WO2023248396A1 - Multi-walled carbon nanotube, electrode paste, electrode, power storage device, and production method - Google Patents

Multi-walled carbon nanotube, electrode paste, electrode, power storage device, and production method Download PDF

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Publication number
WO2023248396A1
WO2023248396A1 PCT/JP2022/024979 JP2022024979W WO2023248396A1 WO 2023248396 A1 WO2023248396 A1 WO 2023248396A1 JP 2022024979 W JP2022024979 W JP 2022024979W WO 2023248396 A1 WO2023248396 A1 WO 2023248396A1
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Prior art keywords
walled carbon
carbon nanotube
electrode
storage device
hole
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PCT/JP2022/024979
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French (fr)
Japanese (ja)
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俊雄 阿部
雅文 江本
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スペースリンク株式会社
株式会社マステック
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Priority to PCT/JP2022/024979 priority Critical patent/WO2023248396A1/en
Publication of WO2023248396A1 publication Critical patent/WO2023248396A1/en

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    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B32/00—Carbon; Compounds thereof
    • C01B32/15—Nano-sized carbon materials
    • C01B32/158—Carbon nanotubes
    • C01B32/168—After-treatment
    • C01B32/178—Opening; Filling
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES OR LIGHT-SENSITIVE DEVICES, OF THE ELECTROLYTIC TYPE
    • H01G11/00—Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof
    • H01G11/04—Hybrid capacitors
    • H01G11/06—Hybrid capacitors with one of the electrodes allowing ions to be reversibly doped thereinto, e.g. lithium ion capacitors [LIC]
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES OR LIGHT-SENSITIVE DEVICES, OF THE ELECTROLYTIC TYPE
    • H01G11/00—Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof
    • H01G11/22—Electrodes
    • H01G11/30—Electrodes characterised by their material
    • H01G11/32—Carbon-based
    • H01G11/36—Nanostructures, e.g. nanofibres, nanotubes or fullerenes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES OR LIGHT-SENSITIVE DEVICES, OF THE ELECTROLYTIC TYPE
    • H01G11/00—Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof
    • H01G11/84—Processes for the manufacture of hybrid or EDL capacitors, or components thereof
    • H01G11/86—Processes for the manufacture of hybrid or EDL capacitors, or components thereof specially adapted for electrodes

Definitions

  • the present disclosure relates to multi-walled carbon nanotubes, electrode pastes, electrodes, electricity storage devices, and manufacturing methods.
  • Ions are intercalated between layers of layered graphene sheets (hereinafter referred to as "multi-graphene sheets”) in an electric double layer capacitor that stores energy by adsorbing ions to the multi-graphene sheets.
  • multi-graphene sheets layers of layered graphene sheets
  • choking resistance
  • the capacitance cannot be increased.
  • an electrode paste, an electrode, a power storage device, and a manufacturing method that can eliminate choking and increase capacity will be described.
  • An electrode paste according to one aspect of the present disclosure is characterized in that it contains a binder and a multi-walled carbon nanotube having a through hole in at least one end or a side wall.
  • MWCNT multi-walled carbon nanotube
  • Multi-walled carbon nanotubes, electrode pastes, electrodes, power storage devices, and manufacturing methods according to embodiments of the present invention have the following configurations.
  • a method for producing multi-walled carbon nanotubes characterized by: [Item 2] In the first step of producing a multi-walled carbon nanotube, the through hole is provided in the side wall, The method for producing multi-walled carbon nanotubes according to item 1.
  • the first step further includes a step of impregnating the multi-walled carbon nanotubes with water before the step of irradiating the multi-walled carbon nanotubes produced by the CVD method with microwaves.
  • the method for producing an electrode paste according to item 1 or 2 characterized in that: [Item 4] Further, a second step of preparing an electrode paste by mixing a binder with a multi-walled carbon nanotube having a through hole in at least one of the one end and the side wall; including, The manufacturing method according to item 1 or 2, characterized in that: [Item 5] Furthermore, it includes a third step of applying the electrode paste to a current collector and drying it to produce an electrode.
  • the manufacturing method according to item 4 characterized in that: [Item 6] Furthermore, a fourth step of manufacturing a power storage device by storing the electrode, the negative electrode, the electrolyte, and the separator in an outer container,
  • the manufacturing method according to item 5 characterized in that: [Item 7] A multi-walled carbon nanotube having a through hole in at least one end and/or a side wall.
  • the through hole is provided in the side wall, The multi-walled carbon nanotube according to item 7, characterized in that: [Item 9] Furthermore, at least a portion of the catalyst is peeled off, The multi-walled carbon nanotube according to item 7 or 8, characterized in that: [Item 10] The proportion of impurities containing catalyst in the multi-walled carbon nanotube is 50% or less, The multi-walled carbon nanotube according to item 7 or 8, characterized in that: [Item 11] Comprising the multi-walled carbon nanotubes and a binder according to item 7 or 8, An electrode paste characterized by: [Item 12] A current collector having a multi-walled carbon nanotube-containing layer formed by drying the electrode paste according to item 11 on at least one main surface; An electrode characterized by: [Item 13] Having the electrode, negative electrode, electrolyte, and separator according to item 12 in an outer container, A power storage device characterized by: [Item 14] The negative electrode includes a graphite-containing layer.
  • the electricity storage device is a multilayer capacitor, specifically an electric double layer capacitor, and more specifically a lithium ion capacitor will be described below.
  • the present invention can be widely applied not only to capacitors but also to batteries, and to power storage devices in which positive electrodes and negative electrodes are alternately stacked.
  • the power storage device is not limited to the laminated type, but may be a wound type, or a laminated shape folded into a bellows, and the type and shape of the power storage device is not limited to these. not.
  • the power storage device 1 is a lithium ion capacitor, and includes an outer container 2, a positive electrode 10, a negative electrode 20, a separator 30, and an electrolyte (not shown) arranged in the outer container 2. and has.
  • the outer container 2 may be a metal sheet material (metal film material) or the like.
  • the positive electrode 10 has a terminal portion 10a and an electrode portion 10b.
  • the terminal portion 10a is, for example, a terminal on a tab connected to the electrode portion 10b, and is made of metal such as aluminum.
  • the positive electrode current collector 11 (for example, a conductive material) constituting the electrode portion 10b may be exposed and used as a terminal.
  • the electrode section 10b has, for example, a rectangular planar shape, and as illustrated in FIG. It has a carbon nanotube-containing layer 12 (hereinafter referred to as "MWCNT-containing layer 12").
  • the positive electrode current collector 11 is preferably made of a conductive metal, and may be, for example, a conductive metal foil.
  • a conductive metal for example, copper (Cu), aluminum (Al), etc. are preferable.
  • the positive electrode current collector 19 may have a plurality of holes formed therein, and preferably has a porosity of 50% or more and 80% or less.
  • the MWCNT-containing layer 12 is, for example, a layer containing MWCNTs having through holes in at least one end and one of the side walls, a conductive agent, and a binder; A positive electrode paste prepared by dispersing a binder and a binder in a solvent is applied onto the current collector 11 and dried.
