WO2014038692A1 - 空気電池の空気極用炭素材料、及び当該炭素材料を含む空気電池 - Google Patents

空気電池の空気極用炭素材料、及び当該炭素材料を含む空気電池 Download PDF

Info

Publication number
WO2014038692A1
WO2014038692A1 PCT/JP2013/074249 JP2013074249W WO2014038692A1 WO 2014038692 A1 WO2014038692 A1 WO 2014038692A1 JP 2013074249 W JP2013074249 W JP 2013074249W WO 2014038692 A1 WO2014038692 A1 WO 2014038692A1
Authority
WO
WIPO (PCT)
Prior art keywords
carbon
air
carbon material
air battery
carbon fiber
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/JP2013/074249
Other languages
English (en)
French (fr)
Japanese (ja)
Inventor
豊田　昌宏
飯坂　浩文
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
NATIONAL UNIVERSITY Corp OITA UNIVERSITY
Toyota Motor Corp
Original Assignee
NATIONAL UNIVERSITY Corp OITA UNIVERSITY
Toyota Motor Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by NATIONAL UNIVERSITY Corp OITA UNIVERSITY, Toyota Motor Corp filed Critical NATIONAL UNIVERSITY Corp OITA UNIVERSITY
Priority to US14/426,918 priority Critical patent/US20150229012A1/en
Priority to CN201380046942.7A priority patent/CN104604021A/zh
Priority to EP13835572.2A priority patent/EP2894707A4/en
Publication of WO2014038692A1 publication Critical patent/WO2014038692A1/ja
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Images

Classifications

    • D—TEXTILES; PAPER
    • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
    • D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
    • D01F11/00—Chemical after-treatment of artificial filaments or the like during manufacture
    • D01F11/10—Chemical after-treatment of artificial filaments or the like during manufacture of carbon
    • D01F11/12—Chemical after-treatment of artificial filaments or the like during manufacture of carbon with inorganic substances ; Intercalation
    • D01F11/122—Oxygen, oxygen-generating compounds
    • D—TEXTILES; PAPER
    • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
    • D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
    • D01F11/00—Chemical after-treatment of artificial filaments or the like during manufacture
    • D01F11/10—Chemical after-treatment of artificial filaments or the like during manufacture of carbon
    • D01F11/12—Chemical after-treatment of artificial filaments or the like during manufacture of carbon with inorganic substances ; Intercalation
    • D01F11/129—Intercalated carbon- or graphite fibres
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M12/00—Hybrid cells; Manufacture thereof
    • H01M12/08—Hybrid cells; Manufacture thereof composed of a half-cell of a fuel-cell type and a half-cell of the secondary-cell type
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/58—Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
    • H01M4/583—Carbonaceous material, e.g. graphite-intercalation compounds or CFx
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/86—Inert electrodes with catalytic activity, e.g. for fuel cells
    • H01M4/96—Carbon-based electrodes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/38—Selection of substances as active materials, active masses, active liquids of elements or alloys
    • H01M4/381—Alkaline or alkaline earth metals elements
    • H01M4/382—Lithium
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
    • Y10T428/2913—Rod, strand, filament or fiber
    • Y10T428/2918—Rod, strand, filament or fiber including free carbon or carbide or therewith [not as steel]

