Composite body, slurry for electrode of secondary battery, electrode for secondary battery, secondary battery, flying body, method for manufacturing composite body, and method for manufacturing electrode for secondary battery

Abstract

Provided is a composite body formed by aggregating at least a plurality of organic active material particles for a secondary battery and a plurality of conductive material particles. Provided is a slurry for an electrode of a secondary battery, the slurry including the composite body and a solvent. Provided is an electrode for a secondary battery, the electrode including a current collector and an active material layer including the composite body. Provided is a secondary battery including: the electrode for a secondary battery; and an electrolyte. Provided is a flying body including the secondary battery and a propulsion force generation device for generating propulsion force by using electric energy accumulated in the secondary battery.

Description

Composite, slurry for secondary battery electrode, electrode for secondary battery, secondary battery, aircraft, method for manufacturing composite, and method for manufacturing electrode for secondary battery

[0001] The present invention relates to a composite, a slurry for a secondary battery electrode, an electrode for a secondary battery, a secondary battery, an aircraft, a method for manufacturing a composite, and a method for manufacturing an electrode for a secondary battery.

[0002] Patent Document 1 describes "the following formula (1) or formula (2): LiNi a Co b Mn c M 1 w O2...(1) LiNi d Co e Al f M 2 x O2 ... (2) on the surface of the lithium composite oxide secondary particle (A) made of lithium composite oxide particles represented by the following formula (3), formula (4), formula (5), or formula (6): LiM 4 i Mn j O4...(4) LiNi k Mn 1-k O4...(5) Li2MnO3-LiM 602 ... (6) and a lithium-based solid electrolyte (C) supported on the surface of the lithium positive electrode active material particles (B) (Claim 1). Patent Document 2 discloses "a carbon-coated active material composite in which charge transfer of lithium ions occurs at the interface between a carbonaceous coating and an electrode active material, characterized in that the activation energy of the lithium ion insertion / extraction reaction occurring at the interface between the carbon-coated active material composite and an electrolyte solution is in the range of 45 kJ / mol to 85 kJ / mol, the value of the amount of carbon supported relative to the specific surface area of ​​the electrode active material particles ([amount of carbon supported] / [specific surface area of ​​electrode active material particles]) is in the range of 0.01 to 0.5, and the activation energy is a value measured using an electrolyte solution in which ethylene carbonate and diethyl carbonate are mixed in a 1:1 ratio" (Claim 1). [Prior art documents] [Patent documents] [Patent document 1] JP 2021-086723 A [Patent document 2] WO2014-185494 A

[0003] [General Disclosure] A first aspect of the present invention provides a composite formed by assembling at least a plurality of organic active material particles for a secondary battery and a plurality of conductive material particles.

[0004] In the above, the composite may contain a binder resin, which may bind the organic active material particles and the conductive material particles together.

[0005] In the above, the D50 particle size of the complex measured by a laser diffraction / scattering method may be 1 to 30 μm.

[0006] In the above, the specific surface area of ​​the composite measured by the physical adsorption method is 1 to 12 m ２ / g.

[0007] In the above, the volume resistivity of the composite is 9.1 × 10 ７ It may be Ω·cm or less.

[0008] In the above, the organic active material particles may contain an nπ-electron organic compound (where n≧2).

[0009] In the above, the organic active material particles may be an organic compound having a quinone-containing skeleton.

[0010] In the above, the organic active material particles may be an organic compound having one or more skeletons selected from anthraquinone, phenazine tetraone, pentacene tetrone, and naphthazarin.

[0011] In the above, the organic active material particles may have a D50 particle size of 0.2 to 5 μm as measured by a laser diffraction / scattering method.

[0012] In the above, the conductive particles may be one or more selected from acetylene black, carbon nanotubes, carbon black, carbon fibers, fullerenes, graphene, and graphite.

[0013] In the above, the binder resin may be one or more selected from carboxymethyl cellulose, styrene-butadiene rubber, acrylic resin, polyacrylonitrile, polyvinylidene fluoride, polyimide, polyamide-imide, polyethylene, polypropylene, polyurethane, and polytetrafluoroethylene polyether.

[0014] In the above, the weight ratio of the organic active material particles to the binder resin may be 100:1 to 100:15.

[0015] In a second aspect of the present invention, there is provided a slurry for a secondary battery electrode, which comprises the above composite and a solvent.

[0016] In a third aspect of the present invention, there is provided an electrode for a secondary battery, comprising a current collector and an active material layer containing the above-described composite.

[0017] In a fourth aspect of the present invention, there is provided a secondary battery comprising the above-described secondary battery electrode and an electrolyte.

[0018] In the above, the secondary battery may be a non-aqueous secondary battery.

[0019] In a fifth aspect of the present invention, there is provided an aircraft comprising the above-described secondary battery and a thrust generating device. The thrust generating device may generate thrust using electrical energy stored in the secondary battery.

[0020] In a sixth aspect of the present invention, there is provided a method for producing a composite, which comprises mixing at least a plurality of organic active material particles for a secondary battery and a plurality of conductive material particles, followed by drying to produce the composite.

[0021] In the above, the production method may include a step of granulating the complex by a tumbling fluidization method or a spray drying method.

[0022] In a seventh aspect of the present invention, there is provided a method for manufacturing an electrode for a secondary battery, comprising a composite manufacturing step, a sheet manufacturing step, and an electrode formation step. In the composite manufacturing step, the composite may be manufactured by mixing and drying at least a plurality of organic active material particles for a secondary battery and a plurality of conductive material particles. In the sheet manufacturing step, an active material sheet may be manufactured by applying and drying an electrode slurry containing the composite and a solvent. In the electrode formation step, an electrode may be formed by pressing the active material sheet against a current collector.

[0023] In the above-mentioned sheet manufacturing step, the electrode slurry may be applied to a film thickness of 10 to 300 μm.

[0024] The above summary of the invention does not list all of the features of the present invention, and subcombinations of these features may also be inventions.

[0025] 1 shows an example of the system configuration of an aircraft 100. FIG. 2 shows an example of a storage cell 112. FIG. 3 shows an example of the configuration of a composite 10 according to the present embodiment. FIG. 4 shows another example of the configuration of a composite 20 according to the present embodiment. FIG. 5 shows an electron microscope photograph of a composite 20 according to the present embodiment. FIG. 6 shows an electron microscope photograph of a positive electrode active material layer 224 according to the present embodiment. FIG. 7 shows a microscope photograph of a positive electrode active material layer 224 that does not include a composite. FIG. 8 shows an example of the flow of a method for manufacturing a composite and a positive electrode according to the present embodiment.

[0026] The present invention will be described below through embodiments of the invention, but the following embodiments do not limit the scope of the invention as claimed. Furthermore, not all of the combinations of features described in the embodiments are necessarily essential to the solution of the invention.

[0027] 1 schematically illustrates an example of the system configuration of an aircraft 100. In this embodiment, the aircraft 100 includes a storage battery 110, a power control circuit 120, one or more electric motors 130, one or more propellers 140, one or more sensors 150, and a control device 160. In this embodiment, the storage battery 110 includes one or more storage cells 112.

[0028] In this embodiment, the flying object 100 flies using electrical energy stored in the storage battery 110. Examples of the flying object 100 include an airplane, an airship, a balloon, a helicopter, a drone, and the like.

[0029] In this embodiment, the storage battery 110 receives electrical energy from an external charging device (not shown) via the power control circuit 120 and stores the electrical energy in one or more storage cells 112. The storage battery 110 also supplies the electrical energy stored in the one or more storage cells 112 to the electric motor 130 via the power control circuit 120.

[0030] In this embodiment, the storage cell 112 stores electric energy (sometimes referred to as charging the storage cell 112). The storage cell 112 also releases the stored electric energy (sometimes referred to as discharging the storage cell 112). The storage cell 112 may be a secondary battery. The storage cell 112 may be a secondary battery, for example, a non-aqueous secondary battery.

[0031] Examples of non-aqueous secondary batteries include sodium ion secondary batteries, lithium ion secondary batteries, lithium metal secondary batteries, lithium-air secondary batteries, lithium-sulfur secondary batteries, magnesium ion secondary batteries, aluminum ion secondary batteries, etc. Furthermore, a lithium ion secondary battery, which is one aspect of a non-aqueous secondary battery, may be a concept that includes non-aqueous lithium ion secondary batteries that use a non-aqueous electrolyte and all-solid-state lithium ion secondary batteries that use a solid electrolyte.

[0032] For example, a material that can store a large amount of charge per unit volume is often selected as the active material for a secondary battery mounted on a vehicle. On the other hand, in this embodiment, the storage cell 112 is mounted on the aircraft 100. Therefore, it is preferable that the active material used in the storage cell 112 be a material that can store a large amount of charge per unit mass.

[0033] The mass energy density of the storage cell 112 is preferably 500 [Wh / kg-storage cell] or more, more preferably 550 Wh / kg-storage cell] or more, even more preferably 600 Wh / kg-storage cell] or more, still more preferably 650 Wh / kg-storage cell] or more, and even more preferably 700 Wh / g-storage cell] or more. This provides a storage cell that is particularly suitable for use as a power source for an aircraft.

[0034] The volumetric energy density of the storage cell 112 is 300 [Wh / m ３ -Storage cell] or more than 1200 [Wh / m ３ -storage cell] or less, and 400 [Wh / m ３ -Storage cell] or more than 1000 [Wh / m ３ When the storage cell 112 is mounted on the aircraft 100 as part of the power supply of the aircraft 100, the volumetric energy density of the storage cell 112 may be 600 [Wh / m ３ -storage cell] or less, and 800 [Wh / m ３ -storage cell] or less.

[0035] The energy storage cell 112 may have a mass energy density within the above-mentioned ranges and a volume energy density within the above-mentioned ranges. This allows the energy storage cell, which is relatively difficult to use as a power source for a vehicle, to be used as a power source for an aircraft. Details of the energy storage cell 112 will be described later.

[0036] In this embodiment, the power control circuit 120 controls the input and output of power to the storage battery 110. The power control circuit 120 may control the input and output of power to the storage battery 110 based on commands from the control device 160. The power control circuit 120 includes, for example, a plurality of switching elements that operate based on control signals from the control device 160.

[0037] In this embodiment, the electric motor 130 receives electrical energy from the storage battery 110 via the power control circuit 120. The electric motor 130 uses the electrical energy received from the storage battery 110 to rotate the propeller 140. In this way, the electric motor 130 can generate thrust for the aircraft 100 using the electrical energy stored in the storage cell 112.

[0038] In this embodiment, the sensor 150 measures various physical quantities related to the position and attitude of the flying object 100. Examples of sensors for measuring various physical quantities related to the position and attitude of the flying object 100 include a GPS signal receiver, an acceleration sensor, an angular acceleration sensor, and a gyro sensor. The sensor 150 may measure various physical quantities related to the state of the storage battery 110. Examples of sensors for measuring various physical quantities related to the state of the storage battery 110 include a temperature sensor, a current sensor, and a voltage sensor.

[0039] In this embodiment, the control device 160 controls the air vehicle 100. The control device 160 may control the input and output of power to the storage battery 110 by controlling the power control circuit 120. For example, the control device 160 controls the output current, output voltage, input current, input voltage, etc. of the storage battery 110. This allows the control device 160 to control the position and attitude of the air vehicle 100. The control device 160 may control the position and attitude of the air vehicle 100 by controlling the power control circuit 120 based on the output from the sensor 150.

[0040] The storage battery 110 may be an example of a secondary battery. The storage cell 112 may be an example of a secondary battery. The electric motor 130 may be an example of a propulsion force generating device that generates propulsion force by utilizing electrical energy stored in the secondary battery. Another device may be used as the propulsion force generating device instead of the electric motor 130.

[0041] 2 is a schematic diagram of an example of the storage cell 112. In this embodiment, the storage cell 112 will be described in detail using as an example a case where the storage cell 112 is a coin-type non-aqueous secondary battery.

[0042] [Storage Cell] In this embodiment, the storage cell 112 includes a positive electrode case 212, a negative electrode case 214, a sealant 216, and a metal spring 218. The storage cell 112 includes a secondary battery electrode and an electrolyte. The secondary battery electrode may include a current collector and an active material layer. The secondary battery electrode may be composed of a positive electrode and a negative electrode.

[0043] For example, the energy storage cell 112 includes a positive electrode 220, a separator 230, a negative electrode 240, and an electrolyte solution 250. In this embodiment, the positive electrode 220 includes a positive electrode current collector 222 and a positive electrode active material layer 224. In this embodiment, the negative electrode 240 includes a negative electrode current collector 242 and a negative electrode active material layer 244.

[0044] In this embodiment, by assembling the positive electrode case 212 and the negative electrode case 214, a space is formed inside the positive electrode case 212 and the negative electrode case 214. A metal spring 218, a positive electrode 220, a separator 230, a negative electrode 240, and an electrolyte 250 are accommodated inside the space formed by the positive electrode case 212 and the negative electrode case 214. The positive electrode 220, the separator 230, and the negative electrode 240 are fixed inside the positive electrode case 212 and the negative electrode case 214 by the repulsive force of the metal spring 218.

[0045] The positive electrode case 212 and the negative electrode case 214 are made of, for example, a thin, disc-shaped plate made of a conductive material. In this embodiment, the sealant 216 seals the gap formed between the positive electrode case 212 and the negative electrode case 214. The sealant 216 includes an insulating material. The sealant 216 insulates the positive electrode case 212 and the negative electrode case 214 from each other.

[0046] [Positive Electrode] In this embodiment, the positive electrode current collector 222 holds the positive electrode active material layer 224. Examples of materials for the positive electrode current collector 222 include aluminum, stainless steel, nickel, titanium, and alloys thereof. Examples of the shape of the positive electrode current collector 222 include foil, mesh, punched metal, and expanded metal. The thickness of the positive electrode current collector 222 is not particularly limited, but is preferably 5 to 200 μm. The thickness of the positive electrode current collector 222 may also be 6 to 20 μm.

[0047] In this embodiment, the positive electrode active material layer 224 is formed on at least one surface of the positive electrode current collector 222. The thickness of the positive electrode active material layer 224 may be 1 to 300 μm, or may be 2 to 200 μm, per surface of the positive electrode current collector 222. Details of the positive electrode active material layer 224 will be described later.

[0048] [Separator] In this embodiment, the separator 230 separates the positive electrode 220 and the negative electrode 240. The separator 230 ensures ionic conductivity between the positive electrode 220 and the negative electrode 240, for example, by retaining an electrolyte solution. Examples of materials for the separator 230 include polyethylene, polypropylene, an ethylene-propylene copolymer, glass, or a composite thereof. Examples of the shape of the separator 230 include a microporous film, a nonwoven fabric, a filter, and the like. The thickness of the separator 230 is not particularly limited, but is preferably 10 to 50 μm. The aperture ratio of the separator 230 is not particularly limited, but is preferably 30 to 70%.

[0049] [Negative Electrode] In this embodiment, the negative electrode current collector 242 holds the negative electrode active material layer 244. Examples of materials for the negative electrode current collector 242 include copper, aluminum, stainless steel, nickel, titanium, and alloys thereof. The negative electrode current collector 242 may include a resin support layer and a metal layer disposed on the surface of the support layer. Examples of the resin include polyethylene, polypropylene, polyethylene terephthalate, and polyimide. The metal layer may be a layer made of copper, aluminum, stainless steel, nickel, titanium, or an alloy thereof. The metal layer may include a layer made of copper, aluminum, stainless steel, nickel, titanium, or an alloy thereof. The metal layer may be a foil or a plated layer.

[0050] When lithium metal is used as the negative electrode active material, the lithium metal can also serve as a current collector. Therefore, when the power storage cell 112 is a lithium metal secondary battery, the power storage cell 112 does not need to include the negative electrode current collector 242.

[0051] Examples of the shape of the negative electrode current collector 242 include foil, mesh, punched metal, and expanded metal. The thickness of the negative electrode current collector 242 is not particularly limited, but may be 5 to 200 μm. The thickness of the negative electrode current collector 242 is preferably 6 to 20 μm.

[0052] In this embodiment, the negative electrode active material layer 244 is formed on at least one surface of the negative electrode current collector 242. The thickness of the negative electrode active material layer 244 may be 1 to 300 μm, or 2 to 200 μm, per surface of the negative electrode current collector 242. The negative electrode active material layer 244 will be described in detail later.

[0053] [Electrolyte] In this embodiment, the electrolytic solution 250 realizes ionic conduction between the positive electrode active material and the negative electrode active material via the electrolyte contained in the electrolytic solution 250. According to this embodiment, a non-aqueous electrolytic solution is used as the electrolytic solution 250. As the non-aqueous electrolytic solution, a known organic electrolytic solution may be used. For example, when the power storage cell 112 is a lithium ion secondary battery or a lithium metal secondary battery, (i) a solvent consisting of one or more of ethylene carbonate, dimethyl carbonate, diethyl carbonate, etc., and (ii) lithium perchlorate, LiPF ６ A solution in which a lithium salt such as the above is dissolved is used as the electrolyte solution 250.

[0054] The non-aqueous electrolyte contains, for example, a metal salt and a non-aqueous solvent. Examples of the metal salt include sodium salt and lithium salt. Examples of the sodium salt include NaPF ６ , NaBF ４ , NaClO ４ and NaAsF ６ Inorganic sodium salts such as NaCF ３ SO ３ , NaN(CF ３ SO ２ ) ２ , NaN(C ２ F ５ SO ２ ) ２ , NaC(CF ３ SO ２ ) ３ Examples of the lithium salt include organic sodium salts such as LiPF ６ , LiBF ４ , LiClO ４ , LiAsF ６ Inorganic lithium salts such as LiCF ３ SO ３ , LiN(CF ３ SO ２ ) ２ , LiN(C ２ F ５ SO ２ ) ２ , LiC(CF ３ SO ２ ) ３Examples of the non-aqueous solvent include ethylene carbonate (EC), propylene carbonate (PC), dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), butylene carbonate (BC), fluoroethylene carbonate (FEC), γ-butyrolactone, sulfolane, acetonitrile, 1,2-dimethoxymethane, 1,3-dimethoxypropane, diethyl ether, tetrahydrofuran, 2-methyltetrahydrofuran, and mixtures thereof.

[0055] The concentration of the sodium salt in the non-aqueous electrolyte is not particularly limited, but may be in the range of 0.5 to 4.0 mol / L. The concentration of the sodium salt may be in the range of 0.7 mol / L to 2.0 mol / L, or in the range of 1.0 mol / L to 1.5 mol / L. The concentration of the lithium salt in the non-aqueous electrolyte is not particularly limited, but may be in the range of 0.5 to 4.0 mol / L. The concentration of the lithium salt may be in the range of 0.7 mol / L to 2.0 mol / L, or in the range of 1.0 mol / L to 1.5 mol / L.

[0056] [Example of Another Embodiment] In this embodiment, the details of the storage cell 112 have been described using an example in which the storage cell 112 is a coin-type secondary battery. However, the type, structure, and the like of the storage cell 112 are not limited to this embodiment. In another embodiment, the storage cell 112 may be a cylindrical battery including a wound electrode assembly in which a positive electrode, a separator, and a negative electrode are wound in a spiral shape. In yet another embodiment, the storage cell 112 may be a laminated battery in which a laminated electrode assembly in which positive electrodes and negative electrodes are alternately stacked with separators sandwiched between them is sealed with a laminate.

[0057] In this embodiment, the details of the energy storage cell 112 have been described using as an example a case where the anode 240 includes the anode current collector 242 and the anode active material layer 244. However, the anode of the energy storage cell 112 is not limited to this embodiment. In other embodiments, for example, when the energy storage cell 112 is a lithium metal secondary battery, metallic lithium may be used as the anode.

[0058] In this embodiment, an example of the storage cell 112 has been described using the electrolytic solution 250 as the electrolyte of the storage cell 112. However, the electrolyte of the storage cell 112 is not limited to this embodiment. In other embodiments, a solid electrolyte or a gel electrolyte may be used as the electrolyte of the storage cell 112. The solid electrolyte may be Li ２ S-P ２ S ５ system, Li ２ S-GeS ２ -P ２ S ５ Examples include inorganic solid electrolytes such as those based on the above-mentioned system.

[0059] As described above, the aircraft 100 and the power storage cell 112 have been outlined using Figures 1 and 2. Next, the active material of the positive electrode active material layer 224 or the negative electrode active material layer 244 will be described in detail.

[0060] [Positive Electrode Active Material Layer 224] The positive electrode active material layer 224 includes a composite formed by assembling at least a plurality of organic active material particles and a plurality of conductive material particles. The positive electrode active material layer 224 is formed from a large number of composites 10. For example, the positive electrode active material layer 224 may be formed by applying and drying a paste containing the composite and an organic solvent.

[0061] [Composite] The composite that forms the positive electrode active material layer 224 will be described below.

[0062] 3 shows an example of the configuration of a composite 10 according to this embodiment. As shown in the figure, the composite 10 is formed by a large number of organic active material particles 12 and conductive material particles 14 aggregating into a single mass. As a result, the conductive material particles 14 are located between the multiple organic active material particles 12 and over the entire surface of the composite 10. As a result, the electronic resistance between the organic active material particles 12 is significantly reduced.

[0063] The composite 10 may have a shape with a relatively small surface area. For example, the composite 10 may have an approximately spherical shape. Additionally or alternatively, the composite 10 may have any other irregular shape, such as a cube, rectangular parallelepiped, polyhedron, cylinder, or polygonal prism.

[0064] Generally, organic active materials have lower electrical conductivity than inorganic active materials, and therefore ensuring electrical conductivity can be a challenge. However, according to this embodiment, the electrical conductivity can be sufficiently increased by disposing the conductive material particles 14 even in the internal region of the organic active material, compared to a method of coating the surface of the organic active material with a conductive material.

[0065] Furthermore, when an electrode including the composite 10 is formed, the electrolyte solution can easily penetrate into the gaps between the composites 10, making it easier to ensure a conductive path in the positive electrode active material layer 224. Therefore, according to this embodiment, the conductivity of the positive electrode active material layer 224 can be increased compared to when an electrode is formed without forming the composite 10.

[0066] Fig. 4 shows another example of the configuration of the composite 20 according to this embodiment. The composite 20 is formed by assembling a large number of organic active material particles 12, conductive material particles 14, and binder resin 16. The composite 20 additionally contains binder resin 16 in comparison with the composite 10 shown in Fig. 3. The composite 20 also provides the same effects as the composite 10. Hereinafter, the composite 10 and the composite 20 may be collectively referred to as "composite 10, etc."

[0067] The binder resin 16 binds the organic active material particles 12 and the conductive material particles 14 together. The binder resin 16 enables the composite 20 to maintain its structure more firmly than the composite 10. Furthermore, like the composite 10, the composite 20 can increase the conductivity of the positive electrode active material layer 224.

[0068] The binder resin 16 may have a particulate shape as shown in the drawing. On the other hand, the binder resin 16 does not have to be particulate, as long as it is in a form that binds the organic active material particles 12 and the conductive material particles 14 together, and may be irregularly shaped and distributed between the organic active material particles 12 and the conductive material particles 14.

[0069] The D50 particle size of composite 10, etc., measured by laser diffraction / scattering method may be 1 to 30 μm, preferably 2 to 20 μm, and more preferably 2 to 10 μm. By setting the particle size of composite 10, etc., to a certain level or above, the solids content of the slurry containing composite 10, etc., can be increased, making it possible to apply the slurry thickly without causing cracks or the like. Furthermore, by setting the particle size to a certain level or below, it is possible to reduce ion conduction loss into the composite without causing cracks or the like. Furthermore, by controlling the particle size within this range, the strength, packing ability, and amount of gaps of composite 10, etc., can be optimized. The D50 particle size may be measured, for example, using a Shimadzu SALD series or a Microtrackbell SYNC series.

[0070] The specific surface area of ​​the composite 10 measured by the physical adsorption method is 1 to 12 m ２ / g, preferably 2 to 11 m ２ / g, more preferably 2m ２ / g to 5m ２ / g. By setting the specific surface area of ​​the composite 10 or the like in this range, the surface of the composite 10 or the like is made smooth, the composite 10 or the like is prevented from being pulverized in the dispersion step into a slurry, and dispersibility can be improved. This makes it possible to prevent cracks and blockages in the electrode.

[0071] Furthermore, by setting the specific surface area of ​​the composite 10, etc. to a relatively low numerical range as described above, the specific surface area of ​​the composite 10, etc. can be closely packed in the positive electrode active material layer 224, and the tortuosity of the electrolyte solution flow path in the electrode depth direction can be reduced. This not only improves the impregnation of the electrolyte solution, but also optimizes the ionic conduction path in the electrode pores, thereby improving charge / discharge performance.

[0072] The specific surface area may be measured by, for example, the flow method of the BET method. As an example, the specific surface area may be measured using a BELSORP MR1 manufactured by MicrotrackBell.

[0073] The volume resistivity of the composite 10 etc. is 1.0 × 10 ７ Ω cm or less, preferably 10 × 10 ５ Ω cm or less, more preferably 2×10 ５By setting the volume resistivity of the composite 10 or the like in this range, the conductivity of the positive electrode active material layer 224 can be increased to a sufficient level.

[0074] 5 shows an electron microscope photograph of a composite 20 according to this embodiment. The composite 20 in the photograph includes organic active material particles 12, conductive material particles 14, and binder resin 16. As shown in the figure, the composite 20 has a substantially spherical shape, and irregularities resulting from the respective components of the organic active material particles 12, conductive material particles 14, and binder resin 16 are observed on the surface.

[0075] Fig. 6 shows an electron microscope photograph of the positive electrode active material layer 224 according to this embodiment. The positive electrode active material layer 224 in Fig. 6 has a cross section in which a large number of composites 20 are pressed and aggregated. In this manner, the positive electrode active material layer 224 is formed while the composites 20 maintain their original shape (for example, a substantially spherical shape). This allows the electrolyte to permeate the gaps between the composites 20, thereby increasing the conductivity of the positive electrode active material layer 224.

[0076] The positive electrode active material layer 224 may further include one or more of organic active material particles 12, conductive material particles 14, and binder resin 16 in addition to the composite 10, etc. For example, the positive electrode active material layer 224 may include conductive material particles 14 and binder resin 16 in addition to the composite 10, etc. In FIG. 6 , conductive material particles 22 in addition to the composite 20 are included.

[0077] 7 shows a micrograph of a positive electrode active material layer 224 that does not contain the composite 10 or the like. The positive electrode active material layer 224 in FIG. 7 is formed from an organic active material, a conductive material, and a binder resin without forming the composite 10 or the like. As shown in the figure, the positive electrode active material layer 224 is densely packed with constituent materials, and there are very few gaps through which the electrolyte solution can penetrate. For this reason, the conductivity of the positive electrode active material layer cannot be sufficiently increased.

[0078] [Active Material Layer Materials] Hereinafter, the materials of the positive electrode active material layer 224 and the negative electrode active material layer 244 will be described in detail.

[0079] [Material of Positive Electrode Active Material Layer 224] The positive electrode active material layer 224 can use a known positive electrode organic active material as the organic active material particles 12. The organic active material particles 12 may contain an nπ-electron organic compound (where n≧2). For example, the organic active material particles 12 may be an organic compound having a quinone-containing skeleton.

[0080] As an example, the organic active material particles 12 may be an organic compound having one or more skeletons selected from benzoquinone, naphthoquinone, anthraquinone, phenazine tetraone, pentacene tetrone, and naphthazarin.

[0081] Specifically, the organic active material particles 12 are selected from the group consisting of p-benzoquinone, o-benzoquinone, 1,2-naphthoquinone, 1,4-naphthoquinone, 2,6-naphthoquinone, 1,2-anthraquinone, 1,4-anthraquinone, 9,10-anthraquinone, 5,8-dihydroxy-1,4-naphthoquinone, 5,8-dihydroxy-1,4-naphthoquinone, 2,4-dihydroxy-p-benzoquinone, 1,2, The compound may be 3,4-phenazine tetrone, 1,4,6,9-phenazine tetrone, 5,7,12,14-pentacene tetrone, lithium 5,7,12,14-tetraoxo-5,7,12,14-tetrahydrodibenzo[b,i]thianthrene-1,4,8,11-tetrakis(olate) (DNP-Li), and 4-nitro-1,2-benzoquinone, or a derivative thereof.

[0082] The derivative may be a compound in which at least one hydrogen atom contained in the compound is substituted with at least one substituent selected from the group consisting of a hydroxyl group, an alkyl group, an aryl group, a carbonyl group, an amino group, a cyano group, a disulfide group, and a nitro group. The derivative may be a compound in which at least one hydrogen atom contained in the compound is substituted with one or more hydroxyl groups and / or one or more carbonyl groups.

[0083] The organic active material particles 12 may be a monomer of the above-mentioned compound or an oligomer formed by linking a plurality of the monomers. The oligomer may be a dimer, a trimer, or a polymer of tetramer or more. In particular, when the degree of polymerization is 10 or less, it is desirable that the organic active material particles 12 be a compound having a quinone skeleton.

[0084] The organic active material particles 12 may have a D50 particle size of 0.2 to 5 μm as measured by a laser diffraction / scattering method. By setting the particle size of the organic active material particles 12 within this range, the strength, packing properties, and amount of gaps of the composite 10 and the like can be optimized. The D50 particle size may be measured, for example, using a Shimadzu SALD series or a Microtrackbell SYNC series.

[0085] The positive electrode active material layer 224 may further contain an inorganic active material in addition to the organic active material. For example, the inorganic active material may be LiMnO ２ , LiNiO ２ , LiCoO ２ , Li(Mn ｘ Ni １－ｘ )O2, Li(Mn ｘ Co １－ｘ ) O ２ , Li(Ni ｙ Co １－ｙ ) O ２ , Li(Mn ｘ Ni ｙ Co １－ｘ－ｙ ) O ２ Layered oxides such as Li ２ MnO ３ -LiNiO ２ , Li ２ MnO ３ -LiCoO ２ , Li ２ MnO ３ -Li(Ni ｙ Co １－ｙ ) O ２ Solid solutions of Li ２ MnSiO ４ , Li ２ NiSiO ４ , Li ２ CoSiO ４ , Li ２ (Mn ｘ Ni１－ｘ ) SiO ４ , Li ２ (Mn ｘ Co １－ｘ ) SiO ４ , Li ２ (Ni ｙ Co １－ｙ ) SiO ４ , Li ２ (Mn ｘ Ni ｙ Co １－ｘ－ｙ ) SiO ４ Silicates such as LiMnBO ３ , LiNiBO ３ , LiCoBO ３ , Li(Mn ｘ Ni １－ｘ ) BO ３ , Li(Mn ｘ Co １－ｘ ) BO ３ , Li(Ni ｙ Co １－ｙ ) BO ３ , Li(Mn ｘ Ni ｙ Co １－ｘ－ｙ ) BO ３ Borates such as V ２ O ５ ; LiV ３ O ６ MnO, etc. In the above formula, 0<x<1, 0<y<1, 0<x+y<1. These inorganic materials may be used alone or in combination of two or more.

[0086] When the storage cell 112 is a sodium ion secondary battery, another example of the inorganic active material is NaFeO ２ , NaNiO ２ , NaCoO ２ , NaMnO ２ , NaVO ２ , Na(Ni Ｘ Mn １－Ｘ ) O ２ , Na(Fe Ｘ Mn １－Ｘ ) O ２ , NaVPO ４ F, Na ２ FePO ４ F, Na ３ V２ (P.O. ４ ) ３ In the above formula, 0<x<1. These materials may be used alone or in combination of two or more.

[0087] The binder resin 16 binds the organic active material particles 12 and the conductive material particles 14 together, and maintains the electrode shape of the positive electrode 220. The type of binder resin 16 is not particularly limited, but may be one or more selected from carboxymethyl cellulose, styrene-butadiene rubber, acrylic resin, polyacrylonitrile, polyvinylidene fluoride, polyimide, polyamide-imide, polyethylene, polypropylene, polyurethane, and polytetrafluoroethylene polyether.

[0088] The conductive material particles 14 reduce the resistance of the positive electrode 220. The type of conductive material particles 14 is not particularly limited as long as it has the desired electronic conductivity, but an example of the material of the conductive material particles 14 is a carbon material. Examples of carbon materials include graphite, carbon black, acetylene black, ketjen black, coke, amorphous carbon, carbon fiber, fullerene, carbon nanotube, and graphene. These materials may be used alone or in combination of two or more.

[0089] The content of the organic active material particles 12 in the positive electrode active material layer 224, the composite 10, etc. is preferably 60 to 98 mass %, more preferably 70 to 96 mass %, and even more preferably 80 to 94 mass %.

[0090] The content of the conductive material particles 14 in the positive electrode active material layer 224, the composite 10, etc. is preferably 0.2 to 20 mass %, more preferably 1 to 10 mass %, and even more preferably 2 to 6 mass %. The weight ratio of the content of the organic active material particles to the content of the conductive material particles is preferably 100:0.5 to 100:15, and more preferably 100:2.5 to 100:4.

[0091] The content of the binder resin in the positive electrode active material layer 224 and the composite 20 is preferably 1 to 40 mass %, more preferably 3 to 30 mass %, and even more preferably 4 to 18 mass %.

[0092] The weight ratio of the organic active material particles to the binder resin in the positive electrode active material layer 224 and the composite 20 is preferably 100:1 to 100:15.

[0093] When the positive electrode active material layer 224 additionally contains organic active material particles 12 in addition to the composite 10, etc., it may contain 0.1 to 100 parts by weight per 100 parts by weight of the composite 10, etc. When the positive electrode active material layer 224 additionally contains conductive material particles 14 in addition to the composite 10, etc., it may contain 0.1 to 100 parts by weight, preferably 1 to 10 parts by weight, per 100 parts by weight of the composite 10, etc. When the positive electrode active material layer 224 additionally contains binder resin 16 in addition to the composite 10, etc., it may contain 0.1 to 100 parts by weight, preferably 1 to 10 parts by weight, per 100 parts by weight of the composite 10, etc.

[0094] [Materials of the Negative Electrode Active Material Layer 244] The negative electrode active material layer 244 contains a negative electrode active material and a binder resin. The negative electrode active material layer 244 may further contain a conductive additive.

[0095] The negative electrode active material layer 244 may contain, as the negative electrode active material, a heterocyclic compound including one or more pyrazine rings and two or more benzene rings, or a salt or derivative thereof. The heterocyclic compound may be a compound including one or more phenazine structures. The phenazine structure (i) includes one pyrazine ring and two benzene rings, and (ii) each of the two benzene rings is connected to the pyrazine ring by sharing one carbon-carbon bond with the pyrazine ring. The pyrazine ring may be substituted with any functional group or may be unsubstituted. The benzene ring may be substituted with any functional group or may be unsubstituted.

[0096] The heterocyclic compound that can be used in the negative electrode active material layer 244 is preferably a compound in which at least four oxygen atoms are bonded to the above-mentioned benzene ring. The heterocyclic compound is preferably a compound in which an even number of oxygen atoms, 4 or more, are bonded to the above-mentioned benzene ring. The heterocyclic compound may be a compound in which an even number of oxygen atoms, 4 or more and 12 or less, are bonded to the above-mentioned benzene ring.

[0097] The negative electrode active material layer 244 may contain a phenazine as the negative electrode active material. The phenazine is preferably a compound having at least four oxygen atoms bonded to a benzene ring contained in a phenazine structure. The phenazine structure is preferably a compound having an even number of oxygen atoms, 4 or more, bonded to the benzene ring. The phenazine structure may be a compound having an even number of oxygen atoms, 4 or more and 8 or less, bonded to the benzene ring.

[0098] The negative electrode active material may include an oligomer in which a plurality of phenazine structures are bonded. The oligomer may be an oligomer in which a plurality of phenazine structures are bonded via a linker. This suppresses dissolution of the negative electrode active material in the electrolyte in the secondary battery and improves the cycle performance of the secondary battery.

[0099] The heterocyclic compound or its salt or derivative, and the phenazines are, for example, included in any of the starting material, product, and intermediate product in at least the charging reaction of the battery electrode reaction. The phenazine oligomer or its salt or derivative that can be used as the negative electrode active material will be described in detail later.

[0100] The negative electrode active material is not limited to the above heterocyclic compounds, etc. When the power storage cell 112 is a lithium ion secondary battery, other examples of the negative electrode active material include (i) graphite, (ii) non-sinterable carbon or non-graphitizable carbon, (iii) tin, silicon, and alloys containing these, and (iv) SiO. When materials such as (i) graphite, (ii) non-sinterable carbon or non-graphitizable carbon, (iii) tin, silicon, and alloys containing these, and (iv) SiO are used as the negative electrode active material, the material may be pre-doped with lithium.

[0101] The negative electrode active material may be a lithium-containing material such as metallic lithium or a lithium alloy. For example, when the power storage cell 112 is a lithium metal secondary battery, metallic lithium is used as the negative electrode. These negative electrode active materials may be used alone, or two or more types of negative electrode active materials may be used in combination.

[0102] The negative electrode active material layer 244 may include lithium metal foil, which supplies lithium to the power storage cell 112. The thickness of the lithium metal foil may be 1 to 300 μm, 2 to 200 μm, or 3 to 100 μm. The thickness and / or mass of the lithium metal foil may be determined depending on the content of the positive electrode active material in the positive electrode active material layer 224.

[0103] When the power storage cell 112 is a sodium-ion secondary battery, other examples of the negative electrode active material include (i) graphite, (ii) non-sinterable carbon or non-graphitizable carbon, (iii) tin, silicon, and alloys containing these, and (iv) titanium oxide. The negative electrode active material may be a sodium-containing material such as metallic sodium or a sodium alloy. These negative electrode active materials may be used alone, or two or more negative electrode active materials may be used in combination.

[0104] In this embodiment, the binder resin binds together materials (e.g., anode active material, conductive additive, etc.) that make up the anode active material layer 244 and maintains the electrode shape of the anode 240. The type of binder resin is not particularly limited, but examples of the binder resin include polyvinylidene fluoride (PVDF), polytetrafluoroethylene, polyacrylic acid, and styrene butadiene rubber. The binder resin may be the same as that of the organic active material particles 12.

[0105] In this embodiment, the conductive additive reduces the resistance of the negative electrode 240. The type of conductive additive is not particularly limited as long as it has the desired electronic conductivity, but the same conductive additive as the conductive material particles 14 may be used.

[0106] When the negative electrode active material layer 244 does not contain a conductive additive, the content of the negative electrode active material in the negative electrode active material layer 244 is preferably 40 to 99 mass %, more preferably 80 to 98.5 mass %, and even more preferably 90 to 98 mass %. The content of the binder resin in the negative electrode active material layer 244 is preferably 1 to 60 mass %, more preferably 1.5 to 20 mass %, and even more preferably 2 to 10 mass %.

[0107] When the negative electrode active material layer 244 contains a conductive additive, the content of the conductive additive in the negative electrode active material layer 244 is preferably 0.1 to 20 mass %, more preferably 1 to 10 mass %, and even more preferably 2 to 5 mass %. In this case, the content of the negative electrode active material in the negative electrode active material layer 244 is preferably 40 to 98 mass %, more preferably 80 to 97 mass %, and even more preferably 90 to 96 mass %. Furthermore, the content of the binder resin in the negative electrode active material layer 244 is preferably 1.9 to 59.9 mass %, more preferably 2 to 19 mass %, and even more preferably 2 to 8 mass %.

[0108] The content of the binder resin in the negative electrode active material layer 244 may be 0.1 to 5 mass %, 0.2 to 3 mass %, or 0.5 to 1 mass %. In this case, the remainder of the negative electrode active material layer 244 may be the negative electrode active material, or may be a mixture of the negative electrode active material and a conductive additive.

[0109] The negative electrode active material layer 244 may be formed from a composite, similar to the positive electrode active material layer 224. In this case, the composite may contain a negative electrode active material, a conductive additive, and, if necessary, a binder resin. When the negative electrode active material layer 244 is formed from a composite, the conductivity of the negative electrode can be improved. The negative electrode active material layer 244 may contain, in addition to the composite, one or more of a negative electrode active material, a conductive additive, and a binder resin. The negative electrode active material layer 244 does not have to be formed from a composite.

[0110] [Manufacturing Method] Hereinafter, a method for manufacturing the positive electrode active material layer 224 and the negative electrode active material layer 244 will be described in detail.

[0111] [Method for Producing Positive Electrode Active Material Layer 224] The positive electrode active material layer 224 may be produced by applying a slurry containing the composite 10 and the like onto at least one surface of the positive electrode current collector 222 and drying the slurry.

[0112] 8 shows an example of a flow of the method for manufacturing the composite and positive electrode according to this embodiment. By performing each of the processes from S100 to S400, a positive electrode having a positive electrode active material layer 224 is manufactured. Some of S100 to S400 and / or some of the subflows may be omitted. Other operations may be performed in addition to S100 to S400.

[0113] First, in S100, the composite 10 and the like are produced. The composite 10 may be produced by granulation using a tumbling fluidization method or a spray drying method.

[0114] First, at least a plurality of organic active material particles 12 for a secondary battery are mixed with a plurality of conductive material particles 14. In addition to the organic active material particles 12 and the conductive material particles 14, a binder resin 16 may also be mixed as needed.

[0115] For example, in the case of the tumbling fluidization method, a dispersion in which conductive particles 14 are dispersed in a solvent, and a binder resin 16 dissolved in a solvent as needed, are sprayed onto organic active material particles 12 in a fluidized state in a tumbling fluidized bed granulator. The mixture is then dried to obtain a composite 10 or the like. The solvent may be appropriately selected depending on the dispersibility of the conductive particles 14 and the solubility of the binder resin 16, and may be selected from, for example, water, ethanol, acetone, N-methylpyrrolidone (NMP), etc. The intake air volume during granulation is 0.1 to 3 m ３ may be in the range of

[0116] For example, in the case of the spray drying method, a suspension in which organic active material particles 12, conductive material particles 14, and optionally a binder resin 16 are uniformly dispersed is sprayed from a nozzle to form droplets, which are then dried with hot air to obtain the composite 10, etc. The solid content of the suspension may be 5 to 50 wt %. The nozzle diameter may be 0.1 to 15 mm. The hot air temperature may be 50 to 200°C.

[0117] Next, in S200, an electrode slurry containing the composite is produced. The electrode slurry is produced by mixing the composite produced in S100 with a solvent. The solvent may be water and / or an organic solvent. The type and amount of the organic solvent are not particularly limited as long as it can sufficiently disperse the composite. For example, N-methylpyrrolidone (NMP) or acetonitrile (AN) may be used as the organic solvent. The solvent may be contained in a ratio of 10 to 1000 parts by weight per 100 parts by weight of the composite.

[0118] Next, in S300, an active material sheet is produced using the electrode slurry. For example, the electrode slurry produced in S200 can be applied and dried to produce an active material sheet. For example, the electrode slurry may be applied to a substrate or the like to a film thickness of 10 to 300 μm and then dried.

[0119] Next, in S400, the active material sheet produced in S300 is pressure-bonded to a current collector to produce a positive electrode. For example, the positive electrode may be formed by pressure-bonding the active material sheet to a metal mesh sheet. The pressure bonding of the positive electrode sheet is preferably performed at a pressure of 1 to 100 MPa.

[0120] The negative electrode may be produced by directly applying a slurry containing the negative electrode active material to a current collector, or by producing a negative electrode sheet from the slurry and attaching the negative electrode sheet to a current collector. The negative electrode may also be produced by the same methods as in S100 to S400 using a composite, as in the positive electrode.

[0121] A secondary battery can be manufactured by disposing a positive electrode, a separator, a negative electrode, and an electrolyte solution inside a battery case. The separator may be, for example, a glass filter (manufactured by Advantech Co., Ltd.) with a diameter of 16 mm and a thickness of 0.4 mm. The electrolyte may be, for example, LiPF ６ Alternatively, a non-aqueous electrolyte solution (manufactured by Kishida Chemical Co., Ltd.) containing a mixture of ethylene carbonate and diethyl carbonate may be used.

[0122] Examples of this embodiment will be described below.

[0123] Example 1 A composite was formed by granulation using 100 parts by weight of 9,10-anthraquinone (AQ) as the organic active material particles for the positive electrode and 4 parts by weight of acetylene black (AB) as the conductive material particles. A Spray Boy SB39 manufactured by PRIS Co., Ltd. was used as the granulation device for the composite. Granulation was performed after adding water so that the solid content was 20% by weight. Granulation was performed under the following conditions: drying temperature: inlet temperature 100°C, supply rate: 1.0 kg / L, spray pressure: 0.5 MPa, and a two-fluid nozzle was used.

[0124] The D50 particle size of the composite measured by the laser diffraction / scattering method was 2 μm, and the volume resistivity was 0.8 × 10 ５ Ωcm, and the specific surface area measured by MicrotrackBell BELSORP MR1 is 4.6 m ２ / g.

[0125] To 100 parts by weight of the composite, 3 parts by weight of acetylene black as additional conductive material particles, 1.5 parts by weight of carboxymethyl cellulose (CMC: Sunrose MAC350HC, Nippon Paper Chemicals Co., Ltd.) as binder resin, and 3 parts by weight of styrene-butadiene rubber (SBR: BM400-B, Nippon Zeon Co., Ltd.) were added and mixed. The mixture was mixed with water and stirred to obtain a slurry. The slurry was applied to a 15 μm thick aluminum foil and dried. Thereafter, the dried sheet was rolled using a roll press to produce a positive electrode.

[0126] The fabricated positive electrode was observed visually and under a microscope to check for the occurrence of cracks and whether the particle structure of the composite was crushed and clogged after compression bonding. As a result, neither cracks nor clogs were found to occur.

[0127] Next, a circular member with a diameter of 13 mm was cut out from a 0.5 mm thick lithium metal foil (manufactured by Honjo Metals Co., Ltd., purity 99.8% or more). The member cut out from the lithium foil was pressed onto a 15.5 mm diameter and 0.5 mm thick stainless steel plate (manufactured by Hosen Co., Ltd.) to prepare a negative electrode.

[0128] A glass filter (manufactured by Advantech Co., Ltd.) with a diameter of 16 mm and a thickness of 0.4 mm was prepared as a separator. ６ A nonaqueous electrolyte (Kishida Chemical Co., Ltd.) containing a mixture of ethylene carbonate and diethyl carbonate was prepared. The positive electrode, separator, negative electrode, and electrolyte were placed inside a battery case conforming to the R2032 coin battery standard to fabricate a test coin battery. The discharge capacity of the fabricated battery during the first cycle was measured to be 215 mAh / g.

[0129] [Example 2] The composite and battery were manufactured, and various measurements and observations were carried out in the same manner as in Example 1, except that the spray pressure of the granulator was increased slightly above 0.5 MPa to granulate the composite so that the D50 particle size of the composite was 5 μm. As a result, the volume resistivity of the composite was found to be 0.8 × 10 ５ Ωcm and the specific surface area is 3.7m ２ The discharge capacity of the battery was 217 mAh / g. No cracks or blockages were observed in the electrodes.

[0130] [Example 3] A composite was produced in the same manner as in Example 1, except that granulation was performed using 100 parts by weight of anthraquinone (AQ), 4 parts by weight of acetylene black (AB), and 3 parts by weight of styrene-butadiene rubber (SBR) as a binder resin to form a composite. The D50 particle size of the composite was 10 μm. Thereafter, a battery was produced, and various measurements and observations were performed in the same manner as in Example 1. As a result, the volume resistivity of the composite was 1.0 × 10 ５ Ωcm and the specific surface area is 2.7m ２ The discharge capacity of the battery was 218 mAh / g. There was no cracking or clogging of the electrode.

[0131] [Example 4] A composite and a battery were produced in the same manner as in Example 1, except that the content of acetylene black (AB) during granulation of the composite was changed from 4 parts by weight to 0.4 parts by weight. The D50 particle size of the composite was 10 μm. The results are shown in the table below.

[0132] Example 5 A composite and a battery were produced in the same manner as in Example 1, except that the D50 particle size of the composite was changed to 1 μm. The results are shown in the table below.

[0133] Example 6 A composite and a battery were produced in the same manner as in Example 1, except that the D50 particle size of the composite was changed to 30 μm. The results are shown in the table below.

[0134] Example 7 A composite and a battery were produced in the same manner as in Example 1, except that 4 parts by weight of acetylene black (AB) used during granulation of the composite was replaced with 2.5 parts by weight of carbon nanotubes (CNT: LB217-54, manufactured by Jiangsu Cnano Technology Ltd.). The D50 particle size of the composite was 10 μm. The results are shown in the table below.

[0135] [Example 8] A composite and a battery were produced in the same manner as in Example 3, except that 3 parts by weight of polyacrylonitrile (PAN) was used as the binder resin instead of 3 parts by weight of styrene-butadiene rubber (SBR) during granulation of the composite. The D50 particle size of the composite was 10 μm. The results are shown in the table below.

[0136] Example 9 A composite and a battery were produced in the same manner as in Example 3, except that 100 parts by weight of 1,4,6,9-phenazinetetraone (PTO) was used instead of 100 parts by weight of anthraquinone (AQ) during granulation of the composite. The D50 particle size of the composite was 10 μm. The results are shown in the table below.

[0137] [Example 10] A composite and a battery were produced in the same manner as in Example 7, except that 100 parts by weight of phenazine tetraone (PTO) was used instead of 100 parts by weight of anthraquinone (AQ) during granulation of the composite. The D50 particle size of the composite was 10 μm. The results are shown in the table below.

[0138] [Example 11] A composite and a battery were produced in the same manner as in Example 8, except that 100 parts by weight of phenazine tetraone (PTO) was used instead of 100 parts by weight of anthraquinone (AQ) during granulation of the composite. The D50 particle size of the composite was 10 μm. The results are shown in the table below.

[0139] Example 12 A composite and a battery were produced in the same manner as in Example 7, except that 100 parts by weight of 5,7,12,14-pentacenetetrone (PT) was used instead of 100 parts by weight of anthraquinone (AQ) during granulation of the composite. The D50 particle size of the composite was 10 μm. The results are shown in the table below.

[0140] Example 13 A composite and a battery were produced in the same manner as in Example 7, except that 100 parts by weight of lithium 5,7,12,14-tetraoxo-5,7,12,14-tetrahydrodibenzo[b,i]thianthrene-1,4,8,11-tetrakis(olate) (DNP-Li) was used instead of 100 parts by weight of anthraquinone (AQ) during granulation of the composite. The D50 particle size of the composite was 10 μm. The results are shown in the table below.

[0141] [Example 14] A composite and a battery were produced in the same manner as in Example 4, except that 100 parts by weight of phenazine tetraone (PTO) was used instead of 100 parts by weight of anthraquinone (AQ) during granulation of the composite. The D50 particle size of the composite was 10 μm. The results are shown in the table below.

[0142] [Example 15] A composite and a battery were produced in the same manner as in Example 6, except that 100 parts by weight of phenazine tetraone (PTO) was used instead of 100 parts by weight of anthraquinone (AQ) during granulation of the composite. The D50 particle size of the composite was 10 μm. The results are shown in the table below.

[0143] Comparative Example 1: 100 parts by weight of anthraquinone (AQ) was used as organic active material particles for the positive electrode. The D50 particle size of the organic active material particles measured by a laser diffraction / scattering method was 1 μm, and the volume resistivity was 2×10 １０ Ωcm and the specific surface area is 15m ２ / g.

[0144] To 100 parts by weight of organic active material particles, 3 parts by weight of acetylene black, 1.5 parts by weight of carboxymethyl cellulose (CMC), and 3 parts by weight of styrene-butadiene rubber (SBR) as a binder resin were added and mixed. A positive electrode active material sheet with a diameter of approximately 10 mm and a thickness of approximately 100 μm was prepared from the mixture. The positive electrode active material sheet was pressed onto a stainless steel mesh (SUS316L, manufactured by Hohsen Co., Ltd.) with a diameter of 14 mm and a thickness of 100 μm to prepare a positive electrode. Thereafter, observations and measurements were performed in the same manner as in Example 1.

[0145] Comparative Example 2 A positive electrode and a battery were produced in the same manner as in Comparative Example 1, except that the amount of acetylene black was changed from 3 parts by weight to 10 parts by weight. Thereafter, observations and measurements were carried out in the same manner as in Example 1.

[0146] The results of the above examples and comparative examples are shown below. The term "slight cracking" indicates that slight cracking occurs but does not affect the battery's usability. The term "present" indicates that cracking occurs to the extent that the positive electrode active material layer may peel off.

[0147] As shown in Tables 1 and 2, in Examples 1 to 15 in which electrodes were produced using the composite, no large cracks or blockages occurred in the electrodes, unlike Comparative Examples 1 and 2. Furthermore, in Examples 1 to 15, the discharge capacity was significantly larger than in Comparative Examples 1 and 2. In Examples 6 and 15, minor cracks occurred, but the structure of the composite was maintained and no blockages occurred.

[0148] Although the present invention has been described above using embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. It will be apparent to those skilled in the art that various modifications and improvements can be made to the above embodiments. It is clear from the claims that such modifications and improvements can also be included within the technical scope of the present invention.

[0149] It should be noted that the order of execution of each process, such as operations, procedures, steps, and stages, in the devices, systems, programs, and methods shown in the claims, specifications, and drawings is not specifically stated as "before," "prior to," etc., and that the processes can be performed in any order unless the output of a previous process is used in a subsequent process. Even if the operational flow in the claims, specifications, and drawings is described using "first," "next," etc. for convenience, this does not mean that the processes must be performed in this order.

[0150] REFERENCE SIGNS LIST 10 Composite 12 Organic active material particles 14 Conductive material particles 16 Binder resin 20 Composite 22 Conductive material particles, etc. 100 Aircraft 110 Storage battery 112 Storage cell 120 Power control circuit 130 Motor 140 Propeller 150 Sensor 160 Control device 212 Positive electrode case 214 Negative electrode case 216 Sealant 218 Metal spring 220 Positive electrode 222 Positive electrode current collector 224 Positive electrode active material layer 230 Separator 240 Negative electrode 242 Negative electrode current collector 244 Negative electrode active material layer 250 Electrolyte

Claims

1. A composite formed by assembling at least a plurality of organic active material particles for a secondary battery and a plurality of conductive material particles.

2. The composite according to claim 1, further comprising a binder resin, wherein the organic active material particles and the conductive material particles are bound together by the binder resin.

3. The complex according to claim 1 or 2, wherein the D50 particle size measured by a laser diffraction / scattering method is 1 μm to 30 μm.

4. The specific surface area measured by the physical adsorption method is 1 m ２ / g~12m ２ The composite of claim 1 , wherein the saturation coefficient is 1 / g.

5. Volume resistivity is 10 x 10 ７ The composite according to any one of claims 1 to 4, having a resistivity of Ω·cm or less.

6. The composite according to any one of claims 1 to 5, wherein the organic active material particles contain an nπ-electron organic compound (where n≧2).

7. The composite according to any one of claims 1 to 5, wherein the organic active material particles are an organic compound having a quinone-containing skeleton.

8. The composite according to any one of claims 1 to 5, wherein the organic active material particles are organic compounds having one or more skeletons selected from anthraquinone, phenazinetetraone, pentacenetetrone, and naphthazarin.

9. The composite according to any one of claims 1 to 8, wherein the organic active material particles have a D50 particle size of 0.2 to 5 µm as measured by a laser diffraction / scattering method.

10. The composite according to any one of claims 1 to 9, wherein the conductive particles are one or more selected from the group consisting of acetylene black, carbon nanotubes, carbon black, carbon fiber, fullerene, graphene, and graphite.

11. The composite according to claim 2, wherein the binder resin is one or more selected from the group consisting of carboxymethyl cellulose, styrene-butadiene rubber, acrylic resin, polyacrylonitrile, polyvinylidene fluoride, polyimide, polyamide-imide, polyethylene, polypropylene, polyurethane, and polytetrafluoroethylene polyether.

12. The composite according to claim 2, wherein the weight ratio of the organic active material particles to the binder resin is 100:1 to 100:

15.

13. A slurry for a secondary battery electrode, comprising the composite of any one of claims 1 to 12 and a solvent.

14. An electrode for a secondary battery, comprising: a current collector; and an active material layer containing the composite of any one of claims 1 to 12.

15. A secondary battery comprising the electrode for a secondary battery according to claim 14 and an electrolyte.

16. The secondary battery according to claim 15, which is a non-aqueous secondary battery.

17. An aircraft comprising: the secondary battery according to claim 15 or 16; and a thrust generating device that generates thrust using the electrical energy stored in the secondary battery.

18. A method for producing a composite according to any one of claims 1 to 12, comprising mixing and drying at least a plurality of organic active material particles for secondary batteries and a plurality of conductive material particles.

19. A method for producing a composite according to claim 18, comprising a step of granulating the composite by a tumbling fluidization method or a spray drying method.

20. A method for manufacturing an electrode for a secondary battery, comprising: a composite manufacturing step of manufacturing the composite according to any one of claims 1 to 12 by mixing and drying at least a plurality of organic active material particles for a secondary battery and a plurality of conductive material particles; a sheet manufacturing step of manufacturing an active material sheet by applying and drying an electrode slurry containing the composite and a solvent; and an electrode formation step of forming an electrode by pressing the active material sheet onto a current collector.

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