  • the conductive aid may be, for example, acetylene black, Ketjen black, vapor grown carbon fiber, graphite, or the like.
  • the binder can be polytetrafluoroethylene, polyvinylidene fluoride, ethylene-propylene-diene copolymer, styrene-butadiene rubber, and the like.
  • the concentration of the conductive additive is preferably 3 wt% or more and 5% or less. Note that the conductive aid is not essential and may not be included.
  • the MWCNT has a through hole in at least one end and one of the side walls.
  • the size of the through hole is preferably in the range of 3 nm or more and 6 nm or less.
  • the fiber length of MWCNT is preferably in the range of 10 nm or more and 1 mm or less.
  • the fiber diameter of the MWCNTs is preferably in the range of 5 nm or more and 50 nm or less.
  • MWCNTs are produced by forming a catalyst layer on at least one main surface of a base material and growing the catalyst layer on the catalyst layer using a chemical vapor deposition (CVD) method.
  • CVD chemical vapor deposition
  • silicon, quartz, copper (Cu), etc. may be used as the base material.
  • the catalyst layer is composed of a seed catalyst for forming carbon nanotubes, for example, a material supported on a substrate and capable of catalyzing the formation of carbon nanotubes (for example, transition metal particles, etc.).
  • the material constituting the catalyst layer for example, Fe-based seed catalyst particles such as iron (Fe) or iron-titanium alloy (FeTi) particles, seed catalyst particles such as cobalt (Co) particles, nickel (Ni) particles, etc. are used. be able to.
  • the catalyst is removed by irradiating the MWCNTs produced by the CVD method with microwaves.
  • the catalyst is connected to one end of the MWCNT, and impurities containing the catalyst are also attached to the side walls of the MWCNT, so irradiation with microwaves causes the catalyst to generate heat.
  • impurities including the catalyst connected to one end and the catalyst attached to the side wall are removed from the MWCNT.
  • portions of the MWCNT to which the catalyst and impurities containing the catalyst were attached are also removed in response to heat generation, thereby forming a through hole in at least one of one end and the side wall (particularly the side wall) of the MWCNT. .
  • the removed catalyst may be dissolved by, for example, acid washing treatment with hydrochloric acid or the like.
  • irradiating microwaves by adding moisture to MWCNTs (for example, by mixing water to form a slurry or paste), the heat generated by microwave irradiation can be suppressed, and the MWCNTs can penetrate one end and side wall of the MWCNTs.
  • the holes are properly formed.
  • the wavelength of the microwave is preferably within the range of 10,000 ⁇ m or more and 100,000 ⁇ m or less, the frequency is preferably within the range of 2 GHz or more and 30 GHz or less, and the irradiation time is within the range of 1 minute or more and 20 minutes or less. It is preferable that
  • the proportion of impurities containing catalyst in the MWCNTs before microwave irradiation is preferably 50 vol% or less, more preferably 20 vol% or less.
  • the negative electrode 20 has a terminal portion 20a and an electrode portion 20b.
  • the terminal portion 20a is, for example, a terminal on a tab connected to the electrode portion 20b, and is made of metal such as copper.
  • the negative electrode current collector 21 (for example, a conductive material) constituting the electrode portion 20b may be exposed and used as a terminal.
  • the negative electrode 20 may have the same configuration as the positive electrode 10.
  • the electrode section 20b has, for example, a rectangular planar shape, and as illustrated in FIG. It has an active material layer 22.
  • the negative electrode current collector 21 is preferably made of a conductive metal, and may be, for example, a conductive metal foil.
  • a conductive metal for example, copper (Cu), aluminum (Al), etc. are preferable.
  • the negative electrode current collector 21 may have a plurality of holes formed therein, and preferably has a porosity of 50% or more and 80% or less.
  • the negative electrode active material layer 22 is, for example, a layer containing at least a negative electrode active material, a conductive agent, and a binder, and a negative electrode paste in which at least the negative electrode active material, a conductive agent, and a binder are dispersed is applied to the current collector 11. It is coated on top and allowed to dry.
  • the negative electrode active material may be carbon powder, graphite powder, etc., and particularly graphite.
  • the conductive aid may be, for example, acetylene black, Ketjen black, vapor grown carbon fiber, graphite, or the like.
  • the binder can be polyvinylidene fluoride, styrene-butadiene rubber, carboxymethyl cellulose, and the like.
  • the concentration of the conductive additive is preferably 3 wt% or more and 5% or less. Note that the conductive aid is not essential and may not be included.
  • the content of the binder is preferably 3 wt% or more and 5 wt
  • a porous body made of an insulating material, a nonwoven fabric, or the like can be used.
  • the electrolytic solution includes an electrolyte and a solvent.
  • the electrolyte when the electricity storage device 1 is an electric double layer capacitor, tetraethylammonium tetrafluoroboric acid and triethylmethylammonium tetrafluoroboric acid are generally used.
  • the solvent is generally propylene carbonate.
  • a lithium salt such as LiPF6, LiBF4, or LiClO4 can be used as the solute that is the electrolytic solution.
  • a non-aqueous solvent including EC (ethylene carbonate), DEC (diethyl carbonate), DMC (dimethyl carbonate), MEC (methyl ethyl carbonate), nitrile solvent (for example, acetonitrile), etc. can be used.
  • the electrode part 10b is formed by a process of manufacturing MWCNTs having a through hole at least at one end and a side wall, a process of manufacturing a positive electrode paste, and a process of applying the positive electrode paste to the positive electrode current collector 11 and drying it. , can be manufactured.
  • the manufacturing method shown below is an example, Comprising: It is not limited to this.
  • MWCNTs having through holes at least at one end and either the side wall are removed by microwave irradiation, thereby producing MWCNTs having through holes at least at one end and either the side wall.
  • the removed catalyst may be dissolved by, for example, acid washing treatment with hydrochloric acid or the like.
  • the MWCNTs from which the catalyst layer has been removed are heated to 350° C. to 400° C. to remove the capping formed at the other end of the MWCNTs, thereby producing MWCNTs with both ends open. At temperatures below 350°C, it is difficult to remove the capping, and at temperatures above 400°C, the CNTs burn and the amount decreases.
  • MWCNT when the length of MWCNT is long, it may include a step of cutting with a rotation-revolution type crusher and a zirconia ball (for example, 100 ⁇ m), or this step may be performed instead of the step of removing the capping. By doing so, MWCNTs with both ends open may be produced.
  • a rotation-revolution type crusher and a zirconia ball for example, 100 ⁇ m
  • MWCNTs having through-holes on at least one end and one of the side walls are oxidized with sulfuric acid and potassium permanganate to introduce OH groups and COOH groups to weaken the bonding force between each layer of MWCNTs. This makes it possible to eliminate choking.
  • An electrode paste for a positive electrode is prepared by mixing MWCNTs having through holes in at least one end and one of the side walls, a conductive additive, and a binder with an organic solvent.
  • the positive electrode paste is applied onto the positive electrode current collector 11 and left to dry in a drying device at 150 degrees for 2 hours.
