Electrode, lithium ion capacitor comprising same, and manufacturing method therefor

Abstract

Disclosed in the present invention is an electrode comprising: a current collector; and electrode layers formed on both sides of the current collector, wherein the electrode layers each have a plurality of perforated holes, and the perforated holes have a diameter of 5-80 ㎛. According to the present invention, lithium pre-doping efficiency of an anode may be increased, the flow of an electrolyte may be smooth, a coating process may be smoothly performed by preventing an electrode slurry from flowing down, and price competitiveness and processability may be excellent.

Description

Electrode, lithium ion capacitor including same, and method for manufacturing same

[0001] The present invention relates to an electrode, a lithium ion capacitor including the same, and a method for manufacturing the same. More specifically, the present invention relates to an electrode that does not use a perforated current collector, forms micro holes on an electrode layer by laser after a coating process is completed, thereby increasing the lithium pre-doping efficiency of an anode, ensuring smooth movement of an electrolyte, preventing electrode slurry from flowing down, thereby enabling a smooth coating process, and having excellent price competitiveness and processability, a lithium ion capacitor including the same, and a method for manufacturing the same.

[0002] Compared to general capacitors, lithium-ion capacitors can secure a wide potential window between the positive and negative electrodes by pre-doping lithium into the negative electrode, and can ensure the stability of the completed capacitor cell by forming an SEI film on the negative electrode side in advance.

[0003] In conventional lithium-ion capacitors, the cathode and lithium electrode are connected separately and charged to dope the cathode with lithium, thereby allowing lithium ions to migrate to the cathode. Furthermore, attempts have been made to use a perforated current collector with holes formed in the electrode current collector to improve lithium ion movement during pre-doping.

[0004] However, perforated current collectors have the problem of being more than three times more expensive than regular current collectors. In addition, when coating electrode slurry using a perforated current collector, the electrode slurry moves through the holes formed on the current collector and flows down to the coating equipment, making it difficult to perform the coating process smoothly. Furthermore, after the coating process is completed, the electrode slurry sticks to the coating roll, making it impossible to perform the coating work continuously, and there is the inconvenience of having to remove the stuck electrode slurry every time the coating process is performed.

[0005] To solve this problem, it is necessary to develop an electrode that does not use a perforated current collector when manufacturing lithium-ion capacitors, and forms micro holes using a laser or other means on an electrode that has completed the coating process.

[0006] Related prior art includes Republic of Korea Patent Publication No. 10-2021-0067935.

[0007] The purpose of the present invention is to provide an electrode that improves the lithium pre-doping efficiency of a negative electrode and allows smooth movement of electrolyte through perforated holes, a lithium ion capacitor including the same, and a method for manufacturing the same.

[0008] Another object of the present invention is to provide an electrode capable of smoothly performing a coating process by preventing electrode slurry from flowing down, a lithium ion capacitor including the same, and a method for manufacturing the same.

[0009] Another object of the present invention is to provide an electrode having excellent price competitiveness and fairness, a lithium ion capacitor including the same, and a method for manufacturing the same.

[0010] The above and other objects of the present invention can all be achieved by the present invention described below.

[0011] 1. One aspect of the present invention relates to an electrode. The electrode comprises a current collector; and an electrode layer formed on both sides of the current collector; wherein the electrode layer has a plurality of perforated holes formed therein, and the diameter of the perforated holes is 5 to 80 μm.

[0012] 2. In the above 1 specific example, the perforated hole can be formed by penetrating the electrode layer and the current collector.

[0013] 3. In the above 1 to 2 specific examples, the entire body may not have a perforated hole formed therein.

[0014] 4. In the above specific examples 1 to 3, the perforation hole can be formed by a laser.

[0015] 5. In the above specific examples 1 to 4, the pitch between the perforated holes may be 50 μm or more.

[0016] 6. In the above specific examples 1 to 5, the pitch between the perforated holes may be 60 to 170 μm.

