument.) the test results are shown in Table 6 below:

TABLE 6

Referring to table 6, the apparent densities and capacitances of examples 1, 12, and 13 were higher than those of comparative example 8.

Furthermore, it was confirmed that in comparison between examples and comparative examples in terms of apparent density and capacitance, a higher content of the electrode material of the present invention can achieve a larger capacitance.

The above description should not be taken in a limiting sense, but is made merely for the purpose of describing the general principles of exemplary embodiments and many additional embodiments of the invention are possible. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended. The scope of the invention should be determined with reference to the claims. Reference throughout this specification to "one embodiment," "an embodiment," or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases "in one embodiment," "in an embodiment," and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment.

Claims

1. An electrochemical device, comprising:

a first electrode;

a second electrode; and

a separator disposed between the first electrode and the second electrode,

wherein at least one of the first electrode and the second electrode comprises an electrode material, wherein the electrode material comprises:

a carbon source comprising:

a crystal portion including a lattice layer; and

an amorphous portion, the amorphous portion comprising a hole,

wherein the specific surface area of the electrode material is 200m²G to 1200m²In the range of/g.

2. The electrochemical device of claim 1, wherein said first electrode is an anode and said second electrode is a cathode.

3. The electrochemical device according to claim 1, wherein the separator is disposed between and in contact with the first electrode and the second electrode.

4. The electrochemical device according to claim 1, wherein the separator has two opposite faces in direct contact with the first electrode and the second electrode, respectively.

5. The electrochemical device of claim 1, further comprising an additional separator on said first electrode.

6. The electrochemical device of claim 1, wherein said first and second electrodes comprise a base substrate and said electrode material on said base substrate.

7. The electrochemical device according to claim 1, wherein leads are connected to the first electrode and the second electrode, respectively.

8. The electrochemical device of claim 1, wherein said pores receive electrolyte ions.

9. The electrochemical device of claim 1, wherein said holes comprise said holes having different diameters.