  • Example 1 In Example 1, the MWCNTs were irradiated with 2.45 GHz microwaves for 17 minutes to remove the catalyst layer and impurities containing the catalyst, and the MWCNTs, a conductive auxiliary agent, and a binder were added and dispersed by ultrasonic waves to form an electrode. A paste was created, applied onto a positive collector electrode, and dried to produce a positive electrode.
  • the negative electrode was prepared by adding a binder to graphite and dispersing it using ultrasonic waves to create an electrode paste, which was then applied onto the negative collector electrode and dried.
  • Comparative Example 1 is the same as Example 1 except that MWCNTs having no through holes at one end and side wall were used instead of MWCNTs in Example 1.
  • the capacitance of the power storage device of Example 1 is equal to that of the power storage device of Comparative Example 1. It was about 7 to 10 times.
  • the MWCNT of Example 1 is shown in FIG.
  • a mass of catalyst is connected to the tip of the MWCNT.
  • the catalyst becomes heated and the surrounding MWCNTs are burned, thereby peeling off the catalyst as shown in FIG.
  • impurities including catalysts that adhere to the side walls of MWCNTs.
  • a through hole is provided in at least one of the tip and side wall of the MWCNT, and ions are easily intercalated through the through hole, and the MWCNT becomes static. It is thought that the capacitance will improve.
  • ⁇ Effect> As described above, by providing a through hole in at least one of the end portion and the side wall of a multi-walled carbon nanotube (hereinafter also referred to as "MWCNT") (particularly by appropriately providing a through hole in the side wall using microwaves). ), choking is eliminated and capacitance is improved.
  • MWCNT multi-walled carbon nanotube

Abstract

[Problem] To provide: a multi-walled carbon nanotube that makes it possible to eliminate choking and increase static electricity capacity by providing a through hole in at least one among a sidewall and an end of the multi-walled carbon nanotube; an electrode paste; an electrode; a power storage device; and a production method. [Solution] A multi-walled carbon nanotube according to the present embodiment comprises a through hole in at least one among a sidewall and an end. Additionally, at least a portion of a catalyst is peeled off from the multi-walled carbon nanotube. Further, the ratio of impurities containing the catalyst in the multi-walled carbon nanotube is 50% or lower. Also provided is a production method comprising a first step in which a multi-walled carbon nanotube produced using CVD is irradiated with microwaves to produce a multi-walled carbon nanotube comprising a through hole in at least one among a sidewall and an end.

Description

多層カーボンナノチューブ、電極ペースト、電極、蓄電デバイス、製造方法Multi-walled carbon nanotubes, electrode paste, electrodes, power storage devices, manufacturing methods
　本開示は、多層カーボンナノチューブ、電極ペースト、電極、蓄電デバイス、製造方法に関する。 The present disclosure relates to multi-walled carbon nanotubes, electrode pastes, electrodes, electricity storage devices, and manufacturing methods.
　従来のグラフェンシートを用いたキャパシタは、シートを層状に重ねて静電容量を稼いでいる。（例えば、非特許文献１（Ｂ－７０２－Ｖ頁、第１３図）参照）。 Conventional capacitors using graphene sheets obtain capacitance by stacking the sheets in layers. (For example, see Non-Patent Document 1 (page B-702-V, FIG. 13)).
　層状のグラフェンシート（以下、「マルチグラフェンシート」という）の層間にイオンをインタカレーションし、マルチグラフェンシートにイオンを吸着させて、エネルギーを蓄える構造の電気二重層キャパシタにおいて、イオンをインタカレーションするのに抵抗（以下チョーキングという）があって、静電容量を稼ぐことができない。 Ions are intercalated between layers of layered graphene sheets (hereinafter referred to as "multi-graphene sheets") in an electric double layer capacitor that stores energy by adsorbing ions to the multi-graphene sheets. However, there is resistance (hereinafter referred to as choking), and the capacitance cannot be increased.
　そこで、本開示では、チョーキングを解消し、大容量化が可能な電極ペースト及び電極、蓄電デバイス、製造方法について説明する。 Therefore, in the present disclosure, an electrode paste, an electrode, a power storage device, and a manufacturing method that can eliminate choking and increase capacity will be described.
　本開示の一態様における電極ペーストは、少なくとも一端及び側壁のいずれかに貫通孔を有する多層カーボンナノチューブ及びバインダを含む、ことを特徴とする電極ペーストである。 An electrode paste according to one aspect of the present disclosure is characterized in that it contains a binder and a multi-walled carbon nanotube having a through hole in at least one end or a side wall.
　本開示によれば、多層カーボンナノチューブ（以下、「ＭＷＣＮＴ」ともいう）の一端及び側壁の少なくともいずれかに貫通孔を設けることにより、チョーキングが解消され、静電容量が向上する。 According to the present disclosure, by providing a through hole in at least one of one end and side wall of a multi-walled carbon nanotube (hereinafter also referred to as "MWCNT"), choking is eliminated and capacitance is improved.
本発明における蓄電デバイス１の構成の例示である。It is an illustration of the structure of the electricity storage device 1 in this invention. 本発明における正極１０の構成の例示である。It is an illustration of the structure of the positive electrode 10 in this invention. 本発明における電極部１０ｂの断面構成の例示である。It is an illustration of the cross-sectional structure of the electrode part 10b in this invention. 本発明における負極２０の構成の例示である。It is an illustration of the structure of the negative electrode 20 in this invention. 本発明における電極部２０ｂの断面構成の例示である。It is an illustration of the cross-sectional structure of the electrode part 20b in this invention. 実施例１の多層カーボンナノチューブの画像である。1 is an image of multi-walled carbon nanotubes of Example 1.
　本発明の実施形態の内容を列記して説明する。本発明の実施の形態による多層カーボンナノチューブ、電極ペースト、電極、蓄電デバイス、製造方法は、以下のような構成を備える。 The contents of the embodiments of the present invention will be listed and explained. Multi-walled carbon nanotubes, electrode pastes, electrodes, power storage devices, and manufacturing methods according to embodiments of the present invention have the following configurations.
