WO2016140168A1

WO2016140168A1 - Composite film and method for manufacturing same

Info

Publication number: WO2016140168A1
Application number: PCT/JP2016/055888
Authority: WO
Inventors: 野田　優; 慈喜青井; 裕介森川; 陽一郎本田
Original assignee: Ｊｘエネルギー株式会社; 学校法人早稲田大学
Priority date: 2015-03-04
Filing date: 2016-02-26
Publication date: 2016-09-09

Abstract

A composite film 100 consisting exclusively of a filamentous carbon layer 20 formed of filamentous carbon 42 and a metal layer 10 formed of a metal, wherein a part or the whole of the metal layer 10 overlaps a part of the filamentous carbon layer 20 so as to give a coexisting area 60 where the filamentous carbon 42 and the metal coexist. Provided are the composite film 100 that has a novel structure and is self-supporting and a method for manufacturing the same.

Description

Composite membrane and manufacturing method thereof

The present invention relates to a composite film, a manufacturing method thereof, and an electrode and an electricity storage device using the composite film.

Energy storage devices such as secondary batteries such as lithium-ion batteries and electric double layer capacitors are used as power sources for mobile devices such as personal computers and mobile phones. In recent years, not only mobile devices but also electric vehicles and It is also used as a power source for automobiles that can reduce the environmental load of CO ₂ such as hybrid cars. However, for the popularization of electric vehicles, it is necessary to increase the weight and capacity per volume of a lithium ion battery and to enable long-distance movement by electric vehicles.

The electrode of the lithium ion battery includes an active material that occludes and releases lithium ions during charging and discharging. As the active material, lithium metal oxide is generally used for the positive electrode, and graphite is used for the negative electrode. In an electrode using such an active material, an active material powder is generally mixed with a binder made of a non-conductive polymer such as polyvinylidene fluoride and a conductor made of carbon fiber (CF), carbon black, or the like. It is manufactured by applying a paste to an aluminum (Al) foil or a copper (Cu) foil as a current collector and baking it. The binder is used for the purpose of fixing the active material on the current collector, and the conductor is used for the purpose of electrically connecting the current collector and the active material. As shown in FIG. 20, in the electrode 500 manufactured in this way, a layer in which the active material 130, the conductor 140, and the nonconductive binder 150 are mixed is formed on the current collector 180.

Currently, in order to increase the capacity of lithium ion batteries, the use of silicon (Si) instead of graphite as an active material for the negative electrode is being studied. The theoretical discharge capacity of the negative electrode using Si as the active material of the negative electrode is as large as about 4200 mAh / g, and is said to be 10 times or more the theoretical discharge capacity of the negative electrode using graphite. Patent Document 1 describes an electrode in which a columnar structure 132 made of Si is directly formed on a current collector 180 as shown in FIG.

WO2011 / 071154

In the conventional electrode 500 as shown in FIG. 20, the interface between the active material 130 and the current collector 180 is two-dimensional and the contact area is small, and further, the two-dimensional interface is non-conductive. Therefore, the resistance between the active material 130 and the current collector 180 is large. Therefore, it is impeded to increase the capacity of the lithium ion battery. Further, there is a problem that the active material 130 is peeled off from the current collector 180 due to deterioration of the binder 150 during use of the lithium ion battery.

In addition, when an electrode configured by directly forming a Si columnar structure on a current collector 180 as shown in FIG. 21 is used for a negative electrode of a lithium ion battery, occlusion of lithium ions during charge / discharge and Since the volume change of the Si active material accompanying the release is large, Si may peel from the current collector during the charge / discharge cycle. Therefore, a lithium ion battery using such a negative electrode has a problem of low storage characteristics such as cycle characteristics. For this reason, the electrical storage device excellent in cycling characteristics is desired.

Accordingly, an object of the present invention is to provide a composite film that can be used as an electrode of an electricity storage device having a high capacity and excellent cycle characteristics, and a method and an apparatus for manufacturing the composite film. Another object of the present invention is to provide a self-supporting film having an aggregate of filamentous carbon having a novel structure, and a manufacturing method and manufacturing apparatus therefor. It is a further object of the present invention to provide a functional composite film that can be used for various applications and is self-supporting, as well as a manufacturing method and a manufacturing apparatus thereof.

According to the first aspect of the present invention, a filamentous carbon layer composed of filamentous carbon;
It consists only of a metal layer composed of metal,
A self-supporting composite film is provided in which a part or all of the metal layer overlaps with a part of the filamentous carbon layer to have a coexistence region where the filamentous carbon and the metal coexist.

In the composite film, a part of the metal layer may overlap with a part of the filamentous carbon layer.

In the composite film, the filamentous carbon layer has a network structure,
In the coexistence region, the metal may enter the mesh of the mesh structure.

In the composite film, the filamentous carbon layer has a vertical alignment structure in which the filamentous carbon is aligned in a thickness direction of the filamentous carbon layer, and in the coexistence region, the filamentous carbon layer has a vertical alignment structure. The metal may enter the gap. The filamentous carbon may be bundled to form an upright wall in the thickness direction of the filamentous carbon layer.

According to the second aspect of the present invention, it consists only of a metal layer composed of metal and an aggregate of filamentous carbon,
A part of the aggregate of filamentous carbon is included in the metal layer,
A self-supporting composite film is provided in which the other part of the aggregate of filamentous carbon is exposed on the metal layer.

In the composite film of the first aspect and the second aspect, the filamentous carbon may include carbon nanotubes.

In the composite film, the metal may be Cu, Al, or Ni.

According to a third aspect of the present invention, the self-supporting composite membrane of the first aspect or the second aspect;
A functional composite film having an active material attached to the filamentous carbon is provided.

According to the fourth aspect of the present invention, a step of producing a filamentous carbon film composed of filamentous carbon;
Depositing a metal on the filamentous carbon film supported on a support;
There is provided a method for producing a composite membrane comprising a step of separating the filamentous carbon membrane and the composite membrane of metal from the support.

In the step of producing the filamentous carbon film in the method for producing the composite film, the filamentous carbon film having a network structure may be produced.

The step of producing the filamentous carbon film of the method for producing the composite film may include forming the filamentous carbon so that the filamentous carbon is oriented in a thickness direction of the filamentous carbon film. . Further, after the step of separating the filamentous carbon film and the metal composite film from the support, the filamentous carbon film is contracted to reduce the thickness of the filamentous carbon layer comprising the bundle of filamentous carbon. Forming a wall upright in the direction may be included.

The method for producing the composite film may include a step of supporting the filamentous carbon film by the support before the step of depositing a metal on the filamentous carbon film.

In the method for producing the composite membrane, the filament-like carbon membrane is produced on the support on the upstream side in the movement direction while moving the support, and the filament-like carbon on the support on the downstream side in the movement direction. The metal may be deposited on the carbon film.

The method for producing the composite film may further include a step of attaching an active material on the surface of the filamentous carbon film opposite to the surface on which the metal is deposited.

According to the fifth aspect of the present invention, there is provided a composite film formed by the manufacturing method of the fourth aspect.

According to the sixth aspect of the present invention, there is provided an electrode having the composite film of the first, second or fifth aspect or the functional composite film of the third aspect.

According to the seventh aspect of the present invention, an electricity storage device including the electrode of the sixth aspect is provided.

According to the eighth aspect of the present invention, only the metal layer and the filamentous carbon aggregate are included, and a part of the filamentous carbon aggregate is included in the metal layer, An apparatus for producing a self-supporting composite film in which the other part of the carbon aggregate is exposed on the metal layer,
A moving mechanism for continuously moving the support;
An assembly forming portion that is provided on the upstream side in the moving direction and forms an assembly of the filamentous carbon on the support;
There is provided a composite film manufacturing apparatus provided with a vapor deposition mechanism provided on the downstream side in the moving direction and vapor-depositing metal on the aggregate of filamentous carbon.

The composite film manufacturing apparatus may include a roll in which the moving mechanism rotates and moves the support.

In the composite film manufacturing apparatus, by continuously operating the assembly forming unit and the vapor deposition mechanism, a long composite film is formed on the support, and the long composite film is continuously formed from the support. Alternatively, the long composite film may be obtained by peeling off the film.

In the composite film manufacturing method of the present invention, by depositing a metal on the filamentous carbon film, a part of the metal layer enters the filamentous carbon film. Therefore, there is a coexistence layer in which the filamentous carbon and the metal coexist. It is formed. Therefore, the composite film manufactured by the manufacturing method of the present invention has a small electrical resistance between the filamentous carbon film and the metal layer. Furthermore, a functional composite film in which a material that can be used as an active material of a lithium ion battery is attached to the surface of the composite film opposite to the metal-deposited surface of the filamentous carbon film is used as an electrode of a lithium ion battery. Can be used. Furthermore, a composite film to which an active material of an electricity storage device such as various secondary batteries or electric double layer capacitors is attached can be used as an electrode of the electricity storage device. The electrode using the composite film of the present invention has low electrical resistance between the current collector and the active material, and even if the active material occludes and releases lithium ions and changes its volume, it peels off from the current collector. Hateful. Therefore, the composite film and the manufacturing method thereof of the present invention can be suitably used for applications such as electrodes of power storage devices such as lithium ion batteries.

FIG. 1A is a schematic cross-sectional view of the composite film of the first embodiment, and FIGS. 1B and 1C are schematic cross-sectional views of the functional composite film of the second embodiment. 2A is a schematic cross-sectional view of the composite film of the third embodiment, and FIG. 2B is a schematic cross-sectional view of a modified form of the composite film of FIG. 2A. FIG. (D) is a schematic sectional drawing of the functional composite film of 4th Embodiment. FIG. 3 is a flowchart showing a method for manufacturing the composite membrane. 4 (a) to 4 (e) are diagrams conceptually showing each process of the manufacturing method of the composite film of the first embodiment and the functional composite film of the second embodiment. FIGS. 5A to 5E are diagrams conceptually showing each process of the method for producing the composite film of the third embodiment and the functional composite film of the fourth embodiment. FIG. 6A is a schematic view of an apparatus for manufacturing the composite film of the first embodiment in a continuous process, and FIG. 6B is an apparatus for manufacturing the composite film of the third embodiment in a continuous process. FIG. FIGS. 7A and 7B show planar SEM photographs of the sample obtained by dividing the CNT-Cu composite film of Example 1 into two, and FIGS. 7C to 7E show the CNT-Cu of Comparative Example 1. FIG. The plane SEM photograph of the sample which divided the composite film into two is shown. FIG. 8A shows a planar SEM image of the CNT film of Example 2. FIG. FIG. 8B shows a planar SEM image of the CNT—Cu composite film of Example 2 as seen from the Cu side. FIG. 8C shows a planar SEM image of the CNT—Cu composite film of Example 3 viewed from the Cu side. FIG. 8D shows a planar SEM image of the CNT—Cu composite film of Example 4 as viewed from the Cu side. FIG. 8E shows a planar SEM image of the CNT—Cu composite film of Example 5 viewed from the Cu side. FIG. 8F shows a planar SEM image of the CNT—Cu composite film of Example 6 viewed from the Cu side. FIG. 8G shows a planar SEM image of the CNT—Cu composite film of Example 7 viewed from the Cu side. FIG. 8H shows a planar SEM image of the CNT—Cu composite film of Example 8 viewed from the Cu side. FIG. 9 shows a cross-sectional SEM image of the Si—CNT—Cu composite film produced in Example 9. FIG. 10 shows the charge / discharge cycle characteristics of the composite films of Example 9 and Comparative Example 2. FIG. 11A is a digital camera photograph showing a state in which the CNT—Cu composite film is peeled from the substrate in Example 10, and FIGS. 11B to 11D are self-supporting CNT—Cu composites of Example 10. It is a digital camera photograph of the film. FIGS. 12A to 12C are digital camera photographs of the self-supporting CNT—Cu composite film of Example 11. FIG. FIG. 13A is a cross-sectional SEM image of the self-supporting CNT—Cu composite film of Example 12. FIG. 13B is a digital camera photograph of the CNT-Cu composite film obtained by shrinking the CNT vertical alignment film in Example 12 taken from the Cu film side. FIG. 13C is a digital camera photograph of the CNT-Cu composite film obtained by shrinking the CNT vertical alignment film in Example 12 taken from the CNT film side. 13D is a cross-sectional SEM image showing a network structure of a CNT-Cu composite film obtained by shrinking a CNT vertical alignment film in Example 12. FIG. FIG. 13E is a planar SEM image showing the network structure of the CNT-Cu composite film obtained by shrinking the CNT vertical alignment film in Example 12. 14A is an SEM image of the surface of the Cu substrate used in Example 13. FIG. FIG. 14B is a digital camera photograph of the substrate after the CNT-Cu composite film and the CNT-Cu composite film of Example 13 were peeled off, and the CNT-Cu composite film was taken from the CNT film side. FIG. 14C is a cross-sectional SEM image of the self-supporting CNT—Cu composite film of Example 13. FIG. 14D is a digital camera photograph of the CNT-Cu composite film obtained by shrinking the CNT vertical alignment film in Example 13 taken from the CNT film side. FIG. 14E is an oblique SEM image showing the streak structure of the CNT-Cu composite film obtained by shrinking the CNT vertical alignment film in Example 13. FIG. 14F is a planar SEM image showing the streak structure of the CNT-Cu composite film obtained by shrinking the CNT vertical alignment film in Example 13. FIG. 15A is a digital camera photograph of the self-supporting CNT-Al composite film and the remaining CNT film of Example 14, and the CNT-Al composite film is taken from the Al film side. FIG. 15B is a digital camera photograph of the self-supporting CNT-Al composite film of Example 14 taken from the CNT film side. FIG. 15C is a planar SEM image of the self-supporting CNT—Al composite film of Example 14. FIG. 15D is a cross-sectional SEM image of the self-supported CNT—Al composite film of Example 14. FIG. 16A is a digital camera photograph of the substrate after peeling the self-standing CNT-Al composite film and the CNT-Al composite film of Example 15, and the CNT-Al composite film was taken from the Al film side. FIG. 16B is a digital camera photograph of the self-standing CNT-Al composite film of Example 15 taken from the CNT film side. FIG. 16C is a planar SEM image of the self-supporting CNT—Al composite film of Example 15. FIG. 16D is a cross-sectional SEM image of the self-supporting CNT—Al composite film of Example 15. FIG. 17A is a digital camera photograph of the substrate after peeling the self-supporting CF + CNT-Al composite film and CF + CNT-Al composite film of Example 16, and the CF + CNT-Al composite film is taken from the Al film side. FIG. 17B is a digital camera photograph of the self-supporting CF + CNT-Al composite film of Example 16 taken from the CNT film side. FIG. 17C is a planar SEM image of the self-supported CF + CNT-Al composite film of Example 16. FIG. 17D is a cross-sectional SEM image of the self-supporting CF + CNT-Al composite film of Example 16. 18A is a cross-sectional SEM image of the vertically aligned CNT film of Example 17. FIG. FIG. 18B is a digital camera photograph of the substrate after peeling the self-standing CNT-Al composite film and the CNT-Al composite film of Example 17, and the CNT-Al composite film was taken from the CNT film side. FIG. 18C is a digital camera photograph of the self-supported CNT-Al composite film of Example 17 taken from the Al film side. FIG. 18D is a cross-sectional SEM image of the self-supported CNT—Al composite film of Example 17. FIG. 19A is a digital camera photograph of the self-supporting AC + CNT-Al composite film of Example 18 taken from the Al film side. FIG. 19B is a planar SEM image of the self-supporting AC + CNT-Al composite film of Example 18. FIG. 19C is a cross-sectional SEM image of the self-supported AC + CNT—Al composite film of Example 18. FIG. 19D is a graph plotting the sheet resistance of the AC + CNT-Al composite film of Example 18 against the equivalent film thickness of the Al film. FIG. 19E is a graph showing the sweep rate dependence of the specific capacity in cyclic voltammetry using the AC + CNT composite film and the AC + CNT-Al composite film of Example 18. FIG. 20 is a schematic cross-sectional view of an electrode of a prior art lithium ion battery using a binder made of a non-conductive polymer. FIG. 21 is a schematic cross-sectional view of an electrode of a prior art lithium ion battery having a Si columnar structure.

