WO2012124582A1 - Method for producing positive electrode for nonaqueous electrolyte secondary batteries, positive electrode for nonaqueous electrolyte secondary batteries, and nonaqueous electrolyte secondary battery - Google Patents

Method for producing positive electrode for nonaqueous electrolyte secondary batteries, positive electrode for nonaqueous electrolyte secondary batteries, and nonaqueous electrolyte secondary battery Download PDF

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WO2012124582A1
WO2012124582A1 PCT/JP2012/055903 JP2012055903W WO2012124582A1 WO 2012124582 A1 WO2012124582 A1 WO 2012124582A1 JP 2012055903 W JP2012055903 W JP 2012055903W WO 2012124582 A1 WO2012124582 A1 WO 2012124582A1
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positive electrode
electrolyte secondary
nonaqueous electrolyte
active material
secondary battery
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PCT/JP2012/055903
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French (fr)
Japanese (ja)
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聖 高務
貴信 千賀
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三洋電機株式会社
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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
    • H01M4/04—Processes of manufacture in general
    • H01M4/0402—Methods of deposition of the material
    • H01M4/0404—Methods of deposition of the material by coating on electrode collectors
    • 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
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H01M4/139—Processes of manufacture
    • 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
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • H01M4/621—Binders
    • H01M4/622—Binders being polymers
    • H01M4/623—Binders being polymers fluorinated polymers
    • 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 method for manufacturing a positive electrode for a non-aqueous electrolyte secondary battery, a positive electrode for a non-aqueous electrolyte secondary battery manufactured by the manufacturing method, and a non-aqueous electrolyte secondary battery including the same.
  • Patent Documents 1 and 2 it is proposed to use two types of positive electrode active materials having different average particle diameters.
  • Patent Document 3 describes that a mixed solvent of a poor solvent for the binder and a good solvent having a boiling point lower than that of the poor solvent is used for forming the positive electrode active material layer containing the binder.
  • PVDF polyvinylidene fluoride
  • dimethylimidazolidinone is used as a good solvent
  • cyclohexanone is used as a poor solvent.
  • Patent Document 3 when the binder is polyvinylidene fluoride (PVDF), dimethylimidazolidinone is used as a good solvent, and cyclohexanone is used as a poor solvent, the flexibility of the positive electrode is sufficient. It cannot be improved.
  • PVDF polyvinylidene fluoride
  • dimethylimidazolidinone is used as a good solvent
  • cyclohexanone is used as a poor solvent
  • Patent Documents 1 and 2 can be applied only when two types of positive electrode active materials having different average particle diameters are used. For this reason, a new method capable of improving the flexibility of the positive electrode is desired regardless of the type of the positive electrode active material to be used.
  • the present invention has been made in view of such points, and an object thereof is to provide a method capable of producing a positive electrode for a non-aqueous electrolyte secondary battery excellent in flexibility and liquid absorption.
  • the method for producing a positive electrode for a nonaqueous electrolyte secondary battery relates to a method for producing a positive electrode for a nonaqueous electrolyte secondary battery comprising a positive electrode current collector and a positive electrode active material layer.
  • the positive electrode active material layer is formed on the positive electrode current collector.
  • the positive electrode active material layer includes a positive electrode active material and a binder.
  • the binder is made of at least one of polyvinylidene fluoride and a fluororesin having a polyvinylidene fluoride unit.
  • a slurry containing a positive electrode active material, a binder, N-methyl-2-pyrrolidone, and a polyol having a boiling point higher than that of N-methyl-2-pyrrolidone is applied on the positive electrode current collector.
  • the forming step includes a positive electrode active material, a binder, 1000 parts by weight to 3000 parts by weight of N-methyl-2-pyrrolidone with respect to 100 parts by weight of the binder, and 100 parts by weight of the binder. And a step of preparing a slurry containing 5 to 50 parts by mass of a polyol.
  • the positive electrode for a nonaqueous electrolyte secondary battery according to the present invention is manufactured by the method for manufacturing a positive electrode for a nonaqueous electrolyte secondary battery according to the present invention.
  • the non-aqueous electrolyte secondary battery according to the present invention includes the positive electrode for a non-aqueous electrolyte secondary battery according to the present invention, a negative electrode, and a non-aqueous electrolyte.
  • FIG. 1 is a schematic cross-sectional view of a nonaqueous electrolyte secondary battery according to an embodiment of the present invention.
  • FIG. 2 is a schematic cross-sectional view of a positive electrode in one embodiment of the present invention.
  • FIG. 3 is a schematic cross-sectional view for explaining a manufacturing process of a positive electrode in one embodiment of the present invention.
  • FIG. 4 is a schematic cross-sectional view for explaining the flexibility evaluation process.
  • FIG. 5 is a schematic cross-sectional view for explaining the flexibility evaluation process.
  • FIG. 6 is an electron micrograph of the coating film a.
  • FIG. 7 is an electron micrograph of the coating film b.
  • FIG. 8 is an electron micrograph of the coating film c.
  • FIG. 9 is an electron micrograph of the coating film d.
  • FIG. 10 is an electron micrograph of the coating film e.
  • FIG. 11 is a graph showing the discharge curves of the nonaqueous electrolyte secondary battery A according to Example 8 and the
  • FIG. 1 is a schematic cross-sectional view of a nonaqueous electrolyte secondary battery according to this embodiment. First, the configuration of the nonaqueous electrolyte secondary battery 1 according to the present embodiment will be described with reference to FIG.
  • the nonaqueous electrolyte secondary battery 1 includes a battery container 17.
  • the battery container 17 has a flat shape.
  • the shape of the battery container is not limited to a flat shape.
  • the battery shape may be, for example, a cylindrical shape in which both ends are closed.
  • an electrode body 10 impregnated with a nonaqueous electrolyte is accommodated.
  • the non-aqueous electrolyte for example, a known non-aqueous electrolyte can be used.
  • the nonaqueous electrolyte solvent include cyclic carbonates, chain carbonates, and mixed solvents of cyclic carbonates and chain carbonates. Of these, a chain carbonate and a mixed solvent of a cyclic carbonate and a chain carbonate are preferably used.