[0017] 7. In the above specific examples 1 to 6, the plurality of perforated holes can satisfy the following formula.

[0018] [Formula 1]

[0019] 0.6 ≤ L1 / L2 ≤ 35

[0020] (In Equation 1, L1 is the pitch between punched holes, and L2 is the diameter of the punched holes)

[0021] 8. Another aspect of the present invention relates to a lithium ion capacitor. The lithium ion capacitor comprises a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode, wherein at least one of the positive electrode and the negative electrode may be an electrode according to any of the above-described specific examples 1 to 7.

[0022] 9. In the above 8 specific examples, the voltage of the lithium ion capacitor may be 3.5 V or higher, and the capacity may be 250 mAh / g or higher.

[0023] 10. Another aspect of the present invention relates to a method for manufacturing an electrode. The method comprises the steps of forming an electrode layer on a current collector; and the step of forming a plurality of perforations in the electrode layer using a laser; wherein the diameter of the perforations is 5 to 80 μm.

[0024] 11. In the above 10 specific examples, the perforated hole can be formed by penetrating the electrode layer and the current collector.

[0025] 12. In the above 10 to 11 specific examples, the entire body may not have a perforated hole formed therein.

[0026] 13. In the above 10 to 12 specific examples, the pitch between the perforated holes may be formed to be 50 μm or more.

[0027] 14. In the above 10 to 13 specific examples, the pitch between the perforated holes may be formed to be 60 to 170 μm.

[0028] 15. In the above 10 to 14 specific examples, the electrode layer may be formed from an electrode composition including an electrode active material, a binder, and a conductive material.

[0029] 16. Another aspect of the present invention relates to a lithium ion capacitor. The lithium ion capacitor comprises an electrode manufactured by the method of any of the above 10 to 15 specific examples.

[0030] 17. In the above 16 specific examples, the voltage of the lithium ion capacitor may be 3.5 V or higher, and the capacity may be 250 mAh / g or higher.

[0031] The present invention has the effects of providing an electrode that increases the lithium pre-doping efficiency of a negative electrode, facilitates the movement of an electrolyte, prevents the electrode slurry from flowing down, thereby enabling a smooth coating process, and has excellent price competitiveness and processability, a lithium ion capacitor including the same, and a manufacturing method thereof.

[0032] Figure 1 illustrates a plurality of perforated holes formed in a portion of the thickness of an electrode layer using a laser according to one specific example of the present invention, and the electrode layer being coated on one surface of a current collector.

[0033] Figure 2 shows a plurality of perforated holes formed over the entire thickness of an electrode layer using a laser according to one specific example of the present invention, and the electrode layer being coated on one surface of a current collector.

[0034] Figure 3 shows a plurality of perforated holes formed up to a portion of the thickness of the current collector using a laser according to one specific example of the present invention, and an electrode layer coated on one surface of the current collector.

[0035] FIG. 4 shows a plurality of perforated holes formed to the entire thickness of the current collector using a laser according to one specific example of the present invention, and an electrode layer coated on one surface of the current collector.

[0036] FIG. 5 illustrates a perforation hole formed by penetrating a current collector and an electrode layer coated on both sides of the current collector using a laser according to one specific example of the present invention.

[0037] Figure 6 is a plan view of an electrode layer having a plurality of perforated holes formed according to one specific example of the present invention.

[0038] Figure 7 shows the amount of lithium metal remaining in the electrode after lithium pre-doping according to Example 1 of the present invention.

[0039] Figure 8 is a graph showing voltage and current over time according to Example 1 of the present invention.

[0040] Figure 9 shows the amount of Li metal remaining in the electrode after lithium pre-doping according to Comparative Example 1 of the present invention.

[0041] Figure 10 is a graph showing voltage and current over time according to Comparative Example 1 of the present invention.

[0042] Figure 11 shows the amount of Li metal remaining in the electrode after lithium pre-doping according to Comparative Example 2 of the present invention.