［項目１］
　ＣＶＤ法により作製された多層カーボンナノチューブにマイクロ波を照射して、少なくとも一端部および側壁の少なくともいずれかに貫通孔を有する多層カーボンナノチューブを作製する第１工程を含む、
　ことを特徴とする多層カーボンナノチューブの製造方法。
［項目２］
　多層カーボンナノチューブを作製する第１工程において、前記貫通孔は、前記側壁に設けられる、
　ことを特徴とする項目１に記載の多層カーボンナノチューブの製造方法。
［項目３］
　前記第１工程は、ＣＶＤ法により作製された多層カーボンナノチューブにマイクロ波を照射する工程の前に、多層カーボンナノチューブに水分を含ませる工程をさらに含む、
　ことを特徴とする項目１または２に記載の電極ペーストの製造方法。
［項目４］
　さらに、少なくとも前記一端及び側壁の少なくともいずれかに貫通孔を有する多層カーボンナノチューブとバインダを混合して電極ペーストを作製する第２工程と、
　を含む、
　ことを特徴とする項目１または２に記載の製造方法。　
［項目５］
　さらに、前記電極ペーストを集電体に塗布して乾燥し電極を作製する第３工程を含む、
　ことを特徴とする項目４に記載の製造方法。
［項目６］
　さらに、前記電極及び負極電極、電解液、セパレータを外装容器内に収納して蓄電デバイスを作製する第４工程を含む、
　ことを特徴とする項目５に記載の製造方法。
［項目７］
　少なくとも一端部及び側壁の少なくともいずれかに貫通孔を有する多層カーボンナノチューブ。
［項目８］
　前記貫通孔は、前記側壁に設けられる、
　ことを特徴とする項目７に記載の多層カーボンナノチューブ。
［項目９］
　さらに触媒の少なくとも一部が剥離されている、
　ことを特徴とする項目７または８に記載の多層カーボンナノチューブ。
［項目１０］
　前記多層カーボンナノチューブにおける触媒を含む不純物の割合は５０％以下である、
　ことを特徴とする項目７または８に記載の多層カーボンナノチューブ。
［項目１１］
　項目７または８に記載の多層カーボンナノチューブ及びバインダを含む、
　ことを特徴とする電極ペースト。
［項目１２］
　項目１１に記載の電極ペーストを乾燥させた多層カーボンナノチューブ含有層を少なくとも一方の主面に形成される集電体を有する、
　ことを特徴とする電極。
［項目１３］
　項目１２に記載の電極、負極電極、電解液、セパレータを外装容器内に有する、
　ことを特徴とする蓄電デバイス。
［項目１４］
　前記負極電極は、グラファイト含有層を含む、
　ことを特徴とする項目１３に記載の蓄電デバイス。
［項目１５］
　前記電解液の溶質は、リチウム塩を含む、
　ことを特徴とする項目１３に記載の蓄電デバイス。 [Item 1]
A first step of irradiating a multi-walled carbon nanotube produced by a CVD method with microwaves to produce a multi-walled carbon nanotube having a through hole in at least one end and at least one of the side walls.
A method for producing multi-walled carbon nanotubes, characterized by:
[Item 2]
In the first step of producing a multi-walled carbon nanotube, the through hole is provided in the side wall,
The method for producing multi-walled carbon nanotubes according to item 1.
[Item 3]
The first step further includes a step of impregnating the multi-walled carbon nanotubes with water before the step of irradiating the multi-walled carbon nanotubes produced by the CVD method with microwaves.
The method for producing an electrode paste according to item 1 or 2, characterized in that:
[Item 4]
Further, a second step of preparing an electrode paste by mixing a binder with a multi-walled carbon nanotube having a through hole in at least one of the one end and the side wall;
including,
The manufacturing method according to item 1 or 2, characterized in that:
[Item 5]
Furthermore, it includes a third step of applying the electrode paste to a current collector and drying it to produce an electrode.
The manufacturing method according to item 4, characterized in that:
[Item 6]
Furthermore, a fourth step of manufacturing a power storage device by storing the electrode, the negative electrode, the electrolyte, and the separator in an outer container,
The manufacturing method according to item 5, characterized in that:
[Item 7]
A multi-walled carbon nanotube having a through hole in at least one end and/or a side wall.
[Item 8]
The through hole is provided in the side wall,
The multi-walled carbon nanotube according to item 7, characterized in that:
[Item 9]
Furthermore, at least a portion of the catalyst is peeled off,
The multi-walled carbon nanotube according to item 7 or 8, characterized in that:
[Item 10]
The proportion of impurities containing catalyst in the multi-walled carbon nanotube is 50% or less,
The multi-walled carbon nanotube according to item 7 or 8, characterized in that:
[Item 11]
Comprising the multi-walled carbon nanotubes and a binder according to item 7 or 8,
An electrode paste characterized by:
[Item 12]
A current collector having a multi-walled carbon nanotube-containing layer formed by drying the electrode paste according to item 11 on at least one main surface;
An electrode characterized by:
[Item 13]
Having the electrode, negative electrode, electrolyte, and separator according to item 12 in an outer container,
A power storage device characterized by:
[Item 14]
The negative electrode includes a graphite-containing layer.
The electricity storage device according to item 13, characterized in that:
[Item 15]
The solute of the electrolyte includes a lithium salt.
The electricity storage device according to item 13, characterized in that:
　以下、本開示の実施形態について図面を参照して説明する。なお、以下に説明する実施形態は、特許請求の範囲に記載された本開示の内容を不当に限定するものではない。また、実施形態に示される構成要素のすべてが、本開示の必須の構成要素であるとは限らない。また、各実施形態で示される特徴は、互いに矛盾しない限り他の実施形態にも適用可能である。 Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Note that the embodiments described below do not unduly limit the content of the present disclosure described in the claims. Furthermore, not all components shown in the embodiments are essential components of the present disclosure. Furthermore, features shown in each embodiment can be applied to other embodiments as long as they do not contradict each other.
　以下において、蓄電デバイスが積層型キャパシタ、具体的には電気二重層キャパシタ、より具体的にはリチウムイオンキャパシタである例について説明する。ただし、以下に説明する作用効果の記載からも理解され得るように、キャパシタに限らず電池であってもよいし、正極と負極を交互に積層してなる蓄電デバイスに広く適用され得る。また、蓄電デバイスは積層型に限らず、例えば巻回型であってもよいし、蛇腹に折り重ねられた積層形状であってもよいし、蓄電デバイスの種類や形状がこれらに限定されるものでもない。 An example in which the electricity storage device is a multilayer capacitor, specifically an electric double layer capacitor, and more specifically a lithium ion capacitor will be described below. However, as can be understood from the description of the effects described below, the present invention can be widely applied not only to capacitors but also to batteries, and to power storage devices in which positive electrodes and negative electrodes are alternately stacked. In addition, the power storage device is not limited to the laminated type, but may be a wound type, or a laminated shape folded into a bellows, and the type and shape of the power storage device is not limited to these. not.
（蓄電デバイス１の構成）
　蓄電デバイス１は、図１に例示されるように、リチウムイオンキャパシタであって、外装容器２と、外装容器２内に配置される、正極１０、負極２０、セパレータ３０、電解液（不図示）と、を有する。外装容器２は、金属製シート材（金属フィルム材）等であり得る。 (Configuration of power storage device 1)
As illustrated in FIG. 1, the power storage device 1 is a lithium ion capacitor, and includes an outer container 2, a positive electrode 10, a negative electrode 20, a separator 30, and an electrolyte (not shown) arranged in the outer container 2. and has. The outer container 2 may be a metal sheet material (metal film material) or the like.