  • the mixing ratio of cyclic carbonate and chain carbonate should be in the range of 1: 9 to 5: 5 by volume ratio. Is preferred.
  • cyclic carbonate examples include ethylene carbonate, fluoroethylene carbonate, propylene carbonate, butylene carbonate, vinylene carbonate, vinyl ethylene carbonate, and the like.
  • chain carbonates examples include dimethyl carbonate, methyl ethyl carbonate, and diethyl carbonate.
  • nonaqueous electrolyte solute examples include, for example, LiPF 6 , LiBF 4 , LiCF 3 SO 3 , LiN (SO 2 CF 3 ) 2 , LiN (SO 2 C 2 F 5 ) 2 , LiC (SO 2 CF 3). ) 3 , LiC (SO 2 C 2 F 5 ) 3 , LiClO 4 and the like.
  • nonaqueous electrolyte a gel polymer electrolyte obtained by impregnating a polymer such as polyethylene oxide or polyacrylonitrile with an electrolytic solution can be used in addition to the above-described solute dissolved in the solvent.
  • the electrode body 10 is formed by winding a negative electrode 11, a positive electrode 12, and a separator 13 disposed between the negative electrode 11 and the positive electrode 12.
  • the separator 13 can be constituted by a known separator, for example.
  • the separator 13 can be comprised by the porous film made from resin, for example.
  • the resin porous membrane include a polyethylene microporous membrane and a polypropylene microporous membrane.
  • the negative electrode 11 has a negative electrode current collector and a negative electrode active material layer formed on at least one surface of the negative electrode current collector.
  • the negative electrode current collector can be composed of, for example, a foil made of a metal such as Cu or an alloy containing a metal such as Cu.
  • the negative electrode active material layer may include a binder, a conductive agent, and the like in addition to the negative electrode active material. Examples of the negative electrode active material include carbon materials such as graphite and coke, metal oxides such as tin oxide, and materials that are alloyed with lithium.
  • the negative electrode active material alloyed with lithium for example, one or more metals selected from the group consisting of silicon, germanium, tin and aluminum, or one or more types selected from the group consisting of silicon, germanium, tin and aluminum
  • the thing which consists of an alloy containing a metal is mentioned.
  • FIG. 2 is a schematic cross-sectional view of the positive electrode 12 in the present embodiment.
  • the positive electrode 12 includes a positive electrode current collector 12a and a positive electrode active material layer 12b.
  • the positive electrode current collector 12a can be formed of, for example, a metal such as Al or an alloy containing a metal such as Al.
  • the positive electrode active material layer 12b is formed on at least one surface of the positive electrode current collector 12a. Specifically, in the present embodiment, the positive electrode active material layer 12b is formed on both surfaces of the positive electrode current collector 12a.
  • the positive electrode active material layer 12b includes a positive electrode active material and a binder. In the present embodiment, the positive electrode active material layer 12b further includes a conductive agent.
  • the positive electrode active material is preferably a material that can occlude and release lithium and has a high potential.
  • the positive electrode active material include lithium transition metal composite oxides having a layered structure, a spinel structure, or an olivine structure. Among these, lithium transition metal composite oxides having a layered structure with high energy density are preferably used.
  • the lithium transition metal composite oxide having a layered structure include lithium nickel composite oxide, lithium nickel cobalt composite oxide, lithium nickel cobalt aluminum composite oxide, lithium nickel cobalt manganese composite oxide, and lithium cobalt composite oxide. It is done. Among these, lithium cobaltate particles in which aluminum or magnesium is solid-solved and zirconium is fixed to the particle surface are more preferably used because of excellent crystal structure stability.
  • lithium transition metal composite oxide in which the proportion of nickel in the transition metal contained in the positive electrode active material is 50 mol% or more is preferably used.
  • a lithium nickel cobalt aluminum composite oxide is more preferably used.
  • the binder of the positive electrode active material layer 12b is made of at least one of polyvinylidene fluoride (PVDF) and a fluororesin having a PVDF unit.
  • PVDF polyvinylidene fluoride
  • fluororesin having a polyvinylidene fluoride unit include, for example, modified polyvinylidene fluoride.
  • modified polyvinylidene fluoride include those produced by copolymerizing a vinylidene fluoride monomer and another monomer.
  • vinylidene fluoride-vinyl fluoride copolymer vinylidene fluoride-trifluoroethylene copolymer, vinylidene fluoride-tetrafluoroethylene copolymer, vinylidene fluoride-hexafluoropropylene copolymer
  • vinylidene fluoride-fluoroalkyl vinyl ether copolymer vinylidene fluoride-maleic anhydride copolymer, vinylidene fluoride-maleic acid monomethyl ester copolymer, and the like.
  • the content of the binder is preferably in the range of 2.0 parts by mass to 5.0 parts by mass with respect to 100 parts by mass of the positive electrode active material.
  • Examples of the conductive agent for the positive electrode active material layer 12b include acetylene black, ketjen black, furnace black, and carbon nanotube.
  • the content of the conductive agent is preferably in the range of 0.1 parts by mass to 5.0 parts by mass with respect to 100 parts by mass of the positive electrode active material.
  • a slurry preparation step for preparing a slurry is performed.
  • the slurry is prepared by appropriately mixing the positive electrode active material, the binder, the conductive agent, N-methyl-2-pyrrolidone (NMP), and a polyol having a boiling point higher than that of NMP. Make it.
  • NMP N-methyl-2-pyrrolidone
  • polyol having a boiling point higher than that of NMP examples include glycerol and trimethylolpropane.
  • the boiling point of the polyol is preferably 40 ° C. or more higher than the boiling point of NMP, more preferably 80 ° C. or more.
  • the boiling point of NMP is 204 ° C.
  • the boiling point of glycerol is 290 ° C., which is 86 ° C. higher than that of NMP.
  • the boiling point of trimethylolpropane is 295 ° C., which is 91 ° C. higher than that of NMP.
  • a slurry application step of applying the prepared slurry onto at least one surface of the positive electrode current collector 12a is performed.
  • the positive electrode mixture layer 12c is formed on at least one surface of the positive electrode current collector 12a.