Definitions

  • the present invention relates to a carbon material for an air electrode of an air battery, which has more reaction starting points for an oxygen reduction reaction than a conventional carbon material, and an air battery including the carbon material.
  • An air battery is a chargeable / dischargeable battery using a single metal or a metal compound as a negative electrode active material and oxygen as a positive electrode active material. Since oxygen, which is a positive electrode active material, is obtained from air, it is not necessary to enclose the positive electrode active material in the battery. Therefore, in theory, an air battery has a larger capacity than a secondary battery using a solid positive electrode active material. realizable.
  • a carbon material is usually used for the air electrode of an air battery.
  • the definitive knowledge about what kind of property of the carbon material affects the air electrode capacity has not been obtained. Therefore, there has been no decisive guide as to how the carbon material blended in the air electrode can be improved to increase the capacity of the air battery.
  • Patent Document 1 discloses a positive electrode mainly composed of a carbonaceous material having a pore volume of 1.0 mL / g or more, which is occupied by pores having a diameter of 1 nm or more, A nonaqueous electrolyte battery comprising a negative electrode including a negative electrode active material that occludes and releases metal ions, and a nonaqueous electrolyte layer sandwiched between the positive electrode and the negative electrode is disclosed.
  • Patent Document 1 describes examples of nonaqueous electrolyte batteries using ketjen black for the air electrode.
  • the inventors further examined the non-aqueous electrolyte battery disclosed in Patent Document 1, and found that when Ketjen Black was used for the air electrode, the capacity was still low and the reaction resistance was also high.
  • the present invention has been accomplished in view of the above circumstances, and provides a carbon material for an air electrode of an air battery, which has more reaction starting points for an oxygen reduction reaction than a conventional carbon material, and an air battery including the carbon material. The purpose is to do.
  • the carbon material for an air electrode of the air battery of the present invention is characterized in that the average aspect ratio of the carbon material is 1 or more and less than 10, and the edge area of the surface of the carbon material is 55 m 2 / g or more. .
  • the carbon material for the air electrode of the air battery of the present invention is preferably an expanded carbon fiber.
  • a first air battery according to the present invention is an air battery including at least an air electrode, a negative electrode, and an electrolyte layer interposed between the air electrode and the negative electrode, wherein the air electrode is an air electrode of the air battery. It contains carbon materials for use.
  • the negative electrode may contain lithium metal or a lithium compound.
  • the second air battery of the present invention is an air battery in which an electrolyte is interposed between an air electrode and a lithium metal or lithium compound negative electrode, and the air electrode has a porous three-phase interface site in communication therewith.
  • the ratio D / G of the graphitized part D to the defect part G obtained by Raman shift of the carbon fiber material is 0.1 to 1.5, and the three-phase interface
  • the edge area of the site is 55 m 2 / g or more.
  • the porous carbon fiber material is preferably expanded carbon fiber.
  • the porous carbon fiber material preferably has an average aspect ratio of 1 or more and less than 10.
  • the edge area of the surface is 55 m 2 / g or more, the reaction starting point of the oxygen reduction reaction is larger than that of the conventional carbon material.
  • a carbon material is used for the air electrode of an air battery.
  • electrons can be exchanged between the carbon material and a larger number of oxygen molecules, and higher capacity can be realized than the conventional air battery.
  • FIG. 1 shows an example of the laminated constitution of the air battery of this invention, Comprising: It is the figure which showed typically the cross section cut
  • 2 is a SEM image of expanded carbon fiber of Example 1.
  • 2 is a TEM image of an expanded carbon fiber of Example 1.
  • the carbon material for an air electrode of an air battery has an average aspect ratio of the carbon material of 1 or more and less than 10, and an edge area of the surface of the carbon material is 55 m 2 / g. It is the above.
  • the air battery using ketjen black for the air electrode layer has a low capacity and has a significant deterioration in durability, and thus cannot withstand repeated use. This is because, in the prior art, sufficient study on the surface structure of the carbon material has not been made, and the amount of functional groups added to the surface of the carbon material and the edge area of the surface of the carbon material so as to improve the capacity of the air battery. This is because almost no knowledge was obtained.
  • the inventors of the present invention focused on a carbon material having a larger edge area on the surface than in the prior art, and repeated studies. As a result, the present inventors increase the number of reaction starting points of the oxygen reduction reaction and suppress the reaction resistance of the air electrode by using a carbon material having a predetermined average aspect ratio and surface edge area for the air electrode. As a result, it has been found that the charge capacity of the air electrode can be improved, and the present invention has been completed.
  • the average aspect ratio of the carbon material used in the present invention is 1 or more and less than 10.
  • a carbon material having a relatively small average aspect ratio it becomes easier to close-pack the carbon material in the air electrode, and as a result, the density of the air electrode can be increased and the electrode reaction sites can be increased.
  • TEM transmission electron microscope
  • a major axis and a minor axis are measured for a plurality of carbon materials, respectively.
  • a method of calculating an aspect ratio from the major axis and the minor axis and taking the average of the aspect ratios can be used.
  • the shape of the carbon material used in the present invention is not particularly limited as long as it is within the range of the above average aspect ratio, and may take a shape such as a flake shape, a fiber shape, a flat plate shape, a prismatic shape, a cylindrical shape, or a bowl shape. it can.
  • the carbon material used in the present invention is preferably in the form of flakes (flakes).
  • the edge area of the surface of the carbon material used in the present invention is 55 m 2 / g or more.
  • the edge area of the surface of the carbon material refers to the area occupied by the carbon edge portion on the surface of the carbon material.
  • the carbon edge portion refers to a portion occupied by edge carbon atoms.
  • FIG. 2 is a schematic diagram showing the chemical structure of the carbon material used in the present invention.
  • FIG. 2 shows a carbon material model having three carbon atom layers.
  • the carbon material model is only an example given for explaining the edge area of the surface, and is used in the present invention.
  • the carbon material is not necessarily limited to that shown in FIG.
  • the carbon material 200 is composed of three carbon atom layers 11 stacked.
  • edge carbon atom in the present invention refers to a carbon atom located at the end of the carbon atom layer, and the end is less than 180 ° centering on the carbon atom. Therefore, as shown by the white circles in FIG. 2, even if it is located at the end of the carbon atom layer, the end is located at a carbon atom whose center is 180 ° or more, or inside the carbon atom layer. Carbon atoms are not edge carbon atoms.
  • edge carbon atom even if it is an edge carbon atom, the carbon atom which does not exist in the carbon material surface and is buried in the carbon material is not taken into consideration in the calculation of the edge area of the carbon material surface. Edge carbon atoms can be bonded to atoms other than carbon atoms, whereas carbon atoms other than edge carbon atoms in the carbon atom layer have no bond in principle other than carbon atoms.
  • the edge area of the surface of the carbon material is the area of the portion occupied by the edge carbon atoms located on the surface of the carbon material.
  • the area of the portion occupied by edge carbon atoms is the distance between the nearest edge carbon atoms multiplied by the distance between the carbon atom layers.
  • a combination of edge carbon atoms represented by black circles 11a 1 and black circles 11a 2 is taken as an example of the combination of edge carbon atoms that are located on the surface of the carbon material and that are closest.
  • the distance 11c between the edge carbon atoms represented by the black circle 11a 1 and the black circle 11a 2 is (0.142 ⁇ sin 60 °).
  • the edge area of the surface of the carbon material is obtained.
  • the edge area of the surface of the carbon material used in the present invention is preferably 80 m 2 / g or more, and more preferably 90 m 2 / g or more.
  • the edge area of the surface of the carbon material used in the present invention is preferably 110m 2 / g or less, more preferably 100 m 2 / g or less.
  • a method for measuring the edge area of the surface of the carbon material will be described below.
  • the following measurement method is merely an example, and the edge area of the surface of the carbon material defined in the present invention is not limited to only one measured by the following measurement method.
  • a carbon material is installed in a temperature raising device equipped with a heating furnace or the like.
  • the temperature inside the temperature raising device is set to 100 ° C. or more, and is kept as it is for a predetermined time, thereby releasing the water adsorbed in the carbon material.
  • the temperature in the temperature raising device is raised to 800 to 1,500 ° C.
  • edge carbon atoms The hydrogen atom (H) bonded to is heated and oxidized to water (H 2 O). Moisture released when the temperature is oxidized is quantified with a moisture meter.