　正極１０は、図２に例示されるように、端子部１０ａと電極部１０ｂを有する。端子部１０ａは、例えば電極部１０ｂに接続されるタブ上の端子であって、例えばアルミニウム等の金属により構成されている。これに代えて、電極部１０ｂを構成する正極集電体１１（例えば、導電性素材）が露出して端子として用いられてもよい。 As illustrated in FIG. 2, the positive electrode 10 has a terminal portion 10a and an electrode portion 10b. The terminal portion 10a is, for example, a terminal on a tab connected to the electrode portion 10b, and is made of metal such as aluminum. Alternatively, the positive electrode current collector 11 (for example, a conductive material) constituting the electrode portion 10b may be exposed and used as a terminal.
　電極部１０ｂは、例えば、矩形状の平面形状であって、図３に例示されるように、正極集電体１１の少なくとも一方の主面（すなわち、片方の主面または両主面）に多層カーボンナノチューブ含有層１２（以下、「ＭＷＣＮＴ含有層１２」という）を有する。 The electrode section 10b has, for example, a rectangular planar shape, and as illustrated in FIG. It has a carbon nanotube-containing layer 12 (hereinafter referred to as "MWCNT-containing layer 12").
　正極集電体１１は、導電性を有する導電性金属で構成されていることが好ましく、例えば、導電性金属箔であり得る。導電性金属としては、例えば、銅（Ｃｕ）、アルミニウム（Ａｌ）等が好ましい。正極集電体１９は、複数の孔が形成されていてもよく、空隙率は５０％以上８０％以下であるのが好ましい。 The positive electrode current collector 11 is preferably made of a conductive metal, and may be, for example, a conductive metal foil. As the conductive metal, for example, copper (Cu), aluminum (Al), etc. are preferable. The positive electrode current collector 19 may have a plurality of holes formed therein, and preferably has a porosity of 50% or more and 80% or less.
　ＭＷＣＮＴ含有層１２は、例えば、少なくとも一端及び側壁のいずれかに貫通孔を有するＭＷＣＮＴ及び導電助剤、バインダを含有する層であり、少なくとも一端及び側壁のいずれかに貫通孔を有するＭＷＣＮＴ及び導電助剤、バインダを溶媒に分散させてなる正極用電極ペーストを、集電体１１上に塗布して乾燥させたものである。導電助剤は、例えば、アセチレンブラック、ケッチェンブラック、気相法炭素繊維、黒鉛等であり得る。バインダは、ポリテトラフルオロエチレン、ポリフッ化ビニリデン、エチレン－プロピレン－ジエン共重合体、スチレン－ブタジエンゴムなどであり得る。導電助剤の濃度は、３ｗｔ％以上５％以下であるのが好ましい。なお、導電助剤は、必須ではなく、含まないようにしてもよい。 The MWCNT-containing layer 12 is, for example, a layer containing MWCNTs having through holes in at least one end and one of the side walls, a conductive agent, and a binder; A positive electrode paste prepared by dispersing a binder and a binder in a solvent is applied onto the current collector 11 and dried. The conductive aid may be, for example, acetylene black, Ketjen black, vapor grown carbon fiber, graphite, or the like. The binder can be polytetrafluoroethylene, polyvinylidene fluoride, ethylene-propylene-diene copolymer, styrene-butadiene rubber, and the like. The concentration of the conductive additive is preferably 3 wt% or more and 5% or less. Note that the conductive aid is not essential and may not be included.
　ＭＷＣＮＴは、少なくとも一端及び側壁のいずれかに貫通孔を有する。貫通孔のサイズは、３ｎｍ以上６ｎｍ以下の範囲内であることが好ましい。ＭＷＣＮＴの繊維長は、１０ｎｍ以上１ｍｍ以下の範囲内であることが好ましい。ＭＷＣＮＴの繊維径は、５ｎｍ以上５０ｎｍ以下の範囲内であることが好ましい。 The MWCNT has a through hole in at least one end and one of the side walls. The size of the through hole is preferably in the range of 3 nm or more and 6 nm or less. The fiber length of MWCNT is preferably in the range of 10 nm or more and 1 mm or less. The fiber diameter of the MWCNTs is preferably in the range of 5 nm or more and 50 nm or less.
　また、ＭＷＣＮＴは、基材の少なくとも一方の主面に触媒層を形成し、化学気相成長（ＣＶＤ：Ｃｈｅｍｉｃａｌ　Ｖａｐｏｒ　Ｄｅｐｏｓｉｔｉｏｎ）法にて触媒層上に成長させて作製される。基材は例えば、シリコン、石英、銅（Ｃｕ）等を用いてもよい。触媒層は、カーボンナノチューブを形成するための種触媒で構成され、例えば、基材に担持された、カーボンナノチューブの形成を触媒することが可能な材料（例えば、遷移金属粒子等）で構成されている。触媒層を構成する材料としては、例えば、鉄（Ｆｅ）又は鉄－チタン合金（ＦｅＴｉ）粒子等のＦｅ系種触媒粒子、コバルト（Ｃｏ）粒子、ニッケル（Ｎｉ）粒子等の種触媒粒子を用いることができる。 Furthermore, MWCNTs are produced by forming a catalyst layer on at least one main surface of a base material and growing the catalyst layer on the catalyst layer using a chemical vapor deposition (CVD) method. For example, silicon, quartz, copper (Cu), etc. may be used as the base material. The catalyst layer is composed of a seed catalyst for forming carbon nanotubes, for example, a material supported on a substrate and capable of catalyzing the formation of carbon nanotubes (for example, transition metal particles, etc.). There is. As the material constituting the catalyst layer, for example, Fe-based seed catalyst particles such as iron (Fe) or iron-titanium alloy (FeTi) particles, seed catalyst particles such as cobalt (Co) particles, nickel (Ni) particles, etc. are used. be able to.
　ここで、ＣＶＤ法にて作製されたＭＷＣＮＴにマイクロ波を照射することで、触媒を除去する。すなわち、ＣＶＤ法にて作製する都合、ＭＷＣＮＴの一端には触媒が繋がっており、ＭＷＣＮＴの側壁にも触媒を含んだ不純物が付着しているので、ここにマイクロ波を照射することで触媒が発熱することでＭＷＣＮＴから一端に繋がる触媒及び側壁に付着する触媒を含んだ不純物が除去される。その際に、触媒及び触媒を含んだ不純物が付着していた部分のＭＷＣＮＴも発熱に応じて除去されることにより、ＭＷＣＮＴの一端及び側壁の少なくともいずれか（特に側壁）に貫通孔が形成される。除去された触媒は、例えば塩酸等による酸洗浄処理によって溶解させてもよい。なお、マイクロ波を照射する際に、ＭＷＣＮＴに水分を含ませる（例えば水を混ぜてスラリー状またはペースト状にする）ことで、マイクロ波を照射による発熱が抑制され、ＭＷＣＮＴの一端及び側壁に貫通孔が適切に形成される。マイクロ波は、波長が１０，０００μｍ以上１００，０００μｍ以下の範囲内であることが好ましく、周波数が２ＧＨｚ以上３０ＧＨｚ以下の範囲内であることが好ましく、照射時間は１分以上２０分以下の範囲内であることが好ましい。ＭＷＣＮＴにおける触媒を含む不純物の割合は、マイクロ波照射前の５０ｖｏｌ％以下であることが好ましく、２０ｖｏｌ％以下であることがより好ましい。 Here, the catalyst is removed by irradiating the MWCNTs produced by the CVD method with microwaves. In other words, due to the CVD method, the catalyst is connected to one end of the MWCNT, and impurities containing the catalyst are also attached to the side walls of the MWCNT, so irradiation with microwaves causes the catalyst to generate heat. By doing so, impurities including the catalyst connected to one end and the catalyst attached to the side wall are removed from the MWCNT. At this time, portions of the MWCNT to which the catalyst and impurities containing the catalyst were attached are also removed in response to heat generation, thereby forming a through hole in at least one of one end and the side wall (particularly the side wall) of the MWCNT. . The removed catalyst may be dissolved by, for example, acid washing treatment with hydrochloric acid or the like. When irradiating microwaves, by adding moisture to MWCNTs (for example, by mixing water to form a slurry or paste), the heat generated by microwave irradiation can be suppressed, and the MWCNTs can penetrate one end and side wall of the MWCNTs. The holes are properly formed. The wavelength of the microwave is preferably within the range of 10,000 μm or more and 100,000 μm or less, the frequency is preferably within the range of 2 GHz or more and 30 GHz or less, and the irradiation time is within the range of 1 minute or more and 20 minutes or less. It is preferable that The proportion of impurities containing catalyst in the MWCNTs before microwave irradiation is preferably 50 vol% or less, more preferably 20 vol% or less.