  • the positive electrode mixture layer 12c is formed on both surfaces of the positive electrode current collector 12a by applying the slurry on both surfaces of the positive electrode current collector 12a.
  • a drying step for forming the positive electrode active material layer 12b shown in FIG. 2 is performed by drying the positive electrode mixture layer 12c. By performing this drying step, the slurry preparation step, and the slurry application step, a forming step for forming the positive electrode active material layer 12b is performed.
  • the drying method of the positive electrode mixture layer 12c is not particularly limited.
  • the positive electrode mixture layer 12c may be dried by heating, or the positive electrode mixture layer 12c may be dried by placing it in a reduced-pressure atmosphere. Moreover, you may dry by heating the positive mix layer 12c, decompressing.
  • NMP and polyol may remain in the positive electrode active material layer 12b as long as the characteristics of the positive electrode active material layer 12b are not significantly deteriorated. Specifically, each content rate of the polyol and NMP in the positive electrode active material layer 12b should just be 100 ppm or less.
  • polyol has a higher boiling point than NMP. Therefore, at least at the initial stage of the drying step, the ratio of the mass of NMP to the mass of NMP and polyol in the positive electrode mixture layer 12c ((NMP mass) / ((NMP mass) + (polyol mass))) becomes small. .
  • the binder is composed of at least one of PVDF and a fluororesin having a PVDF unit.
  • the solubility of the binder in NMP is higher than the solubility of the binder in the polyol. That is, NMP is a good solvent for the binder.
  • the polyol is a poor solvent for the binder. Therefore, at least in the initial stage of the drying step, the content of NMP, which is a good solvent, in the positive electrode mixture layer 12c is reduced, and the content of polyol, which is a poor solvent, is increased. Therefore, the solubility of the binder in the positive electrode mixture layer 12c is lowered at least in the initial stage of the formation process.
  • the binder is precipitated in a gel form. Therefore, the positive electrode active material layer 12b which is porous and excellent in flexibility is formed by subsequent drying. Moreover, since the formed positive electrode active material layer 12b is porous, it has excellent liquid absorbency.
  • the positive electrode 12 manufactured by the manufacturing method of the present embodiment is excellent in flexibility and liquid absorption. Therefore, the nonaqueous electrolyte secondary battery 1 including the positive electrode 12 has high reliability and productivity. The nonaqueous electrolyte secondary battery 1 has excellent discharge load characteristics.
  • the boiling point of the polyol is preferably 40 ° C. or higher, more preferably 80 ° C. or higher than the boiling point of NMP. If the difference between the boiling point of the polyol and the boiling point of NMP is too small, the NMP content in the positive electrode mixture layer 12c is not sufficiently lowered in the drying step, and a sufficiently excellent flexibility may not be obtained. On the other hand, if the boiling point of the polyol is too high, it may be difficult to dry the polyol.
  • the polyol is preferably contained in a proportion of 5 parts by mass or more with respect to 100 parts by mass of the binder, and more preferably in a proportion of 10 parts by mass or more. If the polyol content is too low, sufficiently good flexibility may not be obtained. Further, the polyol is preferably contained in a proportion of 50 parts by mass or less, more preferably 40 parts by mass or less, with respect to 100 parts by mass of the binder. When there is too much content of a polyol, the adhesiveness of the positive electrode active material layer 12b and the positive electrode collector 12a may become low too much.
  • NMP is preferably contained in a proportion of 1000 to 3000 parts by mass with respect to 100 parts by mass of the binder, and more preferably in a proportion of 1500 to 2500 parts by mass. preferable.
  • the content of NMP is too large, the slurry is likely to settle due to a decrease in viscosity, and thus it may be difficult to perform coating.
  • the content of NMP is too small, it may be difficult to apply the slurry to the current collector due to an increase in the viscosity of the slurry.
  • Example 1 LiCoO 2 particles in which 1.0 mol% of aluminum and magnesium were each dissolved and 0.05 mol% of zirconium adhered to the surface were prepared as a positive electrode active material.
  • LiCoO 2 particles, acetylene black (AB) as a conductive agent, polyvinylidene fluoride (PVDF) as a binder, and N-methyl-2-pyrrolidone (NMP) as a good solvent are kneaded. did. Thereafter, an N-methyl-2-pyrrolidone solution containing glycerol as a poor solvent was further added to the kneaded product and stirred to prepare a positive electrode forming slurry.
  • the positive electrode forming slurry was applied on both surfaces of a positive electrode current collector made of an aluminum foil having a thickness of 15 ⁇ m to form a positive electrode mixture layer. Thereafter, the positive electrode mixture layer was dried at 80 ° C. to form a positive electrode active material layer. Through the above steps, a positive electrode a1 according to Example 1 was produced.
  • the packing density in the positive electrode a1 was 3.9 g / cc.
  • Comparative Example 1 A positive electrode b1 according to Comparative Example 1 was produced in the same manner as in Example 1 except that glycerol as a poor solvent was not added.
  • LiCoO 2 particles, acetylene black (AB) as a conductive agent, and ethyl acetoacetate were kneaded. Thereafter, a mixture of PVDF and ethyl acetoacetate was further added to the kneaded product and stirred at 120 ° C. to prepare a positive electrode forming slurry.
  • the positive electrode forming slurry was applied on both surfaces of a positive electrode current collector made of an aluminum foil having a thickness of 15 ⁇ m to form a positive electrode mixture layer. Thereafter, the positive electrode mixture layer was dried at 80 ° C. to form a positive electrode active material layer.
  • the positive electrode b2 which concerns on the comparative example 2 was produced according to the above process. The packing density in the positive electrode b2 was 3.9 g / cc.
  • Example 2 A positive electrode a2 according to Example 2 was produced in the same manner as the positive electrode a1 according to Example 1 except that the drying temperature was set to 120 ° C.
  • Comparative Example 4 A positive electrode b4 according to Comparative Example 4 was produced in the same manner as the positive electrode a2 according to Example 2, except that glycerol was not added.
  • Comparative Example 5 A positive electrode b5 according to Comparative Example 5 was produced in the same manner as the positive electrode a2 according to Example 2, except that ethylene glycol was added instead of glycerol.
