JP2002324545A - Electrode for electrochemical element and electrochemical element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrode for an electrochemical element, which has an excellent adhesion property to an active material layer and to a collector body such as a metal foil even without adding a binder and shows a high capacity even under a high current density and to provide the electrochemical element which shows the high capacity even under the high current density using the electrode. SOLUTION: The electrode for the electrochemical element is constituted by forming a metal oxide dispersing a conductive substance in a continuous film of the metal oxide and a composite layer with the conductive substance at an average thickness of 5 to 50 μm along at least one direction face of the collector body and the electrochemical element is constituted by using the electrode, the counter electrode and the electrolyte. Oxides of metal elements belonging within the range of the 3rd group to the 12th group in the 4th period to the 6th period of periodic table are preferable as the metal oxide, carbon materials are preferable as the conductive substance and metal foils with 5 to 50 μm thickness are preferable as the collector body.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an electrode used for an electrochemical device such as a battery or an electrochemical capacitor, and an electrochemical device using the electrode.

[0002]

2. Description of the Related Art In recent years, due to environmental problems on the earth, expectations for an electric vehicle driven by a motor instead of an engine driven gasoline vehicle or a diesel vehicle, or a hybrid vehicle equipped with both a motor and an engine have been increased. I have. In these electric vehicles and hybrid vehicles, a battery is used as a power source for driving a motor.

[0003] A battery used in an electric vehicle has a very large weight and volume, and in view of cost, a rechargeable battery that can be used repeatedly, that is, a secondary battery is preferable. Examples of such a secondary battery include a lead battery, a nickel-cadmium (NiCad) battery, a nickel-metal hydride battery, and the like. These secondary batteries use an acidic or alkaline aqueous electrolyte having high conductivity. Therefore, a high current can be obtained.

[0004] However, a secondary battery using an aqueous electrolyte solution has the above-mentioned features, but the electrolysis voltage of water is 1.23 V, so that a higher voltage cannot be obtained from a single cell. However, since a high voltage of about 200 V is required as a power supply for an electric vehicle,
In order to obtain such a high voltage, many batteries must be connected in series, which is extremely disadvantageous in reducing the size and weight.

As a high voltage type secondary battery, a lithium ion secondary battery using an organic electrolyte is known. In this lithium ion secondary battery, since an organic solvent having a high decomposition voltage is used as an electrolyte solvent, a battery having a potential of 3 V or more can be provided if lithium (ion) having the lowest potential is used as a reaction medium. It is possible. Currently available lithium ion secondary batteries use carbon capable of inserting and extracting lithium ions as a negative electrode active material, and lithium cobalt oxide (LiCoO 2) which is an oxide of cobalt and lithium.
₂ ) is mainly used as a positive electrode active material, and a lithium salt such as lithium hexafluorophosphate (LiPF ₆ ) is used as an electrolytic solution, such as a cyclic carbonate such as ethylene carbonate and propylene carbonate, dimethyl carbonate, and diethyl carbonate. What is dissolved in a mixed solvent with a chain carbonate such as carbonate is used. The lithium ion secondary battery composed of the positive and negative electrodes and the electrolytic solution exhibits an average operating voltage of 3.6 V.

However, since the lithium ion secondary battery has a higher voltage, it has a higher energy density than a secondary battery using an aqueous electrolyte such as a nickel-cadmium battery or a nickel-metal hydride battery. There is a problem that the output characteristics are inferior because the liquid solvent is used. For this reason, high output has been promoted by thinning the electrodes and improving the electrolytic solution.
Since an instantaneous current of the 00A class is required, there is a problem that it is not possible to sufficiently cope with the problem only by thinning the electrodes.

[0007] Therefore, a capacitor using an electric double layer has been attracting attention as a power source instead of a battery. This electric double layer capacitor has a configuration in which a polarizable electrode such as activated carbon is used as a positive electrode and a negative electrode, and a solution in which a quaternary ammonium salt of boron tetrafluoride is dissolved in an organic solvent such as propylene carbonate is used as an electrolytic solution. Because it is a power supply that stores the electric double layer generated at the interface with the electrolytic solution as capacitance, it does not cause an oxidation-reduction reaction like a battery, and therefore,
It has the advantage that a high current can be taken out and there is no cycle deterioration.