  • the edge area S of the surface of the carbon material is calculated from the following formula (A) by obtaining the molar molar concentration of hydrogen (H 2 ) from the quantitative molar concentration of water (H 2 O).
  • the value of 0.082 in the following formula (A) is the value of the area 11e of the portion occupied by the edge carbon atoms in FIG.
  • the reaction is mainly an oxygen reduction reaction represented by at least one of the above formulas (II) and (III).
  • a D / G ratio can be exemplified.
  • the D / G ratio refers to the ratio of the peak intensity at 1360 cm ⁇ 1 (D band) to the peak intensity at 1580 cm ⁇ 1 (G band) in the Raman spectrum of the carbon material.
  • the D band is a peak corresponding to a defect portion that is likely to be a reaction starting point in the carbon material, such as a carbon edge portion or a strained portion.
  • the G band is a peak corresponding to a graphitized part that is unlikely to be a reaction starting point in a carbon material, such as a carbon network surface. Therefore, it is considered that the number of reaction starting points increases as the D / G ratio value increases.
  • the defect portion corresponding to the D band is considered to be a place where oxygen molecules first receive electrons from the carbon material.
  • the ratio of the defect portion to the graphitized portion obtained by Raman shift is preferably 0.10 to 1.5.
  • the D / G ratio of the carbon material is less than 0.10, the ratio of the defect part (reaction starting point related to oxygen reduction) in the carbon material surface is too low, and the ratio of the graphitized part in the carbon material surface is Since it is too high, when the carbon material is used for the air electrode of an air battery, the effective discharge voltage of the air battery may be reduced.
  • the D / G ratio of the carbon material exceeds 1.5, an undesirable side reaction may occur because the ratio of the defective portion in the surface of the carbon material is too high.
  • the D / G ratio of the carbon material used in the present invention is more preferably 0.15 or more, and further preferably 0.20 or more.
  • the D / G ratio of the carbon material used in the present invention is more preferably 1.4 or less, and further preferably 1.2 or less.
  • examples of the method for measuring the D / G ratio of the carbon material include a method of calculating from the peak intensities of the G band and the D band in the Raman spectrum of the carbon material as described above.
  • the measurement result has a certain width due to the electron density, defect amount, and crystallite in the carbon material. May occur.
  • the amount of the oxygen functional group contained in the carbon material used in the present invention is preferably 50 to 20,000 ⁇ mol / g.
  • the oxygen functional group contained in the carbon material promotes adsorption of a highly polar molecule from both the gas phase and the liquid phase to the carbon material.
  • highly polar molecules such as lithium oxide are competitively adsorbed on the oxygen functional group. It will come off. Therefore, an air battery using a carbon material having an excessive amount of oxygen functional groups may have a low discharge capacity.
  • the amount of the oxygen functional group contained in the carbon material used in the present invention is more preferably 70 ⁇ mol / g or more, and further preferably 100 ⁇ mol / g or more.
  • the amount of the oxygen functional group contained in the carbon material used in the present invention is more preferably 15,000 ⁇ mol / g or less, and further preferably 10,000 ⁇ mol / g or less.
  • the example of the measuring method of the oxygen functional group contained in a carbon material is demonstrated below.
  • the following measurement method is merely an example, and the oxygen functional groups contained in the carbon material used in the present invention are not limited to those measured by this method.
  • a carbon material is installed in a temperature raising device equipped with a heating furnace or the like.
  • the temperature inside the temperature raising device is set to 100 ° C. or more, and is kept as it is for a predetermined time, thereby releasing the water adsorbed in the carbon material.
  • the temperature in the temperature raising device is raised to 800 to 1,500 ° C.
  • an expanded carbon fiber can be exemplified.
  • the carbon material for an air electrode of the air battery of the present invention is preferably an expanded carbon fiber.
  • An expanded carbon fiber refers to a fine carbon fiber obtained by further heat-treating a graphite intercalation compound synthesized using a carbon fiber raw material.
  • the manufacturing method of expanded carbon fiber is not specifically limited, For example, a chemical processing method, an electrochemical processing method, etc. are mentioned.
  • the expanded carbon fiber may be appropriately classified or ground.
  • FIG. 3 (a) is an enlarged schematic view of the structure of the expanded carbon fiber
  • FIG. 3 (b) is a schematic view of the chemical structure of the carbon atom layer of the expanded carbon fiber.
  • FIG. 3B is a schematic diagram further enlarging the inside of the circle of the broken line part of FIG.
  • pitch-based carbon fiber As the carbon fiber raw material used for the production of the expanded carbon fiber, pitch-based carbon fiber, PAN-based carbon fiber, or vapor-grown carbon fiber is preferable. Many of these carbon fibers have sp 2 hybrid orbitals similar to graphite. For example, pitch-based carbon fibers that have been heat-treated at a high temperature have extremely high crystallinity compared to simple graphite, and the strong bonds between carbon atoms derived from them affect the strength and elasticity of the pitch-based carbon fibers. It is exerting. In general, PAN-based carbon fibers and pitch-based carbon fibers are greatly affected by the infusibilization treatment method and heat treatment temperature in improving strength and elastic modulus, and the excellent physical properties of these carbon fiber raw materials are obtained after expansion. It is maintained even in fibrillar microfibers.
  • graphite and carbon fibers having a layered structure carbon atoms in the a-axis direction and the b-axis direction, which are crystallographically substantially parallel to the carbon atom layer, are connected by a strong covalent bond.
  • Examples of a method for synthesizing a graphite intercalation compound using a carbon fiber raw material include a chemical treatment method and an electrochemical treatment method.
  • a chemical treatment method which is one of the chemical treatment methods
  • an oxidizing agent such as concentrated sulfuric acid, nitric acid, potassium permanganate, or a base such as potassium hydroxide or sodium hydroxide is added to the carbon material.
  • the molecule of the oxidizing agent or the molecule of the base is taken in between the carbon atom layers, and the graphite intercalation compound can be synthesized.
  • a graphite intercalation compound is obtained by electrochemically oxidizing a carbon fiber raw material in an acid electrolyte such as nitric acid or sulfuric acid. Can be synthesized.
  • the obtained graphite intercalation compound becomes a small fiber shape having an average particle size of 1 ⁇ m or less after pyrolysis. This is because when the atoms, molecules, ions, etc. inserted between the carbon atom layers are decomposed by heat treatment and the decomposition products are released out of the carbon atom layer, the laminated structure of the carbon atom layer is partially broken.
  • the carbon fiber raw material is changed from a simple carbon fiber shape to a fine fiber shape.
  • the electrochemical treatment method for the expanded carbon fiber preferably includes an electrochemical treatment step, a cleaning step, and a carbonization treatment step.
  • the electrochemical treatment step is a step of producing a graphite intercalation compound by inserting at least one of atoms, molecules and ions (hereinafter sometimes referred to as atoms) between carbon atom layers by electrochemical treatment. It is.
  • the washing step is a step of washing away excess electrolyte components and atoms adhering to the surface of the graphite intercalation compound.
  • the carbonization treatment step is a step of removing atoms inserted between carbon atom layers of the graphite intercalation compound and expanding the carbon atom layer.
  • the electrochemical treatment method is not limited to the above three steps.
  • a drying step for removing the solvent used for washing or the like between the washing step and the carbonization treatment step
  • a grinding step or the like for efficiently advancing the carbonization treatment may be provided, or a classification step or the like for obtaining a carbon material having a particle size within a predetermined range may be used after the carbonization treatment step. .
  • electrochemical treatment apparatus used for the electrochemical treatment method a known apparatus used for electrolytic oxidation can be appropriately used.
  • electrochemical processing devices include current and voltage control devices such as electrochemical cells and potentiostats / galvanostats.
  • electrochemical cell for example, a triode cell having a working electrode, a counter electrode, and a reference electrode can be used.
  • a working electrode, a counter electrode, and a reference electrode to which a carbon fiber raw material is fixed are all immersed in an electrolytic solution.
  • the amount of the electrolyte is preferably such that the carbon fiber raw material is sufficiently immersed.
  • an acid can usually be used.
  • the type of acid is not particularly limited as long as it causes electrolysis when energized.
  • Examples of the acid include organic acids, inorganic acids, and mixtures thereof.
  • examples of inorganic acids include sulfuric acid, concentrated sulfuric acid, nitric acid, concentrated nitric acid, and phosphoric acid.
  • Examples of the organic acid include formic acid and acetic acid. Among these acids, concentrated nitric acid, formic acid, and dilute sulfuric acid having a concentration of 9 mol / dm 3 or less are preferable, and concentrated nitric acid is more preferable.
