Metal substrates for growing carbon nanowalls and metal substrates with carbon nanowalls, and their manufacturing methods.

Abstract

This invention provides a metal substrate for growing carbon nanowalls, capable of forming carbon nanowall films at low temperatures above 0°C and below approximately 500°C, as well as a method for manufacturing the same. The negative current collector N1 is the metal substrate for growing carbon nanowalls. The negative current collector N1 has a first surface N1a. The negative current collector N1 has multiple protrusions PR1 on the first surface N1a. The area of ​​the projected region obtained by projecting the protrusions PR1 onto the first surface N1a is 10 nm. 2 ~10000nm 2 The density of protrusion PR1 is 1 per μm. 2 ~1000 / μm 2 .

Description

Technical Field

[0001] This invention relates to metal substrates for growing carbon nanowalls and metal substrates with carbon nanowalls used in energy storage devices, as well as methods for manufacturing them. Background Technology

[0002] Examples of rechargeable and dischargeable energy storage devices include secondary batteries and double-layer capacitors. Additionally, examples of energy storage devices utilizing lithium ions include lithium-ion secondary batteries, lithium-ion primary batteries, and lithium-ion capacitors.

[0003] For example, Patent Document 1 discloses a lithium-ion secondary battery having a positive electrode, a negative electrode, a separator, and a non-aqueous electrolyte. It discloses a technology using lithium cobalt oxide or lithium nickel oxide as the positive electrode active material and carbon as the negative electrode active material (scope and embodiments of the claims in Patent Document 1). Graphite is commonly used as the carbon material. Graphite allows for the insertion or extraction of one lithium ion per six six-membered ring carbon atoms.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent No. 2668678 Summary of the Invention

[0007] The inventors are currently researching and developing a technology for using carbon nanowalls as the negative electrode in lithium-ion secondary batteries. However, in order to form a film of carbon nanowalls in copper foil (used as the negative electrode current collector) or aluminum foil (used as the positive electrode current collector), film formation at high temperatures of 500°C to 600°C is required. Under these conditions, stress caused by the difference in thermal expansion coefficients occurs between the copper foil or aluminum foil and the carbon nanowalls when heating the copper or aluminum foil before film formation or when cooling the copper or aluminum foil after film formation. Depending on the situation, wrinkles may form on the negative or positive electrode current collector.

[0008] The technical problem to be solved by this specification is to provide a metal substrate for growing carbon nanowalls, capable of forming carbon nanowalls at low temperatures above 0°C and below approximately 500°C, and a metal substrate with carbon nanowalls, as well as a method for manufacturing the same.

[0009] The metal substrate for carbon nanowall growth in the first method is a metal substrate having a first surface. The metal substrate has multiple protrusions on the first surface. The area of ​​the projection region obtained by projecting the protrusions onto the first surface is 10 nm. 2 ~10000nm 2 The density of the protrusions is 1 per μm. 2 ~1000 / μm 2 .

[0010] The metal substrate for growing carbon nanowalls has protrusions on its first surface. These protrusions serve as starting points for the formation of carbon nanowalls. Thus, the protrusions function as, for example, a catalyst. Therefore, carbon nanowalls can be formed on a current collector at low temperatures above 0°C and below approximately 500°C.

[0011] This specification provides a metal substrate for growing carbon nanowalls, capable of forming carbon nanowalls at low temperatures above 0°C and below 500°C, a metal substrate with carbon nanowalls, and a method for manufacturing the same. Attached Figure Description

[0012] Figure 1 This is a simplified structural diagram of the lithium-ion secondary battery LiB1 according to the first embodiment.

[0013] Figure 2 This is a schematic cross-section of the carbon nanowall CNW1 of the lithium-ion secondary battery LiB1 according to the first embodiment.

[0014] Figure 3 This is a diagram conceptually representing the structure of the carbon nanowall CNW1 of the lithium-ion secondary battery LiB1 according to the first embodiment.

[0015] Figure 4 This is a simplified configuration diagram showing the structure of the manufacturing apparatus for growing carbon nanowalls CNW1 in the lithium-ion secondary battery LiB1 of the first embodiment.

[0016] Figure 5 This is a scanning electron microscope image (one of many) showing the surface of a copper foil after it has been irradiated with hydrogen free radicals.

[0017] Figure 6 This is a scanning electron microscope image showing the surface of carbon nanowalls grown at a heater set temperature of 500°C.

[0018] Figure 7 This is a scanning electron microscope image showing a cross-section of carbon nanowalls grown at a heater set temperature of 500°C.

[0019] Figure 8 This is a scanning electron microscope image showing the surface of carbon nanowalls grown at a heater set temperature of 400°C.

[0020] Figure 9 This is a scanning electron microscope image showing a cross-section of carbon nanowalls grown at a heater set temperature of 400°C.

[0021] Figure 10This is a scanning electron microscope image showing the surface of carbon nanowalls grown at a heater set temperature of 300°C.

[0022] Figure 11 This is a scanning electron microscope image showing a cross-section of carbon nanowalls grown at a heater set temperature of 300°C.

[0023] Figure 12 This is a scanning electron microscope image showing the surface of carbon nanowalls grown at a heater set temperature of 200°C.

[0024] Figure 13 This is a scanning electron microscope image showing a cross-section of carbon nanowalls grown at a heater set temperature of 200°C.

[0025] Figure 14 This is a scanning electron microscope image showing the surface of carbon nanowalls grown at a heater set temperature of 20°C.

[0026] Figure 15 This is a scanning electron microscope image showing a cross-section of carbon nanowalls grown at a heater set temperature of 20°C.

[0027] Figure 16 This is a scanning electron microscope image of the surface of a carbon nanowall grown at a substrate temperature of 500°C without irradiation with hydrogen free radicals.

[0028] Figure 17 This is a graph showing the relationship between capacity and voltage of a lithium-ion secondary battery with a negative electrode where carbon nanowalls are grown on copper foil at a substrate temperature of 500°C.

[0029] Figure 18 This is a graph showing the relationship between capacity and voltage of a lithium-ion secondary battery with a negative electrode where carbon nanowalls are grown on copper foil at a substrate temperature of 400°C.

[0030] Figure 19 This is a graph showing the relationship between capacity and voltage of a lithium-ion secondary battery with a negative electrode where carbon nanowalls are grown on copper foil at a substrate temperature of 300°C.

[0031] Figure 20 This is a graph showing the relationship between capacity and voltage of a lithium-ion secondary battery with a negative electrode where carbon nanowalls are grown on copper foil at a substrate temperature of 200°C.

[0032] Figure 21 This is a graph showing the relationship between capacity and voltage of a lithium-ion secondary battery with a negative electrode where carbon nanowalls are grown on copper foil at a substrate temperature of 20°C.

