JPH11250900A - Manufacture and manufacturing device for electrode for nonaqueous electrolyte secondary battery, electrode, and electrolyte secondary battery using its electrode - Google Patents

Abstract

PROBLEM TO BE SOLVED: To further improve conductivity between a collector and an electrode layer, achieve compactness and light weight, and provide a high voltage and a high energy density. SOLUTION: In an electrode 1 for a nonaqueous electrolyte secondary battery having a collector 2, and an electrode layer 4 on the collector 2, a conductive coating layer 3 including at least either one sort of carbon, platinum and gold, for example, is provided to be formed between the collector 2 and the electrode layer 4. As a manufacturing method for the electrode 1, etching is conducted on the surface of the collector 2 using a sputter ion beam etching device, for example, while the coating layer 3 comprising carbon or the like is formed on the collector 2 using an electron beam deposition device, for example.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for manufacturing an electrode for a non-aqueous electrolyte secondary battery, an electrode, and a non-aqueous electrolyte secondary battery using the same.
A method for manufacturing an electrode in which a positive electrode active material layer or a negative electrode active material layer is formed on a current collector, a method for manufacturing an electrode for a nonaqueous electrolyte secondary battery having a manufacturing apparatus, a manufacturing apparatus, and a method for manufacturing these The present invention relates to an electrode manufactured by a manufacturing apparatus and a non-aqueous electrolyte secondary battery using the electrode.

[0002]

2. Description of the Related Art In recent years, EVs (Electric vehicles) such as electric vehicles or hybrid vehicles adapted to the global environment have been developed.
The interest in the field of (c Vehicle) is increasing, and it is increasingly desired that these secondary batteries for power supply be smaller, lighter, and have higher energy density.

As a secondary battery meeting such a demand, a nonaqueous electrolyte secondary battery using a metal such as lithium, sodium and aluminum having a high voltage and a high energy density as a negative electrode active material is promising. . In particular, a non-aqueous electrolyte lithium secondary battery using lithium is easy to handle, and can obtain a high voltage and a high energy density.

The structure of an electrode for a non-aqueous electrolyte secondary battery will be described below with reference to FIG. 4 which is a schematic sectional view of a conventional electrode. The electrode 1 for a non-aqueous electrolyte secondary battery includes a current collector 2
And a positive electrode layer formed on the current collector 2 and containing a positive electrode active material as a positive electrode, and an electrode layer 4 as a negative electrode layer containing a negative electrode active material and the like as a negative electrode. Generally, these electrodes 1 are provided on both sides of a current collector 2 with electrode layers 4.
Is formed.

In order to further increase the energy density of the non-aqueous electrolyte secondary battery, it is indispensable to improve the conductivity between the current collector 2 and the electrode layer 4. In a secondary battery of a type using powder as an active material,
It is common to use a metal foil. If metal oxide or the like remains on the surface of the current collector 2 which is a metal foil, the contact resistance between the electrode layer 4 and the current collector 2 becomes large, and the metal oxide or the like is removed to collect the metal oxide. An effective method for improving the conductivity between the conductor 2 and the electrode layer 4 has been desired.

[0006]

SUMMARY OF THE INVENTION The present invention aims at further improving the conductivity between a current collector and an electrode layer, and is a non-aqueous material having a small size, light weight, high voltage and high energy density. Method for producing electrode for electrolyte secondary battery, production apparatus,
It is another object of the present invention to provide an electrode and a non-aqueous electrolyte secondary battery using the same.

[0007]

According to the method for producing an electrode for a non-aqueous electrolyte secondary battery of the present invention, a composite oxide containing at least one of lithium, sodium and aluminum as a positive electrode active material is contained. Non-aqueous solution for producing a positive electrode having a positive electrode layer formed on a current collector or a negative electrode having a negative electrode layer containing at least one of carbon, lithium, sodium and aluminum as a negative electrode active material formed on a current collector In the method for manufacturing an electrode for an electrolyte secondary battery, before the step of forming an electrode layer on the current collector, plasma etching, for example, parallel plate etching, reactive ion etching, ECR (Elect) is performed in a reduced pressure atmosphere.
tron Cyclotron Resonance)
An etching step of etching the current collector surface by using any one of etching, sputter etching such as magnetron type etching, and ion beam etching such as sputter ion beam etching and reactive ion beam etching; and A coating layer containing at least one of carbon, platinum, and gold is formed by, for example, evaporation, electron beam evaporation, sputtering,
Ion plating, CVD (Chemical V
forming on the current collector by using any one of the following methods: apor deposition, plasma CVD, and ion implantation. In this case, the etching step and the step of forming on the current collector can be performed simultaneously.