Hereinafter, embodiments of a composite film, a method for manufacturing the composite film, and a power storage device using the composite film of the present invention will be described with reference to the drawings.

[First Embodiment]
As shown in FIG. 1A, the composite film 100 of the first embodiment is composed of only a filamentous carbon layer (film) 20 that is an aggregate of filamentous carbon and a metal layer 10 made of metal. A part of the metal layer 10 overlaps with a part of the filamentous carbon layer 20. Therefore, a coexistence layer (coexistence region) 60 in which filamentous carbon and metal coexist exists in the metal layer 10 or the filamentous carbon layer 20. That is, the filamentous carbon film 20 includes the first layer 40 made of only the filamentous carbon 42 and the coexistence layer 60, and the metal layer 10 includes the second layer 80 made of only the metal and the coexistence layer 60. Have The composite film 100 does not have another layer (intermediate layer) between the first layer 40 and the coexistence layer 60 and between the coexistence layer 60 and the second layer 80. It forms an interface or boundary between the two layers 80. If attention is paid to the filamentous carbon layer 20, one side of the filamentous carbon film 20 (a part of the aggregate of filamentous carbon) is included in the metal layer 10, and the other side of the filamentous carbon film 20. (The other part of the aggregate 20 of filamentous carbon) is exposed on the metal layer 10. The filamentous carbon film 20 may contain granular carbon such as activated carbon in addition to the filamentous carbon 42. That is, in the present application, the “filamentous carbon layer”, “aggregate of filamentous carbon”, and “first layer made of only filamentous carbon” may contain granular carbon in addition to the filamentous carbon.

The composite film according to the present invention only needs to have the first layer 40 made of only filamentous carbon and the coexistence layer 60 in which the filamentous carbon and metal coexist, and is made of only the metal shown in FIG. The second layer 80 is not essential. That is, all of the metal layer 10 may overlap with a part of the filamentous carbon layer 20. As described above, the composite film 100 of the first embodiment includes the filamentous carbon film 20 including the first layer 40 and the coexistence layer 60 made of only the filamentous carbon 42, the second layer 80 and the coexistence layer made of only the metal. First, the first layer 40, the second layer 80, and the coexistence layer 60 will be described.

<First layer>
In the composite film 100 of the present embodiment, the first layer 40 is composed of conductive filamentous carbon 42, in particular, an aggregate of filamentous carbon 42. “Aggregate of filamentous carbon” is an aggregate formed by overlapping or intersecting a large number of filamentous carbons while maintaining voids. For example, the filamentous carbon is arranged in a predetermined direction such as a mesh or vertical arrangement type. Including the structure. Examples of the filamentous carbon 42 include carbon nanotubes (hereinafter abbreviated as “CNT” as appropriate), carbon nanofibers represented by vapor-grown carbon fibers (hereinafter abbreviated as “CNF” as appropriate), carbon fibers (hereinafter, as appropriate). The filamentous carbon 42 preferably contains CNT, CNF, or a mixture thereof, and more preferably contains CNT. As the CNT, it is more preferable to use CNT composed of graphene cylinders having an average of 1 to 30 layers. As CNTs, for example, those synthesized by the method described in Carbon 49 (6), 1972-1979 (2011), Carbon 80, 339-350 (2014), etc. can be used. Commercially available CNT, CNF and / or CF may be used.

As shown in FIG. 1A, the filamentous carbon 42 forms a network structure 44. The network structure 44 preferably includes a network (steric void) having a size within a range of 3 nm to 1000 nm.

<Second layer>
The second layer 80 is made of a metal, and is particularly preferably made of a low resistance metal. When the composite film 100 is used for a positive electrode of a lithium ion battery, aluminum or the like may be used as a metal. When the composite film 100 is used for the negative electrode of a lithium ion battery, copper, nickel, or the like may be used as the metal. The thickness of the second layer 80 can be set to any thickness depending on the application. For example, when the composite film 100 of the present embodiment is used for the negative electrode of a lithium ion battery, the thickness is in the range of 0.03 μm to 30 μm. Is preferably within the range of 1 to 10 μm. When the thickness of the second layer 80 is 10 μm or less, the composite film 100 is further reduced in weight. When the thickness of the second layer 80 is 1 μm or more, the resistance of the composite film 100 can be further reduced.

<Coexistence layer>
The coexistence layer 60 is a layer or region in which the filamentous carbon 42 and metal coexist. The metal of the coexistence layer 60 is the same metal as the metal constituting the second layer 80. That is, the coexistence layer 60 has a structure in which the filamentous carbon 42 of the first layer 40 and the metal of the second layer 80 are partially mixed. For this reason, as shown in FIG. 1A, the coexistence layer 60 has a network structure 44 of filamentous carbon 42 as in the first layer 40, and the network (three-dimensional voids) of the network structure 44. There is metal inside. The mesh structure 44 may include a mesh having a size in the range of 3 nm to 1000 nm. Since the metal has entered the mesh with the filamentous carbon 42, the filamentous carbon 42 and the metal are mechanically and electrically connected.

The thickness of the coexistence layer 60 can be set within the range of 0.01 μm to 10 μm by manufacturing the composite film 100 by the manufacturing method described later. When the thickness of the coexistence layer 60 is within the above range, the first layer 40 and the second layer 80 are sufficiently mechanically and electrically connected.

In the composite film 100 of the present embodiment, the metal enters the mesh of the filamentous carbon 42 as described above, so that the filamentous carbon and the metal are mechanically connected without using a binder made of a nonconductive material. Is done. Further, since the metal enters the mesh of the filamentous carbon 42, the filamentous carbon and the metal are also electrically connected, and the composite film 100 includes a binder made of a non-conductive material as described above. Therefore, the composite film 100 of this embodiment has a low resistance. Furthermore, since the filamentous carbon 42 is exposed from the metal, the composite film 100 of this embodiment has a large surface area. Therefore, the composite film 100 of the present embodiment can be suitably used as a current collector foil for an electrode of a lithium ion battery.

[Second Embodiment]
1B and 1C show a functional composite film in which an active material is attached to the self-supporting composite film of the first embodiment. The functional

composite films

300 and 400 of the second embodiment are the same as the composite film 100 of the first embodiment shown in FIG. 1A, and the first layer 40 made of filamentous carbon 42 and the second made of metal. The composite film has a layer 80, a filamentary carbon 42 formed between the first layer 40 and the second layer 80, and a coexistence layer 60 in which a metal coexists. The functional

composite films

300 and 400 adhere to the filamentous carbon 42 on the surface opposite to the surface on which the coexisting layer 60 of the first layer 40 is formed and the self-supporting composite film of the first embodiment. Electrode active material (hereinafter referred to as “active material” as appropriate) 34. That is, the functional

composite films

300 and 400 have a configuration in which the active material 34 is attached to the filamentous carbon 42 that forms the first layer 40 of the composite film 100 of the first embodiment. The first layer 40, the second layer 80, and the coexistence layer 60 of the functional

composite films

300, 400 are configured in the same manner as the first layer 40, the second layer 80, and the coexistence layer 60 of the composite film 100 of the first embodiment. Therefore, the description is omitted.

<Active material>
As the active material 34, materials having various functions can be used. For example, when the functional

composite films

300 and 400 are used as a negative electrode of a lithium ion battery, a material capable of inserting and extracting lithium ions as the active material 34, for example, Si, Si oxide, other metal elements other than Si and Si Si composite oxides containing, carbon materials such as graphite, hard carbon, graphite, and amorphous carbon, materials that form alloys with Li, such as Li, Sn, Al, Sn oxides such as SnO, other than Sn and Sn Sn composite oxides containing other metal elements, lithium titanate, Li, or the like can be used. When used as a positive electrode of a lithium ion battery, LiCoO ₂ , LiMn ₂ O ₄ , LiFePO ₄ , Li (Ni—Mn—Co) O ₂ , S, or the like can be used as the active material 34. These may be used alone or in combination of two or more.

“The active material 34 is attached to the filamentous carbon” means that the active material 34 is inside the network structure 44 of the first layer 40 from the surface opposite to the surface on which the coexisting layer 60 of the first layer 40 is formed. It includes a form in which the active material 34 has entered (see FIG. 1B) and a form in which the active material 34 is attached so as to cover the surface of the filamentous carbon 42 (see FIG. 1C). Further, a part of the active material 34 included in the functional

composite films

300 and 400 may enter the network structure 44 of the filamentous carbon 42, or all of the active material 34 included in the functional

composite films

300 and 400 may be filaments. It may enter the network structure 44 of the carbon-like carbon 42. Further, the active material 34 included in the functional

composite films

300 and 400 may enter the entire network structure 44 of the filamentous carbon 42 and may be in direct contact with the coexisting layer 60, or the functional

composite films

300 and 400 may include the active material 34. The active material 34 does not need to be in direct contact with the coexistence layer 60 by entering a part of the network structure 44 of the filamentous carbon 42.

When the functional

composite films

300 and 400 are used as electrodes of a secondary battery typified by a lithium ion battery, the active material 34 greatly changes in volume with the insertion and extraction of lithium ions during charge and discharge. 34 has entered the network structure 44 of the filamentous carbon 42, or the active material 34 is attached so as to cover the surface of the filamentous carbon 42, so that the volume of the active material 34 is deformed by the deflection of the filamentous carbon 42. The change can be absorbed (relaxed), and the active material 34 is prevented from peeling from the first layer 40.