[0043] Figure 12 is a graph showing voltage and current over time according to Comparative Example 2 of the present invention.

[0044] Hereinafter, the present invention will be described in more detail. In the present specification, where the terms "includes," "has," and "consists of," are used, other parts may be added, unless "only" is used. When a component is expressed in the singular, it also includes the plural, unless otherwise explicitly stated.

[0045] When interpreting a component, it is interpreted as including the error range even if there is no separate explicit description.

[0046] Hereinafter, the present invention will be described in detail with reference to the drawings.

[0047] Figure 1 illustrates a plurality of perforated holes formed in a portion of the thickness of an electrode layer using a laser according to one specific example of the present invention, and the electrode layer being coated on one surface of a current collector.

[0048] Referring to FIG. 1, the electrode (100) includes a current collector (20) and an electrode layer (10) formed on both sides of the current collector (20).

[0049] The current collector (20) collects electrons generated through a chemical reaction in the electrode layer (10) and helps them to efficiently move to an external circuit. The current collector (20) is in the form of a thin, flat plate, and the electrode layer (10) is uniformly distributed on its surface. The current collector (20) may include a metal thin film, and the material of the metal thin film may have high conductivity without causing electrochemical changes in the lithium ion capacitor. In specific examples, aluminum, copper, stainless steel, nickel, platinum, titanium, and alloys thereof may be used, but the present invention is not limited to the materials. In particular, aluminum, which has high electrical conductivity, is lightweight, and is chemically stable, may be used as the positive electrode current collector, and copper, which has high electrical conductivity, high mechanical strength, and high durability, may be used as the negative electrode current collector.

[0050] The thickness of the current collector (20) may be 5 to 50 μm. In a specific example, the thickness of the current collector (20) may be 10 to 40 μm, for example, 15 to 25 μm. Within the above range, the current collector (20) may have high electrical conductivity and may uniformly coat the electrode layer (10), thereby improving the performance of the electrode.

[0051] The above-mentioned perforated hole (50) may be formed by penetrating the electrode layer (10) and the current collector (20). In addition, the current collector (20) may not have the perforated hole (50) formed therein. Since the price of an existing perforated current collector is more than three times higher than that of a general current collector, price competitiveness can be secured through a current collector (20) in which the perforated hole (50) is not formed. In addition, when a current collector (20) in which the perforated hole (50) is not formed is used, the phenomenon of the electrode slurry flowing down through the hole when using the perforated current collector can be prevented, so that the coating process can be smoothly performed, and the problem of having to remove the fixed electrode slurry every time the coating process is performed can be prevented.

[0052] The above electrode layer (10) stores and releases lithium ions, and must have high electrical conductivity and minimize physical deformation during repeated charge and discharge processes. The electrode layer (10) is uniformly formed on both sides of the current collector (20). The electrode layer (10) can be formed by applying an electrode composition including an electrode active material, a binder, and a conductive agent to both sides of the current collector (20), compressing the composition, and then drying the composition.

[0053] The above electrode active material is a material that transfers electrons within the electrode. Activated carbon, polyacene (PAS), lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, etc. can be used as the positive electrode active material. Graphite, non-graphitizable carbon, hard carbon, coke, and polyacene-based materials (PAS) can be used as the negative electrode active material.

[0054] The conductive material may be a conductive carbon black such as furnace black or acetylene black. The conductive material may be used in an amount of 0.1 to 20 parts by weight, specifically 0.5 to 15 parts by weight, for example 1 to 5 parts by weight, relative to 100 parts by weight of the electrode active material. Within the above range, the resistance of the lithium ion capacitor can be lowered and the capacity can be increased.