In the apparatus for producing an electrode for a non-aqueous electrolyte secondary battery according to the present invention, a positive electrode layer of a composite oxide containing at least one of lithium, sodium and aluminum as a positive electrode active material is formed on a current collector. Non-aqueous electrolyte secondary battery having means for forming a positive electrode formed on a negative electrode or a negative electrode for forming a negative electrode layer containing at least one of carbon, lithium, sodium and aluminum as a negative electrode active material on a current collector In the apparatus for manufacturing an electrode for use, means for forming an electrode layer is plasma etching,
For example, a current collector can be formed by using any one of apparatuses such as sputter etching such as parallel plate etching, reactive ion etching, ECR etching, and magnetron etching and ion beam etching such as sputter ion beam etching and reactive ion beam etching. Etching means for etching the surface, and a conductive coating layer containing at least one of carbon, platinum, and gold, for example, evaporation, electron beam evaporation, sputtering, ion plating, CVD, plasma CVD and ion implantation Means for forming on a current collector using any one of the devices.

The electrode of the present invention comprises at least a current collector,
In an electrode for a nonaqueous electrolyte secondary battery having an electrode layer on a current collector, a conductive material containing at least one of carbon, platinum, and gold formed between the current collector and the electrode layer, for example. Characterized by having a coating layer of

The non-aqueous electrolyte secondary battery of the present invention is characterized in that
The electrode is manufactured using the electrode described in Item 4.

The operation of the above means will be described below.
Before forming the electrode layer on the current collector, the surface of the current collector is subjected to plasma etching, sputter etching, or ion beam etching to remove an oxide film and the like on the current collector surface and to remove the oxide film and the like. Since the coating layer having good conductivity is formed on the current collector, the conductivity between the film layer and an electrode layer formed later on the current collector can be improved. Further, it is possible to increase the energy density of a nonaqueous electrolyte secondary battery manufactured using an electrode manufactured using this manufacturing method or manufacturing apparatus.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention relates to a method and apparatus for manufacturing an electrode for a non-aqueous electrolyte secondary battery in which an electrode layer containing a positive electrode active material or a negative electrode active material is formed on a current collector. It can be applied to a non-aqueous electrolyte secondary battery using this.

The structure of the electrode for a non-aqueous electrolyte secondary battery will be described with reference to FIG. 1 which is a schematic sectional view of the electrode of the present invention. Generally, copper foil is used for the negative electrode current collector 2 of the electrode 1 constituting the nonaqueous electrolyte secondary battery, and aluminum foil or the like is used for the positive electrode current collector 2. For example, a paint in which a slurry-like active material of 60 μm is mixed with a binder and the like is applied to a current collector 2 of a metal foil having a thickness of, for example, approximately 20 μm obtained by refining and the like, dried, and then pressed. The electric body 2 and the electrode layer 4 containing the active material are smoothed and the thickness is made uniform. The electrode 1 has a structure in which electrode layers 4 are formed on both surfaces of a current collector 2.

According to the present invention, before forming the electrode layer 4, the surface of the current collector 2 is etched by any one of plasma etching, sputter etching and ion beam etching. By forming the coating layer 3 having the property, the conductivity between the electrode layer 4 to be formed later and the current collector 2 is improved.