　負極２０は、図４に例示されるように、端子部２０ａと電極部２０ｂを有する。端子部２０ａは、例えば電極部２０ｂに接続されるタブ上の端子であって、例えば銅等の金属により構成されている。これに代えて、電極部２０ｂを構成する負極集電体２１（例えば、導電性素材）が露出して端子として用いられてもよい。なお、負極２０は、正極１０と同じ構成であってもよい。 As illustrated in FIG. 4, the negative electrode 20 has a terminal portion 20a and an electrode portion 20b. The terminal portion 20a is, for example, a terminal on a tab connected to the electrode portion 20b, and is made of metal such as copper. Alternatively, the negative electrode current collector 21 (for example, a conductive material) constituting the electrode portion 20b may be exposed and used as a terminal. Note that the negative electrode 20 may have the same configuration as the positive electrode 10.
　電極部２０ｂは、例えば、矩形状の平面形状であって、図５に例示されるように、負極集電体２１の少なくとも一方の主面（すなわち、片方の主面または両主面）に負極活物質層２２を有する。 The electrode section 20b has, for example, a rectangular planar shape, and as illustrated in FIG. It has an active material layer 22.
　負極集電体２１は、導電性を有する導電性金属で構成されていることが好ましく、例えば、導電性金属箔であり得る。導電性金属としては、例えば、銅（Ｃｕ）、アルミニウム（Ａｌ）等が好ましい。負極集電体２１は、複数の孔が形成されていてもよく、空隙率は５０％以上８０％以下であるのが好ましい。 The negative electrode current collector 21 is preferably made of a conductive metal, and may be, for example, a conductive metal foil. As the conductive metal, for example, copper (Cu), aluminum (Al), etc. are preferable. The negative electrode current collector 21 may have a plurality of holes formed therein, and preferably has a porosity of 50% or more and 80% or less.
　負極活物質層２２は、例えば、少なくとも負極活物質及び導電助剤、バインダを含有する層であり、少なくとも負極活物質及び導電助剤、バインダを分散させてなる負極用ペーストを、集電体１１上に塗布して乾燥させたものである。負極活物質は、炭素粉末、黒鉛粉末等であってもよいが、特にグラファイトであってもよい。導電助剤は、例えば、アセチレンブラック、ケッチェンブラック、気相法炭素繊維、黒鉛等であり得る。バインダは、ポリフッ化ビニリデン、スチレン－ブタジエンゴム、カルボキシメチルセルロースなどであり得る。導電助剤の濃度は、３ｗｔ％以上５％以下であるのが好ましい。なお、導電助剤は、必須ではなく、含まないようにしてもよい。バインダは、３ｗｔ％以上５ｗｔ％以下であるのが好ましい。 The negative electrode active material layer 22 is, for example, a layer containing at least a negative electrode active material, a conductive agent, and a binder, and a negative electrode paste in which at least the negative electrode active material, a conductive agent, and a binder are dispersed is applied to the current collector 11. It is coated on top and allowed to dry. The negative electrode active material may be carbon powder, graphite powder, etc., and particularly graphite. The conductive aid may be, for example, acetylene black, Ketjen black, vapor grown carbon fiber, graphite, or the like. The binder can be polyvinylidene fluoride, styrene-butadiene rubber, carboxymethyl cellulose, and the like. The concentration of the conductive additive is preferably 3 wt% or more and 5% or less. Note that the conductive aid is not essential and may not be included. The content of the binder is preferably 3 wt% or more and 5 wt% or less.
　セパレータ３０は、例えば、絶縁性の材料によって形成された多孔質体や不織布等を用いることができる。 For the separator 30, for example, a porous body made of an insulating material, a nonwoven fabric, or the like can be used.
　電解液は、電解質と、溶媒とを含む。電解質は、蓄電デバイス１が電気二重層キャパシタの場合、テトラエチルアンモニウム４フッ化ホウ酸、トリエチルメチルアンモニウム４フッ化ホウ酸が一般的に使用される。溶媒は、プロピレンカーボネートが一般的である。 The electrolytic solution includes an electrolyte and a solvent. As the electrolyte, when the electricity storage device 1 is an electric double layer capacitor, tetraethylammonium tetrafluoroboric acid and triethylmethylammonium tetrafluoroboric acid are generally used. The solvent is generally propylene carbonate.
　蓄電デバイス１がリチウムイオンキャパシタの場合、電解液である溶質は、ＬｉＰＦ６やＬｉＢＦ４、ＬｉＣｌＯ４等のリチウム塩を用いることができる。溶媒は、ＥＣ（エチレンカーボネート）やＤＥＣ（ジエチルカーボネート）、ＤＭＣ（ジメチルカーボネート）、ＭＥＣ（メチルエチルカーボネート）、ニトリル系溶媒（例えば、アセトニトリルなど）等を含む非水溶媒を用いることができる。 When the electricity storage device 1 is a lithium ion capacitor, a lithium salt such as LiPF6, LiBF4, or LiClO4 can be used as the solute that is the electrolytic solution. As the solvent, a non-aqueous solvent including EC (ethylene carbonate), DEC (diethyl carbonate), DMC (dimethyl carbonate), MEC (methyl ethyl carbonate), nitrile solvent (for example, acetonitrile), etc. can be used.
　（電極部１０ｂの製造方法）
　電極部１０ｂは、少なくとも一端及び側壁のいずれかに貫通孔を有するＭＷＣＮＴを作製する工程、正極用電極ペーストを作製する工程、正極用電極ペーストを正極集電体１１に塗布して乾燥する工程によって、製造することができる。なお、以下に示す製造方法は一例であって、これに限られるものではない。 (Method for manufacturing electrode part 10b)
The electrode part 10b is formed by a process of manufacturing MWCNTs having a through hole at least at one end and a side wall, a process of manufacturing a positive electrode paste, and a process of applying the positive electrode paste to the positive electrode current collector 11 and drying it. , can be manufactured. In addition, the manufacturing method shown below is an example, Comprising: It is not limited to this.
　まず、少なくとも一端及び側壁のいずれかに貫通孔を有するＭＷＣＮＴを作製する工程について説明する。 First, a process for producing MWCNTs having a through hole in at least one end and one of the side walls will be described.
　そして、マイクロ波照射により一端に繋がる触媒層及び側壁に付着する触媒を含んだ不純物を除去することで、少なくとも一端及び側壁のいずれかに貫通孔を有するＭＷＣＮＴを作製する。除去された触媒は、例えば塩酸等による酸洗浄処理によって溶解させてもよい。さらに、触媒層が除去されたＭＷＣＮＴを３５０℃～４００℃に加熱して、ＭＷＣＮＴの他端に形成されるキャッピングを除去することで、両端が開放されたＭＷＣＮＴを作製する。３５０℃より低い温度では、キャッピングの除去は困難であり、４００℃より高い温度ではＣＮＴが燃焼し量が減少する。なお、ＭＷＣＮＴの長さが長い場合などには、自転公転式粉砕機及びジルコニア球（例えば１００μｍ）により切断する工程を含んでいてもよいし、キャッピングを除去する工程に代えて、本工程を実施することで両端が開放されたＭＷＣＮＴを作製してもよい。 Then, impurities containing catalyst adhering to the catalyst layer and side wall connected to one end are removed by microwave irradiation, thereby producing MWCNTs having through holes at least at one end and either the side wall. The removed catalyst may be dissolved by, for example, acid washing treatment with hydrochloric acid or the like. Furthermore, the MWCNTs from which the catalyst layer has been removed are heated to 350° C. to 400° C. to remove the capping formed at the other end of the MWCNTs, thereby producing MWCNTs with both ends open. At temperatures below 350°C, it is difficult to remove the capping, and at temperatures above 400°C, the CNTs burn and the amount decreases. In addition, when the length of MWCNT is long, it may include a step of cutting with a rotation-revolution type crusher and a zirconia ball (for example, 100 μm), or this step may be performed instead of the step of removing the capping. By doing so, MWCNTs with both ends open may be produced.
　また、少なくとも一端及び側壁のいずれかに貫通孔を有するＭＷＣＮＴを硫酸と過マンガン酸カリウムで酸化し、ＯＨ基、ＣＯＯＨ基を導入し、ＭＷＣＮＴ各層間の結合力を弱める。これにより、チョーキングを解消することが可能となる。 Additionally, MWCNTs having through-holes on at least one end and one of the side walls are oxidized with sulfuric acid and potassium permanganate to introduce OH groups and COOH groups to weaken the bonding force between each layer of MWCNTs. This makes it possible to eliminate choking.
　次に、正極用電極ペーストを作製する工程について説明する。少なくとも一端及び側壁のいずれかに貫通孔を有するＭＷＣＮＴ及び導電助剤、バインダを有機溶媒と混合して正極用電極ペーストを作製する。 Next, the process of producing a positive electrode paste will be explained. An electrode paste for a positive electrode is prepared by mixing MWCNTs having through holes in at least one end and one of the side walls, a conductive additive, and a binder with an organic solvent.
　次に、正極用電極ペーストを正極集電体１１に塗布して乾燥する工程について説明する。正極用電極ペーストを正極集電体１１上に塗布し、１５０度の乾燥装置にて２時間放置して乾燥する。 Next, the process of applying the positive electrode paste to the positive electrode current collector 11 and drying it will be described. The positive electrode paste is applied onto the positive electrode current collector 11 and left to dry in a drying device at 150 degrees for 2 hours.
　（実施例１）
　実施例１では、ＭＷＣＮＴは２．４５ＧＨｚのマイクロ波を１７分照射して触媒層及び触媒を含んだ不純物を除去しし、当該ＭＷＣＮＴ及び導電性助剤、バインダを加えて超音波により分散し電極ペーストを作成し、正極集電極上に塗布して乾燥させ、正極を作製した。 (Example 1)
In Example 1, the MWCNTs were irradiated with 2.45 GHz microwaves for 17 minutes to remove the catalyst layer and impurities containing the catalyst, and the MWCNTs, a conductive auxiliary agent, and a binder were added and dispersed by ultrasonic waves to form an electrode. A paste was created, applied onto a positive collector electrode, and dried to produce a positive electrode.
　負極はグラファイトにバインダを加えて超音波により分散し電極ペーストを作成し、負極集電極上に塗布して乾燥させて作製した。 The negative electrode was prepared by adding a binder to graphite and dispersing it using ultrasonic waves to create an electrode paste, which was then applied onto the negative collector electrode and dried.
　作製した正極を５層、そして、作製した負極、セパレータ、電解液を外装容器内に配置して蓄電デバイスを作製した。 Five layers of the produced positive electrode, and the produced negative electrode, separator, and electrolytic solution were arranged in an outer container to produce an electricity storage device.
　（比較例１）
　比較例１では実施例１のＭＷＣＮＴに代えて一端及び側壁に貫通孔を有しないＭＷＣＮＴを採用した点を除いて、実施例１と同一である。 (Comparative example 1)
Comparative Example 1 is the same as Example 1 except that MWCNTs having no through holes at one end and side wall were used instead of MWCNTs in Example 1.
　実施例１の蓄電デバイスの静電容量と比較例１の蓄電デバイスの静電容量とを比較した結果、実施例１の蓄電デバイスの静電容量は、比較例１の蓄電デバイスの静電容量の約７～１０倍であった。 As a result of comparing the capacitance of the power storage device of Example 1 and the capacitance of the power storage device of Comparative Example 1, the capacitance of the power storage device of Example 1 is equal to that of the power storage device of Comparative Example 1. It was about 7 to 10 times.
　ここで、実施例１のＭＷＣＮＴを図６に示す。通常、ＭＷＣＮＴの先端部には触媒の塊が繋がっている。しかしながら、マイクロ波を照射することにより触媒が熱を帯び、周囲のＭＷＣＮＴを燃焼することで図６に示されるように触媒が剥離される。また、ＭＷＣＮＴの側壁に付着する触媒を含む不純物についても同様である。そして、上述のとおり、特に塩酸等による酸洗浄処理によって溶解することで、ＭＷＣＮＴの先端部及び側壁の少なくともいずれかに貫通孔が設けられ、当該貫通孔を通してイオンがインタカレーションされやすくなり、静電容量が向上すると考えられる。 Here, the MWCNT of Example 1 is shown in FIG. Usually, a mass of catalyst is connected to the tip of the MWCNT. However, by irradiating the microwave, the catalyst becomes heated and the surrounding MWCNTs are burned, thereby peeling off the catalyst as shown in FIG. Furthermore, the same applies to impurities including catalysts that adhere to the side walls of MWCNTs. As mentioned above, by dissolving the MWCNTs by acid cleaning treatment, especially with hydrochloric acid, a through hole is provided in at least one of the tip and side wall of the MWCNT, and ions are easily intercalated through the through hole, and the MWCNT becomes static. It is thought that the capacitance will improve.
　＜効果＞
　以上のように、多層カーボンナノチューブ（以下、「ＭＷＣＮＴ」ともいう）の一端部及び側壁の少なくともいずれかに貫通孔を設けることにより（特にマイクロ波を用いて側壁に貫通孔を適切に設けることにより）、チョーキングが解消され、静電容量が向上する。 <Effect>
As described above, by providing a through hole in at least one of the end portion and the side wall of a multi-walled carbon nanotube (hereinafter also referred to as "MWCNT") (particularly by appropriately providing a through hole in the side wall using microwaves). ), choking is eliminated and capacitance is improved.
　以上、開示に係る実施形態について説明したが、これらはその他の様々な形態で実施することが可能であり、種々の省略、置換および変更を行なって実施することが出来る。これらの実施形態および変形例ならびに省略、置換および変更を行なったものは、特許請求の範囲の技術的範囲とその均等の範囲に含まれる。 Although the disclosed embodiments have been described above, they can be implemented in various other forms, and can be implemented with various omissions, substitutions, and changes. These embodiments and modifications, as well as omissions, substitutions, and changes, are included within the technical scope of the claims and their equivalents.
　　１　　　蓄電デバイス
　　２　　　外装容器
　１０　　　正極
　２０　　　負極
　３０　　　セパレータ 1 Electricity storage device 2 External container 10 Positive electrode 20 Negative electrode 30 Separator

Claims (15)

  1. 　ＣＶＤ法により作製された多層カーボンナノチューブにマイクロ波を照射して、少なくとも一端部および側壁の少なくともいずれかに貫通孔を有する多層カーボンナノチューブを作製する第１工程を含む、
    　ことを特徴とする多層カーボンナノチューブの製造方法。     A first step of irradiating a multi-walled carbon nanotube produced by a CVD method with microwaves to produce a multi-walled carbon nanotube having a through hole in at least one end and at least one of the side walls.
    A method for producing multi-walled carbon nanotubes, characterized by:
  2. 　多層カーボンナノチューブを作製する第１工程において、前記貫通孔は、前記側壁に設けられる、
    　ことを特徴とする請求項１に記載の多層カーボンナノチューブの製造方法。     In the first step of producing a multi-walled carbon nanotube, the through hole is provided in the side wall,
    The method for producing multi-walled carbon nanotubes according to claim 1.
  3. 　前記第１工程は、ＣＶＤ法により作製された多層カーボンナノチューブにマイクロ波を照射する工程の前に、多層カーボンナノチューブに水分を含ませる工程をさらに含む、
    　ことを特徴とする請求項１または２に記載の電極ペーストの製造方法。     The first step further includes a step of impregnating the multi-walled carbon nanotubes with water before the step of irradiating the multi-walled carbon nanotubes produced by the CVD method with microwaves.
    The method for producing an electrode paste according to claim 1 or 2, characterized in that:
  4. 　さらに、少なくとも前記一端及び側壁の少なくともいずれかに貫通孔を有する多層カーボンナノチューブとバインダを混合して電極ペーストを作製する第２工程と、
    　を含む、
    　ことを特徴とする請求項１または２に記載の製造方法。　     Further, a second step of preparing an electrode paste by mixing a binder with a multi-walled carbon nanotube having a through hole in at least one of the one end and the side wall;
    including,
    The manufacturing method according to claim 1 or 2, characterized in that:
  5. 　さらに、前記電極ペーストを集電体に塗布して乾燥し電極を作製する第３工程を含む、
    　ことを特徴とする請求項４に記載の製造方法。     Furthermore, it includes a third step of applying the electrode paste to a current collector and drying it to produce an electrode.
    The manufacturing method according to claim 4, characterized in that:
  6. 　さらに、前記電極及び負極電極、電解液、セパレータを外装容器内に収納して蓄電デバイスを作製する第４工程を含む、
    　ことを特徴とする請求項５に記載の製造方法。     Furthermore, a fourth step of manufacturing a power storage device by storing the electrode, the negative electrode, the electrolyte, and the separator in an outer container,
    The manufacturing method according to claim 5, characterized in that:
  7. 　少なくとも一端部及び側壁の少なくともいずれかに貫通孔を有する多層カーボンナノチューブ。 A multi-walled carbon nanotube having a through hole in at least one end and at least one of the side walls.
  8. 　前記貫通孔は、前記側壁に設けられる、
    　ことを特徴とする請求項７に記載の多層カーボンナノチューブ。     The through hole is provided in the side wall,
    The multi-walled carbon nanotube according to claim 7, characterized in that:
  9. 　さらに触媒の少なくとも一部が剥離されている、
    　ことを特徴とする請求項７または８に記載の多層カーボンナノチューブ。     Furthermore, at least a portion of the catalyst is peeled off,
    The multi-walled carbon nanotube according to claim 7 or 8, characterized in that:
  10. 　前記多層カーボンナノチューブにおける触媒を含む不純物の割合は５０％以下である、
    　ことを特徴とする請求項７または８に記載の多層カーボンナノチューブ。     The proportion of impurities containing catalyst in the multi-walled carbon nanotube is 50% or less,
    The multi-walled carbon nanotube according to claim 7 or 8, characterized in that:
  11. 　請求項７または８に記載の多層カーボンナノチューブ及びバインダを含む、
    　ことを特徴とする電極ペースト。     comprising a multi-walled carbon nanotube and a binder according to claim 7 or 8;
    An electrode paste characterized by:
  12. 　請求項１１に記載の電極ペーストを乾燥させた多層カーボンナノチューブ含有層を少なくとも一方の主面に形成される集電体を有する、
    　ことを特徴とする電極。     A current collector having a multi-walled carbon nanotube-containing layer formed by drying the electrode paste according to claim 11 on at least one main surface.
    An electrode characterized by:
  13. 　請求項１２に記載の電極、負極電極、電解液、セパレータを外装容器内に有する、
    　ことを特徴とする蓄電デバイス。     Having the electrode, negative electrode, electrolyte, and separator according to claim 12 in an outer container,
    A power storage device characterized by:
  14. 　前記負極電極は、グラファイト含有層を含む、
    　ことを特徴とする請求項１３に記載の蓄電デバイス。     The negative electrode includes a graphite-containing layer.
    The electricity storage device according to claim 13.
  15. 　前記電解液の溶質は、リチウム塩を含む、
    　ことを特徴とする請求項１３に記載の蓄電デバイス。
     

          The solute of the electrolyte includes a lithium salt.
    The electricity storage device according to claim 13.
PCT/JP2022/024979 2022-06-22 2022-06-22 Multi-walled carbon nanotube, electrode paste, electrode, power storage device, and production method WO2023248396A1 (en)

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