Further, as described above, the composite film 100 of the first embodiment has a large surface area because the filamentous carbon 42 is exposed from the metal. Therefore, the functional

composite films

300 and 400 of this embodiment having a configuration in which the active material 34 is attached to the filamentous carbon 42 constituting the first layer 40 of the composite film 100 of the first embodiment include the active material 34 and the first active material 34. The contact area of one layer 40 is large (many contact points). Therefore, in the functional

composite films

300 and 400, the first layer 40 composed of the active material 34 and the filamentous carbon 42 is mechanically well connected. Therefore, when the functional

composite films

300 and 400 are used as electrodes of a lithium ion battery, the active material 34 is unlikely to peel from the first layer 40 even if the volume of the active material 34 changes greatly during charging and discharging. Therefore, a long-life secondary battery can be manufactured by using the functional

composite films

300 and 400 as electrodes of a secondary battery represented by a lithium ion battery.

Further, since the contact area between the active material 34 and the first layer 40 is large, the first layer 40 composed of the active material 34 and the filamentous carbon 42 is electrically connected well (the contact resistance is small). . Furthermore, in the functional

composite films

300 and 400 of the present embodiment, as in the composite film 100 of the first embodiment, since the metal enters the mesh of the filamentous carbon 42, the filamentous carbon 42 and the metal are separated from each other. The connection is made without using a binder made of a non-conductive material. Therefore, the first layer 40 made of filamentary carbon 42 and the metal are connected with low resistance. Therefore, in the functional

composite films

300 and 400 of the present embodiment, the active material 34 and the metal are connected with low resistance. Therefore, by using the functional

composite films

300 and 400 as electrodes of a secondary battery such as a lithium ion battery, a secondary battery such as a high capacity lithium ion battery can be manufactured.

Since the functional

composite films

300 and 400 have a large contact area between the active material 34 and the first layer 40 as described above, the active material 34 can be fixed on the first layer 40 without using a binder. In the functional composite film 300 shown in FIG. 1B, a binder (not shown) made of a non-conductive polymer for fixing the active material 34 to the first layer 40 may be included. In this case, the functional composite film 300 may further include a conductive material (not shown) made of carbon nanofiber (CNF), carbon black, or the like. As described above, the first layer 40 is composed of the conductive filamentous carbon 42 and has a high surface area. Therefore, the contact area between the active material 34 and the filamentous carbon 42 is large, and sufficient conductivity is obtained even when a binder is added. Can be secured. Further, by adding a conductive material, the conductivity in the vertical direction of the layer made of the active material 34 can be sufficiently secured even when the layer made of the active material 34 is thicker than the first layer 40. In addition, since the conductive material enters the network of the first layer 40, sufficient conductivity between the active material 34 and the first layer 40 can be ensured.

[Third Embodiment]
As shown in FIG. 2A, the composite film 100a of the third embodiment, like the composite film 100 of the first embodiment, is a filamentous carbon (film) 20a that is an aggregate of filamentous carbon, It is a self-supporting film comprised only from the metal layer 10a comprised from the metal, and a part of metal layer 10 has overlapped with a part of filamentous carbon layer 20a. For this reason, the coexistence layer (coexistence area | region) 60a in which filamentous carbon and a metal coexist exists in the metal layer 10a or the filamentous carbon layer 20a. That is, the filamentous carbon film 20a has a first layer 40a made only of the filamentous carbon 42 and a coexistence layer 60a, and the metal layer 10 has a second layer 80a made only of a metal and a coexistence layer 60a. Have The composite film 100a does not have another layer (intermediate layer) between the first layer 40a and the coexistence layer 60a, and between the coexistence layer 60a and the second layer 80a. It forms an interface or boundary between the two layers 80a. Paying attention to the filamentous carbon layer 20a, one surface of the filamentous carbon film 20 (part of the aggregate of filamentous carbon) is included in the metal layer 10a, and the other surface of the filamentous carbon film 20a. (The other part of the filament-like carbon aggregate 20) is exposed on the metal layer 10a.

In the composite film 100a of the third embodiment, as shown in FIG. 2A, in the first layer 40a and the coexistence layer 60a, the filamentous carbon 42a is oriented (perpendicular in the thickness direction of the first layer 40a and the coexistence layer 60a. The vertical alignment structure 46 of the filamentous carbon 42a is formed. In the vertical alignment structure 46, a plurality of filamentous carbons 42a extending in a direction perpendicular to the surface of the second layer 80a are adjacent to each other with a gap, and in the coexistence layer 60a, metal enters the gap. It is out. The vertical alignment structure 46 of the filamentous carbon 42a may include voids having a size in the range of 3 nm to 1000 nm. The first layer 40a, the second layer 80a, and the coexistence layer 60a of the composite film 100a are made of the same material as the first layer 40, the second layer 80, and the coexistence layer 60 of the composite film 100 of the first embodiment. ing.

In the composite film 100a of the present embodiment, since the metal enters the vertical hole-like gaps of the filament-like carbon 42a vertically oriented as described above, the filament-like carbon and the metal can be used without using a binder made of a non-conductive material. Are mechanically connected. Further, since the metal enters the mesh of the filamentous carbon 42a, the filamentous carbon and the metal are also electrically connected, and the composite film 100a includes a binder made of a nonconductive material as described above. Therefore, the composite film 100a of this embodiment has a low resistance. Furthermore, since the filamentous carbon 42a is exposed from the metal, the composite film 100a of this embodiment has a large surface area. Therefore, like the composite film 100 of the first embodiment, the composite film 100a of the third embodiment can be suitably used as a current collector foil or the like used for an electrode of an electricity storage device such as a lithium ion battery.

FIG. 2B shows a modification of the composite film 100a of the third embodiment. In the deformed composite film 100b, the vertically oriented filamentous carbon 42b is bundled to form a wall 41b that stands upright in the thickness direction of the first layer 40b and the coexistence layer 60b. The wall 41b forms a random network structure 46b when viewed from the thickness direction of the first layer 40b and the coexistence layer 60b (see FIG. 13E). The network structure 46b may include a network (void) of 1 to 200 μm. With such a structure, various active materials can be introduced into the mesh, the filamentous carbon is less likely to collapse, and an upright structure can be easily maintained, and an electrode of an electricity storage device with excellent performance can be manufactured. Further, the upright wall made of a bundle of filamentous carbon may form an arbitrary structure different from a network structure such as a streak structure regularly arranged in one direction.

[Fourth Embodiment]
The functional

composite films

300a and 400a shown in FIGS. 2C and 2D are functional composite films in which an active material is attached to the self-supporting composite film 100a of the third embodiment. Similar to the composite film 100a shown in FIG. 2A, a first layer 40a made of filamentary carbon 42a, a second layer 80a made of metal, and a filament formed between the first layer 40a and the second layer 80a. A coexistence layer 60a in which the carbon-like carbon 42a and the metal coexist. The functional

composite films

300a and 400a further have an active material 34a attached to the filamentous carbon 42a on the surface of the first layer 40a opposite to the surface on which the coexistence layer 60a is formed. That is, the functional

composite films

300a and 400a of the fourth embodiment have a configuration in which the active material 34a is attached to the filamentous carbon 42a that constitutes the first layer 40a of the composite film 100a of the third embodiment. The first layer 40a, the second layer 80a and the coexistence layer 60a of the functional

composite films

300a and 400a are the same as the first layer 40a, the second layer 80a and the coexistence layer 60a of the functional composite film 300 of the third embodiment. Since the active material 34a of the functional

composite films

300a and 400a is configured similarly to the active material 34 of the functional

composite films

300 and 400 of the second embodiment, detailed description thereof will be omitted.

“The active material 34a is attached to the filamentous carbon” means that the active material 34a is inside the vertical alignment structure 46 of the first layer 40a from the surface opposite to the surface on which the coexisting layer 60a of the first layer 40a is formed. In which the active material 34a enters (see FIG. 2 (c)), or the surface of the filamentous carbon 42a is attached so as to cover the active material 34a (see FIG. 2 (d)). Further, a part of the active material 34a included in the functional

composite films

300a and 400a may enter the vertical alignment structure 46 of the filamentous carbon 42a, or the entire active material 34a included in the functional

composite films

300a and 400a may be included. It may enter the vertical alignment structure 46 by the filamentous carbon 42a. Further, the active material 34a included in the functional

composite films

300a and 400a may enter the entire network structure 44a of the filamentous carbon 42a and may be in direct contact with the coexistence layer 60a, or the functional

composite films

300a and 400a may include the active material 34a. The active material 34a may enter a part of the network structure 44a of the filamentous carbon 42a and may not be in direct contact with the coexistence layer 60a.

When the functional

composite films

300a and 400a are used as electrodes of a lithium ion battery, the active material 34a changes greatly in volume with the insertion and extraction of lithium ions during charging and discharging, but the active material 34a is made of filamentous carbon 42a. Since the vertical alignment structure 46 enters or the active material 34a adheres so as to cover the surface of the filamentous carbon 42a, the filamentous carbon 42a bends to absorb (relax) the volume change of the active material 34a. It is possible to prevent the active material 34a from peeling from the first layer 40a.

Also, as described above, the composite film 100a of the third embodiment has a large surface area because the filamentous carbon 42a is exposed from the metal. Therefore, the functional

composite films

300a and 400a of the present embodiment having a configuration in which the active material 34a is attached to the filamentous carbon 42a constituting the first layer 40a of the composite film 100a of the third embodiment includes the active material 34a and the first active material 34a. The contact area of one layer 40a is large (many contact points). Therefore, in the functional

composite films

300a and 400a, the first layer 40a composed of the active material 34a and the filamentous carbon 42a is mechanically well connected. Therefore, when the functional

composite films

300a and 400a are used as electrodes typified by a lithium ion battery, even if the volume of the active material 34a changes greatly during charging and discharging, the active material 34a is difficult to peel from the first layer 40a. . Therefore, by using the functional

composite films

300a and 400a as electrodes of an electricity storage device such as a lithium ion battery, a long-life electricity storage device can be manufactured.

Further, since the contact area between the active material 34a and the first layer 40a is large, the first layer 40a composed of the active material 34a and the filamentous carbon 42a is electrically connected well (the contact resistance is small). . Furthermore, in the functional

composite films

300a and 400a of the present embodiment, as in the composite film 100a of the third embodiment, the metal enters the vertical alignment structure 46 of the filamentous carbon 42a, whereby the filamentous carbon 42a. And the metal are connected without a binder made of a non-conductive material. Therefore, the first layer 40a made of filamentary carbon 42a and the metal are connected to a low resistance. Therefore, in the functional

composite films

300a and 400a of the present embodiment, the active material 34a and the metal are connected with low resistance. Furthermore, in the functional

composite films

300a and 400a, since the filamentous carbon 42a is oriented perpendicular to the second layer 80a made of metal, the filamentous carbon 42a has the shortest distance and the active material 34a is made of metal. It can be connected to the two layers 80a. Therefore, even when the layer of the active material 34a is thick, the active material 34a and the second layer 80a can be connected with low resistance. Therefore, a secondary battery such as a high-capacity lithium ion battery can be manufactured by using the functional

composite films

300a and 400a as electrodes of a secondary battery represented by a lithium ion battery.

Since the functional

composite films

300a and 400a have a large contact area between the active material 34a and the first layer 40a as described above, the active material 34a can be fixed on the first layer 40a without using a binder. In the functional composite film 300a shown in FIG. 2 (c), a binder made of a nonconductive polymer for fixing the active material 34a to the first layer 40a may be included. In this case, the functional composite film 300a may further include a conductive material made of carbon nanofiber (CNF), carbon black, or the like. As described above, the first layer 40a is made of the conductive filament carbon 42a and has a high surface area. Therefore, the contact area between the active material 34a and the filament carbon 42a is large, and sufficient conductivity can be obtained even if a binder is added. Can be secured. Further, by adding a conductive material, it is possible to sufficiently ensure the conductivity in the vertical direction of the layer made of the active material 34a even when the layer made of the active material 34a is thicker than the first layer 40a. In addition, since the conductive material enters the gap between the first layers 40a, the conductivity between the active material 34a and the first layer 40a can be sufficiently ensured.

In addition, instead of attaching the active material to the self-supporting composite film 100a of the third embodiment, the functional composite film can be obtained by attaching the active material to the composite film 100b in a modified form.