Hereinafter, an etching step performed before forming the electrode layer 4 will be described. As a first method for etching the surface of the current collector 2, there is plasma etching using a cylindrical plasma etching apparatus using a reactive gas in a reduced-pressure atmosphere. As a second method, for example,
In a reduced-pressure atmosphere, a parallel plate etching, a reactive ion etching, in which an inert gas is turned into plasma by a direct current, an alternating current or a high-frequency electric field to etch the sample surface,
There are ECR etching and sputter etching using a magnetron type etching apparatus. As a third method, there are sputter ion beam etching in which an inert gas ion beam is irradiated in a reduced-pressure atmosphere, and ion beam etching using a reactive ion beam etching apparatus or the like. Any one of these methods can be used.

Next, after the surface of the current collector 2 is etched, the surface of the current collector 2 is subjected to, for example, a normal evaporation method, an electron beam evaporation method, a sputtering method, an ion plating method, a CVD method, or the like.
Method, plasma CVD, or ion implantation
The conductive coating layer 3 is formed using two methods.

A step of performing sputter ion beam etching using an inert gas ion beam;
Can be performed simultaneously with the step of forming by vapor deposition. This will be described below with reference to FIG. 2 which is a schematic configuration diagram of a vacuum film forming apparatus. This vacuum film forming apparatus 5 is obtained by adding an ion beam irradiation apparatus 8 such as argon to a conventional vacuum evaporation apparatus using an electron beam. That is, in a reduced-pressure atmosphere evacuated by the vacuum evacuation device 7 in the vacuum chamber 6, the high-speed ion beam 9 of, for example, argon emitted from the ion beam irradiation device 8 is collected into, for example, a roll of aluminum foil or copper foil. Irradiate on the electric body 2. At the same time, the electron beam irradiation device 10 irradiates an electron beam 11 to an evaporation source crucible 12 filled with, for example, any one of carbon, gold and platinum, and evaporates the evaporated atoms 13 dissolved and evaporated by the electron beam 11 into the current collector 2 Deposited on the coating layer 3
To form Thus, the etching step and the step of forming the coating layer 3 can be performed at the same time, which can contribute to an improvement in throughput and the like. Further details are described below.

The current collector 2 is sent out from, for example, a feed roll 14 and supported by guide rolls 17 and 18.
It is vapor-deposited on a can roll 15 and wound up by a take-up roll 16. In the case where the current collector 2 is likely to be thermally damaged, the can roll 15 may incorporate a cooling mechanism (not shown). At this time, the evaporated atoms 13 evaporated from the evaporation source crucible 12 are ionized and accelerated by the argon ion beam 9 and are deposited on the current collector 2. Also,
Since the current collector 2 is negatively applied by a DC power source (not shown), the surface of the current collector 2 has an ion beam 9 of argon.
Is used to perform sputter ion beam etching. Through the above steps, the oxides and fats and the like on the surface of the current collector 2 are removed, thereby preventing the formation of metal oxides and the like serving as resistance components. The coating layer 3 having excellent conductivity and oxidation resistance can be formed. Therefore, the contact resistance with the electrode layer 4 to be formed later can be reduced, and the current collector 2, the coating layer 3, and the non-electrode 1 formed using the electrode 1 formed using the electrode layer 4 can be reduced. The energy density of the water electrolyte secondary battery can be increased, and the battery characteristics can be improved.

Hereinafter, the vacuum film forming apparatus 5 of the case described with reference to FIG. 2 is used for a non-aqueous electrolyte secondary battery having a process of forming an electrode layer 4 on a current collector 2 of a positive electrode and a negative electrode. An example of a non-aqueous electrolyte secondary battery manufactured using these electrodes 1 and a comparative example of a conventional non-aqueous electrolyte secondary battery will be described.

Example 1 A non-aqueous electrolyte secondary battery was fabricated as Example 1 under the following conditions. Electrode 1 was produced as a positive electrode as follows.
Evaporation source filled with carbon while performing sputtering ion beam etching with argon ion beam 9 on both surfaces of current collector 2 of aluminum foil having a thickness of about 20 μm manufactured by rolling using vacuum film forming apparatus 5. Crucible 12
Is irradiated with an electron beam 11 to perform vapor deposition, and approximately 100 n
A coating layer 3 made of m carbon was formed. Next, graphite powder and carbon powder as a positive electrode active material of lithium manganese spinel oxide powder and a conductive auxiliary were respectively 90, 5.94,
0.06 parts by weight and 4 parts by weight of polyvinylidene fluoride as a binder were mixed, and this mixture was dispersed in N-methyl-2-pyrrolidone to form a slurry. It was coated on the deposition surface, dried and pressed to obtain a strip-shaped electrode 1. The thickness of the composite material after forming the electrode 1 is approximately 140
μm.