However, the electric double layer capacitor is
Since the above-described capacitance is used as energy, the energy density is very low (<2 Wh / k) as compared with the battery.
g) Therefore, a larger number of capacitors than batteries are required for use as a power source of an automobile, and it has been difficult to realize the use of only electric double layer capacitors.

Therefore, a so-called electrochemical capacitor has been proposed as an electrochemical element having both a capacitance capable of extracting a large current and a redox capacity by an electrochemical redox reaction having a high energy density. I have. In this electrochemical capacitor, when an organic electrolytic solution is used as an electrolytic solution and lithium ions are used as a reaction medium, an electrochemical device having a high output and a high energy density can be obtained. However, in this case, unlike the electric double layer capacitor, the electrodes are not the same as the positive and negative electrodes, and have substantially the same electrode configuration as that of the lithium ion secondary battery.

In producing the electrode, a method basically similar to that of the lithium ion secondary battery is employed. That is, a binder composed of a polymer compound, for example, a binder liquid in which a binder composed of polyvinylidene fluoride or the like is dissolved in an organic solvent, an active material such as carbon or lithium cobaltate is added and mixed, and the obtained active material-containing paste is mixed. A sheet-shaped electrode is formed by applying the composition to at least one surface of a metal foil and drying by heating to form an active material layer.

In this electrode, in order to improve the output characteristics, it is preferable to make the thickness of the active material layer formed on the surface of the metal foil as small as possible. However, the coating method using a roll coater, a doctor blade, or a roll applicator that is currently employed,
It is difficult to make the film thinner than it is now. This is because the active material-containing paste is a slurry having a relatively high viscosity,
When narrowing the clearance between rolls to make it thinner,
This is because the active material-containing paste cannot be sufficiently applied to the surface of the metal foil, and the formed active material layer cannot be controlled to have a uniform thickness.

Therefore, it is conceivable to prepare a low-viscosity coating solution without adding a binder and apply it to a metal foil in order to make the film thinner. Since the binding between the foil and the active material layer and the binding between the active materials are not sufficiently obtained, as a result, the active material layer is easily separated from the metal foil. It is extremely difficult to manufacture a battery through a removing step, a laminating step, and the like.

[0013]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems of the prior art, and has excellent binding properties between an active material layer and a metal foil without adding a binder, and has a large current. Providing electrodes for electrochemical devices that show high capacity even under density,
It is another object of the present invention to provide an electrochemical device using the electrode and having a high capacity even under a large current density.

[0014]

According to the present invention, a composite layer of a metal oxide and a conductive material in which a conductive material is dispersed in a continuous film of a metal oxide is formed on at least one of the current collectors. The above problem is solved by forming an electrode for an electrochemical element by forming an average thickness of 5 to 50 μm on the surface of the electrode, and forming an electrochemical element using the electrode, the counter electrode, and the electrolyte. It was done.

In the above-mentioned electrode for an electrochemical element, the composite layer of a metal oxide and a conductive substance formed on at least one surface of the current collector acts as an active material layer of the electrode for an electrochemical element. The composite layer as the active material layer is formed, for example, by applying a paste of a mixture in which a conductive material is dispersed in a colloidal solution of a metal oxide to a current collector and performing heat treatment. Is done. That is, the surface of the conductive material is coated with the metal oxide by mixing the metal oxide colloid solution and the conductive material, and the mixture paste is applied to the current collector and then heat-treated. The metal oxide is firmly fixed to the surface of the substance, and the metal oxides are bonded to each other to form a continuous film, and the metal oxide and the conductive substance exist in a state where the conductive substance is dispersed inside the metal oxide. And a composite layer is formed. This composite layer not only functions as an active material layer in the electrode, but also because the metal oxide present at the interface with the current collector adheres firmly to the current collector, so that the binder does not need to be contained. The binding property between the composite layer as the active material layer and the current collector was secured, and the current collector and the composite layer of the metal oxide and the conductive material as the active material layer were integrated. Electrodes can be configured.