  • the working electrode, the counter electrode, and the reference electrode are connected to a current and voltage control device such as a potentiostat / galvanostat and an electrochemical process is performed to insert atoms and the like between the carbon atom layers.
  • a current and voltage control device such as a potentiostat / galvanostat
  • an electrochemical process is performed to insert atoms and the like between the carbon atom layers.
  • acid is used as the electrolyte
  • acid molecules are inserted between the carbon atom layers.
  • the current value and the treatment time during the electrochemical treatment can be appropriately selected depending on the amount of the carbon fiber raw material used for the electrochemical treatment and the type and concentration of the electrolytic solution. For example, when 0.01 to 1 g of pitch-based carbon fiber raw material is used as the carbon fiber raw material, a constant current is applied at a current density of 5 to 15 A / g until the applied charge amount becomes 2,000 to 3,000 C. It is preferable to do.
  • an interlayer reaction is performed over the inside
  • the cleaning solution that can be used in the cleaning step is not particularly limited as long as it can remove the electrolyte component, atoms, and the like that are excessively attached to the surface of the graphite intercalation compound.
  • the cleaning liquid include water, organic acids, organic acid esters, and mixed liquids thereof.
  • organic acids that can be used include formic acid, acetic acid, and oxalic acid.
  • As the organic acid ester an ester of the above organic acid or the like can be used.
  • the graphite intercalation compound washed with the washing liquid may be further subjected to an alkali treatment with a basic solution such as aqueous ammonia, aqueous sodium hydroxide or aqueous potassium hydroxide, or a basic gas such as ammonia, if necessary.
  • a basic solution such as aqueous ammonia, aqueous sodium hydroxide or aqueous potassium hydroxide, or a basic gas such as ammonia, if necessary.
  • These graphite intercalation compounds that have been alkali-treated with a basic solution or a basic gas may be further washed with water or the like, if necessary.
  • the obtained graphite intercalation compound is preferably dehydrated and dried appropriately.
  • the graphite intercalation compound after the washing step may be appropriately ground.
  • the carbonization treatment is a step of performing a carbon fiber expansion treatment by decomposing the graphite intercalation compound after the washing treatment by heat treatment. Specifically, first, the graphite intercalation compound after the cleaning treatment is placed in a heating apparatus, and heat treatment is performed at 700 to 1,200 ° C. for 3 to 10 seconds. Thus, by performing heat processing rapidly in a very short time, a carbon atom layer can be expanded and a desired expanded carbon fiber can be manufactured.
  • the heating temperature in the carbonization treatment is preferably 750 ° C. or higher, and more preferably 1,000 ° C. or higher. If the heating temperature is too low, the edge area of the carbon material may be too small as shown in Comparative Examples 1 to 3 described later.
  • the expanded carbon fiber obtained after the carbonization treatment may be highly dispersed in the dispersion medium by appropriately performing ultrasonic treatment in the dispersion medium.
  • a dispersion medium that can be used for ultrasonic treatment water, alcohols such as methanol and ethanol, acetone, and mixtures thereof can be used.
  • FIG. 4 is an SEM image of the expanded carbon fiber of Example 1 described later.
  • the expanded carbon fiber obtained by the electrochemical processing method has a normal edge on the surface thereof.
  • the normal edge as used herein refers to an end portion of the expanded carbon fiber that contains an edge carbon atom that maintains an angular shape without being rounded and can participate in an oxygen reduction reaction.
  • the expanded carbon fiber obtained by the electrochemical treatment method has a surface edge area wider than that of the conventional carbon fiber. As a result, the reaction resistance is smaller than that of the conventional carbon material and the charge capacity is large.
  • An example of the chemical treatment method for the expanded carbon fiber is an alkali activation method.
  • an alkaline solution such as an alkaline aqueous solution and a known reaction apparatus can be appropriately used.
  • the alkaline aqueous solution that can be used in the alkali activation method is preferably strongly alkaline, and is preferably a potassium hydroxide aqueous solution or a sodium hydroxide aqueous solution having a concentration of 6 mol / L or more, or a tetramethylammonium hydroxide aqueous solution having a concentration of 20% by mass or more.
  • the alkali treatment time and the alkali treatment temperature can be appropriately selected depending on the amount and size of the carbon fiber raw material used for the alkali treatment and the type and concentration of the alkali solution.
  • the alkali treatment is preferably performed at a processing temperature of 60 to 95 ° C. for 1 to 10 hours.
  • Air battery is an air battery comprising at least an air electrode, a negative electrode, and an electrolyte layer interposed between the air electrode and the negative electrode, wherein the air electrode is a carbon for an air electrode of the air battery. Including material.
  • An air battery according to one embodiment of the present invention is an air battery in which an electrolyte is interposed between an air electrode and a lithium metal or lithium compound negative electrode, and the air electrode has a three-phase interface site in communication.
  • the porous carbon fiber material is contained, the ratio D / G of the graphitized part D to the defect part G obtained by Raman shift of the carbon fiber material is 0.1 to 1.5, and the three-phase The edge area of the interface site is 55 m 2 / g or more.
  • “connected three-phase interface site” refers to a site where an electrode reaction proceeds in the presence of a carbon electrode, lithium ions, and oxygen gas.
  • the porous carbon fiber material here is an expanded carbon fiber.
  • the average aspect ratio of the porous carbon fiber material is preferably 1 or more and less than 10.
  • Examples of the method for measuring the average aspect ratio include a method of measuring a major axis and a minor axis of a porous carbon fiber material in a TEM image and calculating an aspect ratio from the major axis and the minor axis.
  • FIG. 1 is a diagram showing an example of a layer configuration of an air battery according to the present invention, and is a diagram schematically showing a cross section cut in a stacking direction.
  • the air battery of the present invention is not necessarily limited to this example.
  • the air battery 100 is sandwiched between the air electrode 6 including the air electrode layer 2 and the air electrode current collector 4, the negative electrode 7 including the negative electrode active material layer 3 and the negative electrode current collector 5, and the air electrode 6 and the negative electrode 7.
  • An electrolyte layer 1 is provided.
  • an air electrode, a negative electrode, an electrolyte layer, and a separator and a battery case that are preferably used for the air battery of the present invention, which constitute the air battery of the present invention, will be described in detail.
  • the air electrode used in the present invention includes an air electrode layer, and usually further includes an air electrode current collector and an air electrode lead connected to the air electrode current collector.
  • the air electrode layer contains at least the carbon material for an air electrode of the air battery according to the present invention described above. Furthermore, you may contain a catalyst, a binder, etc. as needed.
  • the content ratio of the carbon material in the air electrode layer is preferably 10 to 99% by mass and more preferably 20 to 95% by mass when the mass of the entire air electrode layer is 100% by mass. . If the content ratio of the carbon material is too low, the reaction field is reduced, and the battery capacity may be reduced. On the other hand, if the content ratio of the carbon material is too high, the content ratio of the catalyst described later is relatively reduced, and there is a possibility that a sufficient catalyst function cannot be exhibited.
  • Examples of the catalyst used for the air electrode layer include an oxygen active catalyst.
  • oxygen active catalysts include, for example, platinum groups such as nickel, palladium and platinum; perovskite oxides containing transition metals such as cobalt, manganese or iron; inorganic compounds containing noble metal oxides such as ruthenium, iridium or palladium A metal coordination organic compound having a porphyrin skeleton or a phthalocyanine skeleton; manganese oxide and the like. From the viewpoint that the electrode reaction is performed more smoothly, a catalyst may be supported on the carbon material described above.
  • the air electrode layer may contain at least the carbon material, but preferably further contains a binder for immobilizing the carbon material.
  • the binder include rubber resins such as polyvinylidene fluoride (PVdF), polytetrafluoroethylene (PTFE), and styrene / butadiene rubber (SBR rubber).
  • PVdF polyvinylidene fluoride
  • PTFE polytetrafluoroethylene
  • SBR rubber styrene / butadiene rubber
  • the content ratio of the binder in the air electrode layer is not particularly limited. For example, when the mass of the entire air electrode layer is 100% by mass, 1 to 40% by mass, especially 1 to 10% by mass. It is preferable that
  • a method for producing the air electrode layer for example, a method of mixing and rolling the air electrode layer raw material containing the carbon material, a slurry is prepared by adding a solvent to the raw material, and an air electrode current collector described later
  • a method for applying the slurry to the air electrode current collector include known methods such as a spray method, a screen printing method, a doctor blade method, a gravure printing method, and a die coating method.
  • the thickness of the air electrode layer varies depending on the use of the air battery, but is preferably 2 to 500 ⁇ m, and more preferably 5 to 300 ⁇ m.