[Method of Manufacturing Composite Film of First Embodiment and Functional Composite Film of Second Embodiment]
A method for manufacturing the composite film 100 of the first embodiment and the functional

composite films

300 and 400 of the second embodiment will be described. As shown in FIG. 3, the manufacturing method of the present embodiment includes a step S1 for mainly producing a film made of filamentous carbon (hereinafter referred to as “filamentous carbon film” as appropriate), and the produced filamentous carbon film. Supporting a filamentous carbon film supporting step S2 supported by a support (substrate), a metal deposition step S3 for depositing metal on the filamentary carbon film supported by the support, and supporting a composite film of the filamentous carbon film and the metal A composite membrane separation step S4 for separating (separating) from the body, and an active material attaching step S5 for attaching an active material on the surface of the filamentous carbon film opposite to the surface on which the metal is deposited. In addition, the manufacturing method of the composite film according to this invention does not need to have filamentous carbon film support process S2 and active material adhesion process S5. That is, in the method for manufacturing a composite film according to the present embodiment, the filamentous carbon film supporting step S2 and the active material attaching step S5 are optional steps.

<Filamentary carbon film production step S1>
Filamentous carbon films (aggregates of filamentous carbon) are, for example, a method of applying and drying a dispersion of filamentous carbon on a substrate by spray coating or blade coating, a dispersion of filamentous carbon using a membrane filter It can form by the method of filtering.

The dispersion of filamentous carbon can be adjusted by adding filamentous carbon such as CNT or CNF to an aqueous solution of a surfactant and ultrasonically dispersing it. As the surfactant, for example, sodium dodecylbenzenesulfonate (SDBS) can be used. A commercially available CNT dispersion or CNF dispersion may be used.

When forming a filamentous carbon film by a method of filtering a filamentous carbon dispersion using a membrane filter, the filamentous carbon dispersion 120 is suction filtered using a membrane filter 140 as shown in FIG. The filamentous carbon film 20 can be obtained on the membrane filter 140 by separating the filamentous carbon from the dispersion medium. As the membrane filter 140, a VCWP filter, a PTFE filter, a silica fiber filter, or the like can be used.

The filamentous carbon film 20 having the network structure 44 in which filamentous carbon is intertwined can be formed by the above method. The network structure of the filamentous carbon film 20 formed by the above method can include a network (steric void) having a size in the range of 3 nm to 1000 nm. The size of the mesh is generally determined in correlation with the diameter of the filamentous carbon, but further depends on the viscosity of the dispersion, the size of the mesh of the filter, the degree of unevenness of the surface, the presence or absence of compression after drying the filamentous carbon film, etc. Can be adjusted. Furthermore, the size of the mesh can also be adjusted by removing the polymer particles with a solvent after filtration with polymer particles soluble in an organic solvent to form a filamentous carbon film. Since the filamentous carbon film 20 includes a mesh having such a size, metal can enter the filamentous carbon film 20 in a metal vapor deposition step S3 described later.

<Filamentary carbon film support step S2>
Next, as shown in FIG. 4B, the filamentous carbon film 20 formed on the membrane filter 140 is supported (transferred) on the substrate (support) 160. As the substrate 160, a stainless steel substrate, a glass substrate, a ceramic substrate, a silicon substrate, or the like can be used. The filamentous carbon film 20 can be supported on the substrate 160 as follows, for example. A binder is applied onto the substrate 160, the filament carbon film 20 and the binder on the substrate 160 are made to face each other, and the membrane filter 140 on which the filament carbon film 20 is formed is pressed against the substrate 160. After the filamentous carbon film 40 adheres to the substrate 160 via the binder, the membrane filter 140 is peeled off from the filamentous carbon film 20. By these operations, the filamentous carbon film 20 is supported on the substrate 160.

Also, the filamentous carbon film 20 can be supported on the substrate 160 by the following method. The membrane filter 140 on which the filamentous carbon film 20 is formed is pressed against the substrate 160 with the filamentous carbon film 20 and the substrate 160 facing each other. Next, the membrane filter 140 is wetted with a mixed solution of ethanol and water and then dried, and the membrane filter 140 is peeled off from the filamentous carbon film 20. Thereby, the filamentous carbon film 20 can be supported on the substrate 160.

Furthermore, the filamentous carbon film 20 can be supported on the substrate 160 by the following method. The membrane filter 140 on which the filamentous carbon film 20 is formed is impregnated with pure water. Then, since only the filamentous carbon film 20 floats on the water surface, it is scooped by the substrate 160. Thereby, the filamentous carbon film 20 can be supported on the substrate 160. Before scrubbing with the substrate 160, the filamentous carbon film 20 may be washed with heated pure water to remove the surfactant attached to the filamentous carbon film 20.

The filamentous carbon film 20 supported on the substrate 160 by these methods may be annealed in a reducing atmosphere. Thereby, the surfactant remaining on the filamentous carbon film 20 can be decomposed.

In the above-described filamentous carbon film production step S1, when the filamentous carbon film is produced by a method of filtering a filamentous carbon dispersion using a heat resistant membrane filter such as glass fiber, the membrane filter is a substrate. It can also serve as a (supporting substrate). That is, after filtering the filamentous carbon in step S1 to form a film on the membrane filter, step S3 can be entered immediately. In the filamentous carbon film production step S1, the filamentous carbon film support step is also used when the filamentous carbon film is produced on the substrate by applying and drying the filamentous carbon dispersion by spray coating or blade coating. A filamentous carbon film supported on the substrate can be obtained without performing S2.

<Step S3 for depositing metal>
Next, as shown in FIG. 4C, a metal is deposited on the filamentous carbon film 20 supported by the substrate 160. Thereby, as shown in FIG. 4C, the metal layer 10 can be formed on the filamentous carbon film 20.

Metal vapor deposition can be performed by any vapor deposition method such as resistance heating vapor deposition, electron beam vapor deposition, sputtering, and CVD. The vapor deposition thickness of the metal (thickness of the metal layer to be formed) can be set to any thickness depending on the application. For example, the composite film produced by the production method of the present embodiment is used as the negative electrode of the lithium ion battery. When it is used in the above, it is preferably in the range of 0.03 to 30 μm, more preferably in the range of 1 to 10 μm.

<Step S4 of separating the composite film from the substrate>
Next, the composite film 100 composed of the filamentous carbon film 20 and the metal layer 10 is peeled from the substrate 160 (see FIG. 4D). The filamentous carbon film 20 and the metal layer 10 can be mechanically separated from the substrate 160 by, for example, a method of picking the outer periphery of the filamentous carbon film 20 with tweezers and pulling it up from the substrate 160. That is, a self-supporting filamentous carbon and metal composite film 100 is obtained. The composite film 100 obtained in this way has a structure in which a part of the metal layer 10 has entered (sunk into) the mesh of the filamentous carbon film 20 as shown in FIG. That is, the obtained composite film 100 includes a filamentous carbon formed between the first layer 40 made of filamentous carbon, the second layer 80 made of metal, and the first layer 40 and the second layer 80. And a coexistence layer 60 in which a metal coexists. By depositing a metal on the filamentous carbon film by the method as described above, the metal can be penetrated from the surface layer of the filamentous carbon film 20 to a depth in the range of 0.01 μm to 10 μm. That is, the coexistence layer 60 having a thickness in the range of 0.01 μm to 10 μm can be formed.

<Step S5 for attaching an active material>
The process of making the self-supporting composite film obtained from the above process into a functional composite film having a predetermined function will be described. An active material (a material capable of inserting and extracting lithium ions) 34 is attached to the self-supporting composite film 100 obtained as described above. As shown in FIG. 4E, the active material 34 is attached so that the active material 34 enters the inside of the network structure 44 of the filamentous carbon film 20 from the surface opposite to the surface on which the metal of the filamentous carbon film 20 is deposited. The active material 34 may be attached so that the active material 34 covers the surface of the filamentous carbon film 20.

For example, a paste in which a binder, a conductive material, and the like are mixed with a particulate active material is prepared, applied to the filamentous carbon film 20, and then dried, as shown in FIG. The active material 34 can be attached so that the gas enters the inside of the network structure 44 of the filamentous carbon film 20.

Further, the active material 34 can be deposited by depositing the active material 34 on the filamentous carbon film 20 so that the active material 34 covers the surface of the filamentous carbon film 20 (see FIG. 1C). ). As a deposition source, Si, Sn, SnO, a mixture of Si or Sn and other metals, S, or the like can be used. The evaporation source may be doped with impurities. Examples of such impurities include elements such as nitrogen, phosphorus, aluminum, arsenic, boron, gallium, indium, oxygen, and carbon.

As described above, as shown in FIGS. 1B, 1C, and 4E, the active material 34 adheres to the filamentous carbon film 20, and the function composed of filamentous carbon, metal, and active material. Conductive

composite films

300 and 400 are obtained. The obtained functional

composite films

300 and 400 are filaments formed between the first layer 40 made of filamentary carbon, the second layer 80 made of metal, and the first layer 40 and the second layer 80. The active material 34 is attached to the filamentous carbon 42 constituting the first layer 40. The functional

composite films

300 and 400 manufactured by the above method have a structure in which part or all of the active material 34 enters the network structure 44 of the filamentous carbon film 20, or the active material 34 has a surface of the filamentous carbon 42. It can have a structure attached so that it may cover.

In the above, the manufacturing method of the composite film has been described by taking a batch process as an example, but a continuous process in consideration of production efficiency may be used. For example, the above steps S1 to S4 can be continuously performed using the composite film manufacturing apparatus 150 shown in FIG. Below, the method to manufacture the composite film 100 of 1st Embodiment using the manufacturing apparatus 150 is demonstrated. The apparatus 150 shown in FIG. 6A mainly includes a roller pair 52 including a driving roller 52a and a driven roller 52b, an endless conveying belt 54 that moves across the roller pair 52, and an upper portion of the conveying belt 54. A suction filter 63 installed below the feeder 56 via the conveyor belt 54, and downstream of the feeder 56 in the conveyance direction and below the conveyor belt 54. The vapor deposition device 58 is provided. The conveyor belt 54 is a mesh belt having heat resistance and a membrane filter function. The supply unit 56 supplies the filamentous carbon dispersion 51 prepared in the above-described step S <b> 1 to the conveyor belt 54, sucks the dispersion on the conveyor belt 54 by the suction filter 63, and collects the aggregate of filamentous carbon. It remains on the conveyor belt 54. The vapor deposition device 58 includes a boat that accommodates metal pieces therein as a vapor deposition source, and deposits metal on an aggregate of filamentous carbon.

A continuous manufacturing process using this apparatus 150 will be described. When the driving roller 52a rotates in the direction indicated by the arrow and the conveyor belt 54 starts to move, the filament-like carbon dispersion 51 is continuously supplied from the supply device 56 onto the conveyor belt 54 in a predetermined amount. The liquid component of the dispersion liquid is filtered by 63 and the conveyor belt 54 to form a filamentous carbon aggregate 53 as a solid component on the conveyor belt 54. Next, when the filamentous carbon aggregate 53 is conveyed to a position facing the downstream vapor deposition unit 58 by the conveyance belt 54, the metal from the vapor deposition source heated and melted by the vapor deposition unit 58 becomes the filamentous carbon aggregate 53. Adhere to the surface. Thus, a composite film 59 in which the metal 55 is attached to one surface of the filamentous carbon aggregate 53 is obtained. Since the composite film 59 is a continuous film, when the front end in the conveyance direction of the composite film 59 is wound up by the driven roller 52b, the tensile force in the tangential direction (horizontal direction) of the driven roller at the front end is sequentially applied. Thus, a long and self-supporting composite film 59 (composite continuous film) is obtained by removing from the conveyor belt 54. The long self-supporting composite film 59 can be appropriately wound around a roller and collected and managed.

In this specific example, the feeder 56, the suction filter 63, and the conveyor belt 54 functioned as the filament-like carbon aggregate forming unit, but a coater such as a spray coater or a blade coater and a dryer may be used. In this case, the dispersion liquid can be applied onto the conveyor belt with a coater, and the applied dispersion liquid can be dried with a dryer, and the conveyor belt need not have a filter function. Further, a mechanism such as a peeling roller for separating (separating) from the conveying belt 54 by applying a tensile force in the tangential direction (horizontal direction) of the driven roller 52b of the front end of the composite film 59 may be provided.

Furthermore, the conveyance belt 54 can also serve as the driving roller 52. In other words, a cylinder is used instead of the conveyor belt, and while rotating the cylinder, filamentary carbon is continuously deposited on the upper part, and metal is deposited on the filamentous carbon deposited on the lower part. can do. When a cylinder composed of a mesh-like sheet is used, an aggregate of filamentous carbon can be formed from a dispersion of filamentous carbon by suction filtration. When a cylinder composed of a sheet without holes is used, an aggregate of filamentous carbon can be formed from a dispersion of filamentous carbon using a spray coater or a blade coater. One cylinder serves as both the conveyor belt 54 and the driving

rollers

52a and 52b.