[0055] The binder is a compound capable of binding the electrode active material and the conductive material to each other, and may include a polymer compound such as PVDF (Polyvinylidene Fluoride), SBR (Styrene-Butadiene Rubber), PTFE (Polytetrafluoroethylene), acrylate polymer, polyamide, or polyurethane polymer that can be dispersed in a solvent. The binder may be present in an amount of 0.1 to 20 parts by weight, specifically 0.5 to 15 parts by weight, for example 1 to 5 parts by weight, relative to 100 parts by weight of the electrode active material. Within the above range, the adhesiveness can be improved. In addition, the resistance of the lithium ion capacitor can be lowered, the capacity can be increased, and the energy density can be increased.

[0056] The thickness of the electrode layer (10) may be appropriately set depending on the thickness of the target electrode composition layer. Generally, it may be 50 to 500 μm, specifically 50 to 400 μm, and preferably 50 to 350 μm. Within the above range, the ion movement path is optimized, enabling rapid charging and discharging, and allowing electrochemical reactions to occur evenly.

[0057] Figure 6 is a plan view of an electrode layer having a plurality of perforated holes formed according to one specific example of the present invention.

[0058] Referring to Fig. 6, the electrode layer (10) is formed with a plurality of perforated holes (50). The perforated holes (50) can be formed using a laser (60) or the like on at least one of the positive electrode or negative electrode before winding the electrode element after manufacturing the electrode (100). Through this, perforated holes having a constant size and pitch are formed, thereby ensuring cost-effectiveness while ensuring fairness.

[0059] The above plurality of perforated holes (50) can satisfy the following formula.

[0060] [Formula 1]

[0061] 0.6 ≤ L1 / L2 ≤ 35

[0062] (In Equation 1, L1 is the pitch between punched holes, and L2 is the diameter of the punched holes)

[0063] In a specific example, the L1 / L2 may be 0.7 to 30, for example, 0.9 to 20. In the above range, the effect of lithium pre-doping is excellent, the Li doping rate is increased, and the problem of cell capacity deterioration can be prevented.

[0064] The diameter of the above-mentioned perforation hole (50) is 5 to 80 μm. In a specific example, the diameter of the above-mentioned perforation hole (50) may be 10 to 75 μm, for example, 15 to 70 μm. In the above range, the effect of lithium pre-doping is excellent, and the problem of cell capacity reduction can be prevented.

[0065] FIG. 2 illustrates a plurality of perforated holes formed over the entire thickness of an electrode layer using a laser according to one specific embodiment of the present invention and the electrode layer being coated on one surface of a current collector, and FIG. 3 illustrates a plurality of perforated holes formed up to a portion of the thickness of a current collector using a laser according to one specific embodiment of the present invention and the electrode layer being coated on one surface of a current collector. In addition, FIG. 4 illustrates a plurality of perforated holes formed up to the entire thickness of a current collector using a laser according to one specific embodiment of the present invention and the electrode layer being coated on one surface of a current collector, and FIG. 5 illustrates perforated holes formed by penetrating a current collector and electrode layers coated on both surfaces of the current collector using a laser according to one specific embodiment of the present invention.

[0066] Referring to FIGS. 2 to 5, the depth of the perforation hole (50) may be 10% to 100% of the thickness of the electrode layer (10), assuming the entire thickness of the electrode layer (10) to be 100%, and may be 10% to 100% of the entire thickness of the current collector (20), assuming the entire thickness of the current collector (20) to be 100%. In the above range, the overall movement path of lithium increases, thereby increasing the lithium doping speed and being advantageous for voltage formation.

[0067] The pitch between the perforations (50) may be 50 μm or more. In a specific example, the pitch between the perforations (50) may be 60 to 170 μm, for example, 70 to 160 μm. Within the above range, the number of perforations (50) per unit area is appropriate, thereby preventing problems such as reduced capacity and increased resistance. In addition, the overall lithium movement path increases, thereby increasing the lithium doping rate and being advantageous for voltage formation.