  • the air electrode current collector used in the present invention collects current in the air electrode layer.
  • the material for the air electrode current collector is not particularly limited as long as it has conductivity, and examples thereof include stainless steel, nickel, aluminum, iron, titanium, and carbon.
  • Examples of the shape of the air electrode current collector include a foil shape, a plate shape, and a mesh (grid) shape.
  • the air electrode current collector is preferably mesh-shaped from the viewpoint of excellent current collection efficiency. In this case, usually, a mesh-shaped air electrode current collector is disposed inside the air electrode layer.
  • the air battery of the present invention may include another air electrode current collector (for example, a foil-shaped current collector) that collects electric charges collected by the mesh-shaped air electrode current collector.
  • a battery case to be described later may also have the function of an air electrode current collector.
  • the thickness of the air electrode current collector is, for example, preferably 10 to 1000 ⁇ m, more preferably 20 to 400 ⁇ m.
  • the negative electrode used in the present invention preferably includes a negative electrode active material layer containing a negative electrode active material, and generally further includes a negative electrode current collector and a negative electrode lead connected to the negative electrode current collector.
  • the negative electrode may contain lithium metal or a lithium compound.
  • the negative electrode active material layer used in the present invention contains a negative electrode active material containing at least one selected from the group consisting of metal materials, alloy materials, and carbon materials.
  • metals and alloy materials that can be used for the negative electrode active material include alkali metals such as lithium, sodium, and potassium; group 2 elements such as magnesium and calcium; group 13 elements such as aluminum; zinc, Examples include transition metals such as iron; or alloy materials and compounds containing these metals.
  • the alloy containing lithium element include a lithium aluminum alloy, a lithium tin alloy, a lithium lead alloy, and a lithium silicon alloy.
  • a metal oxide containing a lithium element lithium titanium oxide etc. can be mentioned, for example.
  • metal nitride containing a lithium element examples include lithium cobalt nitride, lithium iron nitride, and lithium manganese nitride.
  • lithium coated with a solid electrolyte can also be used for the negative electrode active material layer.
  • the negative electrode active material layer may contain only the negative electrode active material, or may contain at least one of a conductive material and a binder in addition to the negative electrode active material.
  • a negative electrode active material layer containing only the negative electrode active material can be obtained.
  • the negative electrode active material is in a powder form, a negative electrode active material layer containing a negative electrode active material and a binder can be obtained.
  • the kind and content rate of a binder it is as above-mentioned.
  • the conductive material contained in the negative electrode active material layer is not particularly limited as long as it has conductivity.
  • a carbon material, a perovskite-type conductive material, a porous conductive polymer, a metal porous body, etc. Can be mentioned.
  • the carbon material may have a porous structure or may not have a porous structure.
  • Specific examples of the carbon material having a porous structure include mesoporous carbon.
  • specific examples of the carbon material having no porous structure include graphite, acetylene black, carbon nanotube, and carbon fiber.
  • the material of the negative electrode current collector used in the present invention is not particularly limited as long as it has conductivity, and examples thereof include copper, stainless steel, nickel, and carbon. Of these, SUS and Ni are preferably used for the negative electrode current collector.
  • Examples of the shape of the negative electrode current collector include a foil shape, a plate shape, and a mesh (grid) shape.
  • a battery case which will be described later, may have the function of a negative electrode current collector.
  • the electrolyte layer used in the present invention is held between the air electrode layer and the negative electrode active material layer and functions to exchange metal ions between the air electrode layer and the negative electrode active material layer.
  • an electrolytic solution, a gel electrolyte, a solid electrolyte, or the like can be used for the electrolyte layer. These may be used alone or in combination of two or more.
  • an aqueous electrolytic solution and a non-aqueous electrolytic solution can be used.
  • the type of non-aqueous electrolyte is preferably selected as appropriate according to the type of conductive metal ion.
  • a non-aqueous electrolyte used for a lithium-air battery a solution containing a lithium salt and a non-aqueous solvent is usually used.
  • lithium salt examples include inorganic lithium salts such as LiPF 6 , LiBF 4 , LiClO 4, and LiAsF 6 ; LiCF 3 SO 3 , LiN (SO 2 CF 3 ) 2 (Li—TFSA), LiN (SO 2 C 2 F 5 ) Organic lithium salts such as 2 and LiC (SO 2 CF 3 ) 3 can be mentioned.
  • non-aqueous solvent examples include ethylene carbonate (EC), propylene carbonate (PC), dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), ethyl carbonate, butylene carbonate, ⁇ -butyrolactone, sulfolane.
  • the concentration of the lithium salt in the nonaqueous electrolytic solution is, for example, 0.5 to 3 mol / L.
  • a highly viscous thing as a non-aqueous electrolyte solution or a non-aqueous solvent.
  • the highly viscous non-aqueous electrolyte or non-aqueous solvent include ionic liquids.
  • the ionic liquid examples include N-methyl-N-propylpiperidinium bis (trifluoromethanesulfonyl) amide (PP13TFSA), N-methyl-N-propylpyrrolidinium bis (trifluoromethanesulfonyl) amide (P13TFSA), N-butyl-N-methylpyrrolidinium bis (trifluoromethanesulfonyl) amide (P14TFSA), N, N-diethyl-N-methyl-N- (2-methoxyethyl) ammonium bis (trifluoromethanesulfonyl) amide (DEMETFSA) N, N, N-trimethyl-N-propylammonium bis (trifluoromethanesulfonyl) amide (TMPATFSA) and the like.
  • PP13TFSA N-methyl-N-propylpiperidinium bis (trifluoromethanesulfonyl) amide
  • non-aqueous solvents in order to advance the oxygen reduction reaction represented by the formula (II) or (III), it is more preferable to use an electrolyte solution that is stable to oxygen radicals.
  • non-aqueous solvents include acetonitrile (AcN), 1,2-dimethoxyethane (DME), dimethyl sulfoxide (DMSO), N-methyl-N-propylpiperidinium bis (trifluoromethanesulfonyl) amide ( PP13TFSA), N-methyl-N-propylpyrrolidinium bis (trifluoromethanesulfonyl) amide (P13TFSA), N-butyl-N-methylpyrrolidinium bis (trifluoromethanesulfonyl) amide (P14TFSA), and the like.
  • AcN acetonitrile
  • DME 1,2-dimethoxyethane
  • DMSO dimethyl sulfoxide
  • PP13TFSA N-methyl-
  • the type of the aqueous electrolyte is appropriately selected according to the type of the conductive metal ion.
  • a solution containing a lithium salt and water is usually used as an aqueous electrolyte used for a lithium air battery.
  • the lithium salt include lithium salts such as LiOH, LiCl, LiNO 3 , and CH 3 CO 2 Li.
  • the gel electrolyte used in the present invention is usually gelled by adding a polymer to a non-aqueous electrolyte solution.
  • a non-aqueous gel electrolyte of a lithium-air battery is obtained by adding a polymer such as polyethylene oxide (PEO), polyacrylonitrile (PAN), or polymethyl methacrylate (PMMA) to the non-aqueous electrolyte solution described above, and gelling. can get.
  • a polymer such as polyethylene oxide (PEO), polyacrylonitrile (PAN), or polymethyl methacrylate (PMMA)
  • LiTFSA LiN (CF 3 SO 2 ) 2
  • -PEO-based non-aqueous gel electrolyte is preferable.
  • a sulfide-based solid electrolyte As the solid electrolyte, a sulfide-based solid electrolyte, an oxide-based solid electrolyte, a polymer electrolyte, or the like can be used.
  • Specific examples of the sulfide-based solid electrolyte include Li 2 S—P 2 S 5 , Li 2 S—P 2 S 3 , Li 2 S—P 2 S 3 —P 2 S 5 , and Li 2 S—SiS.
  • the oxide-based solid electrolyte LiPON (lithium phosphate oxynitride), Li 1.3 Al 0.3 Ti 0.7 (PO 4 ) 3 , La 0.51 Li 0.34 TiO Examples include 0.74 , Li 3 PO 4 , Li 2 SiO 2 , Li 2 SiO 4 and the like.
  • the polymer electrolyte is preferably selected as appropriate depending on the type of metal ion to be conducted.
  • a polymer electrolyte of a lithium air battery usually contains a lithium salt and a polymer.
  • the lithium salt at least one of the above-described inorganic lithium salt and organic lithium salt can be used.
  • the polymer is not particularly limited as long as it forms a complex with a lithium salt, and examples thereof include polyethylene oxide.
  • the air battery of the present invention may include a separator between the air electrode and the negative electrode.
  • the separator include porous membranes such as polyethylene and polypropylene; and nonwoven fabrics made of resin such as polypropylene and nonwoven fabrics such as glass fiber nonwoven fabric. These materials that can be used for the separator can also be used as a support material for the electrolytic solution by impregnating the above-described electrolytic solution.
  • the air battery of the present invention usually includes a battery case that houses an air electrode, a negative electrode, an electrolyte layer, and the like.
  • the battery case may be an open-air battery case or a sealed battery case.
  • An open-air battery case is a battery case having a structure in which at least the air electrode layer can sufficiently come into contact with the atmosphere.
  • a gas (air) introduction pipe and an exhaust pipe are provided in the sealed battery case.
  • the gas to be introduced and exhausted preferably has a high oxygen concentration, and more preferably is dry air or pure oxygen.
  • An oxygen permeable film or a water repellent film may be provided in the battery case according to the structure of the battery case.
  • FIG. 9 is a schematic diagram of a constant current electrochemical treatment apparatus.