  • Comparative Example 6 A positive electrode b6 according to Comparative Example 6 was produced in the same manner as the positive electrode a2 according to Example 2, except that tetraethylene glycol dimethyl ether was added instead of glycerol.
  • the positive electrodes a1, a2, and b1 to b6 were cut into a size of 50 mm ⁇ 20 mm to prepare a sample for evaluating flexibility. As shown in FIG. 4, both ends of the sample S were attached to an acrylic plate 20 having a width of 30 mm using a double-sided tape (“Nystack NW-20” manufactured by Nichiban Co., Ltd.). Next, the center of the sample S is moved to the center at a constant speed (20 mm / min) using a small desktop testing machine (“FGS-TV” and “FGP-0.5”) manufactured by Nidec Sympo Corporation. Pressing was performed until folding occurred. And the maximum load provided in the pressing process was measured.
  • FGS-TV small desktop testing machine
  • Table 1 shows the maximum loads of the positive electrodes a1, b1 to b3 when the maximum load of the positive electrode b1 according to Comparative Example 1 is normalized as 100.
  • Table 2 shows the maximum loads of the positive electrodes a2, b4 to b6 when the maximum load of the positive electrode b4 according to Comparative Example 4 is normalized as 100.
  • the positive electrode a1 is more flexible than the positive electrode b1.
  • the positive electrode a2 is more flexible than the positive electrode b4. This shows that the softness of the positive electrode can be improved by adding glycerol in addition to NMP.
  • Example 1 The NMP solution in which PVDF was dissolved was applied to the surface of the aluminum foil by a doctor blade method and dried at 80 ° C. to prepare a coating film a. Next, the density of the coating film a was measured. The results are shown in Table 3 below. Moreover, the electron micrograph of the coating film a is shown in FIG.
  • Example 2 The NMP solution in which PVDF was dissolved and NMP to which glycerol was added were mixed by stirring.
  • the mass ratio of NMP to glycerol (NMP: glycerol) in this solution was 98.6: 2.7, and the mass ratio of PVDF to glycerol (PVDF: glycerol) was 100: 20.
  • the above solution was applied to the surface of the aluminum foil by a doctor blade method and dried at 80 ° C. to prepare a coating film b.
  • the density of the coating film b was measured. The results are shown in Table 3 below.
  • the electron micrograph of the coating film b is shown in FIG.
  • Example 3 The above experimental example except that the mass ratio of NMP to glycerol (NMP: glycerol) was 97.3: 5.5 and the mass ratio of PVDF to glycerol (PVDF: glycerol) was 100: 40
  • NMP NMP: glycerol
  • PVDF PVDF
  • Example 3 the density of the coating film c was measured. The results are shown in Table 3 below.
  • the electron micrograph of the coating film c is shown in FIG.
  • Example 4 By stirring PVDF and ethyl acetoacetate at 120 ° C., an ethyl acetoacetate solution in which PVDF was dissolved was obtained. The ethyl acetoacetate solution was applied to the surface of the aluminum foil by a doctor blade method while being kept at 120 ° C., and dried at 80 ° C. to prepare a coating film d. Next, the density of the coating film d was measured. The results are shown in Table 3 below. Moreover, the electron micrograph of the coating film d is shown in FIG.
  • the coating film b and coating film c in which glycerol was added in addition to NMP had more voids and lower density than the coating film a using only NMP.
  • the coating film d using ethyl acetoacetate and the coating film e using dimethylimidazolidinone and cyclohexanone have the same density as the coating film a using NMP, and the void volume is substantially equal. Did not increase.
  • the mass ratio of glycerol to PVDF is preferably 5/100 or more, and more preferably 10/100 or more. It can be seen that 20/100 or more is more preferable.
  • a positive electrode was attached to an acrylic plate of 120 mm ⁇ 30 mm size using a double-sided tape of 70 mm ⁇ 20 mm size (“Nystack NW-20” manufactured by Nichiban Co., Ltd.).
  • the end of the applied positive electrode was placed at 90 ° C. with respect to the surface of the positive electrode active material layer using a small desktop tester (“FGS-TV” and “FGP-5”) manufactured by Nidec Sympo Corporation. In this direction, the film was pulled 55 mm at a constant speed of 50 mm / min, and the strength at the time of peeling was measured.
  • the mass ratio of glycerol to PVDF is preferably 50/100 or less, It can be seen that the ratio is more preferably 40/100 or less.
  • the mass ratio of glycerol to PVDF is preferably 5/100 to 50/100. It can be seen that a value of ⁇ 40 / 100 is more preferable.
  • Example 8 [Production of positive electrode] A positive electrode was produced in the same manner as in Example 2.
  • a slurry for forming a negative electrode was prepared by kneading in an aqueous solution. This negative electrode forming slurry was applied on both sides of a negative electrode current collector made of copper foil, dried, and then rolled to prepare a negative electrode.
  • a lead terminal was attached to each of the positive electrode and the negative electrode, and an electrode body was prepared by pressing a spiral wound through a separator and crushing it into a flat shape.
  • the electrode body was inserted into an aluminum laminate as a battery outer package, and then the non-aqueous electrolyte was injected.
  • the nonaqueous electrolyte secondary battery A according to Example 8 was completed.
  • the battery was designed so that the end-of-charge voltage was 4.4 V and the design capacity was 750 mAh.
  • Comparative Example 7 A battery B according to Comparative Example 7 was produced in the same manner as in Example 8, except that the positive electrode produced in the same manner as in Comparative Example 4 was used.
  • Nonaqueous electrolyte secondary battery 10 Electrode body 11 ... Negative electrode 12 ... Positive electrode 12a ... Positive electrode collector 12b ... Positive electrode active material layer 12c ... Positive electrode mixture layer 13 ... Separator 17 ... Battery container 20 ... Acrylic board

Abstract

Provided is a method by which a positive electrode for nonaqueous electrolyte secondary batteries having excellent flexibility and excellent liquid absorption can be produced. This method comprises a formation step wherein a positive electrode active material layer (12b) is formed by drying a positive electrode mixture layer (12c) that is formed by applying a slurry over a positive electrode collector (12a), said slurry containing a positive electrode active material, a binder that is formed of a polyvinylidene fluoride and/or a fluororesin having a polyvinylidene fluoride unit, N-methyl-2-pyrrolidone and a polyol that has a higher boiling point than N-methyl-2-pyrrolidone.