[0068]

[0069] Another aspect of the present invention relates to a lithium-ion capacitor. The lithium-ion capacitor comprises a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode, wherein at least one of the positive electrode and the negative electrode may be the electrode described above. The lithium-ion capacitor stores and releases energy through the movement of lithium ions, and by using the electrode described above, it can have high energy density and durability, and reduce energy loss. In addition, electrochemical performance can be improved, and the movement paths of electrons and ions can be optimized to increase charging and discharging efficiency, and stability can be promoted.

[0070] The above separator utilizes a material that allows ion movement but blocks electrons, and polymer materials such as polypropylene (PP) or polyethylene (PE) can be used. The negative electrode can be pre-doped with lithium and the voltage between the positive and negative electrodes can be set widely, so that the lithium-ion capacitor can have a high energy density. In addition, by forming a SEI (solid electrolyte interface) film in advance on the negative electrode, side reactions between the electrolyte and the negative electrode can be suppressed, the stability of the negative electrode can be increased, and the lifespan can be extended.

[0071] The voltage of the above lithium ion capacitor may be 3.5 V or higher, and the capacity may be 250 mAh / g or higher. In a specific example, the voltage may be 3.7 V or higher, for example, 3.8 V or higher. In addition, in a specific example, the capacity may be 270 mAh / g or higher, for example, 275 mAh / g or higher. In the above range, the energy density of the lithium ion capacitor is high, so that the charging and discharging speeds are fast, the energy storage efficiency is high, and the lifespan can be long.

[0072]

[0073] Another aspect of the present invention relates to a method for manufacturing an electrode. The method comprises the steps of forming an electrode layer on a current collector; and the step of forming a plurality of perforations in the electrode layer using a laser; wherein the diameter of the perforations is 5 to 80 μm.

[0074] First, a current collector made of a metal film without perforations is prepared. The thickness of the current collector may be 5 to 50 μm. In a specific example, the thickness of the current collector may be 10 to 40 μm, for example, 15 to 20 μm. When the current collector without perforations is used, the phenomenon of electrode slurry flowing down through the holes when using a perforated current collector can be prevented, thereby enabling a smooth coating process, and the problem of having to remove the fixed electrode slurry every time the coating process is performed can be prevented.

[0075] The step of forming an electrode layer on the current collector may be formed by applying an electrode composition including an electrode active material, a binder, and a conductive material to both sides of the current collector, compressing the composition, and then drying the composition. The electrode layer may be formed to have a thickness of generally 50 to 500 μm, specifically 50 to 400 μm, and preferably 50 to 350 μm.

[0076] Methods for applying the above electrode composition onto a current collector include, but are not limited to, direct roll method, doctor blade method, dip method, reverse roll method, gravure method, and brush coating method.

[0077] Drying methods include, but are not limited to, drying methods using warm air, hot air, vacuum drying, and irradiation with (far) infrared rays or electron beams. The drying temperature may be 60 to 200°C, specifically 80 to 160°C, for example 100 to 150°C. In addition, the drying time may be 10 minutes to 48 hours, specifically 20 minutes to 24 hours, for example 1 hour to 20 hours. In the above range, the solvent of the electrode composition applied to the current collector can be completely removed, so that the electrical conductivity of the electrode can be improved. In addition, the electrode composition can be uniformly distributed, thereby improving mechanical stability, increasing stability, and extending the life of the electrode.

[0078] The step of forming a plurality of perforations in the electrode layer using a laser may be performed after forming the electrode layer on the current collector, thereby forming perforations in the electrode layer using a laser. The wavelength of the laser may be 193 nm to 355 nm, and high energy may be provided in the above range to form precise perforations. For example, the wavelength of the laser may be 195 nm to 350 nm. This allows for forming perforations with a constant diameter and pitch, thereby ensuring processability. This provides an electrode coating process that improves the problem that, when applying electrode slurry to a current collector having existing through-holes, the electrode slurry may leak through the through-holes to the back side of the current collector, thereby contaminating the back side.