[0033] Figure 22This is a scanning electron microscope photograph (part two) showing the surface of a copper foil after it has been irradiated with hydrogen free radicals.

[0034] Figure 23 This is a scanning electron microscope photograph (third one) showing the surface of a copper foil after it has been irradiated with hydrogen free radicals.

[0035] Figure 24 It means Figure 23 The measurement results of the concavity and convexity of a line.

[0036] Figure 25 This indicates the hydrogen supply and the area of ​​the protrusion is 10 nm. 2 ~100nm 2 A chart showing the relationship between the number of protrusions.

[0037] Figure 26 This indicates the hydrogen supply and the area of ​​the protrusion is 100m². 2 ~1000nm 2 A chart showing the relationship between the number of protrusions.

[0038] Figure 27 This indicates the hydrogen supply and the area of ​​the protrusion is 1000 nm. 2 ~10000nm 2 A chart showing the relationship between the number of protrusions.

[0039] Figure 28 It is a graph showing the relationship between the amount of hydrogen supplied and the number of protrusions.

[0040] Figure 29 This indicates that the magnitude of the bias voltage and the area of ​​the protrusion are 10 nm. 2 ~100nm 2 A chart showing the relationship between the number of protrusions.

[0041] Figure 30 This indicates that the magnitude of the bias voltage and the area of ​​the protrusion are 100 nm. 2 ~1000nm 2 A chart showing the relationship between the number of protrusions.

[0042] Figure 31 This indicates that the magnitude of the bias voltage and the area of ​​the protrusion are 1000 nm. 2 ~10000nm 2 A chart showing the relationship between the number of protrusions.

[0043] Figure 32 It is a graph showing the relationship between the magnitude of the bias voltage and the number of protrusions.

[0044] Figure 33This is a microscopic photograph of the surface of a substrate when the hydrogen supply is 100 sccm and the bias voltage is -25V.

[0045] Figure 34 It means in Figure 33 Microscopic images of carbon nanowalls growing on a substrate.

[0046] Figure 35 This is a microscopic photograph of the surface of a substrate when the hydrogen supply is 100 sccm and the bias voltage is -100 V.

[0047] Figure 36 It means in Figure 35 Microscopic images of carbon nanowalls growing on a substrate. Detailed Implementation

[0048] Hereinafter, specific embodiments will be described with reference to the accompanying drawings, illustrating metal substrates for growing carbon nanowalls, metal substrates with carbon nanowalls, and their manufacturing methods. In this specification, an energy storage device refers to a device capable of charging and discharging. Energy storage devices include lithium-ion primary batteries, lithium-ion secondary batteries, lithium-ion capacitors, and other devices that utilize lithium ions for charging and discharging.

[0049] (First Implementation)

[0050] 1. Lithium-ion secondary battery

[0051] Figure 1 This is a simplified structural diagram of the lithium-ion secondary battery LiB1 according to the first embodiment. The lithium-ion secondary battery LiB1 has a positive electrode PE, a negative electrode NE, a separator Sp1, an electrolyte ES1, and a container V1.

[0052] The positive electrode PE is the positive electrode of a lithium-ion secondary battery LiB1. The positive electrode PE has a positive current collector P1 and a positive active material layer P2. The positive active material layer P2 is formed on the surface of the first surface P1a and the second surface P1b of the positive current collector P1.

[0053] The positive current collector P1 is a metal substrate. The positive current collector P1 can be, for example, a metal foil. The shape of the positive current collector P1 can also be other shapes. The material of the positive current collector P1 can be, for example, Al or Ti. The material of the positive current collector P1 can also be other conductive materials such as metals.

[0054] The positive electrode active material layer P2 contains a positive electrode active material, a conductive additive, and a binder. The positive electrode active material layer P2 may also contain a thickener, etc. Examples of positive electrode active materials include lithium cobalt oxide, lithium manganese oxide, lithium nickel oxide, and ternary compounds. Examples of conductive additives include carbon black. Examples of binders include SBR. Examples of thickeners include carboxymethyl cellulose. Thus, the positive electrode active material layer P2 contains lithium atoms.

[0055] The negative electrode NE is the negative electrode of a lithium-ion secondary battery LiB1. The negative electrode NE has a negative electrode current collector N1 and a negative electrode active material layer N2. The negative electrode active material layer N2 is formed on the surfaces of the first surface N1a and the second surface N1b of the negative electrode current collector N1. The negative electrode NE is a carbon nanowall with carbon nanowalls CNW1 formed on it.

[0056] The negative current collector N1 is a metal substrate for carbon nanowall growth. The negative current collector N1 is a metal substrate. For example, the negative current collector N1 is a metal foil. The shape of the negative current collector N1 can also be other shapes. The material of the negative current collector N1 is, for example, Cu. The negative current collector N1 is, for example, a copper plate or copper foil. The material of the negative current collector N1 can also be a conductor such as aluminum, titanium, or other metals.

[0057] The negative electrode active material layer N2 contains negative electrode active material. The negative electrode active material layer N2 contains carbon nanowalls CNW1 as the negative electrode active material. The carbon nanowalls CNW1 will be described later.

[0058] The separator Sp1 is used to electrically insulate the positive electrode PE from the negative electrode NE. The separator Sp1 allows lithium ions in the electrolyte ES1 to pass through.

[0059] Electrolyte ES1 has the characteristic of transferring lithium ions between the positive electrode PE and the negative electrode NE. Electrolyte ES1 fills container V1. Electrolyte ES1 is a liquid obtained by dissolving lithium salts such as lithium hexafluoride phosphate (LiPF6) in dimethyl carbonate (DMC), diethyl carbonate (DEC), or methyl ethyl carbonate (EMC).

[0060] The container V1 houses the positive electrode PE, the negative electrode NE, the separator Sp1, and the electrolyte ES1. The container V1 is made of a material that does not readily react with the electrolyte ES1.

[0061] 2. Protrusion

[0062] Figure 2This is a schematic cross-sectional view of the carbon nanowall CNW1 of the lithium-ion secondary battery LiB1 according to the first embodiment. The negative electrode current collector N1 is a metal substrate used for growing the carbon nanowall. The negative electrode current collector N1 has a first surface N1a. The first surface N1a is another surface of the negative electrode current collector N1. A plurality of protrusions PR1 are formed on the first surface N1a of the negative electrode current collector N1.

[0063] The protrusion PR1 is a portion of the negative current collector N1 that partially protrudes from the first surface N1a. The protrusion PR1 can be composed of a single particle GR1 or multiple particles GR1. In this case, the material of the particle GR1 is preferably the same as that of the negative current collector N1. Preferably, the particle GR1 is fused with the first surface N1a of the negative current collector N1 and becomes integral with the negative current collector N1. This is because it improves the adhesion between the negative current collector N1 and the particle GR1, preventing the particle GR1 from peeling off from the negative current collector N1.