[Method for Producing Composite Film of Third Embodiment and Fourth Embodiment]
A method for manufacturing the composite film 100a of the third embodiment and the functional

composite films

300a and 400a of the fourth embodiment will be described. The manufacturing method of the composite film 100a and the functional

composite films

300a and 400a mainly includes a step S1 for producing a film made of filamentous carbon (filamentous carbon film), and a filament shape supported by a support (substrate). Step S3 for depositing metal on the carbon film, Step S4 for separating the filamentary carbon film and the metal composite film from the support, and an active material on the surface of the filamentous carbon film opposite to the surface on which the metal is deposited. And attaching step S5. In addition, the manufacturing method of the composite film according to this embodiment does not need to have active material adhesion process S5.

<Step S1 for producing filamentary carbon film>
In the embodiment of the manufacturing method of the composite film 100 of the first embodiment and the functional

composite films

300 and 400 of the second embodiment, the filamentous carbon film having a network structure is formed in the filamentous carbon film manufacturing step S1. However, in the method of manufacturing the composite film 100a of the third embodiment and the functional

composite films

300a and 400a of the fourth embodiment, the filamentous carbon film in which filamentous carbon is oriented (vertically oriented) in the thickness direction of the filamentous carbon film. Form.

In the vertical alignment film of filamentous carbon, for example, as shown in FIG. 5 (a), a substrate (support) 160a on which particles 48 as a catalyst for synthesizing filamentary carbon are formed is disposed in a reactor. Then, the substrate 160a can be produced by circulating the source gas in the reactor while heating. Fe, Co, Ni, etc. can be used as the catalyst, and Si, Al, Mg oxides, etc. can be used as the catalyst carrier. As the source gas, acetylene, ethylene, ethanol, methane or the like can be used. In this manner, as shown in FIG. 5B, the filamentous carbon film 20a having the structure 46 in which the filamentous carbon 42a is vertically oriented can be formed on the substrate 160a. Since the filamentous carbon film 20a produced by the step S1 for producing the filamentous carbon film is supported by the substrate 160a, the manufacturing method includes the step S2 for supporting the produced filamentary carbon film on the substrate. You don't have to.

<Step S3 for depositing metal>
Step S3 for depositing metal in the method of manufacturing the composite film 100a of the third embodiment and the functional

composite films

300a and 400a of the fourth embodiment is a process of the method of manufacturing the composite film 100 and the functional

composite films

300 and 400. Since it can be performed in the same manner as S3, detailed description is omitted. By this step S3, the metal layer 10a can be formed on the filamentous carbon film 20a. At this time, as shown in FIG. 5 (c), a part of the metal layer 10a has entered (submitted) into the gaps between the filamentous carbons 42a of the filamentous carbon film 20a.

<Step S4 of separating the composite film from the substrate>
Step S4 of separating the composite film from the substrate in the method of manufacturing the composite film 100a of the third embodiment and the functional

composite films

300a and 400a of the fourth embodiment includes the composite film 100 and the functional

composite films

300 and 400. Since it can carry out similarly to process S4 of this manufacturing method, detailed description is abbreviate | omitted. When the composite film 100a composed of the filamentous carbon film 20a and the metal layer 10a is peeled from the substrate 160a, as shown in FIG. 5D, the metal layer 10a is formed in the gap between the filamentous carbons 42a of the filamentous carbon film 20a. As a result, a composite film 100a having a structure in which a part of the film has entered (submerged) is obtained. That is, the obtained composite film 100a has a filament-like shape formed between the first layer 40a made of filamentous carbon 42a, the second layer 80a made of metal, and the first layer 40a and the second layer 80a. It has a coexistence layer 60a in which carbon 42a and metal coexist.

<Step S5 for attaching an active material>
The step S5 of attaching the active material in the manufacturing method of the composite film 100a of the third embodiment and the functional

composite films

300a and 400a of the fourth embodiment is the method of manufacturing the composite film 100 and the functional

composite films

300 and 400. Since it can carry out similarly to process S5, detailed description is abbreviate | omitted.

In this step S5, for example, a paste is prepared by mixing a particulate active material with a binder, a conductive material, etc., and this is applied onto the filamentous carbon film 20a and then dried, as shown in FIG. 5 (e). Thus, the active material 34a can be attached so that the active material 34a enters the inside of the vertical alignment structure 46 of the filamentous carbon film 20a.

Further, by depositing the active material 34a on the filamentous carbon film 20a, the active material 34a can be attached so that the active material 34a covers the surface of the filamentous carbon film 20a (see FIG. 2D). ).

As described above, as shown in FIGS. 2C, 2D, and 5E, the active material 34a is attached to the filamentous carbon film 20a, and the function is composed of filamentous carbon, metal, and active material.

Composite films

300a and 400a are obtained. The obtained functional

composite films

300a and 400a are filaments formed between the first layer 40a made of filamentary carbon, the second layer 80a made of metal, and the first layer 40a and the second layer 80a. The active carbon 34a is attached to the filamentous carbon 42a constituting the first layer 40a. The functional

composite films

300a and 400a manufactured by the above method have a structure in which part or all of the active material 34a enters the vertical alignment structure 46 of the filamentous carbon film 20a, or the active material 34a is made of the filamentous carbon 42a. It can have a structure attached to cover the surface.

In addition, after separating the composite film 100a from the substrate 160a in step S4, the filamentary carbon vertical alignment film is contracted to form a filamentous carbon film 20b having a random network structure 46b composed of the walls 41b of the filamentous carbon 42b. You may form (refer FIG.2 (b)). The network structure 46b composed of the walls 41b of the filamentous carbon 42b can be formed as follows. For example, by exposing the filamentary carbon vertical alignment film to a solvent vapor such as ethanol to condense the solvent on the filament carbon film, and then drying the condensed solvent, the filamentous carbon film 20a is formed by the surface tension of the solvent. The network structure 46b which consists of the wall 41b of the filament-like carbon 42b is shrunk and formed. The mesh size of the mesh structure 46b can be controlled, for example, by changing the height of the vertical alignment film of the filamentous carbon 42b. The height of the filamentary carbon vertical alignment film can be controlled, for example, by changing the time for synthesizing the filamentous carbon in the filamentous carbon film manufacturing step S1. In addition, the structure formed by the filamentous carbon walls can be controlled by the texture (unevenness) of the surface of the substrate 160a used for synthesizing the filamentous carbon in step S1. Therefore, it is possible to form an arbitrary structure different from the network structure. For example, a vertical alignment film of filamentous carbon is formed using a substrate having a streaky (line-like) texture extending in one direction on the surface as the substrate 160a in step S1, and the composite film 100a is formed in step S4. After separating from the substrate 160a, the filamentary carbon vertical alignment film is contracted to form a streak structure in which filamentary carbon walls are regularly arranged in one direction.

Next, a method of manufacturing the composite film 100a of the third embodiment by performing the steps S1 to S4 in the present embodiment continuously using the composite film manufacturing apparatus 170 shown in FIG. 6B will be described. . The apparatus 170 shown in FIG. 6 (b) mainly includes a roller pair 52 composed of a driving roller 52a and a driven roller 52b, an endless conveying belt 54a that moves across the roller pair 52, and an upper portion of the conveying belt 54a. , A CVD device 73 installed on the downstream side in the transport direction, and a vapor deposition device 58 installed on the downstream side in the transport direction of the CVD device 73 and below the transport belt 54a. . The sputtering apparatus 71 attaches a catalyst 74 such as Fe for synthesizing filamentary carbon to a conveyor belt 54 as a support. It is more preferable that a catalyst carrier such as Al ₂ O ₃ is attached to the transport belt and then a catalyst 74 such as Fe is attached. The CVD apparatus 73 supplies a synthesis gas such as acetylene to the catalyst in order to synthesize and grow filamentous carbon on the catalyst 74. As the CVD apparatus 73, a CVD apparatus provided with a nozzle having a shower head structure is suitable. Note that the transport belt 54a in this example does not need to have a filter function, unlike the transport belt 54 used in the apparatus shown in FIG.

A continuous manufacturing process using this apparatus 170 will be described. When the driving roller 52a rotates in the direction of the arrow and the conveying belt 54 starts to move, the catalyst 74 is continuously attached from the sputtering device 71 onto the conveying belt 54a. Next, when a filamentous carbon synthesis gas is blown onto the attached catalyst 74 by the CVD device 73, the filamentous carbon is synthesized and a filamentous carbon aggregate 75 arranged in the vertical direction is formed. When the aggregate 75 is conveyed to a position facing the downstream vapor deposition device 58 by the conveyance belt 54 a, the deposition source metal 55 heated and melted by the vapor deposition device 58 adheres to the aggregate 75. In this way, a composite film 79 in which the metal 55 is adhered to one surface of the filamentous carbon aggregate is obtained. Since the composite film 79 is a continuous film, when the front end in the transport direction of the composite film 59 is wound up by the driven roller 52b, a tensile force in the tangential direction (horizontal direction) of the driven roller at the front end is sequentially applied. Then, a long and self-supporting composite film 79 (composite continuous film) is obtained by separating from the transport belt 54a.

Furthermore, the conveyance belt 54 a can also serve as the driving roller 52. That is, a cylinder is used instead of the conveyor belt, and while rotating the cylinder, the catalyst is attached to the surface of the cylinder, the filamentous carbon is synthesized, the metal is vapor-deposited, and continuously peeled and recovered. The single cylinder serves as both the conveying belt 54a and the driving

rollers

52a and 52b. Further, a mechanism such as a peeling roller for separating (separating) from the conveying belt 54a by applying a tensile force in the tangential direction (horizontal direction) of the driven roller 52b at the front end of the composite film 79 may be provided.

[Power storage device]
The

composite membranes

100, 100a, 100b and the functional

composite membranes

300, 400, 300a, 400a of the above-described embodiments and modifications are suitable as electrodes in an electrochemical storage device such as a secondary battery typified by a lithium ion battery. Can be used. Hereinafter, a lithium ion battery having the functional composite film 300 of the above embodiment as an electrode will be described as an example.

In a lithium ion battery, an electrode group obtained by laminating or laminating and winding a separator, a negative electrode, a separator, and a positive electrode is housed in a battery case such as a battery can, and then an electrolyte is injected into the battery case. Can be manufactured.

As the positive electrode, the composite film 300 having the second layer 80 made of aluminum can be used. In this case, the first layer 40 made of filamentous carbon 42, the second layer 80 made of aluminum, and the coexisting layer 60 of filamentous carbon 42 and aluminum (that is, the filamentous carbon film 20 and the metal layer 10) are current collectors. Work as.

As the negative electrode, the composite film 300 having the second layer 80 made of copper or nickel can be used. In this case, the first layer 40 made of filamentous carbon 42, the second layer 80 made of copper or nickel, and the coexisting layer 60 of the filamentous carbon 42 and copper or nickel (that is, the filamentous carbon film 20 and the metal layer 10). Works as a current collector.

It is more preferable to use two electrodes formed as described above and overlap the metal layers 10 so as to face each other because the capacity of the lithium ion battery can be increased. Furthermore, when two electrodes are overlapped, it is more preferable to apply a binder on the surface of at least one metal layer 10 and then bond them together to improve the strength of the electrodes. In addition, since the binder is sandwiched on both sides by the metal layer, the binder is not easily deteriorated and does not inhibit the in-plane conductivity of the metal layer.

Examples of the shape of the electrode group include a shape in which the cross section when the electrode group is cut in a direction perpendicular to the winding axis is a circle, an ellipse, a rectangle, a rectangle with rounded corners, or the like. Can do. In addition, examples of the shape of the battery case include a paper shape, a coin shape, a cylindrical shape, and a square shape.

The separator may be of any type, and may be, for example, a film having a form of a porous film made of a material such as a polyolefin resin such as polyethylene or polypropylene, or a fluororesin, a nonwoven fabric, or a woven fabric.

Any electrolytic solution may be used, and commercially available one may be used. The electrolyte usually contains an electrolyte and an organic solvent. For example, an electrolyte made of a lithium salt such as lithium hexafluorophosphate (LiPF ₆ ) is converted into propylene carbonate (PC), ethylene carbonate (EC), dimethyl carbonate (DMC), It is obtained by dissolving in an organic solvent such as ethyl methyl carbonate (EMC).

As described above, the composite film 300 used as the electrode of the lithium ion battery of the present embodiment is that the active material 34 is difficult to peel from the first layer 40 even if the volume of the active material 34 changes greatly during charging and discharging. There is an advantage that the electric resistance between the active material 34 and the metal is small. Therefore, the lithium ion battery of this embodiment using the composite film 300 as an electrode has a long life and a high capacity.

In this embodiment, the composite film 300 of the second embodiment is used as an electrode. However, the electrode of the lithium ion battery uses the

composite film

100, 100a, 100b or the functional composite film 300a of the above-described embodiment and the modified embodiment. It can also be manufactured. The lithium ion battery produced thereby also has a high capacity and a long life.