[0079]

[0080] Another aspect of the present invention relates to a lithium-ion capacitor. The lithium-ion capacitor includes an electrode manufactured by the method described above. The lithium-ion capacitor may have a voltage of 3.5 V or higher and a capacity of 250 mAh / g or higher. In a specific embodiment, the voltage may be 3.7 V or higher, for example, 3.8 V or higher. Furthermore, in a specific embodiment, the capacity may be 270 mAh / g or higher, for example, 275 mAh / g or higher. Within the above range, the lithium-ion capacitor has a high energy density, allowing for fast charging and discharging, high energy storage efficiency, and a long lifespan.

[0081]

[0082] Hereinafter, the present invention will be described in more detail through examples and comparative examples; however, these examples are for the purpose of explanation only and should not be construed as limiting the present invention.

[0083]

[0084] Example

[0085] Example 1

[0086] (Polar preparation)

[0087] An electrode composition containing 90 parts by weight of activated carbon, 5 parts by weight of SBR (Styrene-Butadiene Rubber) and PVDF (Polyvinylidene Fluoride), and 5 parts by weight of carbon black was applied to both sides of a 20㎛ thick aluminum positive electrode collector and compressed. Thereafter, the composition was dried at 150℃ for 12 hours to manufacture a positive electrode in which an electrode layer having a thickness of 120㎛ on one side was coated on both sides of the current collector.

[0088]

[0089] (Preparing the cathode)

[0090] An electrode composition including 90 parts by weight of soft carbon, 5 parts by weight of SBR and PVDF, and 5 parts by weight of carbon black was applied to both sides of a 10 μm thick copper negative electrode collector and compressed. Thereafter, the electrode was dried at 150°C for 12 hours to manufacture a negative electrode such that an electrode layer having a thickness of 120 μm on one side was coated on both sides of the current collector.

[0091]

[0092] (Formation of punch holes and preparation of components)

[0093] A laser with a wavelength of 300 nm was used to form perforations across the electrode layers of the above-mentioned positive and negative electrodes. The diameter of the perforations was 50 μm, the pitch between the perforations was 70 μm, and the depth of the perforations was such that they penetrated all the way to the current collector. Thereafter, a separator was interposed between the completed positive and negative electrodes to manufacture a wound device.

[0094]

[0095] (lithium pre-doping)

[0096] After electrically connecting the negative electrode of the completed device to lithium metal, lithium ions were doped onto the negative electrode through charging and discharging. The current was set to 0.02 A, and the negative electrode was discharged until it reached 0.001 V, completing pre-doping and fabricating a lithium-ion capacitor.

[0097]

[0098] Example 2

[0099] The same procedure as Example 1 was followed, except that the diameter of the perforated hole was 5 um and the pitch between the perforated holes was 50 um.

[0100]

[0101] Example 3

[0102] The same procedure as Example 1 was followed, except that the diameter of the perforated hole was 30 um and the pitch between the perforated holes was 100 um.

[0103]

[0104] Example 4

[0105] The same procedure as Example 1 was followed, except that the diameter of the perforated hole was 70 um and the pitch between the perforated holes was 170 um.

[0106]

[0107] Comparative Example 1

[0108] The same procedure as Example 1 was followed, except that a perforated aluminum collector with a thickness of 20 μm was used as the positive electrode collector, and a perforated copper collector with a thickness of 10 μm was used as the negative electrode collector, and the diameter of the perforated holes was 70 μm and the pitch between the perforated holes was 170 μm.

[0109]

[0110] Comparative Example 2

[0111] The same procedure as in Comparative Example 1 was followed, except that a general current collector without perforations was used as the positive and negative current collectors.

[0112]

[0113] Comparative Example 3

[0114] The same procedure as Example 1 was followed, except that the diameter of the perforated hole was 120 um and the pitch between the perforated holes was 40 um.