An electrode 1 was prepared as a negative electrode as follows. An evaporation source crucible filled with carbon was sputter-ion-beam-etched on both surfaces of a current collector 2 made of a 15-μm-thick copper foil by rolling with an ion beam 9 of argon using a vacuum film forming apparatus 5. Vapor deposition was performed by irradiating the electron beam 11 to 12 to form a coating layer 3 of about 100 nm. The electrode layer 4 obtained by mixing 90 parts by weight of the graphite powder with 10 parts by weight of polyvinylidene fluoride as a binder and dispersing the mixture in N-methyl-2-pyrrolidone to form a slurry is a copper foil. The coating layer 3 was coated on the deposition surface, dried and pressed to form a strip-shaped electrode 1. The thickness of the composite material after forming the electrode 1 is approximately 100 μm.

Example 2 A non-aqueous electrolyte secondary battery was produced as Example 2 under the following conditions. Electrode 1 was produced as a positive electrode as follows.
The cathode was manufactured under the same conditions as those of the positive electrode of Example 1, and the deposition thickness of the carbon coating layer 3 on the aluminum foil current collector 2 was set to 50.
nm.

An electrode 1 was prepared as a negative electrode as follows. The electrode 1 was prepared under the same conditions as those of the negative electrode of Example 1, and the thickness of the coating layer 3 made of carbon on the current collector 2 was 5
It was set to 0 nm.

COMPARATIVE EXAMPLE As a comparative example of a non-aqueous electrolyte secondary battery, it was manufactured under the following conditions. An electrode 1 was prepared as a positive electrode under the same conditions as in Example 1 and the coating layer 3 made of carbon was not deposited on the aluminum foil current collector 2.

As a negative electrode, an electrode 1 was prepared under the same conditions as in Example 1, and a carbon coating layer 3 was formed on a current collector 2 of copper foil.
Was not deposited.

Measurement of Electric Resistance of Electrode 1 The electric resistance of the electrode 1 for the non-aqueous electrolyte secondary batteries of Examples 1 and 2 and Comparative Example was measured, and the results are shown in Table 1. From Table 1, the electrodes 1 of Examples 1 and 2 were compared with the electrode 1 of the comparative example by performing the sputter ion beam etching on the surface of the current collector 2 and forming the coating layer 3 made of carbon. It can be seen that the electric resistance decreases.

[0027]

[Table 1]

The discharge characteristics of the non-aqueous electrolyte secondary batteries of Examples 1 and 2 and Comparative Example were measured. FIG. 3 shows a result of measuring a discharge output (energy density) with respect to a discharge depth DOD (Depth of Discharge).
Shown in

From the above results, before the electrode layer 4 is formed on the current collector 2 of the electrode 1, the surface of the metal foil of the current collector 2 is subjected to sputter ion beam etching, and the coating layer 3 made of, for example, carbon is formed. By forming by vapor deposition, the internal resistance of the electrode 1 was reduced, the discharge characteristics of the non-aqueous electrolyte secondary battery manufactured using the electrode 1 were improved, and the effectiveness of the present invention was confirmed.

[0030]

According to the method and apparatus for manufacturing an electrode for a non-aqueous electrolyte secondary battery of the present invention, an electrode having improved conductivity between a current collector and an electrode layer can be manufactured. The non-aqueous electrolyte secondary battery manufactured using this electrode can achieve high energy density.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view of an electrode according to the present invention.

FIG. 2 is a schematic configuration diagram showing a vacuum film forming apparatus of the present invention.

FIG. 3 is a graph showing the discharge characteristics of the non-aqueous electrolyte secondary battery of the present invention, showing the relationship between DOD and energy density.