As described above, since the metal oxide exerts a binding action, a mixture paste in which a conductive substance is dispersed in a colloidal liquid of the metal oxide is used in forming the composite layer on the current collector. However, usually, a binder paste having a low viscosity can be obtained because a binder component is not separately contained. Therefore, it becomes possible to apply the mixture paste thinly and uniformly, and it is possible to obtain an electrode suitable for constituting an electrochemical device capable of increasing the output.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, the metal oxide is a metal element belonging to the range from Group 3 to Group 12 in the fourth to sixth periods of the periodic table (however, a long-period type periodic table). Is preferably used. Specific examples thereof include, for example, Sc, Ti, V, Cr, M
n, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb,
Mo, Tc, Ru, Pd, Ag, Cd, lanthanoid,
Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg
Oxides such as V, Cr, Mn, Fe,
5th to 10th groups of the 4th period of the periodic table such as Co and Ni
Oxides of metal elements belonging to the group III group, composite oxides containing these metals and at least one other metal, and the like are preferable.

The conductive substance is not particularly limited as long as it is a conductive substance such as a metal material or a carbon material. Particularly, a carbon material is preferable. Examples of the carbon material include acetylene black and furnace. Carbon black such as black and channel black, natural graphite, artificial graphite, activated carbon, carbon fiber, and carbon powder such as carbon nanotube are preferably used.

The current collector used in the present invention is a metal foil,
Metal nets, expanded metals, punched metals, porous metal plates such as metal foams, carbon sheets, etc. can be exemplified. Among them, metal foils are preferable, and the average surface roughness is 0.1 to 2 μm. Some are preferred. This is because by using a metal foil, the binding property between the current collector and the composite layer of the metal oxide and the conductive material as the active material layer can be strengthened, and the average surface By setting the roughness to 0.1 μm or more, the binding action of the metal oxide to the metal foil is effectively exhibited, and by setting the average surface roughness to 2 μm or less, the composite layer as an active material layer Thickness unevenness can be hardly generated. In the present invention, the average surface roughness of the metal foil means an average of height differences measured from the average surface in a height direction (Z direction). In the present invention, the surface roughness is measured by a laser microscope.

The material of the metal foil is, for example, copper,
Examples thereof include metal elements such as titanium, aluminum, nickel, and iron, and alloys of the above elements typified by stainless steel.

In the present invention, the thickness and size of the metal foil are appropriately selected according to the size of the electrode to be produced, and are not particularly limited. However, in consideration of the strength and conductivity of the electrode. Usually, a metal foil having a thickness of 5 to 50 μm is suitably used.

The above-mentioned mixture paste in which a conductive substance is dispersed in a colloidal solution of a metal oxide is obtained, for example, by mixing and dispersing a conductive substance in a colloidal solution of a metal oxide. The mixing ratio between the substance and the conductive substance is preferably 70:30 to 10:90 by mass, and particularly preferably 50:50 to 25:75.

The preparation of the metal oxide colloid solution is usually carried out by
Since it is difficult to make the metal oxide itself into a colloidal solution directly, mix the metal powder with a solution containing an oxidizing agent such as hydrogen peroxide, or use a metal acetate, nitrate,
It is preferable to prepare by mixing a carbonate or the like with a liquid containing an oxidizing substance.

In mixing and dispersing the metal oxide colloid solution and the conductive material, a stirrer, a ball mill,
Any mixing means such as ultrasonic dispersion can be employed. The temperature and time during mixing are not particularly limited. For example, it is preferable to mix and disperse at 0 to 40 ° C. for about 1 to 12 hours. The heat treatment after the mixing and dispersion may be performed after a mixture of the metal oxide and the conductive substance is separated from the dispersion to some extent by filtration, centrifugation, or the like, or the mixed dispersion may be used as it is. .

The means for applying a paste of a mixture of a colloidal solution of a metal oxide and a conductive material to the current collector includes:
Although not particularly limited, for example, a roll coater, an applicator, a doctor blade method, or the like can be employed.

After a paste of a mixture of a colloidal liquid of a metal oxide and a conductive material is applied to a metal foil, a heat treatment is performed to remove liquid components in the paste of the mixture.
The conditions for this heat treatment are not particularly limited, but the temperature is preferably 50 ° C. or higher, preferably 80 ° C. or higher, and is preferably 450 ° C. or lower, more preferably 300 ° C. or lower, and the time is 1 hour. Or more, preferably 3 hours or more, and more preferably 24 hours or less.
0 hours or less is more preferable. In particular, in the case where a carbon material is used as the conductive substance, an oxidative decomposition reaction of carbon occurs when the temperature exceeds 450 ° C. Therefore, it is more preferable to perform the heat treatment at 300 ° C. or lower.