[0115]

[0116] The physical properties of the above examples and comparative examples were evaluated using the following methods, and the results are shown in Tables 1 and 2:

[0117]

[0118] Physical property evaluation method

[0119] (1) Fairness

[0120] A device capable of measuring the coating thickness of a current collector sample coated with an electrode composition in real time was used to determine the maximum width of the coatable electrode and the speed of the coating process. Furthermore, strong light was shone onto the coating roll to confirm the distribution of the electrode composition on its surface. Furthermore, coating quality was inspected to assess the uniformity and thickness of the electrode composition, and the cleaning interval was determined based on the point at which quality deterioration occurred.

[0121]

[0122] (2) Voltage and capacity

[0123] Using a digital multimeter, probes were connected to both terminals of the lithium-ion capacitor and the voltage was directly measured.

[0124] Using the galvanostatic charge / discharge method, a lithium-ion capacitor was charged at a constant current via a power supply and a current measuring device, and the charging time and current were recorded. Furthermore, after charging, the lithium-ion capacitor was discharged at a constant current, and the discharge time and current were recorded. The capacity (C) was calculated by multiplying the current (I) by the time (t) and dividing by the voltage (V).

[0125]

[0126] (3) Doping

[0127] Using the ICP-OES (Inductively Coupled Plasma Optical Emission Spectroscopy) method, the electrodes of a lithium-ion capacitor were dissolved in an appropriate solvent, and the prepared sample solution was injected into a high-temperature argon plasma to ionize. Afterwards, the characteristic light emitted by the ionized elements was measured with a spectrometer, and the spectrum of the emitted light was analyzed to quantify the remaining amount of lithium metal.

[0128] The color of the cathode surface after cell disassembly was measured by irradiating light of a specific wavelength using a colorimeter and measuring the reflected light.

[0129]

[0130] (4) Price

[0131] The price was compared by setting the general collector as 100% based on the price per 100M.

[0132]

[0133] Table 1 below compares the fairness of examples and comparative examples, showing the maximum width (mm) of electrodes that can be coated, coating roll smearing, coating roll cleaning interval, and coating process speed:

[0134] Maximum width of electrode that can be coated (mm) Coating roll smearing Coating roll cleaning interval Coating process speed Example 1500 or more X After work is completed 20 M / min or more Example 2500 or more X After work is completed 20 M / min or more Example 3500 or more X After work is completed 20 M / min or more Example 4500 or more X After work is completed 20 M / min or more Comparative example 1250 or less O Always 5 M / min or less Comparative example 2500 or more X After work is completed 20 M / min or more Comparative example 3500 or more X After work is completed 20 M / min or more

[0135] As shown in Table 1 above, Examples 1 to 4 have a large maximum coatable width, no coating roll staining of the electrode slurry, a wide coating roll cleaning interval, and a high coating process speed. This allows the electrode slurry to be prevented from flowing down, enabling the coating process to be performed smoothly, and it can be seen that the processability is excellent.

[0136] Table 2 below compares the voltage, capacity, doping, and price of the examples and comparative examples, and in particular, the doping indicates the ICP (lithium metal residue) and the color of the cathode surface after cell disassembly:

[0137]

[0138] Voltage (V) Capacity (mAh / g) ICP (Lithium metal remaining) Color of cathode surface after cell disassembly Price Example 13.8275 Small Light brown 100% Example 23.8255 Small Light brown 100% Example 33.8270 Small Light brown 100% Example 43.8260 Small Light brown 100% Comparative Example 13.8285 Small Light brown 300% Comparative Example 23.0150 Large Black 100% Comparative Example 33.2180 Small Light brown 100%

[0139] FIG. 7 shows the amount of lithium metal remaining in the electrode after lithium pre-doping according to Example 1 of the present invention, and FIG. 8 is a graph showing voltage and current over time according to Example 1 of the present invention. Referring to FIGS. 7 and 8, in the case of Example 1, it can be confirmed that there is almost no residual lithium metal and that stable charging is performed up to 0.001 V. FIG. 9 shows the amount of lithium metal remaining after lithium pre-doping according to Comparative Example 1 of the present invention, and FIG. 10 is a graph showing voltage and current over time according to Comparative Example 1 of the present invention. Referring to FIGS. 9 and 10, in the case of Comparative Example 1, it can be confirmed that there is almost no residual lithium metal and that stable charging is performed up to 0.001 V.