[0064] The size of the plane of the protrusion PR1 was determined by observing the surface using a scanning electron microscope from a direction perpendicular to the first surface N1a of the negative current collector N1. The area of ​​the projected region obtained by projecting the protrusion PR1 onto the first surface N1a is 10 nm. 2 ~10000nm 2 Preferably 20nm 2 ~5000nm 2 .

[0065] For example, every 10 μm of the first surface N1a of the negative electrode current collector N1 2 There are between 10 and 10,000 protrusions PR1. That is, the density of the projected region obtained by projecting the protrusions PR1 onto the first surface N1a is 1 protrusion / μm. 2 ~1000 / μm 2 Preferably 2 per μm 2 ~800 cells / μm 2 More preferably, 3 per μm. 2 ~500 cells / μm 2 .

[0066] As described below, in the case of forming the protrusion PR1 using hydrogen plasma irradiation, the protrusion PR1 is considered to be formed as follows: Copper particles GR1 are ejected from the first surface N1a of the negative electrode current collector N1. The ejected particles GR1 re-attach to the first surface N1a of the negative electrode current collector N1 and fuse with it, thereby forming the protrusion PR1. It should be noted that the size and density of the protrusion PR1 are considered important factors determining the growth density of the carbon nanowall CNW1.

[0067] The protrusion PR1 serves as the starting point for the growth of carbon nanowalls CNW1. Therefore, carbon nanowalls CNW1 are formed on the first surface N1a of the negative electrode current collector N1, spanning the protrusion PR1.

[0068] 3. Carbon nanowalls

[0069] 3-1. Structure of carbon nanowalls

[0070] In this specification, carbon nanowalls refer to conductive nanostructures with carbon atoms arranged in a wall-like form as the main component on a substrate such as the negative electrode current collector N1.

[0071] Figure 3 This is a diagram conceptually representing the structure of the carbon nanowall CNW1 in the lithium-ion secondary battery LiB1 according to the first embodiment. Figure 3 The image conceptually illustrates a graphene sheet GS1. The carbon nanowalls CNW1 are conductive. CNW1 can be composed of multiple graphene sheets GS1. Furthermore, the graphene sheet GS1 may not be a complete graphene structure but rather a thin film primarily composed of carbon with a six-membered ring structure. Additionally, the graphene sheet GS1 can also be a mosaic structure primarily composed of carbon with a six-membered ring structure. A mosaic structure refers to a structure with multiple regions of a six-membered ring structure discretely arranged. That is, the carbon nanowalls CNW1 may not be a single crystal with a complete six-membered ring surface.

[0072] The negative electrode NE has a negative current collector N1 and a negative active material layer N2. The negative active material layer N2 has carbon nanowalls CNW1.

[0073] Carbon nanowall CNW1 is a graphite-like material formed by stacking approximately 10 layers of graphene sheets GS1 along the thickness direction of the carbon nanowall CNW1. The number of layers can also be other than those mentioned above. Because carbon nanowall CNW1 is a graphite-like material, it exhibits higher electrical conductivity compared to carbon materials such as activated carbon.

[0074] In the carbon nanowall CNW1, a root portion R1 is provided on the side of the negative current collector N1, and a front end portion E1 is provided on the opposite side of the negative current collector N1. The root portion R1 is usually fixed to the negative current collector N1 via a protrusion PR1. In addition, the root portion R1 is also a connecting portion that is electrically connected to the negative current collector N1.

[0075] In the carbon nanowall CNW1, the graphene sheet GS1 is formed with an orientation intersecting the surfaces (first surface N1a, second surface N1b) of the negative electrode current collector N1. Figure 3In the diagram, the graphene sheet GS1 is approximately perpendicular to the negative electrode current collector N1. It should be noted that the carbon nanowall CNW1 can also be non-perpendicular to the negative electrode current collector N1. Even in this case, the carbon nanowall CNW1 functions as the negative electrode NE of the lithium-ion secondary battery LiB1.

[0076] Furthermore, as mentioned above, the carbon nanowall CNW1 is graphite obtained by stacking multiple graphene sheets GS1. In reality, the graphene sheets GS1 do not extend perfectly parallel to each other. Because the graphene sheets GS1 grow in different directions in each initial growth nucleus, the graphene sheets GS1 are actually randomly merged and overlapped (see reference). Figure 6 ).like Figure 3 As shown, the distance between adjacent wall-shaped graphite is called the wall spacing D1.

[0077] The average wall spacing, which is the average value of the wall spacing D1, is related to the density of carbon nanowalls CNW1. That is, the wider the average wall spacing, the lower the density of carbon nanowalls CNW1. Conversely, the narrower the average wall spacing, the higher the density of carbon nanowalls CNW1.

[0078] 3-2. Height of carbon nanotube walls

[0079] The average height H1 of the carbon nanowall CNW1 can be 50 nm or more. Alternatively, the average height H1 can be 200 nm or more. When the average height H1 of the carbon nanowall CNW1 is 100 nm or more, lithium deposition is easier from the carbon nanowall CNW1 as a starting point. The higher the average height H1, the longer the growth time becomes, resulting in higher manufacturing costs. Therefore, for example, the average height H1 is 1 μm to 10 μm.

[0080] The average thickness W1 of the carbon nanowall CNW1 is, for example, 0.5 nm to 100 nm. Preferably, it is 1 nm to 50 nm. More preferably, it is 1.5 nm to 30 nm.

[0081] The interlayer spacing of graphite is approximately 0.35 nm. Therefore, the thickness of a carbon nanowall (CNW1) composed of 10 layers of graphene sheets (GS1) is approximately 3.5 nm. Although it depends on the manufacturing conditions, the average thickness of the carbon nanowall (CNW1) is considered to be approximately 3.5 nm, and it is composed of 5 to 20 layers of graphene sheets (GS1). The thickness of the carbon nanowall (CNW1) is, for example, 1.5 nm to 7 nm.

[0082] 3-3. Wall spacing

[0083] The average wall spacing D1 between adjacent carbon nanowalls CNW1 is, for example, 10 nm to 500 nm. Preferably, it is 15 nm to 100 nm. More preferably, it is 20 nm to 50 nm. These ranges are examples, and values ​​other than those described above are also possible. It should be noted that the long walls of the carbon nanowalls do not necessarily grow in parallel; the walls may merge with each other (see [reference]). Figure 6 Therefore, the spacing between the carbon nanowalls CNW1 near the merging location is narrower than the spacing between the carbon nanowalls CNW1 at other locations.

[0084] Thus, in order to grow carbon nanowalls CNW1 with a wall spacing D1 of 15 nm to 100 nm, the area obtained by projecting the protrusion PR1, which serves as the starting point for the growth of carbon nanowalls CNW1, onto the first surface N1a is preferably 20 nm. 2 ~5000nm 2 The density of the protrusions PR1 is preferably 3 per μm. 2 ~2500 cells / μm 2 If considered in a modeling manner, it would be as follows: To grow carbon nanowalls CNW1 with a wall spacing of 20 nm D1, a protrusion PR1 exists at a lattice point with a spacing of 20 nm, and the carbon nanowall CNW1 grows starting from PR1 located at its lattice point. In this case, assuming the protrusion is hemispherical, a diameter of approximately 10 nm is preferred, and the area obtained by projecting the protrusion PR1 onto the first surface N1a is approximately 80 nm. 2 Additionally, the density of protrusions PR1 is 2500 per μm. 2 Similarly, in order to grow carbon nanowalls CNW1 with a wall spacing D1 of 50 nm, the area obtained by projecting the protrusion PR1 onto the first surface N1a is approximately 500 nm. 2 The density of protrusions PR1 is 400 per μm. 2 Furthermore, in order to grow carbon nanowalls CNW1 with a wall spacing D1 of 100 nm, the area obtained by projecting the protrusion PR1 onto the first surface N1a is approximately 2000 nm. 2 The density of protrusions PR1 is 100 per μm. 2 That is, in order to grow carbon nanowalls CNW1 with a wall spacing D1 of 20 nm to 100 nm, the area obtained by projecting the protrusion PR1, which serves as the starting point for the growth of carbon nanowalls CNW1, onto the first surface N1a is preferably 80 nm. 2 ~2000nm 2 The density of protrusions PR1 is preferably 100 per μm. 2 ~2500 cells / μm 2 In practice, it is believed that it is not necessary for protrusions PR1 to exist at every lattice point; protrusions PR1 with a slightly lower density can also be present.

[0085] 4. Lithium-ion-mediated charge-discharge reaction

[0086] 4-1. Charge and discharge reaction

[0087] The negative electrode NE has carbon nanowalls CNW1. The carbon nanowalls CNW1 can ensure that each carbon atom has more than two lithium ions participating in the charge and discharge reaction during a single charge or discharge cycle.

[0088] Here, charge-discharge reaction refers, for example, a chemical reaction represented by the following chemical reaction formula.

[0089]

[0090]

[0091] Equation (1) represents the reaction in the negative electrode active material layer N2. Equation (2) represents the reaction in the positive electrode active material layer P2. Both reactions involve the involvement of lithium ions and electrons. The charge-discharge reaction refers to the chemical reaction in which lithium ions intervene and generate electron donation and acceptance in the positive electrode PE or negative electrode NE. Through this charge-discharge reaction, phenomena such as lithium ion insertion or extraction, as well as the precipitation, deposition, adsorption, and dissolution of lithium or lithium compounds can occur. It should be noted that in the case of lithium or lithium compound precipitation, the charge-discharge reaction can occur outside the positive electrode active material layer P2 or the negative electrode active material layer N2. It should be noted that the type of charge-discharge reaction varies depending on the materials of the positive electrode active material layer P2 and the negative electrode active material layer N2.

[0092] 5. Manufacturing equipment

[0093] An apparatus for manufacturing carbon nanowalls CNW1 formed on the first surface N1a of the negative electrode current collector N1 will be described.

[0094] Figure 4 This is a simplified configuration diagram showing the structure of a manufacturing apparatus 1 for growing carbon nanowalls CNW1 in a lithium-ion secondary battery (LiB1) according to the first embodiment. The manufacturing apparatus 1 includes a plasma generation chamber 46 and a reaction chamber 10. The plasma generation chamber 46 is used to generate plasma within itself and also generates free radicals that are supplied to the reaction chamber 10. The reaction chamber 10 is configured to form carbon nanowalls CNW1 using the free radicals generated in the plasma generation chamber 46.

[0095] Additionally, the manufacturing apparatus 1 includes a waveguide 47, a quartz window 48, and a slot antenna 49. The waveguide 47 is used to introduce microwaves 39. The slot antenna 49 is used to introduce microwaves 39 from the quartz window 48 into the plasma generation chamber 46.

[0096] The plasma generation chamber 46 is used to generate surface wave plasma (SWP) via microwaves 39. A radical source inlet 42 is provided in the plasma generation chamber 46. The radical source inlet 42 is used to supply a gas, which serves as a radical source, to the interior of the plasma 61 generated in the plasma generation chamber 46.

[0097] A partition wall 44 is provided between the plasma generation chamber 46 and the reaction chamber 10. The partition wall 44 is used to separate the plasma generation chamber 46 and the reaction chamber 10. The partition wall 44 also serves as the first electrode 22 of the applied voltage. Furthermore, a through hole 14 is formed on the partition wall 44 for supplying free radicals generated in the plasma generation chamber 46 to the reaction chamber 10.

[0098] The reaction chamber 10 is used to generate capacitively coupled plasma (CCP). Additionally, the reaction chamber 10 is used to form carbon nanowalls CNW1 on the negative electrode current collector N1. The reaction chamber 10 has a second electrode 24, a heater 25, a feed inlet 12, and an exhaust port 16. The second electrode 24 is used to apply a voltage between itself and the first electrode 22. The heater 25 is used to heat the negative electrode current collector N1 and control its temperature. The feed inlet 12 is used to supply carbon-based gas 32, which serves as the raw material for the carbon nanowalls. The exhaust port 16 is connected to a vacuum pump, etc. The vacuum pump is used to adjust the internal pressure of the reaction chamber 10.

[0099] As described above, partition 44 also functions as the first electrode 22 through which an external voltage is applied between it and the second electrode 24. A power supply and circuit are connected to the first electrode 22. This circuit is used to control the potential of the first electrode 22 in time. The second electrode 24 is used to apply an external voltage between itself and the first electrode 22. Furthermore, the second electrode 24 also serves as a mounting platform for the negative current collector N1. The second electrode 24 is grounded.

[0100] The distance between the first electrode 22 and the second electrode 24 is approximately 5 cm. Of course, it is not limited to this value.

[0101] 6. Manufacturing method of negative electrode

[0102] 6-1. Forming process of protrusion

[0103] First, a negative electrode current collector N1, formed before the carbon nanowall CNW1 is formed, is placed inside the manufacturing apparatus 1. At this time, the first surface N1a of the negative electrode current collector N1 faces upward, and the second surface N1b is in contact with the second electrode 24. Next, microwaves 39 are introduced into the waveguide 47. The microwaves 39 are introduced into the plasma generation chamber 46 through the quartz window 48 via the slot antenna 49. As a result, a high-density plasma 60 is generated.

[0104] Furthermore, the high-density plasma 60 diffuses inside the plasma generation chamber 46, becoming plasma 61. This plasma 61 contains ions from a free radical source supplied from the free radical source inlet 42. A hydrogen-containing gas is used as the free radical source. Most of the ions in plasma 61 are attracted and collide with the partition wall 44. Free radicals 38 in plasma 61 are not attracted by the partition wall 44 but enter the reaction chamber 10 through the through-hole 14 of the partition wall 44. Then, a voltage is applied between the first electrode 22 and the second electrode 24. Thus, plasma 34 is generated inside the reaction chamber 10.

[0105] Free radicals 38 are present in the atmosphere of plasma 34. Moreover, in the atmosphere of plasma 34, protrusions PR1 grow on the first surface N1a of the negative electrode current collector N1. At this time, copper particles GR1 disperse from the first surface N1a of the negative electrode current collector N1 and re-attach to the first surface N1a of the negative electrode current collector N1.

[0106] The internal pressure of the reaction chamber 10 is in the range of 5 to 2000 mTorr (0.65 Pa to 267 Pa). Furthermore, the temperature of the negative electrode current collector N1 is in the range of 0°C to 500°C. Preferably, it is 0°C to 400°C. Of course, these are examples and are not limited to these numerical ranges.

[0107] 6-2. Carbon Nanowall Growth Process

[0108] Next, carbon nanowalls CNW1 are grown on the protrusions PR1 inside the manufacturing apparatus 1. As with the growth of the protrusions PR1, plasma 61 is generated. In addition to free radicals 38, carbonaceous gas 32 is supplied to the interior of the reaction chamber 10 through the feed inlet 12. Hydrogen is used as the free radical source for free radicals 38, and CH4 or C2F6 is used as the carbonaceous gas 32. Of course, other substances can also be used. Furthermore, rare gases such as Ar can be added to these gases.

[0109] In this way, a gas containing carbon atoms is plasmaized inside the manufacturing apparatus 1 and supplied to the negative electrode current collector N1. The protrusion PR1 on the first surface N1a of the negative electrode current collector N1 is used as the growth starting point, and carbon nanowalls are grown on the protrusion PR1.

[0110] The internal pressure of reaction chamber 10 is in the range of 5–2000 mTorr (0.65 Pa–267 Pa). Additionally, the temperature of the negative electrode current collector N1 is in the range of 0 °C–500 °C. Of course, these are examples and are not limited to these numerical ranges.

[0111] Thus, in the first embodiment, a hydrogen-containing gas is plasma-plasmified and supplied to a metal substrate, forming a protrusion on a first surface of the metal substrate by fusing multiple particles of the same material as the metal substrate with the first surface. A carbon-containing gas is plasma-plasmified and supplied to the metal substrate, causing carbon nanowalls to grow on the protrusion on the first surface of the metal substrate.

[0112] 8. Effects of the first implementation method

[0113] The negative electrode NE of the lithium-ion secondary battery LiB1 in the first embodiment has a protrusion PR1. The protrusion PR1 is a structure obtained by fusing an aggregate of multiple particles GR1 onto the first surface N1a of the negative electrode current collector N1. Therefore, carbon nanowalls CNW1 can be easily formed starting from the protrusion PR1. As a result, the film formation temperature of carbon nanowalls CNW1 is 0°C to 500°C, which is lower than the conventional film formation temperature.

[0114] 9. Variations

[0115] 9-1. Amorphous carbon layer

[0116] The negative electrode NE may also have an amorphous carbon layer AC1. The amorphous carbon layer AC1 is conductive. The amorphous carbon layer AC1 is located between the first surface N1a of the negative electrode current collector N1 and the carbon nanowall CNW1. The amorphous carbon layer AC1 is the starting point for the growth of the graphene sheet GS1 that constitutes the carbon nanowall CNW1. The film thickness of the amorphous carbon layer AC1 is, for example, 10 nm to 300 nm. Preferably, it is 10 nm to 100 nm. More preferably, it is 12 nm to 30 nm.

[0117] 9-2. Manufacturing apparatus

[0118] In the first embodiment, the protrusion formation process and the carbon nanowall growth process are performed continuously inside the manufacturing apparatus 1. However, the protrusion formation process and the carbon nanowall growth process can also be performed separately in other apparatuses. Alternatively, a plasma-based film-forming apparatus other than the manufacturing apparatus 1 can also be used.

[0119] 9-3. Process for forming protrusions

[0120] Other treatments can also be performed as part of the protrusion forming process. Examples of treatments in the protrusion forming process include pressure treatment such as stamping, chemical treatment, and sputtering using a copper or aluminum target.

[0121] 9-4.Metal substrate

[0122] The metal substrate may contain at least one of copper and aluminum. For example, the metal substrate may contain copper, copper alloys, aluminum, or aluminum alloys. In addition, the shape of the metal substrate may be a plate, foil, or other shapes.

[0123] 9-5. Combination

[0124] The above variations can be freely combined.

[0125] Example

[0126] (experiment)

[0127] 1. Formation of protrusions

[0128] Inside manufacturing apparatus 1, a protrusion PR1 is formed on a copper foil (copper substrate). The conditions at this time are shown in Table 1. The hydrogen flow rate is 50 sccm. The Ar flow rate is 5 sccm. The microwave power (MW power) is 400 W. The power applied between the electrodes (CCP power) is 400 W. The temperature of heater 25 is 560°C. The processing time is 10 minutes.

[0129] It should be noted that carbon-based gas 32, which serves as the raw material gas for the carbon nanowall CNW1, is not supplied to the interior of manufacturing apparatus 1. Therefore, a hydrogen plasma is generated, and hydrogen radicals are supplied to the copper foil.

[0130] [Table 1]

[0131]

[0132]

[0133] Figure 5 This is a scanning electron microscope image (one of many) showing the surface of a copper foil after it has been irradiated with hydrogen free radicals. Figure 5 This indicates that a large number of copper particles are deposited on the surface of the copper foil, forming protrusions. Based on the observed particle shape, it can be assumed that the copper particles ejected from the copper foil are reattached to the surface of the copper foil after being irradiated by hydrogen free radicals.

[0134] 2. Formation of protrusions and carbon nanowalls

[0135] 2-1. Film formation

[0136] Inside the manufacturing apparatus 1, protrusions PR1 and carbon nanowalls CNW1 are formed on a copper foil (copper substrate). The conditions at this time are shown in Table 2. It should be noted that during the growth of protrusions PR1 and carbon nanowalls CNW1, the temperature of heater 25 is varied between room temperature (RT) and 500°C.

[0137] [Table 2]

[0138]

[0139] 2-2. Photographs of carbon nanowalls

[0140] Figure 6This is a scanning electron microscope image showing the surface of carbon nanowalls grown at a heater set temperature of 500°C. The substrate temperature is determined by the heater set temperature and the energy imparted to the substrate by the plasma. Due to collisions between plasma particles and the substrate, the substrate temperature may be higher than the heater set temperature, but it is presumed that these temperatures are roughly the same. Figure 6 As shown, carbon nanowalls grow randomly and merge with each other.

[0141] Figure 7 This is a scanning electron microscope image showing a cross-section of carbon nanowalls grown at a heater set temperature of 500°C. (Example:) Figure 7 As shown, carbon nanowalls with a height of 1 μm were formed through film formation in 10 minutes.

[0142] Figure 8 This is a scanning electron microscope image showing the surface of carbon nanowalls grown at a heater set temperature of 400°C. For example... Figure 8 As shown, carbon nanowalls grow randomly and merge with each other.

[0143] Figure 9 This is a scanning electron microscope image showing a cross-section of carbon nanowalls grown at a heater set temperature of 400°C. (Example) Figure 9 As shown, carbon nanowalls with a height of 900 nm were formed through film deposition in 10 minutes.

[0144] Figure 10 This is a scanning electron microscope image showing the surface of carbon nanowalls grown at a heater set temperature of 300°C. For example... Figure 10 As shown, carbon nanowalls grow randomly and merge with each other.

[0145] Figure 11 This is a scanning electron microscope image showing a cross-section of carbon nanowalls grown at a heater set temperature of 300°C. (Example:) Figure 11 As shown, carbon nanowalls with a height of 850 nm were formed through film deposition in 10 minutes.

[0146] Figure 12 This is a scanning electron microscope image showing the surface of carbon nanowalls grown at a heater set temperature of 200°C. For example... Figure 12 As shown, carbon nanowalls grow randomly and merge with each other.

[0147] Figure 13 This is a scanning electron microscope image showing a cross-section of carbon nanowalls grown at a heater set temperature of 200°C. (Example:) Figure 13 As shown, carbon nanowalls with a height of 750 nm were formed through film deposition in 10 minutes.

[0148] Figure 14This is a scanning electron microscope image showing the surface of carbon nanowalls grown at a heater set temperature of 20°C. For example... Figure 14 As shown, carbon nanowalls grow randomly and merge with each other.

[0149] Figure 15 This is a scanning electron microscope image showing a cross-section of carbon nanowalls grown at a heater set temperature of 20°C. (Example:) Figure 15 As shown, carbon nanowalls with a height of 800 nm were formed through film deposition in 10 minutes.

[0150] Figure 16 This is a scanning electron microscope image showing the surface of carbon nanowalls grown at a heater set temperature of 500°C without irradiation by hydrogen free radicals. In this case, no protrusions PR1 are formed. (Example:) Figure 16 As shown, carbon nanowalls grow slightly even without irradiation by hydrogen radicals. However, the density of the carbon nanowalls is sparse. Therefore, the density of the carbon nanowalls is insufficient for use as the negative electrode in lithium-ion secondary batteries.

[0151] 2-3. Lithium-ion secondary batteries

[0152] A lithium-ion secondary battery, LiB1, according to the first embodiment, is manufactured. The positive electrode current collector P1 is aluminum, and the positive electrode active material is lithium cobalt oxide. The negative electrode current collector N1 is copper, and the negative electrode active material is carbon nanowalls. The electrolyte is 1M LiPF6. The positive electrode active material layer is a region with a diameter of 1.6 cm. The negative electrode active material layer is a region with a diameter of 1.3 cm.

[0153] The positive electrode active material layer contains lithium cobalt oxide, a conductive additive, and a binder. The conductive additive is acetylene black. The binder is PVDF. The weight ratio of lithium cobalt oxide, acetylene black, and PVDF is 100:5:3.

[0154] Figure 17 This is a graph showing the relationship between capacity and voltage of a lithium-ion secondary battery with a negative electrode where carbon nanowalls are grown on copper foil at a heater set temperature of 500°C. Figure 17 The horizontal axis represents the charge / discharge capacity. Figure 17 The vertical axis represents voltage. The charging or discharging current is 0.5mA. For example... Figure 17 As shown, the discharge capacity of the lithium-ion secondary battery is 13.1mAh.

[0155] Figure 18 This is a graph showing the relationship between the capacity and voltage of a lithium-ion secondary battery with a negative electrode where carbon nanowalls are grown on copper foil at a heater set temperature of 400°C. Figure 18 The horizontal axis represents the charge / discharge capacity. Figure 18 The vertical axis represents voltage. The charging or discharging current is 0.5mA. For example... Figure 18 As shown, the discharge capacity of the lithium-ion secondary battery is 13.1mAh.

[0156] Figure 19 This is a graph showing the relationship between the capacity and voltage of a lithium-ion secondary battery with a negative electrode where carbon nanowalls are grown on copper foil at a heater set temperature of 300°C. Figure 19 The horizontal axis represents the charge / discharge capacity. Figure 19 The vertical axis represents voltage. The charging or discharging current is 0.5mA. For example... Figure 19 As shown, the discharge capacity of the lithium-ion secondary battery is 13.1mAh.

[0157] Figure 20 This is a graph showing the relationship between the capacity and voltage of a lithium-ion secondary battery with a negative electrode where carbon nanowalls are grown on copper foil at a heater set temperature of 200°C. Figure 20 The horizontal axis represents the charge / discharge capacity. Figure 20 The vertical axis represents voltage. The charging or discharging current is 0.5mA. For example... Figure 20 As shown, the discharge capacity of the lithium-ion secondary battery is 12.8mAh.

[0158] Figure 21 This is a graph showing the relationship between the capacity and voltage of a lithium-ion secondary battery with a negative electrode where carbon nanowalls are grown on copper foil at a heater set temperature of 20°C. Figure 21 The horizontal axis represents the charge / discharge capacity. Figure 21 The vertical axis represents voltage. The charging or discharging current is 0.5mA. For example... Figure 21 As shown, the discharge capacity of the lithium-ion secondary battery is 13.1mAh.

[0159] 3. Particles

[0160] 3-1. Plasma Device

[0161] In this experiment, an inductively coupled plasma (ICP) device was used instead of manufacturing device 1 to perform the protrusion formation process. Table 3 shows the processing conditions in the ICP device.

[0162] [Table 3]

[0163]

[0164] 3-2. Hydrogen supply and protrusion

[0165] The number and size of the protrusions were investigated by varying the hydrogen supply. It should be noted that the bias voltage applied to the second electrode 24 was 0V.

[0166] Figure 22This is a scanning electron microscope photograph (part two) showing the surface of a copper foil after it has been irradiated with hydrogen free radicals.

[0167] Figure 23 This is a scanning electron microscope photograph (third one) showing the surface of a copper foil after it has been irradiated with hydrogen free radicals. Figure 23 It is Figure 22 This is a magnified portion of the photo. The white areas represent the protruding parts.

[0168] Figure 24 It means Figure 23 The measurement results of the concavity and convexity of a line. Figure 24 The horizontal axis represents position. Figure 24 The vertical axis represents the height from the reference plane. For example... Figure 24 As shown, a protrusion with a height of approximately 200 nm and a width of approximately 200 nm was observed. According to... Figure 24 As speculated, the height and width of the protrusion are the same.

[0169] The area of ​​the white region in the scanning electron microscope was measured using the scanning electron microscope's functions. The area of ​​the white region corresponds to the two-dimensional size of the protrusion.

[0170] Figure 25 This indicates the hydrogen supply and the area of ​​the protrusion is 10 nm. 2 ~100nm 2 A graph showing the relationship between the number of protrusions. Figure 25 The horizontal axis represents the hydrogen supply (sccm). Figure 25 The vertical axis is per 10μm 2 The number of protrusions. With a hydrogen supply of 100 sccm, the area is 10 nm. 2 ~100nm 2 The number of small protrusions is increasing.

[0171] Figure 26 This indicates the hydrogen supply and the area of ​​the protrusion is 100 nm. 2 ~1000nm 2 A graph showing the relationship between the number of protrusions. Figure 26 The horizontal axis represents the hydrogen supply (sccm). Figure 26 The vertical axis is per 10μm 2 The number of protrusions. With a hydrogen supply of 50 sccm, the area is 100 nm. 2 ~1000nm 2 The number of moderately sized protrusions is showing an increasing trend.

[0172] Figure 27This indicates the hydrogen supply and the area of ​​the protrusion is 1000 nm. 2 ~10000nm 2 A graph showing the relationship between the number of protrusions. Figure 27 The horizontal axis represents the hydrogen supply (sccm). Figure 27 The vertical axis is per 10μm 2 The number of protrusions. With a hydrogen supply of 100 sccm, the area is 1000 nm. 2 ~10000nm 2 The number of large protrusions is increasing.

[0173] Figure 28 This is a graph showing the relationship between the amount of hydrogen supplied and the number of protrusions. Figure 28 The horizontal axis represents the hydrogen supply (sccm). Figure 28 The vertical axis is per 10μm 2 The number of protrusions. When the hydrogen supply is 100 sccm, the number of protrusions tends to increase.

[0174] Thus, with a hydrogen supply of 100 sccm, the number of protrusions tends to increase. In this case, there are more small and large protrusions.

[0175] With a hydrogen supply of 50 sccm, the area is 100 nm. 2 ~1000nm 2 The number of moderately sized protrusions tends to increase. At this point, the number of large and small protrusions is not large. Therefore, in this case, the size of the protrusions is uniformly moderate.

[0176] 3-3. Bias and Protrusion

[0177] The hydrogen supply is set to 100 sccm, and the bias voltage applied to the second electrode 24 is changed. The bias voltage applied to the second electrode 24 is a DC bias voltage.

[0178] Figure 29 This indicates that the magnitude of the bias voltage and the area of ​​the protrusion are 10 nm. 2 ~100nm 2 A graph showing the relationship between the number of protrusions. Figure 29 The horizontal axis represents the bias voltage. Figure 29 The vertical axis is per 10μm 2 The number of protrusions. For example... Figure 29 As shown, by applying an external negative bias voltage, the area of ​​the protrusion is 10 nm. 2 ~100nm 2 The number of protrusions is reduced.

[0179] Figure 30 This indicates that the magnitude of the bias voltage and the area of ​​the protrusion are 100 nm. 2 ~1000nm 2 A graph showing the relationship between the number of protrusions. Figure 30 The horizontal axis represents the bias voltage. Figure 30 The vertical axis is per 10μm 2 The number of protrusions. For example... Figure 30 As shown, with an applied bias voltage of -25V, the area of ​​the protrusion is 100nm. 2 ~1000nm 2 The number of protrusions is the highest. Therefore, in the formation area of ​​100nm... 2 ~1000nm 2 In the case of a substrate with a large number of protrusions, it is preferable to apply an external bias voltage of about -25V.

[0180] Figure 31 This indicates that the magnitude of the bias voltage and the area of ​​the protrusion are 1000 nm. 2 ~10000nm 2 A graph showing the relationship between the number of protrusions. Figure 31 The horizontal axis represents the bias voltage. Figure 31 The vertical axis is per 10μm 2 The number of protrusions. For example... Figure 31 As shown, with an applied bias voltage of -50V, the area of ​​the protrusion is 1000nm. 2 ~10000nm 2 The number of protrusions is the highest. Therefore, in a formation area of ​​1000 nm... 2 ~10000nm 2 In the case of a substrate with a large number of protrusions, it is preferable to apply an external bias voltage of about -50V.

[0181] Figure 32 It is a graph showing the relationship between the magnitude of the bias voltage and the number of protrusions. Figure 32 The horizontal axis represents the bias voltage. Figure 32 The vertical axis is per 10μm 2 The number of protrusions. Under the condition of an applied negative bias voltage, the larger the absolute value of the bias voltage, the more likely the number of protrusions will decrease.

[0182] With a bias voltage of 0V, the area is 10nm. 2 ~100nm 2 The number of small protrusions is showing an increasing trend. With a bias voltage of -25V and an area of ​​100nm... 2 ~1000nm 2 The number of moderately sized protrusions is showing an increasing trend. At a bias voltage of -50V, the area is 1000nm. 2~10000nm 2 The number of large protrusions tends to increase. At a bias voltage of -100V, regardless of the size of the protrusions, there is a tendency for them to become difficult to form.

[0183] The larger the absolute value of the negative bias voltage, the easier it is for hydrogen particles to collide with the substrate. In addition, the kinetic energy of hydrogen particles is also relatively high.

[0184] In this way, by selecting the amount of hydrogen supplied and the value of the bias voltage, the size and number of protrusions formed on the substrate can be controlled to a certain extent.

[0185] Figure 33 This is a microscopic photograph of the substrate surface when the hydrogen supply is 100 sccm and the bias voltage is -25V. For example... Figure 33 As shown, it has a number of protrusions.

[0186] Figure 34 This indicates that the carbon nanowalls are in Figure 33 Microscopic images of carbon nanowalls grown on a substrate. The carbon nanowalls are fully grown and merged together.

[0187] Figure 35 This is a microscopic photograph of the substrate surface when the hydrogen supply is 100 sccm and the bias voltage is -100 V. For example... Figure 35 As shown, the protrusions are sparse and few in number.

[0188] Figure 36 This indicates that the carbon nanowalls are in Figure 35 Microscopic images of carbon nanowalls grown on a substrate. The carbon nanowalls are sparsely grown with wide spacing between them, indicating a low density.

[0189] Therefore, when growing carbon nanowalls, a large number of protrusions tends to result in a higher density of carbon nanowalls.

[0190] (Postscript)

[0191] The metal substrate for growing carbon nanowalls in the first method includes a metal substrate having a first surface. The metal substrate has multiple protrusions on the first surface. The area of ​​the projection region obtained by projecting the protrusions onto the first surface is 10 nm. 2 ~10000nm 2 The density of the protrusions is 1 per μm. 2 ~1000 / μm 2 .

[0192] In the second embodiment, the protrusions are made of the same material as the metal substrate and are fused with the first surface of the metal substrate to become an integral part of the metal substrate.

[0193] In the third method, the metal substrate for growing carbon nanowalls contains at least one of copper and aluminum.

[0194] The fourth method involves a metal substrate with carbon nanowalls, comprising a metal substrate having a first surface and carbon nanowalls formed on the first surface of the metal substrate. The metal substrate has multiple protrusions on the first surface. The area of ​​the projection region obtained by projecting the protrusions onto the first surface is 10 nm. 2 ~10000nm 2 The density of the protrusions is 1 per μm. 2 ~1000 / μm 2 Carbon nanowalls span the protrusions.

[0195] In the fifth method, the protrusion is made of the same material as the metal substrate and is fused with the first surface of the metal substrate to become an integral part of the metal substrate.

[0196] In the sixth method, the metal substrate with carbon nanowalls is a copper plate or copper foil.

[0197] In the seventh method, the metal substrate with carbon nanowalls has an amorphous carbon layer between the first surface of the metal substrate and the carbon nanowalls.

[0198] In the method for manufacturing a metal substrate for carbon nanowall growth in the eighth aspect, a gas containing hydrogen is plasma-plasmated and supplied to the metal substrate, and a plurality of protrusions made of the same material as the metal substrate are formed on the first surface of the metal substrate.

[0199] In the ninth method for manufacturing a metal substrate for carbon nanowall growth, the protrusion is made of the same material as the metal substrate and is fused to the first surface of the metal substrate.

[0200] In the manufacturing method of the metal substrate for carbon nanowall growth in the tenth method, the metal substrate is a copper plate or copper foil.

[0201] In the eleventh method for manufacturing a metal substrate with carbon nanowalls, a gas containing carbon atoms is plasma-entrained and supplied to the metal substrate for growing carbon nanowalls, and the carbon nanowalls are grown by taking the protrusion on the first surface of the metal substrate as the growth starting point.

[0202] In the twelfth method for manufacturing a metal substrate with carbon nanowalls, a gas containing hydrogen is plasma-plasmized and supplied to the metal substrate. Multiple protrusions made of the same material as the metal substrate are formed on the first surface of the metal substrate. A gas containing carbon atoms is plasma-plasmized and supplied to the metal substrate. The protrusions on the first surface of the metal substrate serve as the growth starting point, and the carbon nanowalls are grown.

[0203] In the manufacturing method of the metal substrate with carbon nanowalls in the thirteenth aspect, the protrusion is made of the same material as the metal substrate and is fused to the first surface of the metal substrate.

[0204] In the method for manufacturing a metal substrate with carbon nanowalls in the fourteenth aspect, the metal substrate is a copper plate or copper foil.

[0205] In the fifteenth method for manufacturing a metal substrate with carbon nanowalls, the temperature of the metal substrate during carbon nanowall growth is above 0°C and below 500°C.

[0206] Symbol Explanation

[0207] LiB1…Lithium-ion secondary battery

[0208] PE…positive electrode

[0209] P1…Positive current collector

[0210] P2…Positive electrode active material layer

[0211] NE… Negative electrode

[0212] N1… Negative electrode current collector

[0213] N1a…First page

[0214] PR1…protrusion

[0215] GR1…particles

[0216] N2…Negative electrode active material layer

[0217] CNW1…carbon nanowall

[0218] Sp1…Isolation component

[0219] ES1… Electrolyte

[0220] V1…container

[0221] E1…Front end

[0222] R1...root part

[0223] GS1…Graphene Sheets

Claims

1. A metal substrate with carbon nanowalls, comprising: a metal substrate having a first surface and carbon nanowalls formed on the first surface of the metal substrate. The metal substrate has multiple protrusions on the first surface. The area of ​​the projection region obtained by projecting a single protrusion onto the first surface is 10 nm. 2 ~10000nm 2 , The density of the protrusions is 1 per μm. 2 ~1000 / μm 2 , The carbon nanowall extends across the protrusion; The metal substrate comprises at least one of copper and aluminum; The protrusion is made of the same material as the metal substrate and is fused to the first surface of the metal substrate to become an integral part of the metal substrate; The protrusion is composed of one or more particles; The protrusion is formed by plasma-injecting a hydrogen-containing gas and supplying hydrogen radicals to the metal substrate.

2. The metal substrate with carbon nanowalls according to claim 1, wherein, The metal substrate is a copper plate or copper foil.

3. The metal substrate with carbon nanowalls according to claim 1 or 2, wherein, An amorphous carbon layer is present between the first surface of the metal substrate and the carbon nanowall.

4. A method for manufacturing a metal substrate for carbon nanowall growth, comprising: Hydrogen radicals are supplied to the metal substrate by plasmaizing a gas containing hydrogen. A plurality of protrusions made of the same material as the metal substrate are formed on the first surface of the metal substrate; The metal substrate comprises at least one of copper and aluminum; The protrusion is made of the same material as the metal substrate and is fused to the first surface of the metal substrate; The protrusion is composed of one or more particles.

5. The method for manufacturing a metal substrate for carbon nanowall growth according to claim 4, wherein, The metal substrate is a copper plate or copper foil.

6. A method for manufacturing a metal substrate with carbon nanowalls, comprising: Hydrogen radicals are supplied to the metal substrate by plasmaizing a gas containing hydrogen. A plurality of protrusions made of the same material as the metal substrate are formed on the first surface of the metal substrate. A gas containing carbon atoms is plasma-plasmized and supplied to the metal substrate, and carbon nanowalls are grown using the protrusion on the first surface of the metal substrate as the growth starting point. The metal substrate comprises at least one of copper and aluminum; The protrusion is composed of one or more particles.

7. The method for manufacturing a metal substrate with carbon nanowalls according to claim 6, wherein, The protrusion is made of the same material as the metal substrate and is fused to the first surface of the metal substrate.

8. The method for manufacturing a metal substrate with carbon nanowalls according to claim 6 or 7, wherein, The metal substrate is a copper plate or copper foil.

9. The method for manufacturing a metal substrate with carbon nanowalls according to claim 6 or 7, wherein, The temperature of the metal substrate during the growth of the carbon nanowalls is above 0°C and below 500°C.

10. The method for manufacturing a metal substrate with carbon nanowalls according to claim 8, wherein, The temperature of the metal substrate during the growth of the carbon nanowalls is above 0°C and below 500°C.

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