As described above, a paste of a mixture in which a conductive substance is dispersed in a colloidal liquid of a metal oxide is applied to a current collector and subjected to heat treatment, so that at least one surface of the current collector is coated with a metal oxide. A composite layer of a metal oxide and a conductive substance in which a conductive substance is dispersed in a continuous film of a substance can be formed. The composite layer thus formed has an action as an active material layer, but has excellent conductivity and is suitable for charging and discharging with a large current.

In the composite layer of the metal oxide and the conductive material, a metal oxide layer (film) having a thickness of 1 nm or more is preferably present on the surface of the conductive material. When the thickness of the metal oxide is smaller than 1 nm, the binding action of the metal oxide is reduced, and the composite layer as the active material layer is easily separated from the current collector, or the active material layer is bent when the electrode is bent. This is because cracks are likely to occur in the composite layer. Further, if the thickness of the metal oxide covering the surface of the conductive substance is too large, the function of the conductive substance becomes difficult to be exhibited, and the output characteristics may be reduced.
The following is preferred.

The electrode after the heat treatment may be subjected to a pressure treatment in order to improve the filling property of the composite layer as the active material layer and the physical binding property with the current collector made of a metal foil or the like. Good.
The apparatus for performing the pressure treatment is not particularly limited, and for example, a hand press machine, a roll press machine, or the like is suitably used. In the present invention, the average thickness of the composite layer as the active material layer is set to 5 to 50 μm.
When the thickness is smaller than μm, the energy density is remarkably reduced when the electrochemical device is formed, and the practicality is lost. This is because sufficient output characteristics cannot be obtained. Then, in the present invention, the composite layer as the active material layer may be formed on both surfaces of the current collector,
In that case, the average thickness of the composite layer on each surface is 5 to
The thickness may be set to 50 μm.

Here, an example of the electrode for an electrochemical device of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view schematically showing an example of a main part of an electrode for an electrochemical device of the present invention. Reference numeral 1 denotes a composite layer of a metal oxide 1a and a conductive substance 1b. Is formed in a state in which the conductive substance 1b is dispersed inside the continuous film of the metal oxide 1a and is formed on the current collector 2 with an average thickness of 5 to 50 μm, whereby the electrode for the electrochemical element is formed. Have been. In the electrochemical element electrode, the composite layer 1 acts as an active material layer. The composite layer 1 is not only formed on one surface of the current collector 2 as shown in FIG. , May be formed on both surfaces of the current collector 2. Note that FIG. 1 is only a schematic view of the configuration of the electrode for an electrochemical element, and in an actual electrode for an electrochemical element, the composite layer 1
Are not necessarily arranged in an orderly manner as shown in the figure, and in FIG. 1, the conductive substances 1b are shown in contact with each other, or the conductive substance 1b is Although it is illustrated as if it constitutes a part of the lower surface, the metal oxide 1a basically covers the particles of the conductive material 1b in the form of a film. Has not become Further, in FIG. 1, the upper surface of the composite layer 1 is illustrated as if it were a smooth surface. It is not necessarily a smooth surface as shown. Although the side surface of the electrode for an electrochemical element is also illustrated as being a smooth surface, this is only because the main part of the electrode for an electrochemical element is illustrated in such a cut state when illustrated. Also,
In the present invention, the continuous film of the metal oxide does not necessarily need to be a dense and void-free film, and may have pores or voids as long as sufficient binding properties can be obtained. The composite layer as the active material layer preferably contains no binder in the composite layer in order to be able to cope with high output, but as long as the output characteristics are not significantly reduced. A small amount of binder may be contained.