Note that the composite film and the functional composite film according to the present invention are not limited to the electrode of an electricity storage device such as a lithium ion battery, but can also be applied as an electrode of an electricity storage device in various forms, depending on the combination of materials. It is applicable as both a positive electrode and a negative electrode. For example, an electrode active material such as activated carbon is attached on the layer made of filamentous carbon of the composite film, and can be applied as an electrode of an electric double layer capacitor (whether positive electrode or negative electrode). Alternatively, an electrode active material such as graphite is attached on the layer made of filamentous carbon, and can be applied as an electrode (a positive electrode or a negative electrode) of a lithium ion capacitor. In this application, the “storage device” means a device that can be repeatedly charged and discharged, and includes a secondary battery such as a lithium ion battery, a capacitor such as an electric double layer capacitor and a lithium ion capacitor.

Hereinafter, the composite membrane of the present invention and the production method thereof will be described in detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.

Example 1
4 mg of CNT (eDIPS made by Meijo Nanocarbon) is added to 40 mL of 0.5 wt% SDBS aqueous solution as filamentous carbon, and dispersed for 2 hours at an output of 30 W and a frequency of 45 kHz using an ultrasonic dispersion device (CLEAR VS-50R made by VELVO). To obtain a CNT dispersion. 10 mL of the CNT dispersion was filtered under reduced pressure using a membrane filter having a pore size of 0.1 μm (VCWP manufactured by Millipore) to produce a CNT film having a thickness of about 20 μm on the membrane filter.

The membrane filter with the CNT film formed was impregnated with pure water in a beaker to separate the CNT film and the membrane filter. In order to rinse the SDBS adhering to the CNT film, pure water in the beaker was heated to 100 ° C. with a heater. Next, the CNT film floating on the water surface was scraped off with a Si substrate with a thermal oxide film (hereinafter simply referred to as “substrate”). By these operations, the CNT film was supported on the substrate.

Next, Cu was deposited on the CNT film on the substrate as follows. An 80 mm × 6 mm tungsten boat was installed in the vapor deposition chamber, and a Cu piece (Nilaco Corp. Cu111487, purity 99.9%) was placed thereon, which was used as a vapor deposition source. Since the Cu piece is melted by heating and spreads on the boat, the size of the vapor deposition source is about 30 mm × 6 mm. The substrate was placed so that the CNT film faced the tungsten boat in parallel. At this time, the distance between the evaporation source and the CNT film was set to 35 mm. The substrate was placed on a quartz glass plate stage having an 18 mm square opening at the center with the CNT film surface facing down, and heated to about 400 ° C. with a PG / PBN heater from the top. The inside of the chamber was depressurized to a level of 10 ⁻⁴ Pa with a turbo pump. By energizing the tungsten boat at 588 W and heating the tungsten boat to about 1790 ° C., the Cu piece was melted and Cu was deposited for 80 seconds. The substrate temperature during vapor deposition was 400 ° C. By the above operation, a Cu film was formed on the CNT film on the substrate. Let Cu film thickness calculated | required by remove | dividing the value of the weight change of the sample before and behind vapor deposition by the board | substrate area and the density of copper be a conversion film thickness. In this example, an experiment was performed so that the equivalent film thickness was about 10 μm.

As described above, a composite film (CNT-Cu composite film) in which Cu was deposited on the CNT film on the substrate was obtained. Thereafter, the CNT-Cu composite film was peeled from the substrate with tweezers to obtain a self-supporting CNT-Cu composite film.

The obtained CNT-Cu composite film was torn into two and observed with a scanning electron microscope (SEM, Hitachi S-4800). At low magnification, the CNT film appeared to peel off from the Cu film near the tear. However, when observed at a higher magnification, countless fluffy CNTs adhered to the Cu film (see FIG. 7B). From this, it was found that CNT and Cu were mechanically well connected.

Comparative Example 1
CNT was added to 4 mg and 10 mL of N-methylpyrrolidone, and after dispersion treatment for 1 hour at an output of 40 W and a frequency of 45 kHz using an ultrasonic dispersion device (CLEAR VS-50R manufactured by VELVO), 0.4 mg of PVDF was added. A paste was prepared by stirring. 1 mL of this paste was applied onto a 10 μm thick electrodeposited copper foil (Niraco Cu113173, purity 99.9%) and dried at 200 ° C. and 0.01 Torr for 1 hour. The resulting composite film was mechanically peeled from the substrate and torn into two. SEM observation of the vicinity of the fissure revealed that the CNT film was peeled off near the fissure at low magnification (see FIG. 7C). When observed at a medium magnification, there were a portion where CNTs bound in a ribbon shape adhered to Cu and a portion where CNTs were not seen (see FIG. 7D). When observed at a higher magnification, it was found that there was a part where CNT was completely removed from Cu (see FIG. 7 (e)). From this, it was found that although CNT and Cu can be bonded with a binder, the strength is weak, so that CNT may be completely peeled off from Cu, and the binder binds CNTs in a bundle shape to reduce the surface area.

Example 2
A CNT film supported on a substrate was produced in the same manner as in Example 1 except that the filtration amount of the CNT dispersion was 0.3 mL. When the planar structure of the obtained CNT film was observed with an SEM, a network structure in which CNTs were intertwined was formed (see FIG. 8A).

Next, a Cu film was formed on the CNT film on the substrate in the same manner as in Example 1 except that the tungsten boat was heated to about 1640 ° C. at 462 W during Cu deposition and the deposition time was 1 second. The Cu film thickness (converted film thickness) obtained in the same manner as in Example 1 was 0.033 μm.

FIG. 8B shows a planar SEM image of the CNT-Cu composite film obtained as described above. Note that the planar SEM image in FIG. 8B has a higher magnification than the planar SEM image in FIG. 8A. From the planar SEM image of FIG. 8B, it was observed that particulate Cu was embedded in the CNT network structure. From this, it was found that a coexistence layer in which CNT and Cu coexist was formed.

Example 3
A CNT—Cu composite film was produced in the same manner as in Example 2 except that the tungsten boat was heated to about 1780 ° C. at 576 W during Cu deposition and the deposition time was 3 seconds. The converted film thickness of the Cu film formed by vapor deposition was 0.14 μm. A planar SEM image of the CNT—Cu composite film produced in this example is shown in FIG. 8C. Note that the planar SEM image in FIG. 8C has a higher magnification than the planar SEM image in FIG. 8A. From the planar SEM image of FIG. 8C, it was observed that the particulate Cu was embedded in the CNT network structure. From this, it was found that a coexistence layer in which CNT and Cu coexist was formed.

Example 4
A CNT—Cu composite film was prepared in the same manner as in Example 2 except that the tungsten boat was heated to about 1750 ° C. at 550 W during Cu deposition and the deposition time was 4 seconds. The converted film thickness of the Cu film formed by vapor deposition was 0.38 μm. FIG. 8D shows a planar SEM image of the CNT—Cu composite film produced in this example. From the planar SEM image, Cu was close to a continuous film, and a small amount of CNT was seen on Cu, indicating that Cu was deposited to the vicinity of the outermost surface of the network structure.

Example 5
A CNT—Cu composite film was prepared in the same manner as in Example 2 except that the tungsten boat was heated to about 1720 ° C. at 528 W during Cu deposition and the deposition time was 8 seconds. The converted film thickness of the Cu film formed by vapor deposition was 1.36 μm. FIG. 8E shows a planar SEM image of the CNT—Cu composite film produced in this example. It was found that a continuous film of Cu was formed on the CNT film.

Example 6
A CNT—Cu composite film was prepared in the same manner as in Example 2 except that the tungsten boat was heated to about 1720 ° C. at 525 W during Cu deposition and the deposition time was 24 seconds. The converted film thickness of the Cu film formed by vapor deposition was 4.97 μm. A planar SEM image of the CNT-Cu composite film produced in this example is shown in FIG. 8F. It was found that a continuous film of Cu was formed on the CNT film.

Example 7
A CNT—Cu composite film was prepared in the same manner as in Example 2 except that the tungsten boat was heated to about 1810 ° C. at 600 W during Cu deposition and the deposition time was 60 seconds. The converted film thickness of the Cu film formed by vapor deposition was 6.08 μm. A planar SEM image of the CNT-Cu composite film produced in this example is shown in FIG. 8G. It was found that a continuous film of Cu was formed on the CNT film.

Example 8
A CNT—Cu composite film was produced in the same manner as in Example 2 except that the tungsten boat was heated to about 1740 ° C. at 538 W during the deposition of Cu and the deposition time was set to 80 seconds. The converted film thickness of the Cu film formed by vapor deposition was 17.97 μm. A planar SEM image of the CNT-Cu composite film produced in this example is shown in FIG. 8H. It was found that a continuous film of Cu was formed on the CNT film.

From the planar SEM observation results of Examples 2 to 8, when Cu was formed on the CNT film, Cu entered the CNT film during the initial period when the amount of deposited Cu was small, and a coexistence layer was formed. After Cu was deposited to the surface of the CNT film, it was found that a continuous film of Cu was formed on the coexisting layer of CNT and Cu.

Example 9
A CNT-Cu composite film was obtained in the same manner as in Example 1 except that the filtration amount of the CNT dispersion was 3 mL, and the tungsten boat was heated to about 1720 ° C. at 528 W during Cu deposition, and the deposition time was 80 seconds. . Next, the CNT-Cu composite film was mechanically peeled from the substrate, and Si was deposited on the CNT film of the CNT-Cu composite film as follows. A carbon boat having eight evaporation sections of 2 mm × 4 mm is installed in the vapor deposition chamber, and an organic substance and oxide adhering to the surface are removed on this using a 5 to 10% HF solution (purity) 99.9999% or more) was placed and used as a deposition source. Since the Si piece is melted by heating and spreads on the boat, the size of the deposition source is about 50 mm ² . The CNT-Cu composite film was disposed so that the CNT film faced the tungsten boat in parallel. At this time, the distance between the deposition source and the CNT film was 45 mm. The CNT-Cu composite film was fixed in close contact with the surface of a copper block whose temperature can be controlled with a ceramic heater and an air-cooled tube. The pressure in the chamber was reduced to 1 Pa with a rotary pump, and then argon gas was introduced at 10 sccm, and the pressure in the chamber was set to 13.3 Pa (0.1 Torr). After the pressure became constant, the CNT-Cu composite film was heated to 300 ° C. using a temperature control mechanism. By energizing the carbon boat and heating the carbon boat at 1300 W to 2000 ° C. or higher, the Si piece was melted and Si was deposited for 20 seconds. The temperature of the CNT—Cu composite film during vapor deposition was 300 ° C.

As described above, a composite film (Si-CNT-Cu composite film) in which Cu was deposited on one surface of the CNT film and Si was deposited on the other surface was obtained.

When the cross-sectional structure of the obtained Si—CNT—Cu composite film was observed with an SEM, it was confirmed that Si was formed so as to cover the fluffy CNT (see FIG. 9).

Comparative Example 2
On the electrodeposited copper foil having a thickness of 10 μm (Niraco Cu113173, purity 99.9%), Si was deposited under the same conditions as in Example 9 to prepare a Cu—Si composite film.

<Charge / discharge characteristics evaluation>
On both ends of the 2032 type coin cell, the Si—CNT—Cu composite film of Example 9 was used as a negative electrode, and Li metal was used as a positive electrode. A separator (polypropylene membrane) is inserted between the electrodes, and 1 wt% of vinylene carbonate and 1 mol / L of LiClO ₄ are dissolved in a mixed solvent of ethylene carbonate (EC) and diethyl carbonate (DEC) (volume ratio 1: 1). After pouring the electrolyte solution made, it was pressed and sealed at 3 MPa to produce a coin cell.

The manufactured coin cell was repeatedly charged and discharged at a scanning potential of 0.005 to 1.2 V (vs. Li / Li +) and a discharge rate of 0.1 C to 10 C (1 C = 4 A / g _Si ) to examine changes in the discharge capacity. It was.

Similarly, a coin cell was prepared using the composite film of Comparative Example 2 as a negative electrode, a charge / discharge cycle test was performed, and changes in the discharge capacity were examined.

The result of the charge / discharge cycle test of the composite film of Example 9 and Comparative Example 2 is shown in FIG. When the Si—CNT—Cu composite film of Example 9 was used as the negative electrode, the initial discharge capacity was 3360 mAh / g _Si and the discharge capacity after 70 cycles was 2140 mAh / g _Si , whereas Comparative Example 2 When the Cu—Si composite film is used as the negative electrode, the initial discharge capacity is as low as 2000 mAh / g _Si , the discharge capacity rapidly deteriorates in 20-40 cycles, and the discharge capacity after 70 cycles is 520 mAh / g _Si. It became. From this result, in the Si—CNT—Cu composite film of Example 9, since Si adheres so as to cover the raised CNTs, the contact area between Si and CNT is large, and thus Si is composite film. It is thought that peeling from the surface is suppressed.