  • the constant current electrochemical treatment apparatus 300 used in the present invention includes a potentiostat / galvanostat (manufactured by Solartron, model 1287) and an electrochemical cell. The outline of the electrochemical cell is as follows.
  • a reaction vessel 21 having a volume of 300 mL is equipped with a platinum plate 22 and a platinum plate 23 (length 50 mm ⁇ width 10 mm ⁇ thickness 0.2 mm) as electrodes, and a lower end of the anode (working electrode) platinum plate 22 is 5 cm long.
  • the PAN (polyacrylonitrile) -based carbon fibers 24 that had been trimmed were fixed with tape.
  • a silver / silver chloride electrode 25 was attached in the vicinity of the anode.
  • 100 mL of 13 mol / dm 3 nitric acid (26 in FIG. 9) was added as an electrolyte so that the PAN (polyacrylonitrile) -based carbon fiber 24 was sufficiently immersed.
  • the electrochemical cell platinum plate 22, platinum plate 23, and silver / silver chloride electrode 25 are all connected to a potentiostat / galvanostat, and the amount of charge applied to the PAN (polyacrylonitrile) -based carbon fiber 24 is 2,400C.
  • a constant current was applied at a current density of 10 A / g until a nitric acid-graphite intercalation compound was synthesized.
  • nitric acid-graphite intercalation compound was removed from the electrochemical cell, and the nitric acid-graphite intercalation compound was repeatedly washed with a sufficient amount of water in order to remove the nitric acid adhering to the surface of the nitric acid-graphite intercalation compound. Thereafter, the nitric acid-graphite intercalation compound was dehydrated and dried in a desiccator for 24 hours.
  • Example 1 Carbonization treatment The dried nitric acid-graphite intercalation compound was decomposed by heat treatment, and the carbon fiber was carbonized. Specifically, the nitric acid-graphite intercalation compound after drying was inserted into an electric furnace and subjected to a rapid heat treatment in air at 1,000 ° C. for 5 seconds to expand the carbon atom interlayer. The expanded carbon fiber of Example 1 was produced.
  • Example 2 In the same manner as in Example 1, electrochemical treatment, cleaning, and carbonization treatment (1,000 ° C.) were performed. The carbon material after carbonization treatment was added to ethanol and irradiated with ultrasonic waves, whereby the carbon material was highly dispersed in ethanol and then dried to produce an expanded carbon fiber of Example 2.
  • Example 3 In the same manner as in Example 1, electrochemical treatment, cleaning, and carbonization treatment (1,000 ° C.) were performed. The carbon material after carbonization treatment was added to acetone and irradiated with ultrasonic waves to highly disperse the carbon material in acetone and then dried to produce an expanded carbon fiber of Example 3.
  • Example 4 In Example 1, instead of PAN (polyacrylonitrile) carbon fiber, PITCH carbon fiber (manufactured by Nippon Graphite Fiber Co., Ltd., product name “YS-95”, fiber diameter: 5 ⁇ m, mass: 0.1 g) was used. Except for the above, electrochemical treatment, washing, and carbonization treatment (1,000 ° C.) were performed in the same manner as in Example 1 to produce an expanded carbon fiber of Example 4.
  • Example 5 In Example 1, instead of PAN (polyacrylonitrile) carbon fiber, PITCH carbon fiber (manufactured by Nippon Graphite Fiber Co., Ltd., product name “YS-95”, fiber diameter: 5 ⁇ m, mass: 0.1 g) was used. Except that, electrochemical treatment, washing, and carbonization treatment (1,000 ° C.) were performed in the same manner as in Example 1. The carbon material after carbonization treatment was added to ethanol and irradiated with ultrasonic waves to highly disperse the carbon material in ethanol, and then dried to produce an expanded carbon fiber of Example 5.
  • PAN polyacrylonitrile
  • Example 6 In Example 1, instead of PAN (polyacrylonitrile) carbon fiber, PITCH carbon fiber (manufactured by Nippon Graphite Fiber Co., Ltd., product name “YS-95”, fiber diameter: 5 ⁇ m, mass: 0.1 g) was used. Except that, electrochemical treatment, washing, and carbonization treatment (1,000 ° C.) were performed in the same manner as in Example 1. The carbon material after carbonization treatment was added to acetone and irradiated with ultrasonic waves so that the carbon material was highly dispersed in acetone and then dried to produce an expanded carbon fiber of Example 6.
  • PAN polyacrylonitrile
  • Example 7 In Example 1, instead of PAN (polyacrylonitrile) carbon fiber, PITCH carbon fiber (manufactured by Nippon Graphite Fiber Co., Ltd., product name “YS-95”, fiber diameter: 5 ⁇ m, mass: 0.1 g) was used. Except for this, electrochemical treatment and cleaning were performed in the same manner as in Example 1. A carbonization treatment was performed in the same manner as in Example 1 except that the temperature condition during the carbonization treatment was changed from 1,000 ° C. to 700 ° C., and an expanded carbon fiber of Example 7 was produced.
  • PAN polyacrylonitrile
  • Comparative Example 1 In the same manner as in Example 1, electrochemical treatment and cleaning were performed. A carbonization treatment was performed in the same manner as in Example 1 except that the temperature condition during the carbonization treatment was changed from 1,000 ° C. to 350 ° C., and an expanded carbon fiber of Comparative Example 1 was produced.
  • Example 2 In Example 1, instead of PAN (polyacrylonitrile) carbon fiber, PITCH carbon fiber (manufactured by Nippon Graphite Fiber Co., Ltd., product name “YS-95”, fiber diameter: 5 ⁇ m, mass: 0.1 g) was used. Except for this, electrochemical treatment and cleaning were performed in the same manner as in Example 1. A carbonization treatment was performed in the same manner as in Example 1 except that the temperature condition during the carbonization treatment was changed from 1,000 ° C. to 350 ° C., and an expanded carbon fiber of Comparative Example 2 was produced.
  • PAN polyacrylonitrile
  • Comparative Example 3 In the same manner as in Example 1, electrochemical treatment and cleaning were performed. A carbonization treatment was performed in the same manner as in Example 1 except that the temperature condition during the carbonization treatment was changed from 1,000 ° C. to 700 ° C., and an expanded carbon fiber of Comparative Example 3 was produced.
  • Example 1 was observed with a scanning electron microscope (hereinafter referred to as SEM) under the following conditions. That is, SEM observation was performed using a scanning electron microscope (Hitachi, S-5500) at an acceleration voltage of 10 kV and a magnification of 5,000.
  • SEM scanning electron microscope
  • FIG. 4 is an SEM image of the expanded carbon fiber of Example 1.
  • FIG. 4 the expanded carbon fiber of Example 1 is a flaky solid having a major axis of 1 to 10 ⁇ m, a minor axis of 0.5 to 5 ⁇ m, and an aspect ratio of 2 to 9.
  • Example 2 Measurement of D / G ratio
  • the expanded carbon fiber of Example 1 was subjected to Raman measurement using a laser Raman spectrophotometer.
  • the Raman measurement was performed by irradiating the measurement points (100 points in total) provided every 5 ⁇ m in the vertical and horizontal directions for a measurement region of a square of 45 ⁇ m square for 200 seconds each.
  • the peak areas of 1360 cm ⁇ 1 (D band) and 1580 cm ⁇ 1 (G band) minus the baseline were calculated, and the peak area of the D band relative to the peak area of the G band was calculated. Calculated.
  • the peak area ratio calculated for each measurement point was taken as the D / G ratio at that measurement point.
  • FIG. 5 is a TEM image of the expanded carbon fiber of Example 1.
  • the white frame-shaped scale and the cross (+) in FIG. 5 correspond to measurement points for Raman measurement, respectively.
  • FIG. 6 (a) is a graph showing the transition of the D / G ratio in any three columns among the columns of measurement points in FIG. 5 (that is, column I to column X), and
  • FIG. 6 is a graph showing the transition of the D / G ratio in any three rows among the rows of measurement points in FIG. 5 (that is, rows 1 to 10).
  • FIG. 6A shows that the D / G ratio in the column direction (vertical direction in FIG. 5) changes within a range of about 0.5 to 1.2.
  • FIG. 5 shows that the D / G ratio in the column direction (vertical direction in FIG. 5) changes within a range of about 0.5 to 1.2.
  • FIG. 5 shows that the D / G ratio in the column direction (vertical direction in FIG. 5) changes within a range of about 0.5 to 1.2.
  • FIG. 10 is a schematic diagram of a temperature raising device used for quantifying the edge area.
  • the temperature raising device 400 includes a silica tube 31 and a heating furnace 32.
  • the silica tube 31 includes a gas supply port 31a and a gas discharge port 31b.
  • An arrow 33 indicates the supply direction of the supply gas.
  • An arrow 34 indicates the discharge direction of the exhaust gas. The supply gas and the exhaust gas will be described in detail later.
  • a tape heater 35 was wound around a predetermined range near the gas supply port 31a and the gas discharge port 31b.
  • the silica tube 31 was bent and arranged in a U shape as a whole, and a carbon material sample 36 was installed in the vicinity of the bent portion.
  • a carbon material sample 36 was installed in the vicinity of the bent portion.
  • an appropriate amount of silica wool 37 was filled from both sides of the silica tube so as to sandwich the carbon material sample 36.
  • the heating furnace 32 was installed so that the whole bent part of the silica tube 31 could be heated.
  • a thermocouple 38 was installed to measure the temperature of the carbon material sample 36.
  • helium was supplied from the gas supply port 31a, and the inside of the silica tube 31 was replaced with a helium atmosphere.
  • the temperature in the silica tube 31 was set to 100 ° C. and held for 1 hour to release the water adsorbed in the carbon material sample 36.
  • the temperature in the silica tube 31 is increased to 1,100 ° C. at a temperature increase rate of 4 ° C./min, and maintained for 1 hour as it is to increase the temperature of carbon monoxide (CO) and carbon dioxide (CO 2 ). Desorbed.
  • the temperature in the silica tube 31 was set to 600 ° C., and hydrogen was supplied to the silica tube 31.