When an electrochemical device such as a secondary battery or an electrochemical capacitor is formed using the electrode of the present invention, the above electrode is used as a positive electrode depending on the electrode used as a counter electrode, the electrolyte used, and the structure of the electrochemical device. It may be used or it may be used as a negative electrode. The shape of the electrochemical device using the electrode of the present invention may be any of a cylindrical shape, a square shape, a coin shape, and the like, and there is no particular limitation on the shape. As the electrolyte, any of a liquid electrolyte, a gel electrolyte, and a solid electrolyte can be used depending on the configuration of the electrochemical element.However, a liquid electrolyte called an electrolyte is often used, and the electrode is used as a positive electrode. When a lithium-based battery is used as an electrochemical element when a carbon material capable of occluding and releasing lithium and lithium ions is used as an active material for the negative electrode serving as a counter electrode thereof, a lithium salt is used as an electrolyte in an organic solvent as an electrolyte. An organic electrolyte in which an electrolyte salt such as the above is dissolved is used.

[0032]

Next, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to only these examples. In the following examples,% indicating the concentration of a liquid or the like is% by mass unless otherwise specified.

Example 1 1 g of metal vanadium and 100 ml of 30% hydrogen peroxide solution were mixed and stirred and mixed in an ice bath for 3 hours. This was allowed to stand for 24 hours to obtain a colloid solution in which vanadium pentoxide (V ₂ O ₅ ) was turned into a sol. 0.1 g of acetylene black, 2 g of water and 1 g of acetone were added to 3.8 g of the colloidal solution of vanadium pentoxide, and the mixture was stirred with a stirrer for 3 hours to obtain a mixture paste. Further, dispersion treatment was performed for 5 minutes with an ultrasonic homogenizer having an output of 150 W. This mixture paste has an average surface roughness of 0.32 μm (measured with a laser microscope VL2000 manufactured by Lasertec) and a thickness of 15 μm.
An electrode was produced by applying an aluminum foil to one side of the aluminum foil using an applicator and performing heat treatment at 120 ° C. for 3 hours to form a composite layer of vanadium pentoxide and acetylene black serving as an active material layer. The final composition of the composite layer to be the active material layer was vanadium pentoxide: acetylene black = 1: 2 (mass ratio). According to TEM (transmission electron microscope) observation, the coating thickness of vanadium pentoxide coated on the acetylene black surface was about 2 nm. The thickness of the composite layer as the active material layer was measured at 10 points using a micrometer, and the average value was determined. The average thickness of the composite layer as the active material layer was 15 μm. In order to examine the binding property of the composite layer as the active material layer of the electrode to the current collector, when the electrode was wound, no peeling of the composite layer as the active material layer was observed. It was confirmed that the composite layer as described above had excellent binding property to the current collector.

The electrode fabricated as described above was
mm was punched out into a circular shape, 1 ton / cm ² was used as the positive electrode, metallic lithium punched out to a diameter of 17 mm was used as the negative electrode, a microporous polyethylene film was used as the separator, and propylene carbonate was used as the electrolytic solution. LiPF ₆ was dissolved at a concentration of 1 mol / l using a solution having a diameter of 20 mm and a height of 1.
A coin-shaped lithium secondary battery of 6 mm was produced.

Comparative Example 1 A colloidal solution of vanadium pentoxide obtained in the same manner as in Example 1 was heated at 120 ° C. for 3 hours to obtain a fine powder of vanadium pentoxide. This fine powder of vanadium pentoxide, acetylene black and polytetrafluoroethylene are mixed to prepare an electrode mixture with a composition ratio of vanadium pentoxide: acetylene black: polytetrafluoroethylene = 38: 58: 4 (mass ratio). However, when an attempt was made to produce an electrode in the same manner as in Example 1 except that the electrode mixture was used, the adhesion between particles was poor, and the electrode could not be produced. Therefore, an electrode was produced by increasing the ratio of polytetrafluoroethylene and changing the composition to vanadium pentoxide: acetylene black: polytetrafluoroethylene = 33: 50: 17 (mass ratio). Then, a coin-shaped lithium secondary battery was produced in the same manner as in Example 1 except that the electrode was used.

Comparative Example 2 The average thickness of the composite layer as the active material layer of the electrode was 60 μm.
A coin-shaped lithium secondary battery was produced in the same manner as in Example 1 except that the value was changed to m.

The batteries of Example 1 and Comparative Examples 1 and 2 were charged with a charge cut voltage of 4.2 V and a discharge cut voltage of 2, respectively.
A constant current charge / discharge test was performed at a current density of 1 mA / cm ² and 50 mA / cm ² (expressed as a current value per unit area of the positive electrode) at 0 V, and the discharge capacity in the second cycle was measured. Table 1 shows the results. The term “discharge” used herein means a reaction in which lithium is inserted into the positive electrode, and the discharge capacity shown in Table 1 means a capacity per mass of vanadium pentoxide.

[0038]

[Table 1]

As shown in Table 1, the battery of Example 1 has a capacity of 50
Even when discharging at a large current density of mA / cm ^2, a high capacity of 300 mAh / g was obtained. The discharge capacity of the battery of Example 1 obtained by discharging 50 mA / cm ² was 83 times the discharging capacity obtained by discharging 1 mA / cm ^2.
%. In the battery of Example 1, the high capacity was obtained even when discharging at such a large current density because the thinning of the composite layer as the active material layer of the electrode was achieved. It is considered that this is because the binder which is an insulator was not added to the composite layer, and the thickness of the composite layer as the active material layer was optimized.

On the other hand, the battery of Comparative Example 1 having a positive electrode made of a mixture of vanadium pentoxide and acetylene black with the addition of a binder had a current density of 1 mA during discharge.
/ Cm ² , the discharge capacity was not so different from that of the battery of Example 1, but the current density was 50 mA /
When it was as large as cm ² , no discharge was possible. The thickness of the composite layer as the active material layer is 60
The battery of Comparative Example 2, which was thicker than the range specified in the present invention, had a discharge capacity equivalent to that of the battery of Example 1 when the current density during discharge was as small as 1 mA / cm ^2. Increased to 50 mA / cm ² , the discharge capacity was significantly reduced as compared with the battery of Example 1.

[0041]

As described above, according to the present invention, the binder between the composite layer as an active material layer and a current collector such as a metal foil is excellent and a large current is applied without adding a binder. It is possible to provide an electrode for a high-output electrochemical element exhibiting a high capacity even under a high density, and to provide an electrochemical element exhibiting a high capacity even under a high current density by using the electrode. Was.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view schematically showing an example of a main part of an electrode for an electrochemical device of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Composite layer of metal oxide and conductive material 1a Metal oxide 1b Conductive material 2 Current collector

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (reference) H01M 4/64 H01G 9/00 301A 10/40 301D F-term (reference) 5H017 AA03 AS01 CC01 EE01 HH03 5H029 AJ03 AJ05 AK02 AL12 AM03 AM07 BJ03 CJ02 CJ08 CJ22 DJ07 DJ08 DJ16 EJ01 EJ04 HJ04 5H050 AA07 AA08 BA16 CA02 CB12 DA04 DA10 EA02 EA08 FA17 GA02 GA10 GA22 HA04

Claims (7)

[Claims] 1. A composite layer of a metal oxide and a conductive material, in which a conductive material is dispersed in a continuous film of a metal oxide, is provided on at least one surface of the current collector with an average thickness of 5 to 50 μm. An electrode for an electrochemical device, wherein the electrode is formed in a thickness. 2. A mixture of a conductive material dispersed in a colloidal liquid of a metal oxide and a paste applied to a current collector, and heat-treated to form a conductive material inside a continuous film of the metal oxide. A composite layer of a metal oxide and a conductive material, in which 5 .mu.m is dispersed on at least one surface of the current collector.
An electrode for an electrochemical device, wherein the electrode has an average thickness of m. 3. The metal oxide according to claim 1, wherein the metal oxide is an oxide or a composite oxide of a metal element belonging to the group 3 to group 12 in the fourth to sixth periods of the periodic table. Electrodes for electrochemical devices. 4. The electrode for an electrochemical device according to claim 1, wherein said conductive substance is a carbon material. 5. The electrode for an electrochemical device according to claim 1, wherein a metal foil having a thickness of 5 to 50 μm is used as the current collector. 6. An electrochemical device comprising the electrode for an electrochemical device according to claim 1, a counter electrode thereof, and an electrolyte. 7. A positive electrode comprising the electrode for an electrochemical device according to claim 1, a negative electrode as a counter electrode thereof,
An electrochemical device comprising an organic electrolyte.