Example 10
CNT dispersion was adjusted by adding 2.5 mg of CNT to 20 mL of isopropanol and dispersing with ultrasonic waves, except that 20 mL of the dispersion was filtered using PTFE manufactured by Millipore with a pore size of 0.5 μm as a membrane filter. In the same manner as in Example 1, a CNT film supported on a substrate was produced. Next, a Cu film was formed on the CNT film on the substrate in the same manner as in Example 1 except that the tungsten boat was heated to about 1610 ° C. at 440 W during the deposition of Cu and the deposition time was set to 3 seconds. The obtained CNT—Cu composite film had a CNT film thickness of 37 μm and a Cu film thickness of 0.031 μm.

The obtained CNT-Cu composite film was peeled from the substrate with tweezers to obtain a self-supporting CNT-Cu composite film. Peeling of the CNT-Cu composite film from the substrate could be easily performed using tweezers (see FIG. 11A). FIGS. 11B to 11D show digital camera photographs of the CNT-Cu composite film after peeling from the substrate. In the CNT-Cu composite film produced in this example, Cu itself is 0.031 μm, which is only one hundredth of the thickness of a general copper foil, and is not self-supporting, but the CNT film is self-supporting. As a composite membrane, it was possible to make it a self-supporting membrane. Although Cu foil is generally used for the negative electrode of a lithium ion battery, it is problematic that the Cu foil is heavy. The weight per unit area was reduced to about 1/10 for the CNT film of this example and about 1/500 for the Cu vapor deposition film, compared to the commercially available Cu foil.

Example 11
A CNT—Cu composite film was prepared in the same manner as in Example 2 except that the tungsten boat was heated to about 1720 ° C. at 525 W during Cu deposition and the deposition time was 24 seconds. The thickness of the CNT film was about 1.5 μm. The converted film thickness of the Cu film formed by vapor deposition was 4.97 μm.

The obtained CNT-Cu composite film was peeled from the substrate with tweezers to obtain a self-supporting CNT-Cu composite film. Digital camera photographs of the obtained CNT-Cu composite film are shown in FIGS. 12 (a) to 12 (c). Even when the CNT film was as thin as about 1.5 μm, since the Cu film itself was self-supporting, a CNT-Cu composite film could be obtained as a self-supporting film. Although Cu foil is generally used for the negative electrode of a lithium ion battery, it is problematic that the Cu foil is heavy. The weight per unit area was reduced to about 1/50 for the CNT film of this example and about 1/3 for the Cu vapor deposition film, compared to the commercially available Cu foil.

Example 12
Al was deposited with an average film thickness of 15 nm by RF magnetron sputtering on a Si substrate with a thermal oxide film (hereinafter simply referred to as “substrate”), and Al was oxidized by exposure to the atmosphere to form an Al ₂ O ₃ film. Furthermore, Fe was laminated with an average film thickness of 1 nm by RF magnetron sputtering to prepare a substrate with a catalyst. After the substrate was placed in a quartz glass circular tubular reactor _and reduced for 10 minutes at 800 ° C. in flowing under a mixed gas of _{10.6vol% H 2 / 53ppmvH 2 O} / Ar, 0.15vol% C 2 a mixed gas of _{_{H 2/10% H 2 /}} 50ppmvH 2 O / Ar circulated 5 minutes to obtain a single-layer CNT vertical alignment film with a thickness of 10 [mu] m.

Then, using a 100 mm × 15 mm tungsten boat, using a Cu piece (Nilaco Cu113173, purity 99.9%) as a deposition source, heating the tungsten boat to about 1710 ° C. at 500 W, and setting the deposition time to 60 seconds In the same manner as Cu deposition in Example 1, Cu was deposited on the CNT film. Thereby, a Cu film was formed on the single-walled CNT vertical alignment film on the substrate. In addition, since the Cu piece was melted by heating and spread on the boat, the size of the vapor deposition source was about 40 mm × 10 mm. The equivalent film thickness of the Cu film formed by vapor deposition was 11 μm.

Thus, a CNT-Cu composite film was obtained. Thereafter, the CNT-Cu composite film was peeled from the substrate with tweezers to obtain a self-supporting CNT-Cu composite film. A cross-sectional SEM image of the obtained CNT-Cu composite film is shown in FIG. 13A. It was found that a continuous film of Cu was formed on the vertically aligned CNT film.

Furthermore, the CNT vertical alignment film was shrunk by surface tension by exposing it to ethanol vapor with the CNT side facing down, condensing ethanol on the CNT, and then drying. A digital camera photograph of the CNT-Cu composite film in which the CNT vertical alignment film is contracted is shown in FIGS. 13B and 13C, a cross-sectional SEM image is shown in FIG. 13D, and a planar SEM image is shown in FIG. 13E. FIG. 13B shows a CNT-Cu composite film viewed from the Cu film side, and FIG. 13C shows a CNT-Cu composite film viewed from the CNT film side. A network structure was obtained in which the CNT walls were standing upright at intervals of 10 to 20 μm on the Cu thin film. The interval between CNT walls can be changed over a wide range from 6 to 42 μm by performing the same operation except that the height of the CNT vertical alignment film is changed to 10 to 120 μm by changing the CNT synthesis time. It was.

Example 13
A Cu plate (Niraco Cu113321, purity 99.96%) (hereinafter simply referred to as “Cu substrate”) was prepared. An SEM image of the surface of the Cu substrate is shown in FIG. 14A. The Cu substrate had a streak texture (unevenness) extending in one direction on the surface. The average pitch of the irregularities was about 9 μm. A Cu substrate with a catalyst was prepared by depositing Ta with an average film thickness of 30 nm, Al ₂ O ₃ with an average film thickness of 50 nm, and Fe with an average film thickness of 1 nm on a Cu substrate by RF magnetron sputtering. After the substrate was placed in a quartz glass circular tubular reactor _and reduced for 10 minutes at 800 ° C. in flowing under a mixed gas of _{10.6vol% H 2 / 53ppmvH 2 O} / Ar, 0.15vol% C 2 a mixed gas of _{_{H 2/10% H 2 /}} 50ppmvH 2 O / Ar circulated for 10 minutes to obtain a single-layer CNT vertical alignment film having a thickness of 8.5 .mu.m.

Next, Cu was deposited on the CNT film in the same manner as the Cu deposition in Example 12. Thereby, a Cu film was formed on the single-walled CNT vertical alignment film on the Cu substrate. The converted film thickness of the Cu film formed by vapor deposition was 11 μm.

Thus, a CNT-Cu composite film was obtained. Thereafter, the CNT-Cu composite film was peeled from the Cu substrate with tweezers to obtain a self-supporting CNT-Cu composite film. A digital camera photograph of the obtained CNT-Cu composite film is shown in FIG. 14B, and a cross-sectional SEM image is shown in FIG. 14C. The left side of FIG. 14B shows the Cu substrate after the CNT-Cu composite film is peeled off, and the right side shows the CNT-Cu composite film as viewed from the CNT film side. From these figures, it was found that a continuous film of Cu was formed on the vertically aligned CNT film.

Furthermore, the CNT vertical alignment film was shrunk by surface tension by exposing it to ethanol vapor with the CNT side facing down, condensing ethanol on the CNT, and then drying. A digital camera photograph of the CNT-Cu composite film obtained by shrinking the CNT vertical alignment film is shown in FIG. 14D, an oblique SEM image is shown in FIG. 14E, and a planar SEM image is shown in FIG. 14F. A streak structure in which the CNT walls were regularly arranged in one direction on the Cu thin film was obtained. The wall height was 5-7 μm. The interval between CNT walls can be changed over a wide range from 10 to 64 μm by performing the same operation except that the height of the CNT vertical alignment film is changed to 9 to 64 μm by changing the CNT synthesis time. It was.

Example 14
Add 2 mg of several CNTs produced by the fluidized bed method described in Carbon 80, 339-350 (2014) as filamentous carbon to 30 mL of ethanol, and disperse for 40 minutes at an output of 90 W and a frequency of 45 kHz using an ultrasonic dispersing device. To obtain a CNT dispersion. 30 mL of the CNT dispersion liquid was filtered under reduced pressure using a membrane filter having a pore size of 0.1 μm to produce a CNT film having a thickness of about 30 μm on the membrane filter.

The CNT film and the membrane filter were separated from the membrane filter on which the CNT film was formed using tweezers to obtain a CNT self-supporting film. The CNT film was supported on the substrate by placing the CNT film on the substrate while being wetted with ethanol and drying. The sheet resistance of the CNT film was 5Ω / sq.

Next, an Al piece (Nilaco Al011487, purity 99.99%) was used as the deposition source, the substrate heating temperature was about 150 ° C., the tungsten boat was heated to about 1700 ° C. at 550 W, and the deposition time was 10 seconds. Except for the above, an Al film was deposited on the CNT film on the substrate in the same manner as Cu deposition in Example 12. The converted film thickness of the Al film formed by vapor deposition was 6.3 μm.

As described above, a composite film (CNT-Al composite film) in which Al was deposited on the CNT film on the substrate was obtained. Thereafter, the CNT-Al composite film was peeled from the substrate with tweezers to obtain a self-supporting CNT-Al composite film. Part of the CNT film supported on the substrate by the transfer was transferred to the Al side. The remaining CNT film was peeled off from the substrate because of its low adhesive strength with the substrate. A digital camera photograph of the obtained CNT-Al composite film is shown in FIGS. 15A and 15B, a planar SEM image is shown in FIG. 15C, and a cross-sectional SEM image is shown in FIG. 15D. The left side of FIG. 15A shows the CNT-Al composite film seen from the Al film side, and the right side shows the remaining CNT film removed from the substrate after the CNT-Al composite film is peeled off. FIG. 15B shows the CNT-Al composite film viewed from the CNT film side. As shown in these figures, a composite film was obtained in which both were composed of CNT and Al but were well connected. The sheet resistance of the CNT-Al composite film was 0.011 Ω / sq, which was lower than that of the CNT film alone. Further, as can be seen from FIG. 15A, the remaining CNTs after peeling the CNT-Al composite film maintained the film structure. Another CNT-Al composite film can be newly obtained by holding the CNT film on the substrate again and forming a metal such as Al and peeling it off. That is, a CNT-Al composite film can be repeatedly obtained from the CNT film supported on the substrate.

Example 15
A CNT dispersion was obtained in the same manner as in Example 14 except that 0.5 wt% SDBS aqueous solution was used instead of ethanol. The CNT dispersion was centrifuged at 3000 rpm for 60 minutes, and the supernatant was collected. 20 mL of pure water was added to 0.5 mL of the supernatant and filtered under reduced pressure using a membrane filter having a pore size of 0.1 μm to produce a CNT film having a thickness of about 0.1 to 0.15 μm on the membrane filter.

The membrane filter on which the CNT film was formed was impregnated with pure water in a beaker to separate the CNT film and the membrane filter. Next, the CNT film floating on the water surface was scraped off with a substrate. By these operations, the CNT film was supported on the substrate. Further, a substrate with a CNT film was placed in a quartz glass tube, and kept at 800 ° C. for 20 minutes under a flow of 4 vol% H ₂ diluted with Ar to decompose and remove SDBS adhering to the CNT film.

Next, the substrate was heated to about 350 ° C. with a PG / PBN heater, the tungsten boat was heated to about 1700 ° C. with 500 W, and the deposition time was 30 seconds. An Al film was deposited on the CNT film. The converted film thickness of the Al film formed by vapor deposition was 5.2 μm.

Thus, a CNT-Al composite film was obtained. Thereafter, the CNT-Al composite film was peeled from the substrate with tweezers to obtain a self-supporting CNT-Al composite film. A digital camera photograph of the obtained CNT-Al composite film is shown in FIGS. 16A and 16B, a planar SEM image is shown in FIG. 16C, and a cross-sectional SEM image is shown in FIG. 16D. The left side of FIG. 16A shows the substrate after the CNT-Al composite film is peeled off, and the right side shows the CNT-Al composite film as viewed from the Al film side. FIG. 16B shows a CNT-Al composite film viewed from the CNT film side. As shown in these figures, a composite film was obtained in which both were composed of CNT and Al but were well connected. A single CNT film having a thickness of 0.1 to 0.15 μm is too thin to be self-supporting, but it can be made self-supporting by being combined with Al, and a low resistance of 0.011 Ω / sq has been realized.

Example 16
Filamentous carbon dispersion was filtered under reduced pressure in the same manner as in Example 14 except that 0.1 mg of several layers of CNT and 0.9 mg of vapor grown carbon fiber (CF) (VGCF manufactured by Showa Denko KK) were used as the filamentous carbon. On the membrane filter, a composite film (CF + CNT composite film) made of a mixture of CF and CNT having a thickness of about 13 μm was produced.

The CF + CNT composite membrane was separated from the membrane filter using tweezers and supported on the substrate.

Next, an Al film was deposited on the CF + CNT composite film on the substrate in the same manner as the Al deposition in Example 15. The converted film thickness of the Al film formed by vapor deposition was 5.8 μm.

As described above, a composite film (CF + CNT-Al composite film) in which Al was deposited on the CF + CNT composite film on the substrate was obtained. Thereafter, the CF + CNT-Al composite film was peeled from the substrate with tweezers to obtain a self-supporting CF + CNT-Al composite film. A digital camera photograph of the obtained CF + CNT-Al composite film is shown in FIGS. 17A and 17B, a planar SEM image is shown in FIG. 17C, and a cross-sectional SEM image is shown in FIG. 17D. The left side of FIG. 17A shows the substrate after the CF + CNT-Al composite film is peeled off, and the right side shows the CF + CNT-Al composite film as viewed from the Al film side. FIG. 17B shows a CF + CNT-Al composite film viewed from the CF + CNT composite film side. As shown in these figures, a composite film composed of only CF, CNT, and Al and well connected to each other was obtained. CF alone does not stand by itself because the adhesion force between CFs is too low, but it can be made self-supporting by combining with CNT and Al, and further a low resistance of 0.010 Ω / sq has been realized.

Example 17
CNT was synthesized in the same manner as in Example 12, and a single-walled CNT vertical alignment film having a thickness of 6 μm was formed on the substrate. A cross-sectional SEM image of the single-walled CNT vertical alignment film is shown in FIG. 18A.

Next, an Al film was deposited on the CNT film on the substrate in the same manner as in Example 15 except that the tungsten boat was heated to about 1700 ° C. at 520 W. The converted film thickness of the Al film formed by vapor deposition was 5.0 μm.

Thus, a CNT-Al composite film was obtained. Thereafter, the CNT-Al composite film was peeled from the substrate with tweezers to obtain a self-supporting CNT-Al composite film. A digital camera photograph of the obtained CNT-Al composite film is shown in FIGS. 18B and 18C, and a cross-sectional SEM image is shown in FIG. 18D. The substrate after the CNT-Al composite film is peeled off is shown on the left side of FIG. 18B, and the CNT-Al composite film viewed from the CNT film side is shown on the right side. FIG. 18C shows a CNT-Al composite film viewed from the Al film side. As shown in these figures, a composite film was obtained in which both were composed of CNT and Al but were well connected. A single CNT vertical alignment film having a thickness of 6 μm is not self-supporting because of its vertical alignment and thinness, but it can be made self-supporting by compounding with Al, and a low resistance of 0.013 Ω / sq has been realized.

Example 18
A CNT dispersion was obtained in the same manner as in Example 14 except that 0.5 mg of several-layer CNT was used as the filamentous carbon. Moreover, activated carbon particles (AC) (YP-80F manufactured by Kuraray Chemical Co., Ltd.) (4.5 mg) was added to ethanol (30 mL), and the dispersion liquid was subjected to dispersion treatment at an output of 90 W and a frequency of 45 kHz for 40 minutes using an ultrasonic dispersion device. Obtained. By mixing these two dispersions, 60 mL of a dispersion (AC + CNT mixed dispersion) containing AC and CNT at a mass ratio of 9: 1 was obtained. The AC + CNT mixed dispersion was filtered under reduced pressure using a membrane filter (JMWP manufactured by Millipore) having a pore size of 5 μm, and a composite film (AC + CNT composite film) made of a mixture of AC and CNT having a thickness of about 70 μm was formed on the membrane filter.

The AC + CNT composite membrane was separated from the membrane filter using tweezers, dried at 150 ° C. for 2 hours, and then supported on the substrate.

Then, an Al piece (Niraco Al011487, purity 99.99%) was used as a deposition source, the substrate heating temperature was about 150 ° C., the pressure in the chamber was 1 × 10 ⁻³ Pa, and the tungsten boat was about 110 W. Al was vapor-deposited on the AC + CNT composite film in the same manner as the Cu vapor deposition in Example 1 except that the temperature was raised to 1700 ° C. and the vapor deposition time was 10 seconds. In this example, the amount of Al source material during vapor deposition was changed to four types of 10, 20, 30, 40 mg, so that the equivalent film thickness was 0.3, 0.5, 0.8, 1.7 μm and 4 A street Al film was obtained.

Thus, a composite film (AC + CNT-Al composite film) in which Al was deposited on the AC + CNT composite film on the substrate was obtained. Thereafter, the AC + CNT-Al composite film was peeled from the substrate with tweezers to obtain a self-supporting CF + CNT-Al composite film. A digital camera photograph of the obtained AC + CNT-Al composite film is shown in FIG. 19A, a planar SEM image is shown in FIG. 19B, and a cross-sectional SEM image is shown in FIG. 19C. FIG. 19A shows an AC + CNT-Al composite film viewed from the Al film side. As shown in these figures, a composite film composed of only AC, CNT, and Al and well connected to each other was obtained. AC alone does not stand by itself because the adhesion between ACs is too low, but it can be made independent by combining CNT and Al. The sheet resistance of the AC + CNT-Al composite film is 0.24, 0.14, 0.073, 0.003 when the equivalent film thickness of the Al film is 0.3, 0.5, 0.8, and 1.7 μm, respectively. It was 036Ω / sq (see FIG. 19D).

Furthermore, the AC + CNT-Al composite film and the AC + CNT-Al composite film having an equivalent film thickness of 0.3, 0.5, 0.8, 1.7 μm are used as the working electrode, the AC-CNT film as the counter electrode, and Ag / AgCl. Using the electrode as a reference electrode, cyclic voltammetry was performed in a 1M Na ₂ SO ₄ aqueous solution. The sweep potential range was −1.0 to 0.6 V, and the sweep rate was 5 to 1000 mV / s. FIG. 19E shows the sweep rate dependence of the specific capacity. The AC + CNT film showed a high capacity of 108 F / g (based on the total electrode mass AC + CNT) at a low scanning speed of 5 mV / s, but the capacity greatly decreased to 15 F / g at a high scanning speed of 200 mV / s. On the other hand, the AC + CNT-Al composite film on which Al with a converted film thickness of 0.8 μm is deposited exhibits a high capacity of 116 F / g (total electrode mass AC + CNT + Al standard) at a low scanning speed of 5 mV / s, and a high scanning speed of 200 mV / s. Even in s, the high capacity of 86 F / g was maintained. By combining with Al, the rate characteristics of the AC + CNT composite film were dramatically improved.

As mentioned above, although this invention was demonstrated by embodiment, the composite film of this invention and its manufacturing method are not limited to the said embodiment, It can change suitably within the range of the technical idea described in the claim. it can. For example, the apparatuses for continuously producing the composite membranes of the first embodiment and the third embodiment have been described by taking the apparatus shown in FIGS. 6A and 6B as an example. It is only a specific example, and various changes and improvements can be made. For example, in the apparatus shown in FIGS. 6A and 6B, the conveyance belt is circulated using a pair of rolls around which the conveyance belt is stretched as the conveyance apparatus. However, the conveyance belt is linear or curved or You may arrange | position so that a manufacturing site may be passed by the manufacturing line of arbitrary shapes. Moreover, a drum (single roll) can be used instead of using a conveyor belt or a roll pair as the conveyor. In this case, the surface of the drum can be a support on which an aggregate of filamentous carbon is formed, and a mechanism for forming an aggregate of filamentous carbon or a mechanism for depositing metal can be installed around the drum. it can. Furthermore, by installing a vapor deposition apparatus and a supply device for applying an active material on the downstream side in the transport direction of the apparatus shown in FIGS. 6A and 6B, the composite of the second embodiment and the fourth embodiment is provided. It can be retrofitted into a device that continuously produces membranes.

The composite film of the present invention has an advantage that it has low resistance and is difficult to peel from the current collector even if the volume of the active material changes. Therefore, by applying the composite film of the present invention to an electrode of a lithium ion battery, it is possible to increase the capacity and life of the lithium ion battery.

DESCRIPTION OF SYMBOLS 10 Metal layer, 20 Filament-like carbon film 34 Active material, 40 1st layer, 42 Filament-like carbon 44 Network structure, 46 Vertical alignment structure, 52

Roller pair

54, 54a Conveyor belt, 56 Feeder, 58 Evaporator 60 Coexistence layer , 63 Suction filter, 71 Sputter device 73 CVD device, 74 Catalyst, 80 Second layer, 100

Composite membrane

300, 400 Functional composite membrane, 150, 170 Composite membrane manufacturing device

Claims

A filamentous carbon layer composed of filamentous carbon;
It consists only of a metal layer composed of metal,
A self-supporting composite film, wherein a part or all of the metal layer overlaps with a part of the filamentous carbon layer and has a coexistence region where the filamentous carbon and the metal coexist.
The composite film according to claim 1, wherein a part of the metal layer overlaps a part of the filamentous carbon layer.
The filamentous carbon layer has a network structure;
3. The composite film according to claim 1, wherein in the coexistence region, the metal enters the mesh of the mesh structure.
The filamentous carbon layer has a vertical alignment structure in which the filamentous carbon is aligned in the thickness direction of the filamentous carbon layer,
3. The composite film according to claim 1, wherein in the coexistence region, the metal enters a gap between the filamentous carbons of the vertical alignment structure.
The composite film according to claim 4, wherein the filamentous carbon is bundled to form an upright wall in the thickness direction of the filamentous carbon layer.
It consists only of a metal layer composed of metal and an aggregate of filamentous carbon,
A part of the aggregate of filamentous carbon is included in the metal layer,
A self-supporting composite film, wherein the other part of the aggregate of filamentous carbon is exposed on the metal layer.
The composite film according to any one of claims 1 to 6, wherein the filamentous carbon includes carbon nanotubes.
The composite film according to any one of claims 1 to 7, wherein the metal is Cu, Al, or Ni.
A composite membrane according to any one of claims 1 to 8,
A functional composite film having an active material attached to the filamentous carbon.
Producing a filamentous carbon film composed of filamentous carbon;
Depositing a metal on the filamentary carbon film supported by a support;
Separating the filamentous carbon film and the metal composite film from the support.
The method for producing a composite film according to claim 10, wherein in the step of producing the filamentous carbon film, the filamentous carbon film having a network structure is produced.
11. The composite film according to claim 10, wherein the step of producing the filamentous carbon film includes forming the filamentous carbon so that the filamentous carbon is oriented in a thickness direction of the filamentous carbon film. Production method.
Further, after the step of separating the filamentous carbon film and the metal composite film from the support, the filamentous carbon film is contracted to reduce the thickness of the filamentous carbon layer comprising the bundle of filamentous carbon. The manufacturing method of the composite film of Claim 12 including the process of forming the wall upright in the direction.
The composite film according to any one of claims 10 to 13, further comprising a step of supporting the filamentous carbon film by the support before the step of depositing a metal on the filamentous carbon film. Production method.
While moving the support, the filamentous carbon film is formed on the support on the upstream side in the movement direction, and the metal is deposited on the filamentous carbon film on the support on the downstream side in the movement direction. The method for producing a composite membrane according to any one of claims 10 to 13.
The method of manufacturing a composite film according to any one of claims 10 to 15, further comprising a step of attaching an active material to a surface of the filamentous carbon film opposite to a surface on which the metal is deposited.
A composite film formed by the production method according to any one of claims 10 to 16.
An electrode having the composite film according to any one of claims 1 to 8 or 17.
An electrode having the functional composite film according to claim 9.
An electricity storage device comprising the electrode according to claim 18 or 19.
It consists only of a metal layer and an aggregate of filamentous carbon, a part of the aggregate of filamentous carbon is included in the metal layer, and the other part of the aggregate of filamentous carbon is on the metal layer. An apparatus for producing a self-supporting composite membrane exposed at
A moving mechanism for continuously moving the support;
An assembly forming portion that is provided on the upstream side in the moving direction and forms an assembly of the filamentous carbon on the support;
An apparatus for producing a composite film, comprising: a vapor deposition mechanism that is provided on the downstream side in the movement direction and deposits metal on the filamentary carbon aggregate.
The composite film manufacturing apparatus according to claim 21, wherein the moving mechanism includes a roll that rotates and moves the support.
By continuously operating the assembly forming part and the vapor deposition mechanism, a long composite film is formed on the support, and the long composite film is continuously peeled from the support. The composite film manufacturing apparatus according to claim 21 or 22, wherein the long composite film is obtained.