FIG. 4 is a schematic cross-sectional view of a conventional electrode.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Electrode, 2 ... Current collector, 3 ... Coating layer, 4 ... Electrode layer, 5 ...
Vacuum film forming device, 6 vacuum chamber, 7 vacuum exhaust device, 8 ion beam irradiation device, 9 ion beam, 10 electron beam irradiation device, 11 electron beam, 12 evaporation source crucible, 13 evaporated atoms , 14: feed roll, 15: can roll, 16: take-up roll, 17, 18: guide roll

Continued on the front page (51) Int.Cl. ⁶ Identification code FI H01M 10/40 H01M 10/40 Z

Claims (16)

[Claims] 1. A method for producing an electrode for a non-aqueous electrolyte secondary battery, comprising at least a step of forming an electrode layer on a current collector, wherein the step of forming the electrode layer on the current collector comprises: An etching step of etching the current collector surface using one of plasma etching, sputter etching, and ion beam etching in a reduced pressure atmosphere; and forming a conductive coating layer on the current collector surface. And producing a non-aqueous electrolyte secondary battery electrode. 2. The method according to claim 1, wherein the electrode layer contains any one of a positive electrode active material and a negative electrode active material.
3. The method for producing an electrode for a non-aqueous electrolyte secondary battery according to item 1. 3. The positive electrode active material has a composite oxide containing at least one metal of lithium, sodium and aluminum.
3. The method for producing an electrode for a non-aqueous electrolyte secondary battery according to item 1. 4. The method for producing an electrode for a non-aqueous electrolyte secondary battery according to claim 2, wherein the negative electrode active material contains at least one of carbon, lithium, sodium and aluminum. 5. The method for producing an electrode for a non-aqueous electrolyte secondary battery according to claim 1, wherein the etching step and the step of forming the coating layer are performed simultaneously. 6. The method according to claim 1, wherein the step of forming the coating layer uses any one of vacuum deposition, electron beam deposition, sputtering, ion plating, CVD, plasma CVD, and ion implantation. 3. The method for producing an electrode for a non-aqueous electrolyte secondary battery according to item 1. 7. The method for producing an electrode for a non-aqueous electrolyte secondary battery according to claim 1, wherein the coating layer contains at least one of carbon, platinum and gold. 8. An apparatus for manufacturing an electrode for a non-aqueous electrolyte secondary battery having at least a means for forming an electrode layer on a current collector, wherein the means for forming the electrode layer is plasma-etched in a reduced-pressure atmosphere. Etching means for etching the surface of the current collector using one of sputter etching and ion beam etching; and means for forming a conductive coating layer on the surface of the current collector. For manufacturing a non-aqueous electrolyte secondary battery electrode. 9. The method according to claim 8, wherein the electrode layer contains one of a positive electrode active material and a negative electrode active material.
3. The apparatus for producing an electrode for a non-aqueous electrolyte secondary battery according to claim 1. 10. The positive electrode active material has a composite oxide containing at least one metal of lithium, sodium and aluminum.
3. The apparatus for producing an electrode for a non-aqueous electrolyte secondary battery according to claim 1. 11. The apparatus for manufacturing an electrode for a non-aqueous electrolyte secondary battery according to claim 9, wherein the negative electrode active material contains at least one of carbon, lithium, sodium and aluminum. 12. The apparatus according to claim 8, wherein the means for forming the coating layer uses any one of vacuum deposition, electron beam deposition, sputtering, ion plating, CVD, plasma CVD, and ion implantation. 3. The apparatus for producing an electrode for a non-aqueous electrolyte secondary battery according to claim 1. 13. The method according to claim 8, wherein the coating layer contains at least one of carbon, platinum and gold.
3. The apparatus for producing an electrode for a non-aqueous electrolyte secondary battery according to claim 1. 14. An electrode for a non-aqueous electrolyte secondary battery having at least a current collector and an electrode layer formed on the current collector, wherein the electrode is formed between the current collector and the electrode layer. An electrode having a conductive coating layer. 15. The method according to claim 1, wherein the coating layer contains at least one of carbon, platinum and gold.
5. The electrode according to 4. 16. A non-aqueous electrolyte secondary battery manufactured using the electrode according to claim 14. Description: