WO2020153405A1 - Resin substrate and bipolar battery - Google Patents

Resin substrate and bipolar battery Download PDF

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Publication number
WO2020153405A1
WO2020153405A1 PCT/JP2020/002143 JP2020002143W WO2020153405A1 WO 2020153405 A1 WO2020153405 A1 WO 2020153405A1 JP 2020002143 W JP2020002143 W JP 2020002143W WO 2020153405 A1 WO2020153405 A1 WO 2020153405A1
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Prior art keywords
conductive filler
filler
electrode active
active material
resin
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PCT/JP2020/002143
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French (fr)
Japanese (ja)
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永田　佳秀
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株式会社村田製作所
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Publication of WO2020153405A1 publication Critical patent/WO2020153405A1/en

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    • 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
    • H01M4/64—Carriers or collectors
    • H01M4/66—Selection of materials
    • 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

Definitions

  • the present invention relates to a resin base material and a bipolar battery.
  • a bipolar electrode in which a positive electrode active material layer is provided on a first main surface of a current collector and a negative electrode active material layer is provided on a second main surface of a current collector is used.
  • Patent Document 1 describes that a resin base material to which a conductive filler such as metal and conductive carbon is added is used as a collector of a bipolar battery.
  • An object of the present invention is to provide a resin base material and a bipolar battery that can simultaneously realize low resistivity and local variation in resistivity variation.
  • a first invention is a resin base material used for a current collector of a battery, wherein a first conductive filler having a fibrous shape and a second conductive filler are provided.
  • the resin base material that includes the second conductive filler and has an average filler diameter smaller than that of the first conductive filler.
  • the second invention is a bipolar battery including the resin base material according to the first invention as a current collector.
  • the resin base material according to the first embodiment of the present invention is a resin base material used for a collector such as a bipolar battery, and includes a first conductive filler, a second conductive filler, and a polymer. Including resin.
  • the resin substrate has, for example, a film shape or a plate shape.
  • the first conductive filler and the second conductive filler are dispersed in the resin base material.
  • the average filler diameter of the second filler is smaller than the average filler diameter of the first filler.
  • the first conductive filler is for forming a large conductive path in the resin base material. Since the first conductive filler has a large filler diameter and a low resistance, it has an advantage that the resistivity of the entire resin base material can be reduced. On the other hand, since the first conductive filler has a large filler size, when the first conductive filler is used alone, there is a drawback that the resistivity is locally varied at a location where dispersion is insufficient. There is.
  • the second conductive filler is for forming a small conductive path in the resin base material. Since the second conductive filler has a small filler size, it has advantages that local resistance variation is small and the uniformity of resistivity distribution can be enhanced. On the other hand, since the second conductive filler has a low function of lowering the resistivity of the entire resin base material, when the second conductive filler is used alone, it has a drawback that the resistivity of the resin base material becomes high. doing.
  • first conductive filler and the second conductive filler By combining the first conductive filler and the second conductive filler, their respective defects can be complemented. That is, by using two kinds of conductive fillers having different functions as described above together, it is possible to reduce the resistivity of the entire resin base material and suppress the local variation of the resistivity of the resin base material. it can.
  • the first conductive filler has a fibrous shape.
  • the first conductive filler is, for example, carbon fiber.
  • the carbon fiber is, for example, at least one kind of PAN-based carbon fiber and pitch-based carbon fiber.
  • the second conductive filler has, for example, a spherical shape, an ellipsoidal shape, a needle shape, a plate shape, a scale shape, a tube shape, a wire shape, a rod shape (rod shape), a fibrous shape, or an indefinite shape, but particularly It is not limited. It should be noted that only one kind of conductive filler may be used, or two or more kinds of conductive filler may be used in combination.
  • the second conductive filler is, for example, at least one kind of carbon-based filler and metal-based filler.
  • the carbon-based filler include carbon nanofibers (for example, vapor growth carbon fiber (VGCF)), carbon black (for example, Ketjen black, acetylene black, etc.), porous carbon, fullerene, graphene, carbon nanotubes (for example, SWCNT, MWCNT, etc.). ), at least one of carbon microcoils and carbon nanohorns.
  • the metal-based filler includes, for example, nickel or stainless steel.
  • the average filler diameter of the first conductive filler is preferably 5 ⁇ m or more and 10 ⁇ m or less.
  • the average filler diameter of the first conductive filler is 5 ⁇ m or more, the resistivity of the entire resin base material can be effectively reduced.
  • the average filler diameter of the first conductive filler is 10 ⁇ m or less, it is possible to suppress deterioration of the dispersibility of the first conductive filler.
  • the average filler length of the first conductive filler is preferably 1 mm or more and 10 mm or less.
  • the average filler length of the first conductive filler is 1 mm or more, the resistivity of the entire resin base material can be effectively reduced.
  • the average filler length of the first conductive filler is 10 mm or less, it is possible to suppress deterioration of the dispersibility of the first conductive filler.
  • the average filler diameter of the second conductive filler is preferably 1 nm or more and 200 nm or less. If the average filler diameter of the second conductive filler is smaller than 1 nm, it is difficult to obtain it. On the other hand, when the average filler diameter of the second conductive filler is 200 nm or less, local resistance variation can be effectively suppressed.
  • the average filler length of the second conductive filler is preferably 1 ⁇ m or more and 30 ⁇ m or less. Since carbon nanofibers are generally 1 ⁇ m or more, if the average filler length of the second conductive filler is smaller than 1 ⁇ m, it will be difficult to obtain them. On the other hand, when the average filler length of the second conductive filler is 30 ⁇ m or less, it is possible to suppress deterioration of the dispersibility of the second conductive filler.
  • the average filler diameter and average filler length of the first conductive filler, and the average filler diameter and average filler length of the second conductive filler are measured as follows. First, the first conductive filler and the second conductive filler are taken out from the resin base material, put into N-methyl-2-pyrrolidone (NMP), and subjected to dispersion treatment by an ultrasonic device for 5 minutes. The dispersion treated solution is applied to the sample stage of SEM (Scanning Electron Microscope), dried, and the SEM observation is performed to measure the filler diameter and the filler length of the first conductive filler of 30 or more samples, and the first conductivity is measured. The average filler diameter (D50) and the average filler length (D50) of the filler are calculated. Also for the second conductive filler, the average filler diameter (D50) and the average filler length (D50) are calculated by the same procedure as that for the first conductive filler.
  • NMP N-methyl-2-pyrrolidone
  • the content of the first conductive filler in the resin substrate is preferably more than 5% by mass and less than 15% by mass, more preferably 6% by mass or more and 14% by mass or less, still more preferably 7% by mass or more and 13% by mass. % Or less, particularly preferably 8% by mass or more and 12% by mass or less, and most preferably 9% by mass or more and 11% by mass or less.
  • the content of the first conductive filler exceeds 5% by mass, the resistivity of the entire resin base material can be effectively reduced.
  • the content of the first conductive filler is less than 15% by mass, it is possible to suppress the decrease in strength of the resin base material due to the decrease in the amount of polymer resin.
  • the content of the second conductive filler in the resin base material is preferably 5% by mass or more and 15% by mass or less.
  • the content of the second conductive filler is 5% by mass or more, the uniformity of the resistivity distribution can be further enhanced.
  • the content of the second conductive filler is 15% by mass or less, it is possible to suppress the decrease in strength of the resin base material due to the decrease in the amount of the polymer resin.
  • the content of the first conductive filler in the resin base material and the content of the second conductive filler in the resin base material are calculated as follows. First, the resin base material that has been weighed in advance is dissolved in an appropriate solvent, and the first conductive filler and the second conductive filler are separated by a centrifuge, and then the separated respective are filtered and dried, The first conductive filler and the second conductive filler are taken out. Next, the weights of the first conductive filler and the second conductive filler that were taken out were measured, respectively, and the content of the first conductive filler in the resin base material and the second conductive filler in the resin base material were measured. The content of the functional filler is calculated.
  • polymer resin examples include polyethylene, polypropylene, polyethylene terephthalate, polyether nitrile, polyimide, polyamide, polytetrafluoroethylene, styrene butadiene rubber, polyacrylonitrile, polymethyl acrylate, polymethyl methacrylate, polyvinyl chloride and polyvinylidene fluoride. At least one selected from the group consisting of can be used.
  • a molding material is prepared by mixing the first conductive filler, the second conductive filler, and the polymer resin, and kneading while heating at a melting temperature of the polymer resin or higher.
  • a resin base material is obtained by molding the molding material into a film by, for example, a melt extrusion molding method.
  • the resin base material according to the first embodiment of the present invention includes a first conductive filler having a fibrous shape and a second conductive filler, and an average filler diameter of the second conductive filler is It is smaller than the average filler diameter of the conductive filler 1.
  • the first conductive filler (large-diameter filler) forms a large conductive path capable of significantly reducing the resistivity of the resin base material.
  • the second conductive filler small-diameter filler
  • FIG. 1 shows an example of the configuration of a bipolar battery (hereinafter simply referred to as “battery”) 10 according to a second embodiment of the present invention.
  • the battery 10 is a non-aqueous electrolyte secondary battery (lithium ion secondary battery) and includes a plurality of electrodes 11, a plurality of separators 12, a plurality of electrolyte layers 13, a positive electrode tab 14A, and a negative electrode tab 14B. ..
  • the battery 10 may be housed in an exterior material such as a laminated film.
  • a plurality of electrodes 11, a plurality of separators 12, and a plurality of electrolyte layers 13 are repeatedly laminated in the order of the electrodes 11, the electrolyte layers 13, the separators 12, and the electrolyte layers 13 to form a laminate.
  • the electrodes 11 located at other than both ends in the stacking direction are bipolar electrodes, and a current collector 11A having a first main surface and a second main surface facing each other, and a first main surface of the current collector 11A. And a negative electrode active material layer 11C provided on the second main surface of the current collector 11A.
  • the electrodes 11 adjacent to each other in the stacking direction are stacked such that the first main surface and the second main surface of the current collector 11A face each other, that is, the positive electrode active material layer 11B and the negative electrode active material layer 11C face each other. There is.
  • the positive electrode active material layer 11B is provided on the first main surface of the current collector 11A, while the negative electrode active material layer 11B is provided on the second main surface of the current collector 11A. It is a single-sided electrode without the material layer 11C.
  • the positive electrode tab 14A is connected to the second main surface of the current collector 11A included in the one-sided electrode.
  • the negative electrode active material layer 11C is provided on the second main surface of the current collector 11A, while the positive electrode is provided on the first main surface of the current collector 11A.
  • This is a single-sided electrode in which the active material layer 11B is not provided.
  • the negative electrode tab 14B is connected to the first main surface of the current collector 11A included in the one-sided electrode.
  • the current collector 11A, the positive electrode active material layer 11B, the negative electrode active material layer 11C, the separator 12, the electrolyte layer 13, the positive electrode tab 14A, and the negative electrode tab 14B included in the battery 10 will be sequentially described.
  • the collector 11A is the resin base material according to the first embodiment.
  • the positive electrode active material layer 11B contains one or more positive electrode active materials capable of inserting and extracting lithium.
  • the positive electrode active material layer 11B may further contain at least one of a binder and a conductive agent, if necessary.
  • a lithium-containing compound such as a lithium oxide, a lithium phosphorus oxide, a lithium sulfide, or an intercalation compound containing lithium is suitable, and two or more kinds of these may be mixed and used.
  • a lithium-containing compound containing lithium, a transition metal element, and oxygen is preferable for increasing the energy density.
  • Examples of such a lithium-containing compound include a lithium composite oxide having a layered rock salt type structure represented by formula (A), a lithium composite phosphate having an olivine type structure represented by formula (B), and the like. Can be mentioned.
  • the lithium-containing compound is more preferably a compound containing at least one selected from the group consisting of Co, Ni, Mn and Fe as a transition metal element.
  • a lithium-containing compound include, for example, a lithium composite oxide having a layered rock salt type structure represented by formula (C), formula (D) or formula (E), and a spinel type compound represented by formula (F).
  • LiCoO 2 LiNiO 2 , LiNi a Co 1-a O 2 (0 ⁇ a ⁇ 1), LiMn 2 O 4 or LiFePO 4 and the like.
  • any common material such as LCO, NCM, NCA and LFP can be used.
  • M1 represents at least one element selected from the groups 2 to 15 excluding Ni and Mn.
  • X represents a group consisting of a group 16 element and a group 17 element other than oxygen. At least one is selected, where p, q, y, and z are 0 ⁇ p ⁇ 1.5, 0 ⁇ q ⁇ 1.0, 0 ⁇ r ⁇ 1.0, and ⁇ 0.10 ⁇ y ⁇ 0. 20, a value within the range of 0 ⁇ z ⁇ 0.2.
  • M2 represents at least one element selected from the groups 2 to 15; a and b are 0 ⁇ a ⁇ 2.0 and 0.5 ⁇ b ⁇ 2.0. It is a value within the range of.
  • M3 is at least selected from the group consisting of Co, Mg, Al, B, Ti, V, Cr, Fe, Cu, Zn, Zr, Mo, Sn, Ca, Sr, and W.
  • F, g, h, j and k are 0.8 ⁇ f ⁇ 1.2, 0 ⁇ g ⁇ 0.5, 0 ⁇ h ⁇ 0.5, g+h ⁇ 1, ⁇ 0.1.
  • the values are in the range of ⁇ j ⁇ 0.2 and 0 ⁇ k ⁇ 0.1 (Note that the composition of lithium differs depending on the state of charge and discharge, and the value of f represents the value in the fully discharged state.)
  • M4 is at least selected from the group consisting of Co, Mn, Mg, Al, B, Ti, V, Cr, Fe, Cu, Zn, Mo, Sn, Ca, Sr, and W.
  • m, n, p and q are 0.8 ⁇ m ⁇ 1.2, 0.005 ⁇ n ⁇ 0.5, ⁇ 0.1 ⁇ p ⁇ 0.2, 0 ⁇ q ⁇ 0. The value is within the range of 1.
  • the lithium composition differs depending on the state of charge and discharge, and the value of m represents the value in the completely discharged state.
  • M5 is at least selected from the group consisting of Ni, Mn, Mg, Al, B, Ti, V, Cr, Fe, Cu, Zn, Mo, Sn, Ca, Sr, and W. Representing one type, r, s, t and u are 0.8 ⁇ r ⁇ 1.2, 0 ⁇ s ⁇ 0.5, ⁇ 0.1 ⁇ t ⁇ 0.2, 0 ⁇ u ⁇ 0.1.
  • the composition of lithium differs depending on the state of charge and discharge, and the value of r represents the value in the completely discharged state.
  • M6 is at least selected from the group consisting of Co, Ni, Mg, Al, B, Ti, V, Cr, Fe, Cu, Zn, Mo, Sn, Ca, Sr, and W.
  • V, w, x and y are 0.9 ⁇ v ⁇ 1.1, 0 ⁇ w ⁇ 0.6, 3.7 ⁇ x ⁇ 4.1, and 0 ⁇ y ⁇ 0.1.
  • It is a value within the range. The composition of lithium differs depending on the state of charge and discharge, and the value of v represents the value in the state of complete discharge.
  • Li z M7PO 4 (However, in the formula (G), M7 is selected from the group consisting of Co, Mg, Fe, Ni, Mg, Al, B, Ti, V, Nb, Cu, Zn, Mo, Ca, Sr, W and Zr. Z is a value within the range of 0.9 ⁇ z ⁇ 1.1 Note that the composition of lithium differs depending on the state of charge and discharge, and the value of z indicates the value in the state of complete discharge. It represents.)
  • lithium composite oxide containing Ni examples include a lithium composite oxide (NCM) containing Li, Ni, Co, Mn, and O (oxygen), and a lithium composite oxide containing Li, Ni, Co, Al, and O (oxygen).
  • NCM lithium composite oxide
  • An oxide (NCA) or the like may be used.
  • the lithium composite oxide containing Ni specifically, one represented by the following formula (H) or formula (I) may be used.
  • Li v1 Ni w1 M1′ x1 O z1 (H) (In the formula, 0 ⁇ v1 ⁇ 2, w1+x1 ⁇ 1, 0.2 ⁇ w1 ⁇ 1, 0 ⁇ x1 ⁇ 0.7, 0 ⁇ z ⁇ 3, and M1′ is Co, Fe, Mn, Cu, (At least one element selected from transition metals such as Zn, Al, Cr, V, Ti, Mg, and Zr.)
  • an inorganic compound containing no lithium such as MnO 2 , V 2 O 5 , V 6 O 13 , NiS, and MoS may be used in addition to these. it can.
  • the positive electrode active material capable of inserting and extracting lithium may be other than the above. Further, the positive electrode active materials exemplified above may be mixed in two or more kinds in any combination.
  • the conductive agent for example, at least one carbon material selected from the group consisting of graphite, carbon fiber, carbon black, acetylene black, Ketjen black, carbon nanotube (CNT), carbon nanofiber (CNF), graphene, and the like. Can be used.
  • the conductive agent is not limited to the carbon material, as long as it is a material having conductivity.
  • a metal material or a conductive polymer material may be used as the conductive agent.
  • examples of the shape of the conductive agent include a granular shape, a scale shape, a hollow shape, a needle shape, and a cylindrical shape, but are not particularly limited to these shapes.
  • binder examples include polyvinylidene fluoride (PVdF), polytetrafluoroethylene (PTFE), polyacrylonitrile (PAN), styrene butadiene rubber (SBR), carboxymethyl cellulose (CMC), and one of these resin materials. At least one selected from the group consisting of copolymers as a main component can be used.
  • PVdF polyvinylidene fluoride
  • PTFE polytetrafluoroethylene
  • PAN polyacrylonitrile
  • SBR styrene butadiene rubber
  • CMC carboxymethyl cellulose
  • the negative electrode active material layer 11C includes one or more negative electrode active materials capable of inserting and extracting lithium.
  • the negative electrode active material layer 11C may further contain at least one of a binder and a conductive agent, if necessary.
  • the negative electrode active material examples include non-graphitizable carbon, graphitizable carbon, graphite, pyrolytic carbons, cokes, glassy carbons, organic polymer compound fired bodies, carbon materials such as carbon fiber or activated carbon.
  • the cokes include pitch coke, needle coke, petroleum coke, and the like.
  • the organic polymer compound fired body is obtained by firing a polymer material such as a phenol resin or a furan resin at an appropriate temperature to carbonize it, and part of it is a non-graphitizable carbon or an easily graphitizable carbon. Some are classified as.
  • These carbon materials are preferable because the change in the crystal structure that occurs during charging and discharging is very small, a high charge and discharge capacity can be obtained, and good cycle characteristics can be obtained.
  • graphite is preferable because it has a large electrochemical equivalent and can obtain a high energy density.
  • non-graphitizable carbon is preferable because excellent cycle characteristics can be obtained.
  • a material having a low charge/discharge potential specifically, a material having a charge/discharge potential close to that of lithium metal is preferable because the energy density of the battery 10 can be easily increased.
  • the graphite may be natural graphite, artificial graphite, or a mixture thereof.
  • Mesocarbon microbeads (MCMB) or the like can be used as the artificial graphite.
  • a material containing at least one of a metal element and a metalloid element as a constituent element for example, an alloy, a compound or a mixture
  • a high energy density can be obtained by using such a material.
  • the alloy includes not only an alloy composed of two or more metal elements but also an alloy containing one or more metal elements and one or more metalloid elements.
  • the structure thereof includes a solid solution, a eutectic (eutectic mixture), an intermetallic compound, or a structure in which two or more of them coexist.
  • a negative electrode active material for example, a metal element or a metalloid element capable of forming an alloy with lithium can be mentioned.
  • a metal element or a metalloid element capable of forming an alloy with lithium.
  • Specific examples include Mg, B, Al, Ti, Ga, In, Si, Ge, Sn, Pb, Bi, Cd, Ag, Zn, Hf, Zr, Y, Pd or Pt. These may be crystalline or amorphous.
  • Examples of such a negative electrode active material include those containing a metal element or metalloid element of Group 4B in the short-periodic periodic table as a constituent element, and among them, at least one of Si and Sn is preferable as a constituent element. It includes. This is because Si and Sn have a large ability to insert and extract lithium, and a high energy density can be obtained.
  • Examples of such a negative electrode active material include a simple substance of Si, an alloy or a compound, a simple substance of Sn, an alloy or a compound, and a material having at least a part of one or more of them.
  • Examples of the alloy of Si include Sn, Ni, Cu, Fe, Co, Mn, Zn, In, Ag, Ti, Ge, Bi, Sb, Nb, Mo and Al as the second constituent element other than Si. Examples include those containing at least one selected from the group consisting of P, Ga and Cr.
  • Examples of the alloy of Sn include, as second constituent elements other than Sn, Si, Ni, Cu, Fe, Co, Mn, Zn, In, Ag, Ti, Ge, Bi, Sb, Nb, Mo, Al, Examples include those containing at least one selected from the group consisting of P, Ga and Cr.
  • Sn compound or the Si compound examples include those containing O or C as a constituent element. These compounds may contain the above-mentioned second constituent element.
  • the Sn-based negative electrode active material preferably contains Co, Sn, and C as constituent elements and has a low crystallinity or an amorphous structure.
  • negative electrode active materials include, for example, metal oxides or polymer compounds capable of inserting and extracting lithium.
  • metal oxide include lithium titanium oxide containing Li and Ti such as lithium titanate (Li 4 Ti 5 O 12 ), iron oxide, ruthenium oxide or molybdenum oxide.
  • the polymer compound include polyacetylene, polyaniline, polypyrrole and the like.
  • the same material as the positive electrode active material layer 11B can be used.
  • binder examples include polyvinylidene fluoride (PVdF), polyimide (PI), aramid, polytetrafluoroethylene (PTFE), polyacrylonitrile (PAN), styrene butadiene rubber (SBR), carboxymethyl cellulose (CMC), and these resins. At least one selected from the group consisting of copolymers mainly composed of one of the materials can be used.
  • PVdF polyvinylidene fluoride
  • PI polyimide
  • aramid polytetrafluoroethylene
  • PAN polyacrylonitrile
  • SBR styrene butadiene rubber
  • CMC carboxymethyl cellulose
  • the separator 12 separates the positive electrode active material layer 11B from the negative electrode active material layer 11C, prevents current short circuit due to contact between both electrodes, and allows lithium ions to pass through.
  • the separator 12 is made of, for example, polytetrafluoroethylene, a polyolefin resin (polypropylene (PP) or polyethylene (PE), etc.), an acrylic resin, a styrene resin, a polyester resin or a nylon resin, or a porous resin made by blending these resins. It is composed of a porous membrane, and may have a structure in which two or more kinds of these porous membranes are laminated.
  • the porous film made of polyolefin is preferable because it has an excellent short-circuit prevention effect and can improve the safety of the battery 10 due to the shutdown effect.
  • polyethylene is preferable as a material forming the separator 12 because it can obtain a shutdown effect in the range of 100° C. or higher and 160° C. or lower and is excellent in electrochemical stability.
  • low-density polyethylene, high-density polyethylene and linear polyethylene have suitable melting temperatures and are easily available, and thus are preferably used.
  • a material obtained by copolymerizing or blending a chemically stable resin with polyethylene or polypropylene can be used.
  • the porous membrane may have a structure of three or more layers in which a polypropylene layer, a polyethylene layer, and a polypropylene layer are sequentially laminated.
  • a single layer base material having 100 wt% PP or 100 wt% PE may be used.
  • the separator 12 may be manufactured by either a wet method or a dry method.
  • Nonwoven fabric may be used as the separator 12.
  • fibers constituting the non-woven fabric aramid fibers, glass fibers, polyolefin fibers, polyethylene terephthalate (PET) fibers, nylon fibers or the like can be used. Further, two or more kinds of these fibers may be mixed to form a non-woven fabric.
  • the separator 12 may have a configuration including a base material and a surface layer provided on one surface or both surfaces of the base material.
  • the surface layer includes inorganic particles having electrical insulation properties and a resin material that binds the inorganic particles to the surface of the base material and also binds the inorganic particles to each other.
  • This resin material may have a three-dimensional network structure in which a plurality of fibrils are connected by fibrillation.
  • the inorganic particles are carried on the resin material having this three-dimensional network structure.
  • the resin material may bind the surface of the base material or the inorganic particles to each other without being fibrillated. In this case, higher binding property can be obtained.
  • the base material is a porous film composed of an insulating film that transmits lithium ions and has a predetermined mechanical strength. Since the electrolyte solution is retained in the pores of the base material, the resistance to the electrolyte solution is high. It is preferable that the resin has a property that it is high, has low reactivity, and does not easily expand.
  • the resin material or non-woven fabric forming the separator 12 described above can be used as the material forming the base material.
  • the inorganic particles include at least one selected from the group consisting of metal oxides, metal nitrides, metal carbides, metal sulfides and the like.
  • metal oxides include aluminum oxide (alumina, Al 2 O 3 ), boehmite (hydrated aluminum oxide), magnesium oxide (magnesia, MgO), titanium oxide (titania, TiO 2 ), zirconium oxide (zirconia, ZrO 2 ). ), silicon oxide (silica, SiO 2 ) or yttrium oxide (yttria, Y 2 O 3 ) or the like can be preferably used.
  • silicon nitride Si 3 N 4
  • aluminum nitride AlN
  • boron nitride BN
  • titanium nitride TiN
  • silicon carbide SiC
  • boron carbide B 4 C
  • Barium sulfate BaSO 4
  • the inorganic particles are porous aluminosilicates such as zeolite (M 2 /n 2 O.Al 2 O 3 .xSiO 2 .yH 2 O, M is a metal element, x ⁇ 2, y ⁇ 0), layered silicic acid. Minerals such as salts and barium titanate (BaTiO 3 ) or strontium titanate (SrTiO 3 ) may be included.
  • the inorganic particles have oxidation resistance and heat resistance, and the surface layer on the side surface facing the positive electrode containing the inorganic particles has strong resistance to an oxidizing environment in the vicinity of the positive electrode during charging.
  • the shape of the inorganic particles is not particularly limited, and any of spherical, plate-like, fibrous, cubic and random shapes can be used.
  • the particle size of the inorganic particles is preferably in the range of 1 nm or more and 10 ⁇ m or less. This is because if it is less than 1 nm, it is difficult to obtain it, and if it is more than 10 ⁇ m, the distance between the electrodes becomes large, and the filling amount of the active material cannot be sufficiently obtained in a limited space, so that the battery capacity decreases.
  • Examples of the resin material constituting the surface layer include polyvinylidene fluoride, polytetrafluoroethylene and other fluorine-containing resins, vinylidene fluoride-tetrafluoroethylene copolymer, ethylene-tetrafluoroethylene copolymer and other fluorine-containing rubber, and styrene.
  • resin materials may be used alone or in combination of two or more.
  • a fluorine-based resin such as polyvinylidene fluoride is preferable, and from the viewpoint of heat resistance, it is preferable to contain aramid or polyamide-imide.
  • a slurry comprising a matrix resin, a solvent and inorganic particles is applied onto a substrate (porous membrane), and passed through a poor solvent of the matrix resin and a solvent-solvent bath of the solvent.
  • a method of causing phase separation and then drying can be used.
  • the above-mentioned inorganic particles may be contained in the porous film as the base material.
  • the surface layer may not include inorganic particles and may be composed of only a resin material.
  • the electrolyte layer 13 includes an electrolytic solution and a polymer compound serving as a holder that holds the electrolytic solution.
  • the electrolyte layer 13 preferably has a gel shape. Since the electrolyte layer 13 has a gel shape, it is possible to obtain high ionic conductivity and suppress leakage of the battery 10.
  • the electrolytic solution is a so-called non-aqueous electrolytic solution and contains an organic solvent (non-aqueous solvent) and an electrolyte salt dissolved in this organic solvent.
  • the electrolytic solution may contain a known additive in order to improve battery characteristics.
  • a cyclic carbonic acid ester such as ethylene carbonate or propylene carbonate
  • a chain carbonic acid ester such as diethyl carbonate, dimethyl carbonate, ethylmethyl carbonate or methylpropyl carbonate as the organic solvent. This is because high ionic conductivity can be obtained.
  • the organic solvent preferably further contains 2,4-difluoroanisole or vinylene carbonate. This is because 2,4-difluoroanisole can further improve the discharge capacity, and vinylene carbonate can further improve the cycle characteristics. Therefore, it is preferable to mix and use these, because the discharge capacity and the cycle characteristics can be further improved.
  • organic solvent examples include butylene carbonate, ⁇ -butyrolactone, ⁇ -valerolactone, 1,2-dimethoxyethane, tetrahydrofuran, 2-methyltetrahydrofuran, 1,3-dioxolane, 4-methyl-1.
  • a compound in which at least a part of hydrogen of these organic solvents is replaced by fluorine may be preferable in some cases because the reversibility of the electrode reaction may be improved depending on the type of electrodes to be combined.
  • Examples of the electrolyte salt include a lithium salt, and one kind may be used alone, or two or more kinds may be mixed and used.
  • Examples of the lithium salt include LiPF 6 , LiBF 4 , LiAsF 6 , LiClO 4 , LiB(C 6 H 5 ) 4 , LiCH 3 SO 3 , LiCF 3 SO 3 , LiN(SO 2 CF 3 ) 2 , LiC(SO 2 CF). 3 ) 3 , LiAlCl 4 , LiSiF 6 , LiCl, difluoro[oxolato-O,O′] lithium borate, lithium bisoxalate borate, or LiBr.
  • LiPF 6 is preferable because it can obtain high ionic conductivity and further improve cycle characteristics.
  • the polymer compound is a holding body that holds the electrolytic solution and is swollen by the electrolytic solution.
  • the polymer compound include polyacrylonitrile, polyvinylidene fluoride, a copolymer of vinylidene fluoride and hexafluoropropylene, polytetrafluoroethylene, polyhexafluoropropylene, polyethylene oxide, polypropylene oxide, polyphosphazene, polysiloxane. , Polyvinyl acetate, polyvinyl alcohol, polymethyl methacrylate, polyacrylic acid, polymethacrylic acid, styrene-butadiene rubber, nitrile-butadiene rubber, polystyrene or polycarbonate. Particularly, from the viewpoint of electrochemical stability, polyacrylonitrile, polyvinylidene fluoride, polyhexafluoropropylene or polyethylene oxide is preferable.
  • the positive electrode tab 14A and the negative electrode tab 14B are each made of a metal material such as Al, Cu, Ni or stainless steel, and have a thin plate shape or a mesh shape, respectively.
  • the positive electrode tab 14A and the negative electrode tab 14B are led out from the inside of the exterior material toward the outside.
  • the positive electrode active material layer 11B is manufactured as follows. First, for example, a positive electrode active material, a binder, and a conductive agent are mixed to prepare a positive electrode mixture, and this positive electrode mixture is dispersed in a solvent such as N-methyl-2-pyrrolidone (NMP) to prepare a positive electrode mixture. Make an agent paint. Next, this positive electrode mixture coating material is applied onto a transfer sheet and the solvent is dried to obtain the positive electrode active material layer 11B.
  • NMP N-methyl-2-pyrrolidone
  • the transfer sheet for example, a release film in which the surface of a metal foil or a resin film is subjected to a release treatment can be used.
  • the transfer sheet it is preferable to use a transfer sheet that does not swell or deteriorate with the solvent used for the positive electrode mixture paint.
  • the positive electrode active material layer 11B formed on the transfer sheet is pressed and vacuum dried. As a result, excessive voids in the positive electrode active material layer 11B can be compressed and the volume energy density can be improved, and excess water can be removed from the positive electrode active material layer 11B to prevent deterioration of battery characteristics due to water. Can be suppressed.
  • the negative electrode active material layer 11C is manufactured as follows. First, for example, a negative electrode active material and a binder are mixed to prepare a negative electrode mixture, and the negative electrode mixture is dispersed in a solvent such as N-methyl-2-pyrrolidone (NMP) to prepare a paste-like negative electrode mixture. Make paint. Next, this negative electrode mixture coating material is applied onto a transfer sheet and the solvent is dried to obtain a negative electrode active material layer 11C. As the transfer sheet, the same one as in the “process for producing the positive electrode active material layer” can be used. Next, the negative electrode active material layer 11C formed on the transfer sheet is pressed and vacuum dried. As a result, excess voids in the negative electrode active material layer 11C can be compressed to improve the volumetric energy density, and excess water can be removed from the negative electrode active material layer 11C to prevent deterioration of battery characteristics due to water. Can be suppressed.
  • NMP N-methyl-2-pyrrolidone
  • the electrolyte layer 13 is formed as follows. First, for example, a sol-like precursor solution is prepared by mixing an electrolytic solution, a polymer compound as a holding body for holding the electrolytic solution, and an organic solvent (diluting solvent). Next, this precursor solution is uniformly applied and impregnated on the surface of each of the positive electrode active material layer 11B and the negative electrode active material layer 11C. Then, the gelled electrolyte layer 13 is formed by vaporizing and removing the organic solvent.
  • the plurality of electrode elements 10A are manufactured as follows. First, the positive electrode active material layer 11B having the electrolyte layer 13 (the positive electrode active material layer 11B with the transfer sheet), the negative electrode active material layer 11C having the separator 12 and the electrolyte layer 13 (the negative electrode active material layer with the transfer sheet). 11C) is laminated to obtain a laminate in which the positive electrode active material layer 11B, the electrolyte layer 13, the separator 12, the electrolyte layer 13, and the negative electrode active material layer 11C are laminated in this order. Subsequently, the obtained laminated body is heated and pressed to integrate the layers constituting the laminated body, and then the transfer sheet is peeled from the laminated body to obtain the electrode element 10A.
  • the first main surface of the current collector 11A is bonded to the positive electrode active material layer 11B of the electrode element 10A, and the second main surface of the current collector 11A is bonded to the negative electrode active material layer 11C of another electrode element 10A.
  • the battery 10 is obtained by alternately stacking the current collector 11A and the electrode element 10A so as to be adhered to the. At this time, the stacking order is adjusted so that the current collector 11A is arranged on each of the uppermost layer and the lowermost layer of the battery 10.
  • the positive electrode tab 14A and the negative electrode tab 14B are attached to the surface of the current collector 11A arranged in the lowermost layer.
  • the battery 10 according to the second embodiment of the present invention includes a resin base material (a resin base material according to the first embodiment) that can simultaneously realize low resistivity and local suppression of variation in resistivity. It is provided as an electric body 11A. Therefore, good cycle characteristics can be obtained.
  • the resin base material is used as the current collector 11A, when a short circuit occurs in the battery 10 due to external damage or damage, the current collector 11A is melted and the short circuit is released. Therefore, the safety of the battery 10 can be improved.
  • the average filler diameter and the average filler length of each of the first conductive filler and the second conductive filler are obtained by the measuring method described in the first embodiment. It is a thing.
  • the positive electrode active material layer was produced as follows. First, a positive electrode mixture was obtained by mixing 96 parts by mass of the positive electrode active material (LiCoO 2 ), 3 parts by mass of the positive electrode binder (polyvinylidene fluoride), and 1 part by mass of the positive electrode conductive material (carbon black). Next, the positive electrode mixture was dispersed in an organic solvent (N-methyl-2-pyrrolidone) to obtain a positive electrode mixture coating material. Next, the obtained positive electrode mixture coating material was applied onto a transfer sheet (release film) and the organic solvent was dried to obtain a positive electrode layer. Next, the positive electrode layer formed on the transfer sheet was pressed and vacuum dried.
  • the positive electrode active material LiCoO 2
  • 3 parts by mass of the positive electrode binder polyvinylidene fluoride
  • carbon black carbon black
  • the positive electrode mixture was dispersed in an organic solvent (N-methyl-2-pyrrolidone) to obtain a positive electrode mixture coating material.
  • the obtained positive electrode mixture coating material was applied onto
  • the negative electrode active material layer was produced as follows. First, 90 parts by mass of the negative electrode active material (artificial graphite) and 10 parts by mass of the negative electrode binder (polyvinylidene fluoride) were mixed to obtain a negative electrode mixture. Next, the negative electrode mixture was dispersed in an organic solvent (N-methyl-2-pyrrolidone) to obtain a negative electrode mixture coating material. Next, the obtained negative electrode mixture coating material was applied onto a transfer sheet (release film) and the organic solvent was dried to obtain a negative electrode active material layer. Next, the negative electrode layer formed on the transfer sheet was pressed and vacuum dried.
  • the negative electrode active material artificial graphite
  • the negative electrode binder polyvinylidene fluoride
  • EC ethylene carbonate
  • PC propylene carbonate
  • resin current collector manufacturing process Two resin current collectors were produced as follows. First, as shown in Table 1, 75 to 85% by mass of resin pellets (polypropylene (PP) pellets) and 10% by mass of the first conductive filler (carbon fiber having an average filler diameter of 7 ⁇ m and an average filler length of 6000 ⁇ m). After roughly mixing 5 to 15% by mass of the second conductive filler (carbon nanofiber (VGCF) having an average filler diameter of 0.15 ⁇ m and an average filler length of 10 ⁇ m), the mixture is put into a biaxial extruder. The kneading was performed while heating the resin pellets at a temperature higher than the melting temperature.
  • PP polypropylene
  • VGCF carbon nanofiber
  • the battery was manufactured as follows. First, stacking a positive electrode active material layer (a positive electrode active material layer with a transfer sheet) on which an electrolyte layer is formed and a negative electrode positive electrode active material layer (a negative electrode active material layer with a transfer sheet) on which a separator and an electrolyte layer are formed. Thus, a laminated body was obtained in which the positive electrode active material layer, the electrolyte layer, the separator, the electrolyte layer, and the negative electrode active material layer were laminated in this order.
  • a positive electrode active material layer a positive electrode active material layer with a transfer sheet
  • a negative electrode positive electrode active material layer a negative electrode active material layer with a transfer sheet
  • the obtained laminated body was heated and pressed (105° C., 3 sec) to integrate the layers constituting the laminated body, and then the transfer sheet was peeled from the laminated body to obtain an electrode element.
  • the first main surface of one resin current collector is bonded to the positive electrode side main surface of the electrode element, and the other resin current collector second main surface is attached to the negative electrode side main surface of the electrode element.
  • the positive electrode tab metal plate
  • the negative electrode tab metal plate
  • Examples 4 and 5 As shown in Table 1, batteries were obtained in the same manner as in Examples 2 and 3 except that spherical carbon black having an average filler diameter of 0.05 ⁇ m was used as the second conductive filler.
  • batteries were obtained in the same manner as in Examples 1 to 3 except that carbon fibers having an average filler diameter of 5 ⁇ m and an average filler length of 6000 ⁇ m were used as the first conductive filler.
  • Example 9 As shown in Table 1, 70 mass% of resin pellets (polypropylene (PP) pellets), 15 mass% of the first conductive filler (carbon fiber having an average filler diameter of 7 ⁇ m and an average filler length of 6000 ⁇ m), and a second A battery was obtained in the same manner as in Example 3, except that 15% by mass of the conductive filler (carbon nanofiber (VGCF) having an average filler diameter of 0.15 ⁇ m and an average filler length of 10 ⁇ m) was mixed to obtain a mixture. It was
  • Example 3 As shown in Table 1, a battery was obtained in the same manner as in Example 3 except that carbon fibers having an average filler diameter of 3 ⁇ m and an average filler length of 6000 ⁇ m were used as the first conductive filler.
  • resistivity in the film thickness direction The resistivity in the film thickness direction of the resin current collector used for the above-mentioned battery was measured according to JIS C 2139, and the average value, maximum value, minimum value and maximum value/minimum value of the resistivity were obtained.
  • the discharge capacity of the second cycle was measured by charging and discharging the battery (1 cycle) in the same environment.
  • the battery was repeatedly charged and discharged (300 cycles) to measure the discharge capacity at the 301st cycle.
  • the battery was charged at a constant current with a current of 1 C until the voltage reached 4.45 V, and then the battery was charged with a constant voltage at a voltage of 4.45 V until the current reached 0.02 C.
  • the battery was discharged at a constant current with a current of 1C until the voltage reached 3.0V.
  • “1C” is a current value at which the battery capacity (theoretical capacity) is completely charged or discharged in 1 hour.
  • Table 1 shows the configurations and evaluation results of the resin current collectors used in the batteries of Examples 1 to 9 and Comparative Examples 1 to 5.
  • the resin substrates of Examples 1 to 3 and 6 to 9 in which carbon fibers having an average filler diameter of 5 ⁇ m or more are used as the first conductive filler and carbon nanofibers are used as the second conductive filler have low resistivity. It is possible to simultaneously realize local suppression of variations in resistivity. However, in the resin base material of Example 9 in which the mixing amount of the first conductive filler was 15% by mass, the strength decrease of the resin base material was observed because the mixing amount of the first conductive filler was excessive.
  • the low resistivity and the local resistivity were Good cycle characteristics can be obtained as compared with the batteries of Comparative Examples 1 to 5 in which the resin base material, which was not able to realize the variation suppression at the same time, was used as the current collector.
  • the battery of Example 9 using the resin base material in which the mixing amount of the first conductive filler was 15% by mass as the current collector had lower cycle characteristics than the batteries of Examples 1 to 8.
  • the present invention is not limited to the above-described embodiment, the modification, and the example of the present invention.
  • Various modifications based on the technical idea are possible.
  • the upper limit or the lower limit of the numerical range of a certain stage may be replaced with the upper limit or the lower limit of the numerical range of another stage.
  • Good. The materials exemplified in the above-described embodiments and their modifications can be used alone or in combination of two or more unless otherwise specified.
  • the electrolyte layer containing the electrolyte solution and the polymer compound is used as the electrolyte
  • the electrolyte solution or the solid electrolyte may be used as the electrolyte.
  • a high-viscosity electrolytic solution may be used, and the laminated body may be manufactured by applying the electrolytic solution onto the electrode or the separator in the battery manufacturing process.
  • an electrolytic solution having a general viscosity may be used, and the electrolytic solution may be injected into the exterior material after the battery is housed in the exterior material.

Abstract

This resin substrate is used for a current collector for a battery, and includes a first conductive filler and a second conductive filler which have a fibrous shape, wherein the average filler diameter of the second conductive filler is smaller than the average filler diameter of the first conductive filler.

Description

樹脂基材およびバイポーラ型電池Resin base material and bipolar battery
　本発明は、樹脂基材およびバイポーラ型電池に関する。 The present invention relates to a resin base material and a bipolar battery.
　バイポーラ電池では、集電体の第１の主面に正極活物質層が設けられ、集電体の第２の主面に負極活物質層が設けられたバイポーラ電極が用いられる。特許文献１には、バイポーラ型電池の集電体として、金属および導電性カーボン等の導電性フィラーが添加された樹脂基材を用いることが記載されている。 In a bipolar battery, a bipolar electrode in which a positive electrode active material layer is provided on a first main surface of a current collector and a negative electrode active material layer is provided on a second main surface of a current collector is used. Patent Document 1 describes that a resin base material to which a conductive filler such as metal and conductive carbon is added is used as a collector of a bipolar battery.
特開２０１１－９０３９号公報JP, 2011-9039, A
　しかしながら、特許文献１に記載された樹脂基材では、低い抵抗率と局所的な抵抗率のばらつき抑制とを同時に実現することは困難である。 However, with the resin base material described in Patent Document 1, it is difficult to simultaneously achieve low resistivity and local suppression of resistivity variation.
　本発明の目的は、低い抵抗率と局所的な抵抗率のばらつき抑制とを同時に実現することができる樹脂基材およびバイポーラ型電池を提供することにある。 An object of the present invention is to provide a resin base material and a bipolar battery that can simultaneously realize low resistivity and local variation in resistivity variation.
　上述の課題を解決するために、第１の発明は、電池の集電体に用いられる樹脂基材であって、繊維状を有する第１の導電性フィラーと、第２の導電性フィラーとを含み、第２の導電性フィラーの平均フィラー径が、第１の導電性フィラーの平均フィラー径よりも小さい樹脂基材である。 In order to solve the above-mentioned problems, a first invention is a resin base material used for a current collector of a battery, wherein a first conductive filler having a fibrous shape and a second conductive filler are provided. The resin base material that includes the second conductive filler and has an average filler diameter smaller than that of the first conductive filler.
　第２の発明は、第１の発明に係る樹脂基材を集電体として備えるバイポーラ型電池である。 The second invention is a bipolar battery including the resin base material according to the first invention as a current collector.
　本発明によれば、低い抵抗率と局所的な抵抗率のばらつき抑制とを同時に実現することができる。 According to the present invention, low resistivity and suppression of local variation in resistivity can be realized at the same time.
本発明の第１の実施形態に係るバイポーラ型電池の構成の一例を示す断面図である。It is a sectional view showing an example of composition of a bipolar type battery concerning a 1st embodiment of the present invention.
　本発明の実施形態について以下の順序で説明する。
１　第１の実施形態（樹脂基材の例）
２　第２の実施形態（バイポーラ型電池の例） Embodiments of the present invention will be described in the following order.
1 First embodiment (example of resin base material)
2 Second embodiment (example of bipolar battery)
＜１　第１の実施形態＞
　本発明の第１の実施形態に係る樹脂基材は、バイポーラ型電池等の集電体に用いられる樹脂基材であり、第１の導電性フィラーと、第２の導電性フィラーと、高分子樹脂とを含む。樹脂基材は、例えば、フィルム状または板状を有する。第１の導電性フィラーおよび第２の導電性フィラーは、樹脂基材中に分散している。第２のフィラーの平均フィラー径が、第１のフィラーの平均フィラー径よりも小さい。 <1 First Embodiment>
The resin base material according to the first embodiment of the present invention is a resin base material used for a collector such as a bipolar battery, and includes a first conductive filler, a second conductive filler, and a polymer. Including resin. The resin substrate has, for example, a film shape or a plate shape. The first conductive filler and the second conductive filler are dispersed in the resin base material. The average filler diameter of the second filler is smaller than the average filler diameter of the first filler.
　第１の導電性フィラーは、樹脂基材中に大きな導電性パスを形成するためのものである。第１の導電性フィラーは、フィラー径が大きく抵抗が小さいため、樹脂基材全体の抵抗率を低下させることができるという利点を有している。一方、第１の導電性フィラーはフィラーサイズが大きいため、第１の導電性フィラーを単独で用いた場合には、分散不足な箇所で局所的な抵抗率のばらつきが生じるという欠点を有している。 The first conductive filler is for forming a large conductive path in the resin base material. Since the first conductive filler has a large filler diameter and a low resistance, it has an advantage that the resistivity of the entire resin base material can be reduced. On the other hand, since the first conductive filler has a large filler size, when the first conductive filler is used alone, there is a drawback that the resistivity is locally varied at a location where dispersion is insufficient. There is.
　第２の導電性フィラーは、樹脂基材中に小さな導電性パスを形成するためのものである。第２の導電性フィラーは、フィラーサイズが小さいため、局所的な抵抗ばらつきが小さく、抵抗率分布の均一性を高めることができるという利点を有している。一方、第２の導電性フィラーは樹脂基材全体の抵抗率低下機能は低いため、第２の導電性フィラーを単独で用いた場合には、樹脂基材の抵抗率が高くなるという欠点を有している。 The second conductive filler is for forming a small conductive path in the resin base material. Since the second conductive filler has a small filler size, it has advantages that local resistance variation is small and the uniformity of resistivity distribution can be enhanced. On the other hand, since the second conductive filler has a low function of lowering the resistivity of the entire resin base material, when the second conductive filler is used alone, it has a drawback that the resistivity of the resin base material becomes high. doing.
　第１の導電性フィラーと第２の導電性フィラーとを組み合わせることで、互いの欠点を補完することができる。すなわち、上述のように機能の異なる２種類の導電性フィラーを併用することで、樹脂基材全体の抵抗率を低減し、かつ、樹脂基材の局所的な抵抗率のばらつきを抑制することができる。 By combining the first conductive filler and the second conductive filler, their respective defects can be complemented. That is, by using two kinds of conductive fillers having different functions as described above together, it is possible to reduce the resistivity of the entire resin base material and suppress the local variation of the resistivity of the resin base material. it can.
　第１の導電性フィラーは、繊維状を有する。第１の導電性フィラーは、例えば、カーボンファイバーである。カーボンファイバーは、例えば、ＰＡＮ系カーボンファイバーおよびピッチ系カーボンファイバーのうちの少なくとも１種である。 The first conductive filler has a fibrous shape. The first conductive filler is, for example, carbon fiber. The carbon fiber is, for example, at least one kind of PAN-based carbon fiber and pitch-based carbon fiber.
　第２の導電性フィラーは、例えば、球状、楕円体状、針状、板状、鱗片状、チューブ状、ワイヤー状、棒状（ロッド状）、繊維状または不定形状等を有するが、特にこれらに限定されるものではない。なお、１種状の形状の導電性フィラーのみを用いてもよいし、２種以上の形状の導電性フィラーを組み合わせて用いてもよい。 The second conductive filler has, for example, a spherical shape, an ellipsoidal shape, a needle shape, a plate shape, a scale shape, a tube shape, a wire shape, a rod shape (rod shape), a fibrous shape, or an indefinite shape, but particularly It is not limited. It should be noted that only one kind of conductive filler may be used, or two or more kinds of conductive filler may be used in combination.
　第２の導電性フィラーは、例えば、炭素系フィラーおよび金属系フィラーのうちの少なくとも１種である。炭素系フィラーは、例えば、カーボンナノファイバー（例えば気相成長炭素繊維（ＶＧＣＦ））、カーボンブラック（例えばケッチェンブラック、アセチレンブラック等）、ポーラスカーボン、フラーレン、グラフェン、カーボンナノチューブ（例えばＳＷＣＮＴ、ＭＷＣＮＴ等）、カーボンマイクロコイルおよびカーボンナノホーンのうちの少なくとも１種である。金属系フィラーは、例えば、ニッケルまたはステンレス鋼を含む。 The second conductive filler is, for example, at least one kind of carbon-based filler and metal-based filler. Examples of the carbon-based filler include carbon nanofibers (for example, vapor growth carbon fiber (VGCF)), carbon black (for example, Ketjen black, acetylene black, etc.), porous carbon, fullerene, graphene, carbon nanotubes (for example, SWCNT, MWCNT, etc.). ), at least one of carbon microcoils and carbon nanohorns. The metal-based filler includes, for example, nickel or stainless steel.
　第１の導電性フィラーの平均フィラー径は、５μｍ以上１０μｍ以下であることが好ましい。第１の導電性フィラーの平均フィラー径が５μｍ以上であると、樹脂基材全体の抵抗率を効果的に低下させることができる。一方、第１の導電性フィラーの平均フィラー径が１０μｍ以下であると、第１の導電性フィラーの分散性の低下を抑制することができる。 The average filler diameter of the first conductive filler is preferably 5 μm or more and 10 μm or less. When the average filler diameter of the first conductive filler is 5 μm or more, the resistivity of the entire resin base material can be effectively reduced. On the other hand, when the average filler diameter of the first conductive filler is 10 μm or less, it is possible to suppress deterioration of the dispersibility of the first conductive filler.
　第１の導電性フィラーの平均フィラー長さは、１ｍｍ以上１０ｍｍ以下であることが好ましい。第１の導電性フィラーの平均フィラー長さが１ｍｍ以上であると、樹脂基材全体の抵抗率を効果的に低下させることができる。一方、第１の導電性フィラーの平均フィラー長さが１０ｍｍ以下であると、第１の導電性フィラーの分散性の低下を抑制することができる。 The average filler length of the first conductive filler is preferably 1 mm or more and 10 mm or less. When the average filler length of the first conductive filler is 1 mm or more, the resistivity of the entire resin base material can be effectively reduced. On the other hand, when the average filler length of the first conductive filler is 10 mm or less, it is possible to suppress deterioration of the dispersibility of the first conductive filler.
　第２の導電性フィラーの平均フィラー径は、１ｎｍ以上２００ｎｍ以下であることが好ましい。第２の導電性フィラーの平均フィラー径が１ｎｍより小さいと、入手が困難である。一方、第２の導電性フィラーの平均フィラー径が２００ｎｍ以下であると、局所的な抵抗ばらつきを効果的に抑制することができる。 The average filler diameter of the second conductive filler is preferably 1 nm or more and 200 nm or less. If the average filler diameter of the second conductive filler is smaller than 1 nm, it is difficult to obtain it. On the other hand, when the average filler diameter of the second conductive filler is 200 nm or less, local resistance variation can be effectively suppressed.
　第２の導電性フィラーがカーボンナノファイバーである場合、第２の導電性フィラーの平均フィラー長さは、１μｍ以上３０μｍ以下であることが好ましい。カーボンナノファイバーは一般的に１μｍ以上であるため、第２の導電性フィラーの平均フィラー長さが１μｍより小さいと、入手が困難となる。一方、第２の導電性フィラーの平均フィラー長さが３０μｍ以下であると、第２の導電性フィラーの分散性の低下を抑制することができる。　　　 When the second conductive filler is carbon nanofiber, the average filler length of the second conductive filler is preferably 1 μm or more and 30 μm or less. Since carbon nanofibers are generally 1 μm or more, if the average filler length of the second conductive filler is smaller than 1 μm, it will be difficult to obtain them. On the other hand, when the average filler length of the second conductive filler is 30 μm or less, it is possible to suppress deterioration of the dispersibility of the second conductive filler. ：
　第１の導電性フィラーの平均フィラー径および平均フィラー長さ、ならびに第２の導電性フィラーの平均フィラー径および平均フィラー長さは、以下のようにして測定される。まず、樹脂基材から第１の導電性フィラーおよび第２の導電性フィラーを取り出し、Ｎ－メチル－２－ピロリドン（ＮＭＰ）中に投入し、超音波装置で５分間、分散処理する。分散処理した溶液をＳＥＭ（Scanning Electron Microscope）のサンプルステージに塗布乾燥し、ＳＥＭ観察にて３０検体以上の第１の導電性フィラーについて、フィラー径とフィラー長さを測定し、第１の導電性フィラーの平均フィラー径（Ｄ５０）および平均フィラー長さ（Ｄ５０）を算出する。第２の導電性フィラーについても、第１の導電性フィラーと同様の手順で、平均フィラー径（Ｄ５０）および平均フィラー長さ（Ｄ５０）を算出する。 The average filler diameter and average filler length of the first conductive filler, and the average filler diameter and average filler length of the second conductive filler are measured as follows. First, the first conductive filler and the second conductive filler are taken out from the resin base material, put into N-methyl-2-pyrrolidone (NMP), and subjected to dispersion treatment by an ultrasonic device for 5 minutes. The dispersion treated solution is applied to the sample stage of SEM (Scanning Electron Microscope), dried, and the SEM observation is performed to measure the filler diameter and the filler length of the first conductive filler of 30 or more samples, and the first conductivity is measured. The average filler diameter (D50) and the average filler length (D50) of the filler are calculated. Also for the second conductive filler, the average filler diameter (D50) and the average filler length (D50) are calculated by the same procedure as that for the first conductive filler.
　樹脂基材中における第１の導電性フィラーの含有量は、好ましくは５質量％を超え１５質量％未満、より好ましくは６質量％以上１４質量％以下、さらにより好ましくは７質量％以上１３質量％以下、特に好ましくは８質量％以上１２質量％以下、最も好ましくは９質量％以上１１質量％以下である。第１の導電性フィラーの含有量が５質量％を超えると、樹脂基材全体の抵抗率を効果的に低下させることができる。一方、第１の導電性フィラーの含有量が１５質量％未満であると、高分子樹脂量の減少による樹脂基材の強度低下を抑制することができる。 The content of the first conductive filler in the resin substrate is preferably more than 5% by mass and less than 15% by mass, more preferably 6% by mass or more and 14% by mass or less, still more preferably 7% by mass or more and 13% by mass. % Or less, particularly preferably 8% by mass or more and 12% by mass or less, and most preferably 9% by mass or more and 11% by mass or less. When the content of the first conductive filler exceeds 5% by mass, the resistivity of the entire resin base material can be effectively reduced. On the other hand, when the content of the first conductive filler is less than 15% by mass, it is possible to suppress the decrease in strength of the resin base material due to the decrease in the amount of polymer resin.
　樹脂基材中における第２の導電性フィラーの含有量は、好ましくは５質量％以上１５質量％以下である。第２の導電性フィラーの含有量が５質量％以上であると、抵抗率分布の均一性をさらに高めることができる。一方、第２の導電性フィラーの含有量が１５質量％以下であると、高分子樹脂量の減少による樹脂基材の強度低下を抑制することができる。 The content of the second conductive filler in the resin base material is preferably 5% by mass or more and 15% by mass or less. When the content of the second conductive filler is 5% by mass or more, the uniformity of the resistivity distribution can be further enhanced. On the other hand, when the content of the second conductive filler is 15% by mass or less, it is possible to suppress the decrease in strength of the resin base material due to the decrease in the amount of the polymer resin.
　樹脂基材中における第１の導電性フィラーの含有量、および樹脂基材中における第２の導電性フィラーの含有量は以下のようにして求められる。まず、予め重量測定した樹脂基材を適切な溶媒に溶解し、遠心分離機にて第１の導電性フィラーと第２の導電性フィラーを分離したのち、分離したそれぞれを濾過乾燥することにより、第１の導電性フィラーおよび第２の導電性フィラーを取り出す。次に、取り出した第１の導電性フィラー、第２の導電性フィラーの重量をそれぞれ測定し、樹脂基材中における第１の導電性フィラーの含有量、および樹脂基材中における第２の導電性フィラーの含有量を算出する。 The content of the first conductive filler in the resin base material and the content of the second conductive filler in the resin base material are calculated as follows. First, the resin base material that has been weighed in advance is dissolved in an appropriate solvent, and the first conductive filler and the second conductive filler are separated by a centrifuge, and then the separated respective are filtered and dried, The first conductive filler and the second conductive filler are taken out. Next, the weights of the first conductive filler and the second conductive filler that were taken out were measured, respectively, and the content of the first conductive filler in the resin base material and the second conductive filler in the resin base material were measured. The content of the functional filler is calculated.
　高分子樹脂としては、例えば、ポリエチレン、ポリプロピレン、ポリエチレンテレフタレート、ポリエーテルニトリル、ポリイミド、ポリアミド、ポリテトラフルオロエチレン、スチレンブタジエンゴム、ポリアクリロニトリル、ポリメチルアクリレート、ポリメチルメタクリレート、ポリ塩化ビニルおよびポリフッ化ビニリデンからなる群より選ばれる少なくとも１種を用いることができる。 Examples of the polymer resin include polyethylene, polypropylene, polyethylene terephthalate, polyether nitrile, polyimide, polyamide, polytetrafluoroethylene, styrene butadiene rubber, polyacrylonitrile, polymethyl acrylate, polymethyl methacrylate, polyvinyl chloride and polyvinylidene fluoride. At least one selected from the group consisting of can be used.
［樹脂基材の製造方法］
　次に、本発明の第１の実施形態に係る樹脂基材の製造方法の一例について説明する。まず、第１の導電性フィラーと、第２の導電性フィラーと、高分子樹脂とを混合し、高分子樹脂の溶融温度以上で加熱しつつ混練を行うことにより、成形材料を調製する。次に、例えば溶融押出成形法により成形材料をフィルム状に成形することにより、樹脂基材を得る。 [Method for producing resin base material]
Next, an example of the method for manufacturing the resin base material according to the first embodiment of the present invention will be described. First, a molding material is prepared by mixing the first conductive filler, the second conductive filler, and the polymer resin, and kneading while heating at a melting temperature of the polymer resin or higher. Next, a resin base material is obtained by molding the molding material into a film by, for example, a melt extrusion molding method.
［効果］
　本発明の第１の実施形態に係る樹脂基材は、繊維状を有する第１の導電性フィラーと、第２の導電性フィラーとを含み、第２の導電性フィラーの平均フィラー径が、第１の導電性フィラーの平均フィラー径よりも小さい。第１の導電性フィラー（太径フィラー）は、樹脂基材の抵抗率を大幅に低下させることが可能な大きな導電性パスを形成する。一方、第２の導電性フィラー（細径フィラー）は、樹脂基材の抵抗率を均一に下げることが可能な小さな導電性パスを形成する。このように機能の異なる２種類の導電性フィラーを併用することにより、低い抵抗率と局所的な抵抗率のばらつき抑制を同時に実現することができる。 [effect]
The resin base material according to the first embodiment of the present invention includes a first conductive filler having a fibrous shape and a second conductive filler, and an average filler diameter of the second conductive filler is It is smaller than the average filler diameter of the conductive filler 1. The first conductive filler (large-diameter filler) forms a large conductive path capable of significantly reducing the resistivity of the resin base material. On the other hand, the second conductive filler (small-diameter filler) forms a small conductive path capable of uniformly reducing the resistivity of the resin base material. By using two kinds of conductive fillers having different functions in this way, it is possible to simultaneously realize low resistivity and local suppression of resistivity variation.
＜２　第２の実施形態＞
［電池の構成］
　図１は、本発明の第２の実施形態に係るバイポーラ型電池（以下単に「電池」という。）１０の構成の一例を示す。電池１０は、非水電解質二次電池（リチウムイオン二次電池）であり、複数の電極１１と、複数のセパレータ１２と、複数の電解質層１３と、正極タブ１４Ａと、負極タブ１４Ｂとを備える。電池１０は、ラミネートフィルム等の外装材に収容されていてもよい。複数の電極１１、複数のセパレータ１２および複数の電解質層１３が、電極１１、電解質層１３、セパレータ１２、電解質層１３の順で繰り返し積層されて積層体が構成されている。 <2 Second Embodiment>
[Battery configuration]
FIG. 1 shows an example of the configuration of a bipolar battery (hereinafter simply referred to as “battery”) 10 according to a second embodiment of the present invention. The battery 10 is a non-aqueous electrolyte secondary battery (lithium ion secondary battery) and includes a plurality of electrodes 11, a plurality of separators 12, a plurality of electrolyte layers 13, a positive electrode tab 14A, and a negative electrode tab 14B. .. The battery 10 may be housed in an exterior material such as a laminated film. A plurality of electrodes 11, a plurality of separators 12, and a plurality of electrolyte layers 13 are repeatedly laminated in the order of the electrodes 11, the electrolyte layers 13, the separators 12, and the electrolyte layers 13 to form a laminate.
　積層方向の両端以外に位置する電極１１は、バイポーラ型電極であり、対向する第１の主面と第２の主面とを有する集電体１１Ａと、集電体１１Ａの第１の主面に設けられた正極活物質層１１Ｂと、集電体１１Ａの第２の主面に設けられた負極活物質層１１Ｃとを備える。なお、積層方向に隣り合う電極１１は、集電体１１Ａの第１の主面と第２の主面同士、すなわち正極活物質層１１Ｂと負極活物質層１１Ｃ同士が対向するように積層されている。 The electrodes 11 located at other than both ends in the stacking direction are bipolar electrodes, and a current collector 11A having a first main surface and a second main surface facing each other, and a first main surface of the current collector 11A. And a negative electrode active material layer 11C provided on the second main surface of the current collector 11A. The electrodes 11 adjacent to each other in the stacking direction are stacked such that the first main surface and the second main surface of the current collector 11A face each other, that is, the positive electrode active material layer 11B and the negative electrode active material layer 11C face each other. There is.
　積層方向の一端に位置する電極１１は、集電体１１Ａの第１の主面に正極活物質層１１Ｂが設けられているのに対して、集電体１１Ａの第２の主面に負極活物質層１１Ｃが設けられていない片面電極である。この片面電極が有する集電体１１Ａの第２の主面には、正極タブ１４Ａが接続されている。 In the electrode 11 located at one end in the stacking direction, the positive electrode active material layer 11B is provided on the first main surface of the current collector 11A, while the negative electrode active material layer 11B is provided on the second main surface of the current collector 11A. It is a single-sided electrode without the material layer 11C. The positive electrode tab 14A is connected to the second main surface of the current collector 11A included in the one-sided electrode.
　積層方向の他端に位置する電極１１は、集電体１１Ａの第２の主面に負極活物質層１１Ｃが設けられているのに対して、集電体１１Ａの第１の主面に正極活物質層１１Ｂが設けられていない片面電極である。この片面電極が有する集電体１１Ａの第１の主面には、負極タブ１４Ｂが接続されている。 In the electrode 11 located at the other end in the stacking direction, the negative electrode active material layer 11C is provided on the second main surface of the current collector 11A, while the positive electrode is provided on the first main surface of the current collector 11A. This is a single-sided electrode in which the active material layer 11B is not provided. The negative electrode tab 14B is connected to the first main surface of the current collector 11A included in the one-sided electrode.
　積層された正極活物質層１１Ｂ、電解質層１３、セパレータ１２、電解質層１３および負極活物質層１１Ｃにより、１つの電極素子１０Ａが構成される。したがって、電池１０は、複数の電極素子１０Ａと複数の集電体１１Ａとが交互に積層された構造を有している。なお、この積層構造の積層方向の両端にはそれぞれ、集電体１１Ａが配置されている。 The positive electrode active material layer 11B, the electrolyte layer 13, the separator 12, the electrolyte layer 13 and the negative electrode active material layer 11C that are stacked together form one electrode element 10A. Therefore, the battery 10 has a structure in which the plurality of electrode elements 10A and the plurality of current collectors 11A are alternately stacked. A current collector 11A is arranged at each end of the laminated structure in the laminating direction.
　以下、電池１０に備えられる集電体１１Ａ、正極活物質層１１Ｂ、負極活物質層１１Ｃ、セパレータ１２、電解質層１３、正極タブ１４Ａおよび負極タブ１４Ｂについて順次説明する。 Hereinafter, the current collector 11A, the positive electrode active material layer 11B, the negative electrode active material layer 11C, the separator 12, the electrolyte layer 13, the positive electrode tab 14A, and the negative electrode tab 14B included in the battery 10 will be sequentially described.
（集電体）
　集電体１１Ａは、第１の実施形態に係る樹脂基材である。 (Current collector)
The collector 11A is the resin base material according to the first embodiment.
（正極活物質層）
　正極活物質層１１Ｂは、リチウムを吸蔵および放出することが可能な１種または２種以上の正極活物質を含む。正極活物質層１１Ｂは、必要に応じてバインダーおよび導電剤のうちの少なくとも１種をさらに含んでいてもよい。 (Cathode active material layer)
The positive electrode active material layer 11B contains one or more positive electrode active materials capable of inserting and extracting lithium. The positive electrode active material layer 11B may further contain at least one of a binder and a conductive agent, if necessary.
（正極活物質）
　正極活物質としては、例えば、リチウム酸化物、リチウムリン酸化物、リチウム硫化物またはリチウムを含む層間化合物等のリチウム含有化合物が適当であり、これらの２種以上を混合して用いてもよい。エネルギー密度を高くするには、リチウムと遷移金属元素と酸素とを含むリチウム含有化合物が好ましい。このようなリチウム含有化合物としては、例えば、式（Ａ）に示した層状岩塩型の構造を有するリチウム複合酸化物、式（Ｂ）に示したオリビン型の構造を有するリチウム複合リン酸塩等が挙げられる。リチウム含有化合物としては、遷移金属元素として、Ｃｏ、Ｎｉ、ＭｎおよびＦｅからなる群より選ばれる少なくとも１種を含むものであればより好ましい。このようなリチウム含有化合物としては、例えば、式（Ｃ）、式（Ｄ）もしくは式（Ｅ）に示した層状岩塩型の構造を有するリチウム複合酸化物、式（Ｆ）に示したスピネル型の構造を有するリチウム複合酸化物、または式（Ｇ）に示したオリビン型の構造を有するリチウム複合リン酸塩等が挙げられ、具体的には、ＬｉＮｉ０．５０Ｃｏ０．２０Ｍｎ０．３０Ｏ２、ＬｉＣｏＯ２、ＬｉＮｉＯ２、ＬｉＮｉａＣｏ１－ａＯ２（０＜ａ＜１）、ＬｉＭｎ２Ｏ４またはＬｉＦｅＰＯ４等がある。
　正極活物質としてはＬＣＯ、ＮＣＭ、ＮＣＡ、ＬＦＰ等一般的なものをいずれも使用できる。 (Cathode active material)
As the positive electrode active material, for example, a lithium-containing compound such as a lithium oxide, a lithium phosphorus oxide, a lithium sulfide, or an intercalation compound containing lithium is suitable, and two or more kinds of these may be mixed and used. A lithium-containing compound containing lithium, a transition metal element, and oxygen is preferable for increasing the energy density. Examples of such a lithium-containing compound include a lithium composite oxide having a layered rock salt type structure represented by formula (A), a lithium composite phosphate having an olivine type structure represented by formula (B), and the like. Can be mentioned. The lithium-containing compound is more preferably a compound containing at least one selected from the group consisting of Co, Ni, Mn and Fe as a transition metal element. Examples of such a lithium-containing compound include, for example, a lithium composite oxide having a layered rock salt type structure represented by formula (C), formula (D) or formula (E), and a spinel type compound represented by formula (F). Examples thereof include a lithium composite oxide having a structure, or a lithium composite phosphate having an olivine type structure represented by the formula (G), and specifically, LiNi 0.50 Co 0.20 Mn 0.30 O. 2 , LiCoO 2 , LiNiO 2 , LiNi a Co 1-a O 2 (0<a<1), LiMn 2 O 4 or LiFePO 4 and the like.
As the positive electrode active material, any common material such as LCO, NCM, NCA and LFP can be used.
　ＬｉｐＮｉ（１－ｑ－ｒ）ＭｎｑＭ１ｒＯ（２－ｙ）Ｘｚ　・・・（Ａ）
（但し、式（Ａ）中、Ｍ１は、Ｎｉ、Ｍｎを除く２族～１５族から選ばれる元素のうち少なくとも一種を示す。Ｘは、酸素以外の１６族元素および１７族元素からなる群より選ばれる少なくとも１種を示す。ｐ、ｑ、ｙ、ｚは、０≦ｐ≦１．５、０≦ｑ≦１．０、０≦ｒ≦１．０、－０．１０≦ｙ≦０．２０、０≦ｚ≦０．２の範囲内の値である。） Li p Ni (1-q-r) Mn q M1 r O (2-y) X z ... (A)
(In the formula (A), M1 represents at least one element selected from the groups 2 to 15 excluding Ni and Mn. X represents a group consisting of a group 16 element and a group 17 element other than oxygen. At least one is selected, where p, q, y, and z are 0≦p≦1.5, 0≦q≦1.0, 0≦r≦1.0, and −0.10≦y≦0. 20, a value within the range of 0≦z≦0.2.)
　ＬｉａＭ２ｂＰＯ４　・・・（Ｂ）
（但し、式（Ｂ）中、Ｍ２は、２族～１５族から選ばれる元素のうち少なくとも一種を示す。ａ、ｂは、０≦ａ≦２．０、０．５≦ｂ≦２．０の範囲内の値である。） Li a M2 b PO 4 (B)
(However, in the formula (B), M2 represents at least one element selected from the groups 2 to 15; a and b are 0≦a≦2.0 and 0.5≦b≦2.0. It is a value within the range of.)
　ＬｉｆＭｎ(１－ｇ－ｈ)ＮｉｇＭ３ｈＯ(２－ｊ)Ｆｋ　・・・（Ｃ）
（但し、式（Ｃ）中、Ｍ３は、Ｃｏ、Ｍｇ、Ａｌ、Ｂ、Ｔｉ、Ｖ、Ｃｒ、Ｆｅ、Ｃｕ、Ｚｎ、Ｚｒ、Ｍｏ、Ｓｎ、Ｃａ、ＳｒおよびＷからなる群より選ばれる少なくとも１種を表す。ｆ、ｇ、ｈ、ｊおよびｋは、０．８≦ｆ≦１．２、０＜ｇ＜０．５、０≦ｈ≦０．５、ｇ＋ｈ＜１、－０．１≦ｊ≦０．２、０≦ｋ≦０．１の範囲内の値である。なお、リチウムの組成は充放電の状態によって異なり、ｆの値は完全放電状態における値を表している。） Li f Mn (1-g-h) Ni g M3 h O (2-j) F k ... (C)
(However, in the formula (C), M3 is at least selected from the group consisting of Co, Mg, Al, B, Ti, V, Cr, Fe, Cu, Zn, Zr, Mo, Sn, Ca, Sr, and W. F, g, h, j and k are 0.8≦f≦1.2, 0<g<0.5, 0≦h≦0.5, g+h<1, −0.1. The values are in the range of ≦j≦0.2 and 0≦k≦0.1 (Note that the composition of lithium differs depending on the state of charge and discharge, and the value of f represents the value in the fully discharged state.)
　ＬｉｍＮｉ(１－ｎ)Ｍ４ｎＯ(２－ｐ)Ｆｑ　・・・（Ｄ）
（但し、式（Ｄ）中、Ｍ４は、Ｃｏ、Ｍｎ、Ｍｇ、Ａｌ、Ｂ、Ｔｉ、Ｖ、Ｃｒ、Ｆｅ、Ｃｕ、Ｚｎ、Ｍｏ、Ｓｎ、Ｃａ、ＳｒおよびＷからなる群より選ばれる少なくとも１種を表す。ｍ、ｎ、ｐおよびｑは、０．８≦ｍ≦１．２、０．００５≦ｎ≦０．５、－０．１≦ｐ≦０．２、０≦ｑ≦０．１の範囲内の値である。なお、リチウムの組成は充放電の状態によって異なり、ｍの値は完全放電状態における値を表している。） Li m Ni (1-n) M4 n O (2-p) F q ... (D)
(However, in the formula (D), M4 is at least selected from the group consisting of Co, Mn, Mg, Al, B, Ti, V, Cr, Fe, Cu, Zn, Mo, Sn, Ca, Sr, and W. Represents one kind, m, n, p and q are 0.8≦m≦1.2, 0.005≦n≦0.5, −0.1≦p≦0.2, 0≦q≦0. The value is within the range of 1. The lithium composition differs depending on the state of charge and discharge, and the value of m represents the value in the completely discharged state.)
　ＬｉｒＣｏ(１－ｓ)Ｍ５ｓＯ(２－ｔ)Ｆｕ　・・・（Ｅ）
（但し、式（Ｅ）中、Ｍ５は、Ｎｉ、Ｍｎ、Ｍｇ、Ａｌ、Ｂ、Ｔｉ、Ｖ、Ｃｒ、Ｆｅ、Ｃｕ、Ｚｎ、Ｍｏ、Ｓｎ、Ｃａ、ＳｒおよびＷからなる群より選ばれる少なくとも１種を表す。ｒ、ｓ、ｔおよびｕは、０．８≦ｒ≦１．２、０≦ｓ＜０．５、－０．１≦ｔ≦０．２、０≦ｕ≦０．１の範囲内の値である。なお、リチウムの組成は充放電の状態によって異なり、ｒの値は完全放電状態における値を表している。） Li r Co (1-s) M5 s O (2-t) Fu (E)
(However, in the formula (E), M5 is at least selected from the group consisting of Ni, Mn, Mg, Al, B, Ti, V, Cr, Fe, Cu, Zn, Mo, Sn, Ca, Sr, and W. Representing one type, r, s, t and u are 0.8≦r≦1.2, 0≦s<0.5, −0.1≦t≦0.2, 0≦u≦0.1. The composition of lithium differs depending on the state of charge and discharge, and the value of r represents the value in the completely discharged state.)
　ＬｉｖＭｎ２－ｗＭ６ｗＯｘＦｙ　・・・（Ｆ）
（但し、式（Ｆ）中、Ｍ６は、Ｃｏ、Ｎｉ、Ｍｇ、Ａｌ、Ｂ、Ｔｉ、Ｖ、Ｃｒ、Ｆｅ、Ｃｕ、Ｚｎ、Ｍｏ、Ｓｎ、Ｃａ、ＳｒおよびＷからなる群より選ばれる少なくとも１種を表す。ｖ、ｗ、ｘおよびｙは、０．９≦ｖ≦１．１、０≦ｗ≦０．６、３．７≦ｘ≦４．１、０≦ｙ≦０．１の範囲内の値である。なお、リチウムの組成は充放電の状態によって異なり、ｖの値は完全放電状態における値を表している。） Li v Mn 2-w M6 w O x F y ... (F)
(However, in the formula (F), M6 is at least selected from the group consisting of Co, Ni, Mg, Al, B, Ti, V, Cr, Fe, Cu, Zn, Mo, Sn, Ca, Sr, and W. V, w, x and y are 0.9≦v≦1.1, 0≦w≦0.6, 3.7≦x≦4.1, and 0≦y≦0.1. (It is a value within the range. The composition of lithium differs depending on the state of charge and discharge, and the value of v represents the value in the state of complete discharge.)
　ＬｉｚＭ７ＰＯ４　・・・（Ｇ）
（但し、式（Ｇ）中、Ｍ７は、Ｃｏ、Ｍｇ、Ｆｅ、Ｎｉ、Ｍｇ、Ａｌ、Ｂ、Ｔｉ、Ｖ、Ｎｂ、Ｃｕ、Ｚｎ、Ｍｏ、Ｃａ、Ｓｒ、ＷおよびＺｒからなる群より選ばれる少なくとも１種を表す。ｚは、０．９≦ｚ≦１．１の範囲内の値である。なお、リチウムの組成は充放電の状態によって異なり、ｚの値は完全放電状態における値を表している。） Li z M7PO 4 (G)
(However, in the formula (G), M7 is selected from the group consisting of Co, Mg, Fe, Ni, Mg, Al, B, Ti, V, Nb, Cu, Zn, Mo, Ca, Sr, W and Zr. Z is a value within the range of 0.9≦z≦1.1 Note that the composition of lithium differs depending on the state of charge and discharge, and the value of z indicates the value in the state of complete discharge. It represents.)
　Ｎｉを含むリチウム複合酸化物としては、ＬｉとＮｉとＣｏとＭｎとＯ（酸素）とを含むリチウム複合酸化物（ＮＣＭ）、ＬｉとＮｉとＣｏとＡｌとＯ（酸素）とを含むリチウム複合酸化物（ＮＣＡ）等を用いてもよい。Ｎｉを含むリチウム複合酸化物としては、具体的には、以下の式（Ｈ）または式（Ｉ）に示したものを用いてもよい。 Examples of the lithium composite oxide containing Ni include a lithium composite oxide (NCM) containing Li, Ni, Co, Mn, and O (oxygen), and a lithium composite oxide containing Li, Ni, Co, Al, and O (oxygen). An oxide (NCA) or the like may be used. As the lithium composite oxide containing Ni, specifically, one represented by the following formula (H) or formula (I) may be used.
　Ｌｉｖ１Ｎｉｗ１Ｍ１’ｘ１Ｏｚ１　・・・（Ｈ）
（式中、０＜ｖ１＜２、ｗ１＋ｘ１≦１、０．２≦ｗ１≦１、０≦ｘ１≦０．７、０＜ｚ＜３であり、Ｍ１’は、Ｃｏ、Ｆｅ、Ｍｎ、Ｃｕ、Ｚｎ、Ａｌ、Ｃｒ、Ｖ、Ｔｉ、ＭｇおよびＺｒ等の遷移金属からなる元素を少なくとも１種類以上である。） Li v1 Ni w1 M1′ x1 O z1 (H)
(In the formula, 0<v1<2, w1+x1≦1, 0.2≦w1≦1, 0≦x1≦0.7, 0<z<3, and M1′ is Co, Fe, Mn, Cu, (At least one element selected from transition metals such as Zn, Al, Cr, V, Ti, Mg, and Zr.)
　Ｌｉｖ２Ｎｉｗ２Ｍ２’ｘ２Ｏｚ２　・・・（Ｉ）
（式中、０＜ｖ２＜２、ｗ２＋ｘ２≦１、０．６５≦ｗ２≦１、０≦ｘ２≦０．３５、０＜ｚ２＜３であり、Ｍ２’は、Ｃｏ、Ｆｅ、Ｍｎ、Ｃｕ、Ｚｎ、Ａｌ、Ｃｒ、Ｖ、Ｔｉ、ＭｇおよびＺｒ等の遷移金属からなる元素を少なくとも１種類以上である。） Li v2 Ni w2 M2′ x2 O z2 ... (I)
(In the formula, 0<v2<2, w2+x2≦1, 0.65≦w2≦1, 0≦x2≦0.35, 0<z2<3, and M2′ is Co, Fe, Mn, Cu, (At least one element selected from transition metals such as Zn, Al, Cr, V, Ti, Mg, and Zr.)
　リチウムを吸蔵および放出することが可能な正極活物質としては、これらの他にも、ＭｎＯ２、Ｖ２Ｏ５、Ｖ６Ｏ１３、ＮｉＳ、ＭｏＳ等のリチウムを含まない無機化合物を用いることもできる。 As the positive electrode active material capable of inserting and extracting lithium, an inorganic compound containing no lithium such as MnO 2 , V 2 O 5 , V 6 O 13 , NiS, and MoS may be used in addition to these. it can.
　リチウムを吸蔵および放出することが可能な正極活物質は、上記以外のものであってもよい。また、上記で例示した正極活物質は、任意の組み合わせで２種以上混合されてもよい。 The positive electrode active material capable of inserting and extracting lithium may be other than the above. Further, the positive electrode active materials exemplified above may be mixed in two or more kinds in any combination.
（導電剤）
　導電剤としては、例えば、黒鉛、炭素繊維、カーボンブラック、アセチレンブラック、ケッチェンブラック、カーボンナノチューブ（ＣＮＴ）、カーボンナノファイバー（ＣＮＦ）およびグラフェン等からなる群より選ばれる少なくとも１種の炭素材料を用いることができる。なお、導電剤は導電性を有する材料であればよく、炭素材料に限定されるものではない。例えば、導電剤として金属材料または導電性高分子材料等を用いるようにしてもよい。また、導電剤の形状としては、例えば、粒状、鱗片状、中空状、針状または筒状等が挙げられるが、特にこれらの形状に限定されるものではない。 (Conductive agent)
As the conductive agent, for example, at least one carbon material selected from the group consisting of graphite, carbon fiber, carbon black, acetylene black, Ketjen black, carbon nanotube (CNT), carbon nanofiber (CNF), graphene, and the like. Can be used. The conductive agent is not limited to the carbon material, as long as it is a material having conductivity. For example, a metal material or a conductive polymer material may be used as the conductive agent. Moreover, examples of the shape of the conductive agent include a granular shape, a scale shape, a hollow shape, a needle shape, and a cylindrical shape, but are not particularly limited to these shapes.
（バインダー）
　バインダーとしては、例えば、ポリフッ化ビニリデン（ＰＶｄＦ）、ポリテトラフルオロエチレン（ＰＴＦＥ）、ポリアクリロニトリル（ＰＡＮ）、スチレンブタジエンゴム（ＳＢＲ）、カルボキシメチルセルロース（ＣＭＣ）、およびこれら樹脂材料のうちの１種を主体とする共重合体等からなる群より選ばれる少なくとも１種を用いることができる。 (binder)
Examples of the binder include polyvinylidene fluoride (PVdF), polytetrafluoroethylene (PTFE), polyacrylonitrile (PAN), styrene butadiene rubber (SBR), carboxymethyl cellulose (CMC), and one of these resin materials. At least one selected from the group consisting of copolymers as a main component can be used.
（負極活物質層）
　負極活物質層１１Ｃは、リチウムを吸蔵および放出することが可能な１種または２種以上の負極活物質を含む。負極活物質層１１Ｃは、必要に応じてバインダーおよび導電剤のうちの少なくとも１種をさらに含んでいてもよい。 (Negative electrode active material layer)
The negative electrode active material layer 11C includes one or more negative electrode active materials capable of inserting and extracting lithium. The negative electrode active material layer 11C may further contain at least one of a binder and a conductive agent, if necessary.
（負極活物質）
　負極活物質としては、例えば、難黒鉛化性炭素、易黒鉛化性炭素、黒鉛、熱分解炭素類、コークス類、ガラス状炭素類、有機高分子化合物焼成体、炭素繊維または活性炭等の炭素材料が挙げられる。このうち、コークス類には、ピッチコークス、ニードルコークスまたは石油コークス等がある。有機高分子化合物焼成体というのは、フェノール樹脂やフラン樹脂等の高分子材料を適当な温度で焼成して炭素化したものをいい、一部には難黒鉛化性炭素または易黒鉛化性炭素に分類されるものもある。これら炭素材料は、充放電時に生じる結晶構造の変化が非常に少なく、高い充放電容量を得ることができると共に、良好なサイクル特性を得ることができるので好ましい。特に黒鉛は、電気化学当量が大きく、高いエネルギー密度を得ることができ好ましい。また、難黒鉛化性炭素は、優れたサイクル特性が得られるので好ましい。さらにまた、充放電電位が低いもの、具体的には充放電電位がリチウム金属に近いものが、電池１０の高エネルギー密度化を容易に実現することができるので好ましい。また、黒鉛は天然黒鉛であってもよいし、人造黒鉛であってもよいし、これらを混合して用いてもよい。人造黒鉛としては、メソカーボンマイクロビーズ（ＭＣＭＢ）等を用いることができる。 (Negative electrode active material)
Examples of the negative electrode active material include non-graphitizable carbon, graphitizable carbon, graphite, pyrolytic carbons, cokes, glassy carbons, organic polymer compound fired bodies, carbon materials such as carbon fiber or activated carbon. Are listed. Among these, the cokes include pitch coke, needle coke, petroleum coke, and the like. The organic polymer compound fired body is obtained by firing a polymer material such as a phenol resin or a furan resin at an appropriate temperature to carbonize it, and part of it is a non-graphitizable carbon or an easily graphitizable carbon. Some are classified as. These carbon materials are preferable because the change in the crystal structure that occurs during charging and discharging is very small, a high charge and discharge capacity can be obtained, and good cycle characteristics can be obtained. Particularly, graphite is preferable because it has a large electrochemical equivalent and can obtain a high energy density. Further, non-graphitizable carbon is preferable because excellent cycle characteristics can be obtained. Furthermore, a material having a low charge/discharge potential, specifically, a material having a charge/discharge potential close to that of lithium metal is preferable because the energy density of the battery 10 can be easily increased. The graphite may be natural graphite, artificial graphite, or a mixture thereof. Mesocarbon microbeads (MCMB) or the like can be used as the artificial graphite.
　また、高容量化が可能な他の負極活物質としては、金属元素および半金属元素のうちの少なくとも１種を構成元素（例えば、合金、化合物または混合物）として含む材料も挙げられる。このような材料を用いれば、高いエネルギー密度を得ることができるからである。特に、炭素材料と共に用いるようにすれば、高エネルギー密度を得ることができると共に、優れたサイクル特性を得ることができるのでより好ましい。なお、本発明において、合金には２種以上の金属元素からなるものに加えて、１種以上の金属元素と１種以上の半金属元素とを含むものも含める。また、非金属元素を含んでいてもよい。その組織には固溶体、共晶（共融混合物）、金属間化合物またはそれらのうちの２種以上が共存するものがある。 Further, as another negative electrode active material capable of increasing the capacity, a material containing at least one of a metal element and a metalloid element as a constituent element (for example, an alloy, a compound or a mixture) can also be mentioned. This is because a high energy density can be obtained by using such a material. In particular, when used together with a carbon material, it is more preferable because a high energy density can be obtained and excellent cycle characteristics can be obtained. In the present invention, the alloy includes not only an alloy composed of two or more metal elements but also an alloy containing one or more metal elements and one or more metalloid elements. Moreover, you may contain the nonmetallic element. The structure thereof includes a solid solution, a eutectic (eutectic mixture), an intermetallic compound, or a structure in which two or more of them coexist.
　このような負極活物質としては、例えば、リチウムと合金を形成することが可能な金属元素または半金属元素が挙げられる。具体的には、Ｍｇ、Ｂ、Ａｌ、Ｔｉ、Ｇａ、Ｉｎ、Ｓｉ、Ｇｅ、Ｓｎ、Ｐｂ、Ｂｉ、Ｃｄ、Ａｇ、Ｚｎ、Ｈｆ、Ｚｒ、Ｙ、ＰｄまたはＰｔが挙げられる。これらは結晶質のものでもアモルファスのものでもよい。 As such a negative electrode active material, for example, a metal element or a metalloid element capable of forming an alloy with lithium can be mentioned. Specific examples include Mg, B, Al, Ti, Ga, In, Si, Ge, Sn, Pb, Bi, Cd, Ag, Zn, Hf, Zr, Y, Pd or Pt. These may be crystalline or amorphous.
　このような負極活物質としては、短周期型周期表における４Ｂ族の金属元素または半金属元素を構成元素として含むものが挙げられ、その中で好ましいのはＳｉおよびＳｎの少なくとも一方を構成元素として含むものである。ＳｉおよびＳｎは、リチウムを吸蔵および放出する能力が大きく、高いエネルギー密度を得ることができるからである。このような負極活物質としては、例えば、Ｓｉの単体、合金または化合物や、Ｓｎの単体、合金または化合物や、それらの１種または２種以上を少なくとも一部に有する材料が挙げられる。 Examples of such a negative electrode active material include those containing a metal element or metalloid element of Group 4B in the short-periodic periodic table as a constituent element, and among them, at least one of Si and Sn is preferable as a constituent element. It includes. This is because Si and Sn have a large ability to insert and extract lithium, and a high energy density can be obtained. Examples of such a negative electrode active material include a simple substance of Si, an alloy or a compound, a simple substance of Sn, an alloy or a compound, and a material having at least a part of one or more of them.
　Ｓｉの合金としては、例えば、Ｓｉ以外の第２の構成元素として、Ｓｎ、Ｎｉ、Ｃｕ、Ｆｅ、Ｃｏ、Ｍｎ、Ｚｎ、Ｉｎ、Ａｇ、Ｔｉ、Ｇｅ、Ｂｉ、Ｓｂ、Ｎｂ、Ｍｏ、Ａｌ、Ｐ、ＧａおよびＣｒからなる群より選ばれる少なくとも１種を含むものが挙げられる。Ｓｎの合金としては、例えば、Ｓｎ以外の第２の構成元素として、Ｓｉ、Ｎｉ、Ｃｕ、Ｆｅ、Ｃｏ、Ｍｎ、Ｚｎ、Ｉｎ、Ａｇ、Ｔｉ、Ｇｅ、Ｂｉ、Ｓｂ、Ｎｂ、Ｍｏ、Ａｌ、Ｐ、ＧａおよびＣｒからなる群より選ばれる少なくとも１種を含むものが挙げられる。 Examples of the alloy of Si include Sn, Ni, Cu, Fe, Co, Mn, Zn, In, Ag, Ti, Ge, Bi, Sb, Nb, Mo and Al as the second constituent element other than Si. Examples include those containing at least one selected from the group consisting of P, Ga and Cr. Examples of the alloy of Sn include, as second constituent elements other than Sn, Si, Ni, Cu, Fe, Co, Mn, Zn, In, Ag, Ti, Ge, Bi, Sb, Nb, Mo, Al, Examples include those containing at least one selected from the group consisting of P, Ga and Cr.
　Ｓｎの化合物またはＳｉの化合物としては、例えば、ＯまたはＣを構成元素として含むものが挙げられる。これらの化合物は、上述した第２の構成元素を含んでいてもよい。 Examples of the Sn compound or the Si compound include those containing O or C as a constituent element. These compounds may contain the above-mentioned second constituent element.
　中でも、Ｓｎ系の負極活物質としては、Ｃｏと、Ｓｎと、Ｃとを構成元素として含み、結晶性の低いまたは非晶質な構造を有していることが好ましい。 Among them, the Sn-based negative electrode active material preferably contains Co, Sn, and C as constituent elements and has a low crystallinity or an amorphous structure.
　その他の負極活物質としては、例えば、リチウムを吸蔵および放出することが可能な金属酸化物または高分子化合物等も挙げられる。金属酸化物としては、例えば、チタン酸リチウム（Ｌｉ４Ｔｉ５Ｏ１２）等のＬｉとＴｉとを含むリチウムチタン酸化物、酸化鉄、酸化ルテニウムまたは酸化モリブデン等が挙げられる。高分子化合物としては、例えば、ポリアセチレン、ポリアニリンまたはポリピロール等が挙げられる。 Other negative electrode active materials include, for example, metal oxides or polymer compounds capable of inserting and extracting lithium. Examples of the metal oxide include lithium titanium oxide containing Li and Ti such as lithium titanate (Li 4 Ti 5 O 12 ), iron oxide, ruthenium oxide or molybdenum oxide. Examples of the polymer compound include polyacetylene, polyaniline, polypyrrole and the like.
（導電剤）
　導電剤としては、正極活物質層１１Ｂと同様のものを用いることができる。 (Conductive agent)
As the conductive agent, the same material as the positive electrode active material layer 11B can be used.
（バインダー）
　バインダーとしては、例えば、ポリフッ化ビニリデン（ＰＶｄＦ）、ポリイミド（ＰＩ）、アラミド、ポリテトラフルオロエチレン（ＰＴＦＥ）、ポリアクリロニトリル（ＰＡＮ）、スチレンブタジエンゴム（ＳＢＲ）、カルボキシメチルセルロース（ＣＭＣ）、およびこれら樹脂材料のうちの１種を主体とする共重合体等からなる群より選ばれる少なくとも１種を用いることができる。 (binder)
Examples of the binder include polyvinylidene fluoride (PVdF), polyimide (PI), aramid, polytetrafluoroethylene (PTFE), polyacrylonitrile (PAN), styrene butadiene rubber (SBR), carboxymethyl cellulose (CMC), and these resins. At least one selected from the group consisting of copolymers mainly composed of one of the materials can be used.
（セパレータ）
　セパレータ１２は、正極活物質層１１Ｂと負極活物質層１１Ｃとを隔離し、両極の接触による電流の短絡を防止しつつ、リチウムイオンを通過させるものである。セパレータ１２は、例えば、ポリテトラフルオロエチレン、ポリオレフィン樹脂（ポリプロピレン（ＰＰ）またはポリエチレン（ＰＥ）等）、アクリル樹脂、スチレン樹脂、ポリエステル樹脂またはナイロン樹脂、または、これらの樹脂をブレンドした樹脂からなる多孔質膜によって構成されており、これらの２種以上の多孔質膜を積層した構造とされていてもよい。 (Separator)
The separator 12 separates the positive electrode active material layer 11B from the negative electrode active material layer 11C, prevents current short circuit due to contact between both electrodes, and allows lithium ions to pass through. The separator 12 is made of, for example, polytetrafluoroethylene, a polyolefin resin (polypropylene (PP) or polyethylene (PE), etc.), an acrylic resin, a styrene resin, a polyester resin or a nylon resin, or a porous resin made by blending these resins. It is composed of a porous membrane, and may have a structure in which two or more kinds of these porous membranes are laminated.
　中でも、ポリオレフィン製の多孔質膜は短絡防止効果に優れ、かつシャットダウン効果による電池１０の安全性向上を図ることができるので好ましい。特にポリエチレンは、１００℃以上１６０℃以下の範囲内においてシャットダウン効果を得ることができ、かつ電気化学的安定性にも優れているので、セパレータ１２を構成する材料として好ましい。その中でも、低密度ポリエチレン、高密度ポリエチレン、線状ポリエチレンは溶融温度が適当であり、入手が容易なので好適に用いられる。他にも、化学的安定性を備えた樹脂を、ポリエチレンまたはポリプロピレンと共重合またはブレンド化した材料を用いることができる。あるいは、多孔質膜は、ポリプロピレン層と、ポリエチレン層と、ポリプロピレン層を順次に積層した３層以上の構造を有していてもよい。例えば、ＰＰ／ＰＥ／ＰＰの三層構造とし、ＰＰとＰＥの質量比［ｗｔ％］が、ＰＰ：ＰＥ＝６０：４０～７５：２５とすることが望ましい。あるいは、コストの観点から、ＰＰが１００ｗｔ％またはＰＥが１００ｗｔ％の単層基材とすることもできる。セパレータ１２の作製方法としては、湿式、乾式を問わない。 Among them, the porous film made of polyolefin is preferable because it has an excellent short-circuit prevention effect and can improve the safety of the battery 10 due to the shutdown effect. In particular, polyethylene is preferable as a material forming the separator 12 because it can obtain a shutdown effect in the range of 100° C. or higher and 160° C. or lower and is excellent in electrochemical stability. Among them, low-density polyethylene, high-density polyethylene and linear polyethylene have suitable melting temperatures and are easily available, and thus are preferably used. Alternatively, a material obtained by copolymerizing or blending a chemically stable resin with polyethylene or polypropylene can be used. Alternatively, the porous membrane may have a structure of three or more layers in which a polypropylene layer, a polyethylene layer, and a polypropylene layer are sequentially laminated. For example, it is desirable to have a three-layer structure of PP/PE/PP, and the mass ratio [wt%] of PP and PE is PP:PE=60:40 to 75:25. Alternatively, from the viewpoint of cost, a single layer base material having 100 wt% PP or 100 wt% PE may be used. The separator 12 may be manufactured by either a wet method or a dry method.
　セパレータ１２としては、不織布を用いてもよい。不織布を構成する繊維としては、アラミド繊維、ガラス繊維、ポリオレフィン繊維、ポリエチレンテレフタレート（ＰＥＴ）繊維、またはナイロン繊維等を用いることができる。また、これら２種以上の繊維を混合して不織布としてもよい。 Nonwoven fabric may be used as the separator 12. As the fibers constituting the non-woven fabric, aramid fibers, glass fibers, polyolefin fibers, polyethylene terephthalate (PET) fibers, nylon fibers or the like can be used. Further, two or more kinds of these fibers may be mixed to form a non-woven fabric.
　セパレータ１２は、基材と、基材の片面または両面に設けられた表面層を備える構成を有していてもよい。表面層は、電気的な絶縁性を有する無機粒子と、無機粒子を基材の表面に結着すると共に、無機粒子同士を結着する樹脂材料とを含む。この樹脂材料は、例えば、フィブリル化し、複数のフィブリルが繋がった三次元的なネットワーク構造を有していてもよい。無機粒子は、この三次元的なネットワーク構造を有する樹脂材料に担持されている。また、樹脂材料はフィブリル化せずに基材の表面や無機粒子同士を結着してもよい。この場合、より高い結着性を得ることができる。上述のように基材の片面または両面に表面層を設けることで、セパレータ１２の耐酸化性、耐熱性および機械強度を高めることができる。 The separator 12 may have a configuration including a base material and a surface layer provided on one surface or both surfaces of the base material. The surface layer includes inorganic particles having electrical insulation properties and a resin material that binds the inorganic particles to the surface of the base material and also binds the inorganic particles to each other. This resin material may have a three-dimensional network structure in which a plurality of fibrils are connected by fibrillation. The inorganic particles are carried on the resin material having this three-dimensional network structure. Further, the resin material may bind the surface of the base material or the inorganic particles to each other without being fibrillated. In this case, higher binding property can be obtained. By providing the surface layer on one side or both sides of the base material as described above, the oxidation resistance, heat resistance and mechanical strength of the separator 12 can be enhanced.
　基材は、リチウムイオンを透過し、所定の機械的強度を有する絶縁性の膜から構成される多孔質膜であり、基材の空孔には電解液が保持されるため、電解液に対する耐性が高く、反応性が低く、膨張しにくいという特性を有することが好ましい。 The base material is a porous film composed of an insulating film that transmits lithium ions and has a predetermined mechanical strength. Since the electrolyte solution is retained in the pores of the base material, the resistance to the electrolyte solution is high. It is preferable that the resin has a property that it is high, has low reactivity, and does not easily expand.
　基材を構成する材料としては、上述したセパレータ１２を構成する樹脂材料や不織布を用いることができる。 As the material forming the base material, the resin material or non-woven fabric forming the separator 12 described above can be used.
　無機粒子は、金属酸化物、金属窒化物、金属炭化物および金属硫化物等からなる群より選ばれる少なくとも１種を含む。金属酸化物としては、酸化アルミニウム（アルミナ、Ａｌ２Ｏ３）、ベーマイト（水和アルミニウム酸化物）、酸化マグネシウム（マグネシア、ＭｇＯ）、酸化チタン（チタニア、ＴｉＯ２）、酸化ジルコニウム（ジルコニア、ＺｒＯ２）、酸化ケイ素（シリカ、ＳｉＯ２）または酸化イットリウム（イットリア、Ｙ２Ｏ３）等を好適に用いることができる。金属窒化物としては、窒化ケイ素（Ｓｉ３Ｎ４）、窒化アルミニウム（ＡｌＮ）、窒化硼素（ＢＮ）または窒化チタン（ＴｉＮ）等を好適に用いることができる。金属炭化物としては、炭化ケイ素（ＳｉＣ）または炭化ホウ素（Ｂ４Ｃ）等を好適に用いることができる。金属硫化物としては、硫酸バリウム（ＢａＳＯ４）等を好適に用いることができる。上述の金属酸化物の中でも、アルミナ、チタニア（特にルチル型構造を有するもの）、シリカまたはマグネシアを用いることが好ましく、アルミナを用いることがより好ましい。 The inorganic particles include at least one selected from the group consisting of metal oxides, metal nitrides, metal carbides, metal sulfides and the like. Examples of metal oxides include aluminum oxide (alumina, Al 2 O 3 ), boehmite (hydrated aluminum oxide), magnesium oxide (magnesia, MgO), titanium oxide (titania, TiO 2 ), zirconium oxide (zirconia, ZrO 2 ). ), silicon oxide (silica, SiO 2 ) or yttrium oxide (yttria, Y 2 O 3 ) or the like can be preferably used. As the metal nitride, silicon nitride (Si 3 N 4 ), aluminum nitride (AlN), boron nitride (BN), titanium nitride (TiN), or the like can be preferably used. Silicon carbide (SiC), boron carbide (B 4 C), or the like can be preferably used as the metal carbide. Barium sulfate (BaSO 4 ) or the like can be preferably used as the metal sulfide. Among the above metal oxides, it is preferable to use alumina, titania (in particular, one having a rutile structure), silica or magnesia, and it is more preferable to use alumina.
　また、無機粒子が、ゼオライト（Ｍ２／ｎＯ・Ａｌ２Ｏ３・ｘＳｉＯ２・ｙＨ２Ｏ、Ｍは金属元素、ｘ≧２、ｙ≧０）等の多孔質アルミノケイ酸塩、層状ケイ酸塩、チタン酸バリウム（ＢａＴｉＯ３）またはチタン酸ストロンチウム（ＳｒＴｉＯ３）等の鉱物を含むようにしてもよい。無機粒子は耐酸化性および耐熱性を備えており、無機粒子を含有する正極対向側面の表面層は、充電時の正極近傍における酸化環境に対しても強い耐性を有する。無機粒子の形状は特に限定されるものではなく、球状、板状、繊維状、キュービック状およびランダム形状等のいずれも用いることができる。 The inorganic particles are porous aluminosilicates such as zeolite (M 2 /n 2 O.Al 2 O 3 .xSiO 2 .yH 2 O, M is a metal element, x≧2, y≧0), layered silicic acid. Minerals such as salts and barium titanate (BaTiO 3 ) or strontium titanate (SrTiO 3 ) may be included. The inorganic particles have oxidation resistance and heat resistance, and the surface layer on the side surface facing the positive electrode containing the inorganic particles has strong resistance to an oxidizing environment in the vicinity of the positive electrode during charging. The shape of the inorganic particles is not particularly limited, and any of spherical, plate-like, fibrous, cubic and random shapes can be used.
　無機粒子の粒径は、１ｎｍ以上１０μｍ以下の範囲内であることが好ましい。１ｎｍより小さいと入手が困難であり、１０μｍより大きいと電極間距離が大きくなり、限られたスペースで活物質充填量が十分得られず電池容量が低下してしまうからである。 The particle size of the inorganic particles is preferably in the range of 1 nm or more and 10 μm or less. This is because if it is less than 1 nm, it is difficult to obtain it, and if it is more than 10 μm, the distance between the electrodes becomes large, and the filling amount of the active material cannot be sufficiently obtained in a limited space, so that the battery capacity decreases.
　表面層を構成する樹脂材料としては、ポリフッ化ビニリデン、ポリテトラフルオロエチレン等の含フッ素樹脂、フッ化ビニリデン－テトラフルオロエチレン共重合体、エチレン－テトラフルオロエチレン共重合体等の含フッ素ゴム、スチレン－ブタジエン共重合体またはその水素化物、アクリロニトリル－ブタジエン共重合体またはその水素化物、アクリロニトリル－ブタジエン－スチレン共重合体またはその水素化物、メタクリル酸エステル－アクリル酸エステル共重合体、スチレン－アクリル酸エステル共重合体、アクリロニトリル－アクリル酸エステル共重合体、エチレンプロピレンラバー、ポリビニルアルコール、ポリ酢酸ビニル等のゴム類、エチルセルロース、メチルセルロース、ヒドロキシエチルセルロース、カルボキシメチルセルロース等のセルロース誘導体、ポリフェニレンエーテル、ポリスルホン、ポリエーテルスルホン、ポリフェニレンスルフィド、ポリエーテルイミド、ポリイミド、全芳香族ポリアミド（アラミド）等のポリアミド、ポリアミドイミド、ポリアクリロニトリル、ポリビニルアルコール、ポリエーテル、アクリル酸樹脂またはポリエステル等の融点およびガラス転移温度の少なくとも一方が１８０℃以上の高い耐熱性を有する樹脂等が挙げられる。これら樹脂材料は、単独で用いてもよいし、２種以上を混合して用いてもよい。中でも、耐酸化性および柔軟性の観点からは、ポリフッ化ビニリデン等のフッ素系樹脂が好ましく、耐熱性の観点からは、アラミドまたはポリアミドイミドを含むことが好ましい。 Examples of the resin material constituting the surface layer include polyvinylidene fluoride, polytetrafluoroethylene and other fluorine-containing resins, vinylidene fluoride-tetrafluoroethylene copolymer, ethylene-tetrafluoroethylene copolymer and other fluorine-containing rubber, and styrene. -Butadiene copolymer or hydride thereof, acrylonitrile-butadiene copolymer or hydride thereof, acrylonitrile-butadiene-styrene copolymer or hydride thereof, methacrylic acid ester-acrylic acid ester copolymer, styrene-acrylic acid ester Copolymers, acrylonitrile-acrylic acid ester copolymers, rubbers such as ethylene propylene rubber, polyvinyl alcohol, polyvinyl acetate, cellulose derivatives such as ethyl cellulose, methyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, polyphenylene ether, polysulfone, polyether sulfone Polyamide, polyphenylene sulfide, polyether imide, polyimide, polyamide such as wholly aromatic polyamide (aramid), polyamide imide, polyacrylonitrile, polyvinyl alcohol, polyether, acrylic resin or polyester, and the like, at least one of melting point and glass transition temperature is 180 Examples thereof include resins having a high heat resistance of not less than 0°C. These resin materials may be used alone or in combination of two or more. Among them, from the viewpoint of oxidation resistance and flexibility, a fluorine-based resin such as polyvinylidene fluoride is preferable, and from the viewpoint of heat resistance, it is preferable to contain aramid or polyamide-imide.
　表面層の形成方法としては、例えば、マトリックス樹脂、溶媒および無機粒子からなるスラリーを基材（多孔質膜）上に塗布し、マトリックス樹脂の貧溶媒且つ上記溶媒の親溶媒浴中を通過させて相分離させ、その後、乾燥させる方法を用いることができる。 As a method for forming the surface layer, for example, a slurry comprising a matrix resin, a solvent and inorganic particles is applied onto a substrate (porous membrane), and passed through a poor solvent of the matrix resin and a solvent-solvent bath of the solvent. A method of causing phase separation and then drying can be used.
　なお、上述した無機粒子は、基材としての多孔質膜に含有されていてもよい。また、表面層が無機粒子を含まず、樹脂材料のみにより構成されていてもよい。 The above-mentioned inorganic particles may be contained in the porous film as the base material. In addition, the surface layer may not include inorganic particles and may be composed of only a resin material.
（電解質層）
　電解質層１３は、電解液と、この電解液を保持する保持体となる高分子化合物とを含む。電解質層１３は、ゲル状を有していることが好ましい。電解質層１３がゲル状を有していることで、高いイオン伝導率を得ることができると共に、電池１０の漏液を抑制することができる。 (Electrolyte layer)
The electrolyte layer 13 includes an electrolytic solution and a polymer compound serving as a holder that holds the electrolytic solution. The electrolyte layer 13 preferably has a gel shape. Since the electrolyte layer 13 has a gel shape, it is possible to obtain high ionic conductivity and suppress leakage of the battery 10.
　電解液は、いわゆる非水電解液であり、有機溶媒（非水溶媒）と、この有機溶媒に溶解された電解質塩とを含む。電解液が、電池特性を向上するために、公知の添加剤を含んでいてもよい。 The electrolytic solution is a so-called non-aqueous electrolytic solution and contains an organic solvent (non-aqueous solvent) and an electrolyte salt dissolved in this organic solvent. The electrolytic solution may contain a known additive in order to improve battery characteristics.
　有機溶媒としては、炭酸エチレンまたは炭酸プロピレン等の環状の炭酸エステルを用いることができ、炭酸エチレンおよび炭酸プロピレンのうちの一方、特に両方を混合して用いることが好ましい。サイクル特性をさらに向上させることができるからである。 As the organic solvent, a cyclic carbonic acid ester such as ethylene carbonate or propylene carbonate can be used, and it is preferable to use one of ethylene carbonate and propylene carbonate, particularly both as a mixture. This is because the cycle characteristics can be further improved.
　有機溶媒としては、また、これらの環状の炭酸エステルに加えて、炭酸ジエチル、炭酸ジメチル、炭酸エチルメチルまたは炭酸メチルプロピル等の鎖状の炭酸エステルを混合して用いることが好ましい。高いイオン伝導性を得ることができるからである。 In addition to these cyclic carbonic acid esters, it is preferable to use a chain carbonic acid ester such as diethyl carbonate, dimethyl carbonate, ethylmethyl carbonate or methylpropyl carbonate as the organic solvent. This is because high ionic conductivity can be obtained.
　有機溶媒としては、さらにまた、２，４－ジフルオロアニソールまたは炭酸ビニレンを含むこと好ましい。２，４－ジフルオロアニソールは放電容量をさらに向上させることができ、また、炭酸ビニレンはサイクル特性をさらに向上させることができるからである。よって、これらを混合して用いれば、放電容量およびサイクル特性をさらに向上させることができるので好ましい。 The organic solvent preferably further contains 2,4-difluoroanisole or vinylene carbonate. This is because 2,4-difluoroanisole can further improve the discharge capacity, and vinylene carbonate can further improve the cycle characteristics. Therefore, it is preferable to mix and use these, because the discharge capacity and the cycle characteristics can be further improved.
　これらの他にも、有機溶媒としては、例えば、炭酸ブチレン、γ－ブチロラクトン、γ－バレロラクトン、１，２－ジメトキシエタン、テトラヒドロフラン、２－メチルテトラヒドロフラン、１，３－ジオキソラン、４－メチル－１，３－ジオキソラン、酢酸メチル、プロピオン酸メチル、アセトニトリル、グルタロニトリル、アジポニトリル、メトキシアセトニトリル、３－メトキシプロピロニトリル、Ｎ，Ｎ－ジメチルフォルムアミド、Ｎ－メチルピロリジノン、Ｎ－メチルオキサゾリジノン、Ｎ，Ｎ－ジメチルイミダゾリジノン、ニトロメタン、ニトロエタン、スルホラン、ジメチルスルフォキシドおよびリン酸トリメチル等からなる群より選ばれる少なくとも１種を用いることができる。 In addition to these, examples of the organic solvent include butylene carbonate, γ-butyrolactone, γ-valerolactone, 1,2-dimethoxyethane, tetrahydrofuran, 2-methyltetrahydrofuran, 1,3-dioxolane, 4-methyl-1. , 3-dioxolane, methyl acetate, methyl propionate, acetonitrile, glutaronitrile, adiponitrile, methoxyacetonitrile, 3-methoxypropyronitrile, N,N-dimethylformamide, N-methylpyrrolidinone, N-methyloxazolidinone, N, At least one selected from the group consisting of N-dimethylimidazolidinone, nitromethane, nitroethane, sulfolane, dimethyl sulfoxide, trimethyl phosphate and the like can be used.
　なお、これらの有機溶媒の少なくとも一部の水素をフッ素で置換した化合物は、組み合わせる電極の種類によっては、電極反応の可逆性を向上させることができる場合があるので、好ましい場合もある。 Incidentally, a compound in which at least a part of hydrogen of these organic solvents is replaced by fluorine may be preferable in some cases because the reversibility of the electrode reaction may be improved depending on the type of electrodes to be combined.
　電解質塩としては、例えば、リチウム塩が挙げられ、１種を単独で用いてもよく、２種以上を混合して用いてもよい。リチウム塩としては、ＬｉＰＦ６、ＬｉＢＦ４、ＬｉＡｓＦ６、ＬｉＣｌＯ４、ＬｉＢ（Ｃ６Ｈ５）４、ＬｉＣＨ３ＳＯ３、ＬｉＣＦ３ＳＯ３、ＬｉＮ（ＳＯ２ＣＦ３）２、ＬｉＣ（ＳＯ２ＣＦ３）３、ＬｉＡｌＣｌ４、ＬｉＳｉＦ６、ＬｉＣｌ、ジフルオロ［オキソラト－Ｏ，Ｏ'］ホウ酸リチウム、リチウムビスオキサレートボレート、またはＬｉＢｒ等が挙げられる。中でも、ＬｉＰＦ６は高いイオン伝導性を得ることができると共に、サイクル特性をさらに向上させることができるので好ましい。 Examples of the electrolyte salt include a lithium salt, and one kind may be used alone, or two or more kinds may be mixed and used. Examples of the lithium salt include LiPF 6 , LiBF 4 , LiAsF 6 , LiClO 4 , LiB(C 6 H 5 ) 4 , LiCH 3 SO 3 , LiCF 3 SO 3 , LiN(SO 2 CF 3 ) 2 , LiC(SO 2 CF). 3 ) 3 , LiAlCl 4 , LiSiF 6 , LiCl, difluoro[oxolato-O,O′] lithium borate, lithium bisoxalate borate, or LiBr. Among them, LiPF 6 is preferable because it can obtain high ionic conductivity and further improve cycle characteristics.
　高分子化合物は、電解液を保持する保持体であり、電解液により膨潤されている。高分子化合物としては、例えば、ポリアクリロニトリル、ポリフッ化ビニリデン、フッ化ビニリデンとヘキサフルオロプロピレンとの共重合体、ポリテトラフルオロエチレン、ポリヘキサフルオロプロピレン、ポリエチレンオキサイド、ポリプロピレンオキサイド、ポリフォスファゼン、ポリシロキサン、ポリ酢酸ビニル、ポリビニルアルコール、ポリメタクリル酸メチル、ポリアクリル酸、ポリメタクリル酸、スチレン－ブタジエンゴム、ニトリル－ブタジエンゴム、ポリスチレンまたはポリカーボネートが挙げられる。特に電気化学的な安定性の観点からは、ポリアクリロニトリル、ポリフッ化ビニリデン、ポリヘキサフルオロプロピレンまたはポリエチレンオキサイドが好ましい。 The polymer compound is a holding body that holds the electrolytic solution and is swollen by the electrolytic solution. Examples of the polymer compound include polyacrylonitrile, polyvinylidene fluoride, a copolymer of vinylidene fluoride and hexafluoropropylene, polytetrafluoroethylene, polyhexafluoropropylene, polyethylene oxide, polypropylene oxide, polyphosphazene, polysiloxane. , Polyvinyl acetate, polyvinyl alcohol, polymethyl methacrylate, polyacrylic acid, polymethacrylic acid, styrene-butadiene rubber, nitrile-butadiene rubber, polystyrene or polycarbonate. Particularly, from the viewpoint of electrochemical stability, polyacrylonitrile, polyvinylidene fluoride, polyhexafluoropropylene or polyethylene oxide is preferable.
（正極タブ、負極タブ）
　正極タブ１４Ａおよび負極タブ１４Ｂは、例えば、Ａｌ、Ｃｕ、Ｎｉまたはステンレス鋼等の金属材料によりそれぞれ構成されており、それぞれ薄板状または網目状とされている。電池１０が外装材に収容されている場合には、正極タブ１４Ａおよび負極タブ１４Ｂはそれぞれ、外装材の内部から外部に向かい導出される。 (Positive electrode tab, negative electrode tab)
The positive electrode tab 14A and the negative electrode tab 14B are each made of a metal material such as Al, Cu, Ni or stainless steel, and have a thin plate shape or a mesh shape, respectively. When the battery 10 is housed in the exterior material, the positive electrode tab 14A and the negative electrode tab 14B are led out from the inside of the exterior material toward the outside.
［電池の動作］
　上述の構成を有する電池１０では、充電を行うと、例えば、正極活物質層１１Ｂからリチウムイオンが放出され、電解質層１３を介して負極活物質層１１Ｃに吸蔵される。また、放電を行うと、例えば、負極活物質層１１Ｃからリチウムイオンが放出され、電解質層１３を介して正極活物質層１１Ｂに吸蔵される。 [Battery operation]
When the battery 10 having the above-described configuration is charged, for example, lithium ions are released from the positive electrode active material layer 11B and occluded in the negative electrode active material layer 11C via the electrolyte layer 13. When discharged, for example, lithium ions are released from the negative electrode active material layer 11C and are occluded in the positive electrode active material layer 11B via the electrolyte layer 13.
［電池の製造方法］
　次に、本発明の第２の実施形態に係る電池１０の製造方法の一例について説明する。 [Battery manufacturing method]
Next, an example of a method for manufacturing the battery 10 according to the second embodiment of the present invention will be described.
（正極活物質層の作製工程）
　正極活物質層１１Ｂは次のようにして作製される。まず、例えば、正極活物質と、バインダーと、導電剤とを混合して正極合剤を調製し、この正極合剤をＮ－メチル－２－ピロリドン（ＮＭＰ）等の溶剤に分散させて正極合剤塗料を作製する。次に、この正極合剤塗料をトランスファーシート上に塗布し溶剤を乾燥させることにより、正極活物質層１１Ｂを得る。トランスファーシートとしては、例えば、金属箔または樹脂フィルムの表面に離型処理が施された離型フィルム等を用いることができる。トランスファーシートとしては、正極合剤塗料に用いられる溶剤で膨潤および劣化しないものを用いることが好ましい。次に、トランスファーシート上に形成された正極活物質層１１Ｂにプレスおよび真空乾燥を施す。これにより、正極活物質層１１Ｂ内の過剰な空隙を圧縮し、体積エネルギー密度を向上させることができると共に、余分な水分を正極活物質層１１Ｂ内から除去し、水分起因の電池特性の劣化を抑制することができる。 (Production process of positive electrode active material layer)
The positive electrode active material layer 11B is manufactured as follows. First, for example, a positive electrode active material, a binder, and a conductive agent are mixed to prepare a positive electrode mixture, and this positive electrode mixture is dispersed in a solvent such as N-methyl-2-pyrrolidone (NMP) to prepare a positive electrode mixture. Make an agent paint. Next, this positive electrode mixture coating material is applied onto a transfer sheet and the solvent is dried to obtain the positive electrode active material layer 11B. As the transfer sheet, for example, a release film in which the surface of a metal foil or a resin film is subjected to a release treatment can be used. As the transfer sheet, it is preferable to use a transfer sheet that does not swell or deteriorate with the solvent used for the positive electrode mixture paint. Next, the positive electrode active material layer 11B formed on the transfer sheet is pressed and vacuum dried. As a result, excessive voids in the positive electrode active material layer 11B can be compressed and the volume energy density can be improved, and excess water can be removed from the positive electrode active material layer 11B to prevent deterioration of battery characteristics due to water. Can be suppressed.
（負極活物質層の作製工程）
　負極活物質層１１Ｃは次のようにして作製される。まず、例えば、負極活物質と、バインダーとを混合して負極合剤を調製し、この負極合剤をＮ－メチル－２－ピロリドン（ＮＭＰ）等の溶剤に分散させてペースト状の負極合剤塗料を作製する。次に、この負極合剤塗料をトランスファーシート上に塗布し溶剤を乾燥させることにより、負極活物質層１１Ｃを得る。トランスファーシートとしては、“正極活物質層の作製工程”と同様のものを用いることができる。次に、トランスファーシート上に形成された負極活物質層１１Ｃにプレスおよび真空乾燥を施す。これにより、負極活物質層１１Ｃ内の過剰な空隙を圧縮し、体積エネルギー密度を向上させることができると共に、余分な水分を負極活物質層１１Ｃ内から除去し、水分起因の電池特性の劣化を抑制することができる。 (Production process of negative electrode active material layer)
The negative electrode active material layer 11C is manufactured as follows. First, for example, a negative electrode active material and a binder are mixed to prepare a negative electrode mixture, and the negative electrode mixture is dispersed in a solvent such as N-methyl-2-pyrrolidone (NMP) to prepare a paste-like negative electrode mixture. Make paint. Next, this negative electrode mixture coating material is applied onto a transfer sheet and the solvent is dried to obtain a negative electrode active material layer 11C. As the transfer sheet, the same one as in the “process for producing the positive electrode active material layer” can be used. Next, the negative electrode active material layer 11C formed on the transfer sheet is pressed and vacuum dried. As a result, excess voids in the negative electrode active material layer 11C can be compressed to improve the volumetric energy density, and excess water can be removed from the negative electrode active material layer 11C to prevent deterioration of battery characteristics due to water. Can be suppressed.
（電解質層の形成工程）
　電解質層１３は次のようにして形成される。まず、例えば、電解液と、電解液を保持する保持体としての高分子化合物と、有機溶剤（希釈溶剤）とを混合することにより、ゾル状の前駆体溶液を調製する。次に、この前駆体溶液を正極活物質層１１Ｂ、負極活物質層１１Ｃそれぞれの表面に均一に塗布して含浸させる。その後、有機溶剤を気化させて除去することにより、ゲル状の電解質層１３を形成する。 (Process of forming electrolyte layer)
The electrolyte layer 13 is formed as follows. First, for example, a sol-like precursor solution is prepared by mixing an electrolytic solution, a polymer compound as a holding body for holding the electrolytic solution, and an organic solvent (diluting solvent). Next, this precursor solution is uniformly applied and impregnated on the surface of each of the positive electrode active material layer 11B and the negative electrode active material layer 11C. Then, the gelled electrolyte layer 13 is formed by vaporizing and removing the organic solvent.
（電池の作製工程）
　複数の電極素子１０Ａは次のようにして作製される。まず、電解質層１３が形成された正極活物質層１１Ｂ（トランスファーシート付きの正極活物質層１１Ｂ）、セパレータ１２および電解質層１３が形成された負極活物質層１１Ｃ（トランスファーシート付きの負極活物質層１１Ｃ）を積層することにより、正極活物質層１１Ｂ、電解質層１３、セパレータ１２、電解質層１３、負極活物質層１１Ｃの順で積層された積層体を得る。続いて、得られた積層体を加温プレスし、積層体を構成する層を一体化したのち、積層体からトランスファーシートを剥離することで、電極素子１０Ａを得る。 (Battery manufacturing process)
The plurality of electrode elements 10A are manufactured as follows. First, the positive electrode active material layer 11B having the electrolyte layer 13 (the positive electrode active material layer 11B with the transfer sheet), the negative electrode active material layer 11C having the separator 12 and the electrolyte layer 13 (the negative electrode active material layer with the transfer sheet). 11C) is laminated to obtain a laminate in which the positive electrode active material layer 11B, the electrolyte layer 13, the separator 12, the electrolyte layer 13, and the negative electrode active material layer 11C are laminated in this order. Subsequently, the obtained laminated body is heated and pressed to integrate the layers constituting the laminated body, and then the transfer sheet is peeled from the laminated body to obtain the electrode element 10A.
　次に、集電体１１Ａの第１の主面を電極素子１０Ａの正極活物質層１１Ｂに接着すると共に、集電体１１Ａの第２の主面を別の電極素子１０Ａの負極活物質層１１Ｃに接着するようにして、集電体１１Ａと電極素子１０Ａを交互に積層することにより電池１０を得る。この際、電池１０の最上層、最下層にはそれぞれ集電体１１Ａが配置されるように積層順序を調整する。次に、最下層に配置された集電体１１Ａの表面に、正極タブ１４Ａを貼り付け、負極タブ１４Ｂを貼り付ける。 Next, the first main surface of the current collector 11A is bonded to the positive electrode active material layer 11B of the electrode element 10A, and the second main surface of the current collector 11A is bonded to the negative electrode active material layer 11C of another electrode element 10A. The battery 10 is obtained by alternately stacking the current collector 11A and the electrode element 10A so as to be adhered to the. At this time, the stacking order is adjusted so that the current collector 11A is arranged on each of the uppermost layer and the lowermost layer of the battery 10. Next, the positive electrode tab 14A and the negative electrode tab 14B are attached to the surface of the current collector 11A arranged in the lowermost layer.
［効果］
　本発明の第２の実施形態に係る電池１０は、低い抵抗率と局所的な抵抗率のばらつき抑制を同時に実現することができる樹脂基材（第１の実施形態に係る樹脂基材）を集電体１１Ａとして備えている。したがって、良好なサイクル特性を得ることができる。 [effect]
The battery 10 according to the second embodiment of the present invention includes a resin base material (a resin base material according to the first embodiment) that can simultaneously realize low resistivity and local suppression of variation in resistivity. It is provided as an electric body 11A. Therefore, good cycle characteristics can be obtained.
　また、集電体１１Ａとして樹脂基材を用いているため、外傷や破損等により電池１０内で短絡が生じた場合、集電体１１Ａが溶断して、短絡が解除される。したがって、電池１０の安全性を向上することができる。 Further, since the resin base material is used as the current collector 11A, when a short circuit occurs in the battery 10 due to external damage or damage, the current collector 11A is melted and the short circuit is released. Therefore, the safety of the battery 10 can be improved.
　以下、実施例により本発明を具体的に説明するが、本発明はこれらの実施例のみに限定されるものではない。 Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited to these examples.
　以下の実施例および比較例において、第１の導電性フィラー、第２の導電性フィラーそれぞれの平均フィラー径、平均フィラー長さは、上述の第１の実施形態にて説明した測定方法により求められたものである。 In the following examples and comparative examples, the average filler diameter and the average filler length of each of the first conductive filler and the second conductive filler are obtained by the measuring method described in the first embodiment. It is a thing.
［実施例１～３］
（正極活物質層の作製工程）
　正極活物質層は次のようにして作製された。まず、正極活物質（ＬｉＣｏＯ２）９６質量部と、正極バインダー（ポリフッ化ビニリデン）３質量部と、正極導電剤（カーボンブラック）１質量部とを混合することにより、正極合剤を得た。次に、正極合剤を有機溶剤（Ｎ－メチル－２－ピロリドン）に分散させることにより、正極合剤塗料を得た。次に、得られた正極合剤塗料をトランスファーシート（離型フィルム）上に塗布し有機溶剤を乾燥することにより、正極電極層を得た。次に、トランスファーシート上に形成された正極電極層にプレスおよび真空乾燥を施した。 [Examples 1 to 3]
(Production process of positive electrode active material layer)
The positive electrode active material layer was produced as follows. First, a positive electrode mixture was obtained by mixing 96 parts by mass of the positive electrode active material (LiCoO 2 ), 3 parts by mass of the positive electrode binder (polyvinylidene fluoride), and 1 part by mass of the positive electrode conductive material (carbon black). Next, the positive electrode mixture was dispersed in an organic solvent (N-methyl-2-pyrrolidone) to obtain a positive electrode mixture coating material. Next, the obtained positive electrode mixture coating material was applied onto a transfer sheet (release film) and the organic solvent was dried to obtain a positive electrode layer. Next, the positive electrode layer formed on the transfer sheet was pressed and vacuum dried.
（負極活物質層の作製工程）
　負極活物質層は次のようにして作製された。まず、負極活物質（人造黒鉛）９０質量部と、負極バインダー（ポリフッ化ビニリデン）１０質量部とを混合することにより、負極合剤を得た。次に、負極合剤を有機溶剤（Ｎ－メチル－２－ピロリドン）に分散させることにより、負極合剤塗料を得た。次に、得られた負極合剤塗料をトランスファーシート（離型フィルム）上に塗布し有機溶剤を乾燥することにより、負極活物質層を得た。次に、トランスファーシート上に形成された負極電極層にプレスおよび真空乾燥を施した。 (Production process of negative electrode active material layer)
The negative electrode active material layer was produced as follows. First, 90 parts by mass of the negative electrode active material (artificial graphite) and 10 parts by mass of the negative electrode binder (polyvinylidene fluoride) were mixed to obtain a negative electrode mixture. Next, the negative electrode mixture was dispersed in an organic solvent (N-methyl-2-pyrrolidone) to obtain a negative electrode mixture coating material. Next, the obtained negative electrode mixture coating material was applied onto a transfer sheet (release film) and the organic solvent was dried to obtain a negative electrode active material layer. Next, the negative electrode layer formed on the transfer sheet was pressed and vacuum dried.
（電解質層の形成工程）
　電解質層は次のようにして作製された。まず、炭酸エチレン（ＥＣ）と炭酸プロピレン（ＰＣ）とを、質量比でＥＣ：ＰＣ＝５０：５０となるようにして混合して混合溶媒を調製した。次に、この混合溶媒に、電解質塩（ＬｉＰＦ６）を１ｍｏｌ／ｋｇとなるように溶解させて電解液を調製した。次に、電解液３１質量部と、高分子化合物としてポリフッ化ビニリデン（ＰＶｄＦ）２質量部と、有機溶剤として炭酸ジメチル６７質量部とを混合することにより、ゾル状の前駆体溶液を得た。次に、得られたゾル状の前駆体溶液を正極、負極それぞれの表面に均一に塗布した。その後、乾燥させて炭酸ジメチルを除去することにより、正極、負極それぞれの表面にゲル状の電解質層を形成した。 (Process of forming electrolyte layer)
The electrolyte layer was prepared as follows. First, ethylene carbonate (EC) and propylene carbonate (PC) were mixed at a mass ratio of EC:PC=50:50 to prepare a mixed solvent. Next, an electrolyte salt (LiPF 6 ) was dissolved in this mixed solvent so as to be 1 mol/kg to prepare an electrolytic solution. Next, 31 parts by mass of the electrolytic solution, 2 parts by mass of polyvinylidene fluoride (PVdF) as a polymer compound, and 67 parts by mass of dimethyl carbonate as an organic solvent were mixed to obtain a sol-like precursor solution. Next, the obtained sol-form precursor solution was uniformly applied to the surface of each of the positive electrode and the negative electrode. Then, by drying to remove dimethyl carbonate, a gel electrolyte layer was formed on each surface of the positive electrode and the negative electrode.
（樹脂集電体の作製工程）
　２つの樹脂集電体は次のようにして作製された。まず、表１に示すように、樹脂ペレット（ポリプロピレン（ＰＰ）のペレット）７５～８５質量％と、第１の導電性フィラー（平均フィラー径７μｍ、平均フィラー長さ６０００μｍのカーボンファイバー）１０質量％と、第２の導電性フィラー（平均フィラー径０．１５μｍ、平均フィラー長さ１０μｍのカーボンナノファイバー（ＶＧＣＦ））５～１５質量％とを粗く混合したのち、混合物を２軸エクストルーダーに投入し、樹脂ペレットの溶融温度以上に加熱しつつ混練を行った。これにより、樹脂中に導電性フィラーがまんべんなく分散した混合物が得られた。次に、混合物を再び溶融温度以上に加熱溶融したのち、Ｔダイ押出成形機を用いて成膜し、フィルム状の樹脂集電体を得た。 (Resin current collector manufacturing process)
Two resin current collectors were produced as follows. First, as shown in Table 1, 75 to 85% by mass of resin pellets (polypropylene (PP) pellets) and 10% by mass of the first conductive filler (carbon fiber having an average filler diameter of 7 μm and an average filler length of 6000 μm). After roughly mixing 5 to 15% by mass of the second conductive filler (carbon nanofiber (VGCF) having an average filler diameter of 0.15 μm and an average filler length of 10 μm), the mixture is put into a biaxial extruder. The kneading was performed while heating the resin pellets at a temperature higher than the melting temperature. As a result, a mixture in which the conductive filler was evenly dispersed in the resin was obtained. Next, the mixture was again heated and melted to a melting temperature or higher, and then a film was formed using a T-die extrusion molding machine to obtain a film-shaped resin current collector.
（電池の作製工程）
　電池は次のようにして作製された。まず、電解質層が形成された正極活物質層（トランスファーシート付きの正極活物質層）、セパレータおよび電解質層が形成された負極正極活物質層（トランスファーシート付きの負極活物質層）を積層することにより、正極活物質層、電解質層、セパレータ、電解質層、負極活物質層の順で積層された積層体を得た。続いて、得られた積層体を加温プレス（１０５℃、３ｓｅｃ）し、積層体を構成する層を一体化したのち、積層体からトランスファーシートを剥離することで、電極素子を得た。次に、電極素子の正極側の主面に一方の樹脂集電体の第１の主面を接着すると共に、電極素子の負極側の主面に他方の樹脂集電体の第２の主面を接着した。次に、一方の樹脂集電体の第２の主面に正極タブ（金属板）を貼り付け、他方の樹脂集電体の第１の主面に負極タブ（金属板）を貼り付けた。
これにより、目的とする電池が得られた。 (Battery manufacturing process)
The battery was manufactured as follows. First, stacking a positive electrode active material layer (a positive electrode active material layer with a transfer sheet) on which an electrolyte layer is formed and a negative electrode positive electrode active material layer (a negative electrode active material layer with a transfer sheet) on which a separator and an electrolyte layer are formed. Thus, a laminated body was obtained in which the positive electrode active material layer, the electrolyte layer, the separator, the electrolyte layer, and the negative electrode active material layer were laminated in this order. Subsequently, the obtained laminated body was heated and pressed (105° C., 3 sec) to integrate the layers constituting the laminated body, and then the transfer sheet was peeled from the laminated body to obtain an electrode element. Next, the first main surface of one resin current collector is bonded to the positive electrode side main surface of the electrode element, and the other resin current collector second main surface is attached to the negative electrode side main surface of the electrode element. Glued. Next, the positive electrode tab (metal plate) was attached to the second main surface of one resin current collector, and the negative electrode tab (metal plate) was attached to the first main surface of the other resin current collector.
As a result, the intended battery was obtained.
［実施例４、５］
　表１に示すように、第２の導電性フィラーとして平均フィラー径０．０５μｍの球状のカーボンブラックを用いたこと以外は実施例２、３と同様にして電池を得た。 [Examples 4 and 5]
As shown in Table 1, batteries were obtained in the same manner as in Examples 2 and 3 except that spherical carbon black having an average filler diameter of 0.05 μm was used as the second conductive filler.
［実施例６～８］
　表１に示すように、第１の導電性フィラーとして平均フィラー径５μｍ、平均フィラー長さ６０００μｍのカーボンファイバーを用いたこと以外は実施例１～３と同様にして電池を得た。 [Examples 6 to 8]
As shown in Table 1, batteries were obtained in the same manner as in Examples 1 to 3 except that carbon fibers having an average filler diameter of 5 μm and an average filler length of 6000 μm were used as the first conductive filler.
［実施例９］
　表１に示すように、樹脂ペレット（ポリプロピレン（ＰＰ）のペレット）７０質量％と、第１の導電性フィラー（平均フィラー径７μｍ、平均フィラー長さ６０００μｍのカーボンファイバー）１５質量％と、第２の導電性フィラー（平均フィラー径０．１５μｍ、平均フィラー長さ１０μｍのカーボンナノファイバー（ＶＧＣＦ））１５質量％とを混合して混合物を得たこと以外は実施例３と同様にして電池を得た。 [Example 9]
As shown in Table 1, 70 mass% of resin pellets (polypropylene (PP) pellets), 15 mass% of the first conductive filler (carbon fiber having an average filler diameter of 7 μm and an average filler length of 6000 μm), and a second A battery was obtained in the same manner as in Example 3, except that 15% by mass of the conductive filler (carbon nanofiber (VGCF) having an average filler diameter of 0.15 μm and an average filler length of 10 μm) was mixed to obtain a mixture. It was
［比較例１］
　表１に示すように、樹脂ペレット（ポリプロピレン（ＰＰ）のペレット）９０質量％と、第１の導電性フィラー（平均フィラー径７μｍ、平均フィラー長さ６０００μｍのカーボンファイバー）１０質量％とを混合して混合物を得たこと以外は実施例１と同様にして電池を得た。 [Comparative Example 1]
As shown in Table 1, 90% by mass of resin pellets (polypropylene (PP) pellets) and 10% by mass of the first conductive filler (carbon fiber having an average filler diameter of 7 μm and an average filler length of 6000 μm) were mixed. A battery was obtained in the same manner as in Example 1 except that the mixture was obtained as a result.
［比較例２］
　表１に示すように、樹脂ペレット（ポリプロピレン（ＰＰ）のペレット）９０質量％と、第１の導電性フィラー（平均フィラー径５μｍ、平均フィラー長さ６０００μｍのカーボンファイバー）１０質量％とを混合して混合物を得たこと以外は実施例１と同様にして電池を得た。 [Comparative example 2]
As shown in Table 1, 90% by mass of resin pellets (polypropylene (PP) pellets) and 10% by mass of a first conductive filler (carbon fiber having an average filler diameter of 5 μm and an average filler length of 6000 μm) were mixed. A battery was obtained in the same manner as in Example 1 except that the mixture was obtained as a result.
［比較例３］
　表１に示すように、第１の導電性フィラーとして平均フィラー径３μｍ、平均フィラー長さ６０００μｍのカーボンファイバーを用いたこと以外は実施例３と同様にして電池を得た。 [Comparative Example 3]
As shown in Table 1, a battery was obtained in the same manner as in Example 3 except that carbon fibers having an average filler diameter of 3 μm and an average filler length of 6000 μm were used as the first conductive filler.
［比較例４］
　表１に示すように、樹脂ペレット（ポリプロピレン（ＰＰ）のペレット）８０質量％と、第１の導電性フィラー（平均フィラー径７μｍ、平均フィラー長さ６０００μｍのカーボンファイバー）５質量％と、第２の導電性フィラー（平均フィラー径０．１５μｍ、平均フィラー長さ１０μｍのカーボンナノファイバー（ＶＧＣＦ））１５質量％とを混合して混合物を得たこと以外は実施例３と同様にして電池を得た。 [Comparative Example 4]
As shown in Table 1, 80% by mass of resin pellets (polypropylene (PP) pellets), 5% by mass of the first conductive filler (carbon fiber having an average filler diameter of 7 μm and an average filler length of 6000 μm), and a second A battery was obtained in the same manner as in Example 3, except that 15% by mass of the conductive filler (carbon nanofiber (VGCF) having an average filler diameter of 0.15 μm and an average filler length of 10 μm) was mixed to obtain a mixture. It was
［比較例５］
　表１に示すように、樹脂ペレット（ポリプロピレン（ＰＰ）のペレット）８５質量％と、第２の導電性フィラー（平均フィラー径０．１５μｍ、平均フィラー長さ１０μｍのカーボンナノファイバー（ＶＧＣＦ））１５質量％とを混合して混合物を得たこと以外は実施例１と同様にして電池を得た。 [Comparative Example 5]
As shown in Table 1, 85% by mass of resin pellets (polypropylene (PP) pellets) and a second conductive filler (carbon nanofiber (VGCF) having an average filler diameter of 0.15 μm and an average filler length of 10 μm) 15 A battery was obtained in the same manner as in Example 1 except that the mixture was mixed with the content of 3% by mass.
（膜厚方向の抵抗率）
　上述の電池に用いた樹脂集電体の膜厚方向の抵抗率をJIS C 2139に準拠して測定し、抵抗率の平均値、最大値、最小値および最大値／最小値を求めた。 (Resistivity in the film thickness direction)
The resistivity in the film thickness direction of the resin current collector used for the above-mentioned battery was measured according to JIS C 2139, and the average value, maximum value, minimum value and maximum value/minimum value of the resistivity were obtained.
（３００サイクル後のサイクル維持率）
　まず、電池の状態を安定化させるために、常温環境中（温度２３℃）において電池を充放電（１サイクル）させた。なお、充電時には、０．１Ｃの電流で電圧が４．４５Ｖに到達するまで定電流充電したのち、４．４５Ｖの電圧で電流が０．０２Ｃに到達するまで定電圧充電した。放電時には、０．１Ｃの電流で電圧が３．０Ｖに到達するまで放電した。なお、“０．１Ｃ”とは、電池容量（理論容量）を１０時間で充電または放電しきる電流値である。また、“０．０２Ｃ”とは、電池容量（理論容量）を５０時間で充電または放電しきる電流値である。 (Cycle maintenance rate after 300 cycles)
First, in order to stabilize the state of the battery, the battery was charged and discharged (1 cycle) in a room temperature environment (temperature 23° C.). During charging, constant current charging was performed with a current of 0.1 C until the voltage reached 4.45 V, and then constant voltage charging was performed with a current of 4.45 V until the current reached 0.02 C. At the time of discharging, it was discharged with a current of 0.1 C until the voltage reached 3.0 V. In addition, "0.1 C" is a current value at which the battery capacity (theoretical capacity) is fully charged or discharged in 10 hours. Further, "0.02C" is a current value at which the battery capacity (theoretical capacity) is fully charged or discharged in 50 hours.
　続いて、同環境中において電池を充放電（１サイクル）させることにより、２サイクル目の放電容量を測定した。次に、同環境中において電池を繰り返して充放電（３００サイクル）させることにより、３０１サイクル目の放電容量を測定した。なお、充電時には、１Ｃの電流で電圧が４．４５Ｖに到達するまで電池を定電流充電させたのち、４．４５Ｖの電圧で電流が０．０２Ｃに到達するまで電池を定電圧充電させた。放電時には、１Ｃの電流で電圧が３．０Ｖに到達するまで電池を定電流放電させた。なお、“１Ｃ”とは、電池容量（理論容量）を１時間で充填または放電しきる電流値である。最後に、下記の式により、３００サイクル後の容量維持率を算出した。
　３００サイクル後の容量維持率（％）＝（３０１サイクル目の放電容量／２サイクル目の放電容量）×１００ Then, the discharge capacity of the second cycle was measured by charging and discharging the battery (1 cycle) in the same environment. Next, in the same environment, the battery was repeatedly charged and discharged (300 cycles) to measure the discharge capacity at the 301st cycle. At the time of charging, the battery was charged at a constant current with a current of 1 C until the voltage reached 4.45 V, and then the battery was charged with a constant voltage at a voltage of 4.45 V until the current reached 0.02 C. During discharge, the battery was discharged at a constant current with a current of 1C until the voltage reached 3.0V. In addition, "1C" is a current value at which the battery capacity (theoretical capacity) is completely charged or discharged in 1 hour. Finally, the capacity retention rate after 300 cycles was calculated by the following formula.
Capacity retention rate (%) after 300 cycles=(Discharge capacity at 301th cycle/Discharge capacity at 2nd cycle)×100
　表１は、実施例１～９、比較例１～５の電池に用いた樹脂集電体の構成および評価結果を示す。
Figure JPOXMLDOC01-appb-T000001
 Table 1 shows the configurations and evaluation results of the resin current collectors used in the batteries of Examples 1 to 9 and Comparative Examples 1 to 5.
Figure JPOXMLDOC01-appb-T000001
　表１から以下のことがわかる。
　第１の導電性フィラーとして平均フィラー径が５μｍ以上のカーボンファイバーを用い、第２の導電性フィラーとしてカーボンナノファイバーを用いた実施例１～３、６～９の樹脂基板では、低い抵抗率と局所的な抵抗率のばらつき抑制とを同時に実現することができる。但し、第１の導電性フィラーの混合量が１５質量％である実施例９の樹脂基材では、第１の導電性フィラーの混合量が過多であるため、樹脂基材の強度低下が見られた。
　第１の導電性フィラーとして平均フィラー径が５μｍ以上のカーボンファイバーを用い、第２の導電性フィラーとして球状のカーボンナノ粒子を用いた実施例４、５の樹脂基板でも、低い抵抗率と局所的な抵抗率のばらつき抑制とを同時に実現することができる。 The following can be seen from Table 1.
The resin substrates of Examples 1 to 3 and 6 to 9 in which carbon fibers having an average filler diameter of 5 μm or more are used as the first conductive filler and carbon nanofibers are used as the second conductive filler have low resistivity. It is possible to simultaneously realize local suppression of variations in resistivity. However, in the resin base material of Example 9 in which the mixing amount of the first conductive filler was 15% by mass, the strength decrease of the resin base material was observed because the mixing amount of the first conductive filler was excessive. It was
Also in the resin substrates of Examples 4 and 5 in which carbon fibers having an average filler diameter of 5 μm or more were used as the first conductive filler and spherical carbon nanoparticles were used as the second conductive filler, low resistivity and local It is possible to simultaneously realize a large variation in resistivity.
　第１の導電性フィラーを含むが、第２の導電性フィラーを含まない比較例１、２の樹脂基板では、低い抵抗率（低い抵抗率の平均値）を得ることができるが、局所的な抵抗率のばらつきが大きい。
　第１の導電性フィラーとして平均フィラー径が５μｍ未満のカーボンファイバーを用い、第２の導電性フィラーとしてカーボンナノファイバーを用いた比較例３の樹脂基材では、局所的な抵抗率のばらつきを抑制することができるが、抵抗率が高くなる。
　第１の導電性フィラーの混合量が５質量％であり、第２の導電性フィラーの混合量が１５質量％である比較例４の樹脂基材では、局所的な抵抗率のばらつきを抑制することができるが、抵抗率が高くなる。
　第２の導電性フィラーを含むが、第１の導電性フィラーを含まない比較例５の樹脂基板では、局所的な抵抗率のばらつきを抑制できるが、抵抗率が高くなる。 In the resin substrates of Comparative Examples 1 and 2 which contain the first conductive filler but do not contain the second conductive filler, low resistivity (average value of low resistivity) can be obtained, but local There is a large variation in resistivity.
In the resin base material of Comparative Example 3 in which carbon fibers having an average filler diameter of less than 5 μm are used as the first conductive filler and carbon nanofibers are used as the second conductive filler, local variation in resistivity is suppressed. Can be done, but the resistivity is high.
In the resin base material of Comparative Example 4 in which the mixing amount of the first conductive filler is 5% by mass and the mixing amount of the second conductive filler is 15% by mass, local variation in resistivity is suppressed. However, the resistivity is high.
In the resin substrate of Comparative Example 5 which contains the second conductive filler but does not contain the first conductive filler, it is possible to suppress local variations in the resistivity, but the resistivity is increased.
　低い抵抗率と局所的な抵抗率のばらつき抑制とを同時に実現することができた樹脂基材を集電体として用いた実施例１～８の電池では、低い抵抗率と局所的な抵抗率のばらつき抑制とを同時に実現することができなかった樹脂基材を集電体として用いた比較例１～５の電池に比べて、良好なサイクル特性を得ることができる。
　第１の導電性フィラーの混合量が１５質量％である樹脂基材を集電体として用いた実施例９の電池では、実施例１～８の電池に比べて、サイクル特性が低下する。 In the batteries of Examples 1 to 8 in which the resin base material capable of simultaneously realizing the low resistivity and the local suppression of the variation in the resistivity was used, the low resistivity and the local resistivity were Good cycle characteristics can be obtained as compared with the batteries of Comparative Examples 1 to 5 in which the resin base material, which was not able to realize the variation suppression at the same time, was used as the current collector.
The battery of Example 9 using the resin base material in which the mixing amount of the first conductive filler was 15% by mass as the current collector had lower cycle characteristics than the batteries of Examples 1 to 8.
　以上、本発明の実施形態およびその変形例、ならびに実施例について具体的に説明したが、本発明は、上述の実施形態およびその変形例、ならびに実施例に限定されるものではなく、本発明の技術的思想に基づく各種の変形が可能である。 Although the embodiment of the present invention, the modification thereof, and the example have been specifically described above, the present invention is not limited to the above-described embodiment, the modification, and the example of the present invention. Various modifications based on the technical idea are possible.
　例えば、上述の実施形態およびその変形例、ならびに実施例において挙げた構成、方法、工程、形状、材料および数値等はあくまでも例に過ぎず、必要に応じてこれと異なる構成、方法、工程、形状、材料および数値等を用いてもよい。 For example, the configurations, methods, steps, shapes, materials, numerical values, and the like described in the above-described embodiment and its modified examples, and the examples are merely examples, and configurations, methods, steps, and shapes different from these as necessary. , Materials and numerical values may be used.
　また、上述の実施形態およびその変形例、ならびに実施例の構成、方法、工程、形状、材料および数値等は、本発明の主旨を逸脱しない限り、互いに組み合わせることが可能である。 Also, the configurations and methods, steps, shapes, materials, numerical values, and the like of the above-described embodiments and modifications thereof, and examples can be combined with each other without departing from the gist of the present invention.
　また、上述の実施形態およびその変形例で段階的に記載された数値範囲において、ある段階の数値範囲の上限値または下限値は、他の段階の数値範囲の上限値または下限値に置き換えてもよい。上述の実施形態およびその変形例に例示した材料は、特に断らない限り、１種を単独でまたは２種以上を組み合わせて用いることができる。 Further, in the numerical ranges described stepwise in the above-described embodiment and its modifications, the upper limit or the lower limit of the numerical range of a certain stage may be replaced with the upper limit or the lower limit of the numerical range of another stage. Good. The materials exemplified in the above-described embodiments and their modifications can be used alone or in combination of two or more unless otherwise specified.
　また、上述の実施形態では、電解質として電解液と高分子化合物とを含む電解質層を用いる場合について説明したが、電解質として電解液または固体電解質等を用いるようにしてもよい。電解液としては高粘度のものを用い、電池の作製工程において、電極またはセパレータ上に電解液を塗布し積層体を作製するようにしてもよい。また、電解液としては一般的な粘度のものを用い、電池を外装材に収容したのち、電解液を外装材内に注入するようにしてもよい。 Further, in the above-described embodiment, the case where the electrolyte layer containing the electrolyte solution and the polymer compound is used as the electrolyte has been described, but the electrolyte solution or the solid electrolyte may be used as the electrolyte. A high-viscosity electrolytic solution may be used, and the laminated body may be manufactured by applying the electrolytic solution onto the electrode or the separator in the battery manufacturing process. Alternatively, an electrolytic solution having a general viscosity may be used, and the electrolytic solution may be injected into the exterior material after the battery is housed in the exterior material.
　１０　　バイポーラ型電池
　１０Ａ　　電極素子
　１１　　バイポーラ型電極
　１１Ａ　　集電体
　１１Ｂ　　正極活物質層
　１１Ｃ　　負極活物質層
　１２　　セパレータ
　１３　　電解質層
　１４Ａ　　正極タブ
　１４Ｂ　　負極タブ 10 Bipolar Battery 10A Electrode Element 11 Bipolar Electrode 11A Current Collector 11B Positive Electrode Active Material Layer 11C Negative Electrode Active Material Layer 12 Separator 13 Electrolyte Layer 14A Positive Electrode Tab 14B Negative Tab

Claims (5)

  1. 　電池の集電体に用いられる樹脂基材であって、
    　繊維状を有する第１の導電性フィラーと、
    　第２の導電性フィラーと
    　を含み、
    　前記第２の導電性フィラーの平均フィラー径が、前記第１の導電性フィラーの平均フィラー径よりも小さい樹脂基材。     A resin base material used for a current collector of a battery,
    A first conductive filler having a fibrous shape,
    And a second conductive filler,
    A resin base material in which the average filler diameter of the second conductive filler is smaller than the average filler diameter of the first conductive filler.
  2. 　前記第１の導電性フィラーが、カーボンファイバーであり、
    　前記第２の導電性フィラーが、炭素系フィラーおよび金属系フィラーのうちの少なくとも１種である請求項１に記載の樹脂基材。     The first conductive filler is carbon fiber,
    The resin base material according to claim 1, wherein the second conductive filler is at least one of a carbon-based filler and a metal-based filler.
  3. 　前記第１の導電性フィラーが、カーボンファイバーであり、
    　前記第２の導電性フィラーが、カーボンナノファイバーである請求項１に記載の樹脂基材。     The first conductive filler is carbon fiber,
    The resin base material according to claim 1, wherein the second conductive filler is carbon nanofiber.
  4. 　前記第１の導電性フィラーの平均フィラー径が、５μｍ以上１０μｍ以下であり、
    　前記第２の導電性フィラーの平均フィラー径が、１ｎｍ以上２００ｎｍ以下である請求項１から３のいずれかに記載の樹脂基材。     The average filler diameter of the first conductive filler is 5 μm or more and 10 μm or less,
    The resin base material according to any one of claims 1 to 3, wherein an average filler diameter of the second conductive filler is 1 nm or more and 200 nm or less.
  5. 　請求項１から４のいずれかに記載された前記樹脂基材を集電体として備えるバイポーラ型電池。 A bipolar battery including the resin base material according to any one of claims 1 to 4 as a current collector.
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Citations (6)

* Cited by examiner, † Cited by third party
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JP2010092606A (en) * 2008-10-03 2010-04-22 Nissan Motor Co Ltd Current collector for bipolar secondary battery
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JP2012518891A (en) * 2009-02-25 2012-08-16 アプライド マテリアルズ インコーポレイテッド Thin-film electrochemical energy storage device having a three-dimensional anode structure
JP2015015074A (en) * 2013-07-03 2015-01-22 電気化学工業株式会社 Compound current collector, electrode employing the same, and secondary battery
WO2017145874A1 (en) * 2016-02-24 2017-08-31 日産自動車株式会社 Electrode for lithium ion secondary battery and production method therefor
KR101883674B1 (en) * 2017-10-31 2018-07-31 울산과학기술원 Stretchable Current Collector, Manufacturing Method of the Same, Stretchable Electrode including the Same and Stretchable Battery including the Same

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010092606A (en) * 2008-10-03 2010-04-22 Nissan Motor Co Ltd Current collector for bipolar secondary battery
JP2012518891A (en) * 2009-02-25 2012-08-16 アプライド マテリアルズ インコーポレイテッド Thin-film electrochemical energy storage device having a three-dimensional anode structure
JP2012059413A (en) * 2010-09-06 2012-03-22 Konica Minolta Holdings Inc Fuel cell
JP2015015074A (en) * 2013-07-03 2015-01-22 電気化学工業株式会社 Compound current collector, electrode employing the same, and secondary battery
WO2017145874A1 (en) * 2016-02-24 2017-08-31 日産自動車株式会社 Electrode for lithium ion secondary battery and production method therefor
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