[0140] Fig. 11 shows the amount of lithium metal remaining after lithium pre-doping according to Comparative Example 2 of the present invention, and Fig. 12 is a graph showing voltage and current over time according to Comparative Example 2 of the present invention. Referring to Figs. 11 and 12, it can be confirmed that in the case of Comparative Example 2, there is a lot of residual lithium metal, and stable charging is not achieved up to 0.001 V.

[0141]

[0142] As shown in the above Figures 7 to 12 and Table 2, Examples 1 to 4 have similar voltage and capacity to Comparative Example 1, and the residual amount of lithium metal is small. In addition, the color of the negative electrode surface after cell disassembly is light brown, and the price per 100M is relatively low. This shows that the negative electrode has high lithium pre-doping efficiency, smooth electrolyte movement, and excellent price competitiveness.

[0143]

[0144] Simple modifications or changes of the present invention can be easily implemented by a person having ordinary skill in the art, and all such modifications or changes can be considered to be included in the scope of the present invention.

[0145] [Explanation of symbols]

[0146] 10: Electrode layer 20: Current collector

[0147] 50: Perforated hole 60: Laser

[0148] 100: Electrode L1: Pitch between punched holes

[0149] L2: Diameter of punched hole

Claims

1. The entire house; and including an electrode layer formed on both sides of the above-mentioned collector; The above electrode layer has a plurality of perforated holes formed therein, An electrode having a diameter of the above punched hole of 5 to 80 μm.

2. In paragraph 1, An electrode in which the above-mentioned perforated hole is formed by penetrating the electrode layer and the current collector.

3. In paragraph 1, An electrode in which the above-mentioned collector does not have a perforated hole formed.

4. In paragraph 1, An electrode in which the above perforated hole is formed by a laser.

5. In paragraph 1, An electrode having a pitch between the above punched holes of 50㎛ or more.

6. In paragraph 1, An electrode having a pitch between the above punched holes of 60 to 170 μm.

7. In paragraph 1, An electrode wherein the plurality of perforated holes satisfy the following formula. [Formula 1] 0.6 ≤ L1 / L2 ≤ 35 (In Equation 1, L1 is the pitch between punched holes, and L2 is the diameter of the punched holes) 8. Including a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode, A lithium ion capacitor, wherein at least one of the positive and negative electrodes is an electrode according to any one of claims 1 to 7.

9. A lithium ion capacitor according to claim 8, wherein the voltage of the lithium ion capacitor is 3.5 V or higher and the capacity is 250 mAh / g or higher.

10. A step of forming an electrode layer on the current collector; and A step of forming a plurality of perforated holes in the electrode layer using a laser; The diameter of the above punched hole is 5 to 80㎛, Method for manufacturing electrodes.

11. In paragraph 10, A method for manufacturing an electrode, wherein the above-mentioned perforated hole is formed by penetrating the electrode layer and the current collector.

12. In paragraph 10, A method for manufacturing an electrode, wherein the above-mentioned collector does not have a perforated hole formed therein.

13. In paragraph 10, A method for manufacturing an electrode, wherein the pitch between the above punched holes is formed to be 50㎛ or more.

14. In paragraph 10, A method for manufacturing an electrode, wherein the pitch between the above punched holes is formed to be 60 to 170 μm.

15. In paragraph 10, A method for manufacturing an electrode, wherein the electrode layer is formed from an electrode composition including an electrode active material, a binder, and a conductive material.

16. A lithium ion capacitor comprising an electrode manufactured by the method of any one of claims 10 to 15.

17. In paragraph 16, A lithium ion capacitor having a voltage of 3.5 V or higher and a capacity of 250 mAh / g or higher.

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