  • the carbon material sample after temperature programmed desorption was directly treated with hydrogen for 1 hour to bond hydrogen to the edge carbon atoms in the sample.
  • the supply of hydrogen was stopped, and instead helium was supplied to the silica tube 31, and the inside of the silica tube 31 was replaced with a helium atmosphere and cooled to room temperature.
  • the temperature in the silica tube 31 was increased to 800 ° C. at a temperature increase rate of 20 ° C./min.
  • oxygen was supplied at a rate of 5% with respect to the supply amount of helium, and the temperature was increased to 1,000 ° C. at a temperature increase rate of 4 ° C./min.
  • the edge area S of the surface of the carbon material was calculated from the following formula (A) by determining the molar molar concentration of hydrogen (H 2 ) from the quantitative molar concentration of water (H 2 O).
  • S (M ⁇ 6.0 ⁇ 10 23 ) ⁇ 0.082
  • S represents the edge area (m 2 ) of the surface of the carbon material
  • M represents the molar mass of hydrogen (mol / g).
  • Example 8 Production of air electrode
  • the expanded carbon fiber of Example 1 and the PTFE binder manufactured by Daikin
  • PTFE 90 mass%: 10 mass%
  • a predetermined amount of ethanol was further added to the mixture as a solvent. added.
  • the mixture was rolled by a roll press and pre-dried under a temperature condition of 60 ° C. and a vacuum condition.
  • the dried mixture was appropriately cut out and further dried under a temperature condition of 120 ° C. and a vacuum condition, whereby an air electrode of Example 8 was produced.
  • Example 8 In Example 8, in place of the expanded carbon fiber of Example 1, the expanded carbon fiber of Example 2 to Example 7 was used, except that the materials were mixed, pre-dried, and cut out in the same manner as in Example 8. Then, final drying was performed to produce air electrodes of Examples 9 to 14, respectively.
  • Example 8 Materials were mixed, pre-dried, cut out, and finally dried in the same manner as in Example 8, except that Ketjen Black (Ketjen-EC600JD) was used instead of the expanded carbon fiber of Example 1. The air electrode of Comparative Example 4 was produced.
  • Ketjen Black Ketjen-EC600JD
  • Example 8 in place of the expanded carbon fiber of Example 1, carbon black (Vulcan XC72) was used, except that the materials were mixed, pre-dried, cut out, and finally dried in the same manner as in Example 8. The air electrode of Example 5 was produced.
  • carbon black Vulcan XC72
  • Example 8 In Example 8, in place of the expanded carbon fiber of Example 1, the expanded carbon fibers of Comparative Examples 1 to 3 were used, except that the materials were mixed, pre-dried, and cut out in the same manner as in Example 8. Then, final drying was performed to prepare air electrodes of Comparative Examples 6 to 8.
  • Example 15 The air electrode of Example 8 was used as the air electrode.
  • As an electrolyte N-methyl-N-propylpiperidinium bis (trifluoromethanesulfonyl) amide (manufactured by Kanto Chemical Co., PP13TFSA), lithium bis (trifluoromethanesulfonyl) amide (manufactured by Kishida Chemical Co., Ltd.) at 0.32 mol / kg
  • a solution was prepared so as to have a concentration and stirred and mixed overnight under an argon atmosphere.
  • a polypropylene nonwoven fabric JH1004N
  • Metal lithium manufactured by Kyokuto Metal, thickness: 200 ⁇ m, ⁇ 15 mm
  • An F-type cell (made by Hokuto Denko) was prepared as a battery case.
  • Each member is housed in the battery case so as to be laminated in the order of metallic lithium, a separator impregnated with an electrolytic solution, and an air electrode containing expanded carbon fiber from the bottom of the battery case, thereby producing an air battery of Example 15. did. Furthermore, the entire battery case was housed in a 500 mL glass desiccator with a gas replacement cock so that the atmosphere inside the battery case could be controlled. All the above steps were performed in a glove box under a nitrogen atmosphere.
  • Example 16 to Example 21 were used by using the same members as in Example 15 except that the air electrode of Examples 9 to 14 was used instead of the air electrode of Example 8. Each air battery was manufactured.
  • Example 15 In Example 15, the same members as in Example 15 were used except that the air electrodes of Comparative Examples 4 to 8 were used instead of the air electrode of Example 8, and Comparative Examples 9 to 13 were used. Each air battery was manufactured.
  • Charge / Discharge Test of Air Battery The charge / discharge test was performed on the air batteries of Example 15 to Example 21 and Comparative Example 9 to Comparative Example 13, and the charge capacity and reaction resistance were measured. First, each air battery was left under a temperature condition of 60 ° C. for 3 hours. Then, using a charge / discharge test apparatus (manufactured by Nagano, BTS2004H), while supplying pure oxygen (Taiyo Nippon Sanso, 99.9%) to the air electrode layer of each air battery, A charge / discharge test was performed under the conditions of a current density of 0.05 mA / cm 2 , a discharge start voltage of 2.0 V, and a charge start voltage of 3.8 V.
  • FIG. 7 is a graph showing the relationship between reaction resistance and charge capacity for the air batteries of Example 15, Example 18, Comparative Example 9, and Comparative Example 10.
  • FIG. 8 shows the relationship between the reaction resistances of the air cells of Example 15 to Example 21 and Comparative Example 11 to Comparative Example 13, and the edge area of the surface of the expanded carbon fiber used in these air cells. It is a graph.
  • Table 1 below shows the type of carbon material used for the air electrode and the edge area (m 2 / g) of the carbon material for the air batteries of Example 15 to Example 21 and Comparative Example 9 to Comparative Example 13. And a table summarizing the reaction resistance and charge capacity of the air battery.
  • FIG. 7 is a graph in which the vertical axis represents the charge capacity (mAh / g) and the horizontal axis represents the reaction resistance ( ⁇ ).
  • the charge capacity of the air battery of Comparative Example 9 using ketjen black for the air electrode is 125 mAh / g, and the reaction resistance is 220 ⁇ .
  • the charge capacity of the air battery of Comparative Example 10 using carbon black for the air electrode is 200 mAh / g, and the reaction resistance is 150 ⁇ .
  • the charge capacity of the air battery of Example 15 using the expanded carbon fiber of Example 1 for the air electrode is 440 mAh / g, and the reaction resistance is 85 ⁇ .
  • the charge capacity of the air battery of Example 18 using the expanded carbon fiber of Example 4 for the air electrode is 483 mAh / g, and the reaction resistance is 70 ⁇ .
  • the air battery of Example 15 and Example 18 was obtained by using the expanded carbon fiber for the air electrode. It can be seen that the charge capacity is improved and the reaction resistance is reduced.
  • the air battery according to the present invention using the expanded carbon fiber having a relatively large average aspect ratio is ketjen black, which is a spherical carbon material having a small average aspect ratio.
  • FIG. 8 is a graph showing a comparison of edge areas between expanded carbon fibers and a comparison of reaction resistance of an air battery using the expanded carbon fibers.
  • FIG. 8 is a graph in which the vertical axis represents the reaction resistance ( ⁇ ) of the air battery and the horizontal axis represents the edge area (m 2 / g) of the surface of the carbon material.
  • the reaction resistance of the air battery of Comparative Example 11 is 591 ⁇
  • the edge area of the surface of the expanded carbon fiber (Comparative Example 1) used in the air battery of Comparative Example 11 is 50 m. 2 / g.
  • the reaction resistance of the air battery of Comparative Example 12 is 918 ⁇ , and the edge area of the surface of the expanded carbon fiber (Comparative Example 2) used in the air battery of Comparative Example 12 is 49 m 2 / g.
  • the reaction resistance of the air battery of Comparative Example 13 is 183 ⁇ , and the edge area of the surface of the expanded carbon fiber (Comparative Example 3) used in the air battery of Comparative Example 13 is 54 m 2 / g.
  • the reaction resistance of the air battery of Example 15 is 85 ⁇
  • the edge area of the surface of the expanded carbon fiber (Example 1) used in the air battery of Example 15 Is 100 m 2 / g.
  • the reaction resistance of the air battery of Example 16 is 75 ⁇ , and the edge area of the surface of the expanded carbon fiber (Example 2) used in the air battery of Example 16 is 93 m 2 / g.
  • the reaction resistance of the air battery of Example 17 is 95 ⁇ , and the edge area of the surface of the expanded carbon fiber (Example 3) used in the air battery of Example 17 is 90 m 2 / g.
  • the reaction resistance of the air battery of Example 18 is 70 ⁇ , and the edge area of the surface of the expanded carbon fiber (Example 4) used in the air battery of Example 18 is 69 m 2 / g.
  • the reaction resistance of the air battery of Example 19 is 45 ⁇ , and the edge area of the surface of the expanded carbon fiber (Example 5) used in the air battery of Example 19 is 63 m 2 / g.
  • the reaction resistance of the air battery of Example 20 is 40 ⁇ , and the edge area of the surface of the expanded carbon fiber (Example 6) used in the air battery of Example 20 is 65 m 2 / g.
  • the reaction resistance of the air battery of Example 21 is 138 ⁇ , and the edge area of the surface of the expanded carbon fiber (Example 7) used in the air battery of Example 21 is 59 m 2 / g.
  • the expanded carbon fibers (Comparative Example 1 to Comparative Example 3) used in the air batteries of Comparative Example 11 to Comparative Example 13 all had an edge area of 54 m 2 / g or less.
  • Example 15-The expanded carbon fibers used in the air cell of Example 21 (Example 1 to Example 7) all have an edge area of greater than 55 m 2 / g.
  • the air batteries of Comparative Examples 9 and 10 using conventional carbon materials and the air batteries of Comparative Examples 11 to 13 using the expanded carbon fibers of Comparative Example 1 to Comparative Example 3 are all used. While the reaction resistance is 150 ⁇ or more, the air batteries of Examples 15 to 21 using the expanded carbon fibers of Example 1 to Example 7 all have a reaction resistance of less than 140 ⁇ .

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Electrochemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Inorganic Chemistry (AREA)
  • Textile Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Inert Electrodes (AREA)
  • Hybrid Cells (AREA)
  • Materials Engineering (AREA)
PCT/JP2013/074249 2012-09-10 2013-09-09 空気電池の空気極用炭素材料、及び当該炭素材料を含む空気電池 Ceased WO2014038692A1 (ja)

Priority Applications (3)

Application Number Priority Date Filing Date Title
US14/426,918 US20150229012A1 (en) 2012-09-10 2013-09-09 Carbonaceous material for air electrode of air battery, and air battery comprising the carbonaceous material
CN201380046942.7A CN104604021A (zh) 2012-09-10 2013-09-09 空气电池的空气极用碳材料、以及包含该碳材料的空气电池
EP13835572.2A EP2894707A4 (en) 2012-09-10 2013-09-09 CARBON MATERIAL FOR AIR ELECTRODE FOR AIR BATTERY AND AIR BATTERY WITH THIS CARBON MATERIAL

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2012198890A JP5859936B2 (ja) 2012-09-10 2012-09-10 空気電池の空気極用炭素材料、及び当該炭素材料を含む空気電池
JP2012-198890 2012-09-10

Publications (1)

Publication Number Publication Date
WO2014038692A1 true WO2014038692A1 (ja) 2014-03-13

Family

ID=50237296

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2013/074249 Ceased WO2014038692A1 (ja) 2012-09-10 2013-09-09 空気電池の空気極用炭素材料、及び当該炭素材料を含む空気電池

Country Status (5)

Country Link
US (1) US20150229012A1 (enExample)
EP (1) EP2894707A4 (enExample)
JP (1) JP5859936B2 (enExample)
CN (1) CN104604021A (enExample)
WO (1) WO2014038692A1 (enExample)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2016088891A1 (ja) * 2014-12-04 2016-06-09 独立行政法人国立高等専門学校機構 空気電池用正極、この正極を用いた空気電池、及び、該正極の製造方法

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108258305B (zh) 2016-12-28 2020-08-18 财团法人工业技术研究院 电解质与电池
KR102347745B1 (ko) * 2017-05-17 2022-01-05 현대자동차주식회사 전고체 리튬공기전지용 양극 및 그 제조방법
US10566623B2 (en) * 2017-06-22 2020-02-18 Aselsan Elektronik Sanayi Ve Ticaret A.S Thin cathode for micro-battery
CN114471519B (zh) * 2022-02-11 2023-03-24 青岛科技大学 一种活性锌催化剂及其制备方法和在催化布洛芬重排反应中的应用

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002015737A (ja) 2000-06-30 2002-01-18 Toshiba Corp 非水電解質電池
JP2005125187A (ja) * 2003-10-22 2005-05-19 Fuji Xerox Co Ltd ガス分解器、燃料電池用電極およびその製造方法
WO2011055739A1 (ja) * 2009-11-05 2011-05-12 国立大学法人群馬大学 炭素触媒並びにその製造方法及びこれを用いた電極並びに電池
WO2012172656A1 (ja) * 2011-06-15 2012-12-20 トヨタ自動車株式会社 空気電池
JP2013110106A (ja) * 2011-10-24 2013-06-06 Nagoya Univ 空気電池

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2005216772A (ja) * 2004-01-30 2005-08-11 Nissan Motor Co Ltd 電極触媒、該触媒を用いた触媒担持電極およびｍｅａ
US20090053594A1 (en) * 2007-08-23 2009-02-26 Johnson Lonnie G Rechargeable air battery and manufacturing method
US7790285B2 (en) * 2007-12-17 2010-09-07 Nanotek Instruments, Inc. Nano-scaled graphene platelets with a high length-to-width aspect ratio
US8501348B2 (en) * 2009-12-07 2013-08-06 Nanotek Instruments, Inc. Submicron-scale and lower-micron graphitic fibrils as an anode active material for a lithium ion battery
US8962188B2 (en) * 2010-01-07 2015-02-24 Nanotek Instruments, Inc. Anode compositions for lithium secondary batteries

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002015737A (ja) 2000-06-30 2002-01-18 Toshiba Corp 非水電解質電池
JP2005125187A (ja) * 2003-10-22 2005-05-19 Fuji Xerox Co Ltd ガス分解器、燃料電池用電極およびその製造方法
WO2011055739A1 (ja) * 2009-11-05 2011-05-12 国立大学法人群馬大学 炭素触媒並びにその製造方法及びこれを用いた電極並びに電池
WO2012172656A1 (ja) * 2011-06-15 2012-12-20 トヨタ自動車株式会社 空気電池
JP2013110106A (ja) * 2011-10-24 2013-06-06 Nagoya Univ 空気電池

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP2894707A4

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2016088891A1 (ja) * 2014-12-04 2016-06-09 独立行政法人国立高等専門学校機構 空気電池用正極、この正極を用いた空気電池、及び、該正極の製造方法
CN107004863A (zh) * 2014-12-04 2017-08-01 独立行政法人国立高等专门学校机构 空气电池用正极、利用该正极的空气电池和该正极的制造方法
JPWO2016088891A1 (ja) * 2014-12-04 2017-10-19 独立行政法人国立高等専門学校機構 空気電池用正極、この正極を用いた空気電池、及び、該正極の製造方法
US10396347B2 (en) 2014-12-04 2019-08-27 National Institute of Technology Positive electrode for air battery, air battery using the positive electrode, and method of manufacturing the positive electrode
CN107004863B (zh) * 2014-12-04 2020-09-25 独立行政法人国立高等专门学校机构 空气电池用正极、利用该正极的空气电池和该正极的制造方法

Also Published As

Publication number Publication date
US20150229012A1 (en) 2015-08-13
EP2894707A4 (en) 2015-10-07
CN104604021A (zh) 2015-05-06
JP5859936B2 (ja) 2016-02-16
EP2894707A1 (en) 2015-07-15
JP2014053270A (ja) 2014-03-20

Similar Documents

Publication Publication Date Title
JP6955622B2 (ja) リチウムイオン二次電池
Kretschmer et al. A free-standing LiFePO 4–carbon paper hybrid cathode for flexible lithium-ion batteries
US10396361B2 (en) Nonaqueous lithium-type power storage element
JP6774396B2 (ja) 非水系リチウム型蓄電素子の製造方法
JP6815305B2 (ja) 非水系リチウム蓄電素子の製造方法
US9385376B2 (en) Manufacturing method of fibrous perovskite-type oxide catalyst
KR101599693B1 (ko) 리튬 공기 전지 정극용 탄소 재료 및 리튬 공기 전지
EP4269361A1 (en) Binder that is composite of single-walled carbon nanotubes and ptfe, and composition for electrode production and secondary battery using same
Qiu et al. Hierarchical 3D Co3O4@ MnO2 core/shell nanoconch arrays on Ni foam for enhanced electrochemical performance
Hyun et al. Mesoporous Co-CoO/N-CNR nanostructures as high-performance air cathode for lithium-oxygen batteries
JP2015018621A (ja) ナトリウム電池用正極活物質およびその製造方法
KR20220013544A (ko) 슈퍼커패시터
JP5859936B2 (ja) 空気電池の空気極用炭素材料、及び当該炭素材料を含む空気電池
JP2013109896A (ja) 電極材料及び電極材料の製造方法
JP6957250B2 (ja) 非水系リチウム型蓄電素子
EP3171436A1 (en) Lithium air battery and method for manufacturing same
JP2018056021A (ja) リチウムイオン二次電池
JP2014053271A (ja) 空気電池の空気極用炭素材料の製造方法、空気電池の空気極用炭素材料、及び当該炭素材料を含む空気電池
WO2012172656A1 (ja) 空気電池
CN121079796A (zh) 电池反应辅助材料、包含电池反应辅助材料的正极或者负极、具备该正极或者负极的锂离子电池、以及电极的制造方法
JP6754659B2 (ja) 非水系リチウム型蓄電素子
JP2018056401A (ja) 非水系リチウム型蓄電素子
Mamidi et al. Candle soot-metal-organic framework-based hierarchical electrode as high-performance anode for Li-ion batteries
JP2014053269A (ja) 空気電池の空気極用炭素材料、当該炭素材料を含む空気電池、及び空気電池の空気極用炭素材料の製造方法
JP2013030362A (ja) 非水電解質二次電池用負極、および、それを用いた非水電解質二次電池。

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 13835572

Country of ref document: EP

Kind code of ref document: A1

DPE1 Request for preliminary examination filed after expiration of 19th month from priority date (pct application filed from 20040101)
REEP Request for entry into the european phase

Ref document number: 2013835572

Country of ref document: EP

WWE Wipo information: entry into national phase

Ref document number: 14426918

Country of ref document: US

Ref document number: 2013835572

Country of ref document: EP

NENP Non-entry into the national phase

Ref country code: DE