Description

非水電解質二次電池用正極の製造方法、非水電解質二次電池用正極及び非水電解質二次電池Method for producing positive electrode for nonaqueous electrolyte secondary battery, positive electrode for nonaqueous electrolyte secondary battery, and nonaqueous electrolyte secondary battery
　本発明は、非水電解質二次電池用正極の製造方法、その製造方法により製造された非水電解質二次電池用正極及びそれを備える非水電解質二次電池に関する。 The present invention relates to a method for manufacturing a positive electrode for a non-aqueous electrolyte secondary battery, a positive electrode for a non-aqueous electrolyte secondary battery manufactured by the manufacturing method, and a non-aqueous electrolyte secondary battery including the same.
　近年、携帯電話機、ノート型パソコン、ＰＤＡ（Ｐｅｒｓｏｎａｌ　Ｄｉｇｉｔａｌ　Ａｓｓｉｓｔａｎｔ）等の携帯型情報端末の小型化及び軽量化が急速に進んできている。これに伴い、携帯型情報端末の駆動電源として用いられる非水電解質二次電池に対する高容量化の要求もさらに高まってきている。 In recent years, portable information terminals such as mobile phones, notebook personal computers, PDAs (Personal Digital Assistants) and the like have been rapidly reduced in size and weight. In connection with this, the request | requirement of high capacity | capacitance is increasing further with respect to the nonaqueous electrolyte secondary battery used as a drive power supply of a portable information terminal.
　従来、非水電解質二次電池の高容量化は、例えば、電極における活物質の充填密度の向上や、電極に占める活物質層の割合の向上などにより図られてきた。しかしながら、電極における活物質の充填密度を高めると、電極の柔軟性が低下する傾向にある。また、電極に占める活物質の割合を高めた場合も、電極の柔軟性が低下する傾向にある。このため、電極の巻回時に、電極が破断する等の問題が生じやすくなる。その結果、非水電解質二次電池の生産性が低下してしまう。 Conventionally, increasing the capacity of a nonaqueous electrolyte secondary battery has been achieved, for example, by improving the packing density of the active material in the electrode or by increasing the proportion of the active material layer in the electrode. However, when the packing density of the active material in the electrode is increased, the flexibility of the electrode tends to decrease. Also, when the proportion of the active material in the electrode is increased, the flexibility of the electrode tends to decrease. For this reason, problems such as electrode breakage tend to occur when the electrode is wound. As a result, the productivity of the nonaqueous electrolyte secondary battery is reduced.
　このような問題に鑑み、例えば下記の特許文献１，２においては、平均粒子径の異なる２種類の正極活物質を用いることが提案されている。 In view of such problems, for example, in Patent Documents 1 and 2 below, it is proposed to use two types of positive electrode active materials having different average particle diameters.
　また、下記の特許文献３には、結着剤を含む正極活物質層の形成に、結着剤の貧溶媒と、この貧溶媒よりも沸点が低い良溶媒との混合溶媒を用いることが記載されている。具体的には、結着剤をポリフッ化ビニリデン（ＰＶＤＦ）とし、良溶媒としてジメチルイミダゾリジノンを用い、貧溶媒としてシクロヘキサノンを用いる例が記載されている。 Patent Document 3 below describes that a mixed solvent of a poor solvent for the binder and a good solvent having a boiling point lower than that of the poor solvent is used for forming the positive electrode active material layer containing the binder. Has been. Specifically, an example is described in which polyvinylidene fluoride (PVDF) is used as a binder, dimethylimidazolidinone is used as a good solvent, and cyclohexanone is used as a poor solvent.
特開２００６－１８５８８７号公報JP 2006-185887 A 特開２００８－２３５１５７号公報JP 2008-235157 A 特開平１１－８６８６５号公報Japanese Patent Laid-Open No. 11-86865
　しかしながら、特許文献３に記載のように、結着剤をポリフッ化ビニリデン（ＰＶＤＦ）とし、良溶媒としてジメチルイミダゾリジノンを用い、貧溶媒としてシクロヘキサノンを用いた場合は、正極の柔軟性を十分に向上することはできない。 However, as described in Patent Document 3, when the binder is polyvinylidene fluoride (PVDF), dimethylimidazolidinone is used as a good solvent, and cyclohexanone is used as a poor solvent, the flexibility of the positive electrode is sufficient. It cannot be improved.
　また、特許文献１，２に記載の方法は、平均粒子径の異なる２種類の正極活物質を用いる場合にのみ適用できるものである。このため、使用する正極活物質の種類に関わらず、正極の柔軟性を向上させることができる新たな方法が望まれている。 The methods described in Patent Documents 1 and 2 can be applied only when two types of positive electrode active materials having different average particle diameters are used. For this reason, a new method capable of improving the flexibility of the positive electrode is desired regardless of the type of the positive electrode active material to be used.
　本発明は、斯かる点に鑑みて成されたものであり、その目的は、柔軟性及び吸液性に優れた非水電解質二次電池用正極を製造し得る方法を提供することにある。 The present invention has been made in view of such points, and an object thereof is to provide a method capable of producing a positive electrode for a non-aqueous electrolyte secondary battery excellent in flexibility and liquid absorption.
　本発明に係る非水電解質二次電池用正極の製造方法は、正極集電体と、正極活物質層とを備える非水電解質二次電池用正極の製造方法に関する。正極活物質層は、正極集電体の上に形成されている。正極活物質層は、正極活物質と、結着剤とを含む。結着剤は、ポリフッ化ビニリデン及びポリフッ化ビニリデン単位を有するフッ素樹脂の少なくとも一方からなる。本発明に係る非水電解質二次電池用正極の製造方法は、形成工程を備えている。形成工程は、正極活物質と、結着剤と、Ｎ－メチル－２－ピロリドンと、Ｎ－メチル－２－ピロリドンよりも沸点が高いポリオールとを含むスラリーを正極集電体の上に塗布することにより形成した正極合剤層を乾燥させることにより正極活物質層を形成する工程である。 The method for producing a positive electrode for a nonaqueous electrolyte secondary battery according to the present invention relates to a method for producing a positive electrode for a nonaqueous electrolyte secondary battery comprising a positive electrode current collector and a positive electrode active material layer. The positive electrode active material layer is formed on the positive electrode current collector. The positive electrode active material layer includes a positive electrode active material and a binder. The binder is made of at least one of polyvinylidene fluoride and a fluororesin having a polyvinylidene fluoride unit. The manufacturing method of the positive electrode for nonaqueous electrolyte secondary batteries which concerns on this invention is provided with the formation process. In the forming step, a slurry containing a positive electrode active material, a binder, N-methyl-2-pyrrolidone, and a polyol having a boiling point higher than that of N-methyl-2-pyrrolidone is applied on the positive electrode current collector. This is a step of forming the positive electrode active material layer by drying the positive electrode mixture layer formed in this manner.
　形成工程は、正極活物質と、結着剤と、前記結着剤１００質量部に対して１０００質量部～３０００質量部のＮ－メチル－２－ピロリドンと、前記結着剤１００質量部に対して５質量部～５０質量部のポリオールとを含むスラリーを調製する工程を含んでいてもよい。 The forming step includes a positive electrode active material, a binder, 1000 parts by weight to 3000 parts by weight of N-methyl-2-pyrrolidone with respect to 100 parts by weight of the binder, and 100 parts by weight of the binder. And a step of preparing a slurry containing 5 to 50 parts by mass of a polyol.
　本発明に係る非水電解質二次電池用正極は、上記本発明に係る非水電解質二次電池用正極の製造方法により製造されたものである。 The positive electrode for a nonaqueous electrolyte secondary battery according to the present invention is manufactured by the method for manufacturing a positive electrode for a nonaqueous electrolyte secondary battery according to the present invention.
　本発明に係る非水電解質二次電池は、上記本発明に係る非水電解質二次電池用正極と、負極と、非水電解質とを備えている。 The non-aqueous electrolyte secondary battery according to the present invention includes the positive electrode for a non-aqueous electrolyte secondary battery according to the present invention, a negative electrode, and a non-aqueous electrolyte.
　本発明によれば、柔軟性及び吸液性に優れた非水電解質二次電池用正極を製造し得る方法を提供することができる。 According to the present invention, it is possible to provide a method capable of producing a positive electrode for a nonaqueous electrolyte secondary battery excellent in flexibility and liquid absorption.
図１は、本発明の一実施形態に係る非水電解質二次電池の略図的断面図である。FIG. 1 is a schematic cross-sectional view of a nonaqueous electrolyte secondary battery according to an embodiment of the present invention. 図２は、本発明の一実施形態における正極の略図的断面図である。FIG. 2 is a schematic cross-sectional view of a positive electrode in one embodiment of the present invention. 図３は、本発明の一実施形態における正極の製造工程を説明するための略図的断面図である。FIG. 3 is a schematic cross-sectional view for explaining a manufacturing process of a positive electrode in one embodiment of the present invention. 図４は、柔軟性の評価工程を説明するための略図的断面図である。FIG. 4 is a schematic cross-sectional view for explaining the flexibility evaluation process. 図５は、柔軟性の評価工程を説明するための略図的断面図である。FIG. 5 is a schematic cross-sectional view for explaining the flexibility evaluation process. 図６は、塗膜ａの電子顕微鏡写真である。FIG. 6 is an electron micrograph of the coating film a. 図７は、塗膜ｂの電子顕微鏡写真である。FIG. 7 is an electron micrograph of the coating film b. 図８は、塗膜ｃの電子顕微鏡写真である。FIG. 8 is an electron micrograph of the coating film c. 図９は、塗膜ｄの電子顕微鏡写真である。FIG. 9 is an electron micrograph of the coating film d. 図１０は、塗膜ｅの電子顕微鏡写真である。FIG. 10 is an electron micrograph of the coating film e. 図１１は、実施例８に係る非水電解質二次電池Ａと、比較例７に係る非水電解質二次電池Ｂとのそれぞれの放電曲線を表すグラフである。FIG. 11 is a graph showing the discharge curves of the nonaqueous electrolyte secondary battery A according to Example 8 and the nonaqueous electrolyte secondary battery B according to Comparative Example 7.
　以下、本発明を実施した好ましい形態の一例について説明する。但し、以下の実施形態は、単なる一例である。本発明は、以下の実施形態に何ら限定されない。 Hereinafter, an example of a preferable embodiment in which the present invention is implemented will be described. However, the following embodiment is merely an example. The present invention is not limited to the following embodiments.
　図１は、本実施形態に係る非水電解質二次電池の略図的断面図である。まず、図１を参照しながら、本実施形態に係る非水電解質二次電池１の構成について説明する。 FIG. 1 is a schematic cross-sectional view of a nonaqueous electrolyte secondary battery according to this embodiment. First, the configuration of the nonaqueous electrolyte secondary battery 1 according to the present embodiment will be described with reference to FIG.
　非水電解質二次電池１は、電池容器１７を備えている。本実施形態では、電池容器１７は、扁平形状を有する。但し、本発明において、電池容器の形状は、扁平形状に限定されない。電池形状は、例えば、両端が塞がれた円筒型であってもよい。 The nonaqueous electrolyte secondary battery 1 includes a battery container 17. In the present embodiment, the battery container 17 has a flat shape. However, in the present invention, the shape of the battery container is not limited to a flat shape. The battery shape may be, for example, a cylindrical shape in which both ends are closed.
　電池容器１７内には、非水電解質が含浸した電極体１０が収納されている。非水電解質としては、例えば、公知の非水電解質を用いることができる。非水電解質の溶媒の具体例としては、例えば、環状カーボネート、鎖状カーボネート及び環状カーボネートと鎖状カーボネートとの混合溶媒等が挙げられる。なかでも、鎖状カーボネート及び環状カーボネートと鎖状カーボネートとの混合溶媒が好ましく用いられる。環状カーボネートと鎖状カーボネートとの混合溶媒においては、環状カーボネートと鎖状カーボネートとの混合比（環状カーボネート：鎖状カーボネート）は、体積比で、１：９～５：５の範囲内であることが好ましい。 In the battery container 17, an electrode body 10 impregnated with a nonaqueous electrolyte is accommodated. As the non-aqueous electrolyte, for example, a known non-aqueous electrolyte can be used. Specific examples of the nonaqueous electrolyte solvent include cyclic carbonates, chain carbonates, and mixed solvents of cyclic carbonates and chain carbonates. Of these, a chain carbonate and a mixed solvent of a cyclic carbonate and a chain carbonate are preferably used. In the mixed solvent of cyclic carbonate and chain carbonate, the mixing ratio of cyclic carbonate and chain carbonate (cyclic carbonate: chain carbonate) should be in the range of 1: 9 to 5: 5 by volume ratio. Is preferred.
　環状カーボネートの具体例としては、エチレンカーボネート、フルオロエチレンカーボネート、プロピレンカーボネート、ブチレンカーボネート、ビニレンカーボネート、ビニルエチレンカーボネート等が挙げられる。 Specific examples of the cyclic carbonate include ethylene carbonate, fluoroethylene carbonate, propylene carbonate, butylene carbonate, vinylene carbonate, vinyl ethylene carbonate, and the like.
　鎖状カーボネートとしては、ジメチルカーボネート、メチルエチルカーボネート、ジエチルカーボネート等が挙げられる。 Examples of chain carbonates include dimethyl carbonate, methyl ethyl carbonate, and diethyl carbonate.
　非水電解質の溶質の具体例としては、例えば、ＬｉＰＦ６、ＬｉＢＦ４、ＬｉＣＦ３ＳＯ３、ＬｉＮ（ＳＯ２ＣＦ３）２，ＬｉＮ（ＳＯ２Ｃ２Ｆ５）２，ＬｉＣ（ＳＯ２ＣＦ３）３，ＬｉＣ（ＳＯ２Ｃ２Ｆ５）３，ＬｉＣｌＯ４等が挙げられる。 Specific examples of the nonaqueous electrolyte solute include, for example, LiPF 6 , LiBF 4 , LiCF 3 SO 3 , LiN (SO 2 CF 3 ) 2 , LiN (SO 2 C 2 F 5 ) 2 , LiC (SO 2 CF 3). ) 3 , LiC (SO 2 C 2 F 5 ) 3 , LiClO 4 and the like.
　また、非水電解質として、上記溶媒に上記溶質が溶解したものの他に、ポリエチレンオキシドやポリアクリロニトリル等のポリマーに電解液を含浸させたゲル状ポリマー電解質を用いることもできる。 Further, as the nonaqueous electrolyte, a gel polymer electrolyte obtained by impregnating a polymer such as polyethylene oxide or polyacrylonitrile with an electrolytic solution can be used in addition to the above-described solute dissolved in the solvent.
　電極体１０は、負極１１と、正極１２と、負極１１及び正極１２の間に配置されているセパレータ１３とが巻回されてなる。 The electrode body 10 is formed by winding a negative electrode 11, a positive electrode 12, and a separator 13 disposed between the negative electrode 11 and the positive electrode 12.
　セパレータ１３は、例えば公知のセパレータにより構成することができる。具体的には、セパレータ１３は、例えば、樹脂製の多孔膜により構成することができる。樹脂製の多孔膜の具体例としては、例えば、ポリエチレン製微多孔膜，ポリプロピレン製微多孔膜などが挙げられる。 The separator 13 can be constituted by a known separator, for example. Specifically, the separator 13 can be comprised by the porous film made from resin, for example. Specific examples of the resin porous membrane include a polyethylene microporous membrane and a polypropylene microporous membrane.
　負極１１は、負極集電体と、負極集電体の少なくとも一方の表面の上に形成されている負極活物質層とを有する。負極集電体は、例えば、Ｃｕなどの金属や、Ｃｕなどの金属を含む合金からなる箔により構成することができる。負極活物質層は、負極活物質に加えて、バインダーや導電剤等を含むものであってもよい。負極活物質としては、黒鉛やコークス等の炭素材料、酸化スズ等の金属酸化物、リチウムと合金化するもの等が挙げられる。リチウムと合金化する負極活物質としては、例えば、シリコン、ゲルマニウム、スズ及びアルミニウムからなる群から選ばれた一種以上の金属、またはシリコン、ゲルマニウム、スズ及びアルミニウムからなる群から選ばれた一種以上の金属を含む合金からなるものが挙げられる。 The negative electrode 11 has a negative electrode current collector and a negative electrode active material layer formed on at least one surface of the negative electrode current collector. The negative electrode current collector can be composed of, for example, a foil made of a metal such as Cu or an alloy containing a metal such as Cu. The negative electrode active material layer may include a binder, a conductive agent, and the like in addition to the negative electrode active material. Examples of the negative electrode active material include carbon materials such as graphite and coke, metal oxides such as tin oxide, and materials that are alloyed with lithium. As the negative electrode active material alloyed with lithium, for example, one or more metals selected from the group consisting of silicon, germanium, tin and aluminum, or one or more types selected from the group consisting of silicon, germanium, tin and aluminum The thing which consists of an alloy containing a metal is mentioned.
　図２は、本実施形態における正極１２の略図的断面図である。図２に示すように、正極１２は、正極集電体１２ａと、正極活物質層１２ｂとを有する。正極集電体１２ａは、例えば、Ａｌなどの金属や、Ａｌなどの金属を含む合金により形成することができる。 FIG. 2 is a schematic cross-sectional view of the positive electrode 12 in the present embodiment. As shown in FIG. 2, the positive electrode 12 includes a positive electrode current collector 12a and a positive electrode active material layer 12b. The positive electrode current collector 12a can be formed of, for example, a metal such as Al or an alloy containing a metal such as Al.
　正極活物質層１２ｂは、正極集電体１２ａの少なくとも一方の表面の上に形成されている。具体的には、本実施形態では、正極活物質層１２ｂは、正極集電体１２ａの両面の上に形成されている。 The positive electrode active material layer 12b is formed on at least one surface of the positive electrode current collector 12a. Specifically, in the present embodiment, the positive electrode active material layer 12b is formed on both surfaces of the positive electrode current collector 12a.
　正極活物質層１２ｂは、正極活物質と結着剤とを含む。本実施形態では、正極活物質層１２ｂは、導電剤をさらに含む。 The positive electrode active material layer 12b includes a positive electrode active material and a binder. In the present embodiment, the positive electrode active material layer 12b further includes a conductive agent.
　正極活物質は、リチウムを吸蔵及び放出することができ、電位が貴な材料であることが好ましい。正極活物質としては、層状構造、スピネル型構造またはオリビン型構造を有するリチウム遷移金属複合酸化物等が挙げられる。なかでも、エネルギー密度が高い層状構造を有するリチウム遷移金属複合酸化物が好ましく用いられる。層状構造を有するリチウム遷移金属複合酸化物としては、リチウムニッケル複合酸化物、リチウムニッケルコバルト複合酸化物、リチウムニッケルコバルトアルミニウム複合酸化物、リチウムニッケルコバルトマンガン複合酸化物、リチウムコバルト複合酸化物等が挙げられる。なかでも、アルミニウムまたはマグネシウムが固溶しており、かつジルコニウムが粒子表面に固着したコバルト酸リチウム粒子は、結晶構造の安定性に優れているため、より好ましく用いられる。また、高価なコバルトの使用量を低減する観点からは、正極活物質中に含まれる遷移金属に占めるニッケルの割合が５０モル％以上であるリチウム遷移金属複合酸化物が好ましく用いられ、なかでも、リチウムニッケルコバルトアルミニウム複合酸化物がより好ましく用いられる。 The positive electrode active material is preferably a material that can occlude and release lithium and has a high potential. Examples of the positive electrode active material include lithium transition metal composite oxides having a layered structure, a spinel structure, or an olivine structure. Among these, lithium transition metal composite oxides having a layered structure with high energy density are preferably used. Examples of the lithium transition metal composite oxide having a layered structure include lithium nickel composite oxide, lithium nickel cobalt composite oxide, lithium nickel cobalt aluminum composite oxide, lithium nickel cobalt manganese composite oxide, and lithium cobalt composite oxide. It is done. Among these, lithium cobaltate particles in which aluminum or magnesium is solid-solved and zirconium is fixed to the particle surface are more preferably used because of excellent crystal structure stability. In addition, from the viewpoint of reducing the amount of expensive cobalt used, lithium transition metal composite oxide in which the proportion of nickel in the transition metal contained in the positive electrode active material is 50 mol% or more is preferably used. A lithium nickel cobalt aluminum composite oxide is more preferably used.
　正極活物質層１２ｂの結着剤は、ポリフッ化ビニリデン（ＰＶＤＦ）及びＰＶＤＦ単位を有するフッ素樹脂のうちの少なくとも一方からなる。ポリフッ化ビニリデン単位を有するフッ素樹脂の具体例としては、例えば、ポリフッ化ビニリデンの変性体等が挙げられる。ポリフッ化ビニリデンの変性体としては、フッ化ビニリデン単量体と他の単量体を共重合して製造されるものが挙げられる。具体的には、例えば、フッ化ビニリデン－フッ化ビニル共重合体、フッ化ビニリデン－トリフルオロエチレン共重合体、フッ化ビニリデン－テトラフルオロエチレン共重合体、フッ化ビニリデン－ヘキサフルオロプロピレン共重合体、フッ化ビニリデン－フルオロアルキルビニルエーテル共重合体、フッ化ビニリデン－無水マレイン酸共重合体、フッ化ビニリデン－マレイン酸モノメチルエステル共重合体等が挙げられる。 The binder of the positive electrode active material layer 12b is made of at least one of polyvinylidene fluoride (PVDF) and a fluororesin having a PVDF unit. Specific examples of the fluororesin having a polyvinylidene fluoride unit include, for example, modified polyvinylidene fluoride. Examples of the modified polyvinylidene fluoride include those produced by copolymerizing a vinylidene fluoride monomer and another monomer. Specifically, for example, vinylidene fluoride-vinyl fluoride copolymer, vinylidene fluoride-trifluoroethylene copolymer, vinylidene fluoride-tetrafluoroethylene copolymer, vinylidene fluoride-hexafluoropropylene copolymer Vinylidene fluoride-fluoroalkyl vinyl ether copolymer, vinylidene fluoride-maleic anhydride copolymer, vinylidene fluoride-maleic acid monomethyl ester copolymer, and the like.
　正極活物質層１２ｂにおいて、結着剤の含有量は、正極活物質１００質量部に対して２．０質量部～５．０質量部の範囲内であることが好ましい。 In the positive electrode active material layer 12b, the content of the binder is preferably in the range of 2.0 parts by mass to 5.0 parts by mass with respect to 100 parts by mass of the positive electrode active material.
　正極活物質層１２ｂの導電剤としては、例えば、アセチレンブラックや、ケッチェンブラック、ファーネスブラック、カーボンナノチューブ等が挙げられる。正極活物質層１２ｂにおいて、導電剤の含有量は、正極活物質１００質量部に対して０．１質量部～５．０質量部の範囲内であることが好ましい。 Examples of the conductive agent for the positive electrode active material layer 12b include acetylene black, ketjen black, furnace black, and carbon nanotube. In the positive electrode active material layer 12b, the content of the conductive agent is preferably in the range of 0.1 parts by mass to 5.0 parts by mass with respect to 100 parts by mass of the positive electrode active material.
　次に、本実施形態における正極１２の製造方法について詳細に説明する。本実施形態においては、まず、スラリーを調製するスラリー調製工程を行う。このスラリー調製工程においては、正極活物質と、上記結着剤と、導電剤と、Ｎ－メチル－２－ピロリドン（ＮＭＰ）と、ＮＭＰよりも沸点が高いポリオールとを適宜混合することによりスラリーを作製する。 Next, the manufacturing method of the positive electrode 12 in this embodiment will be described in detail. In this embodiment, first, a slurry preparation step for preparing a slurry is performed. In this slurry preparation step, the slurry is prepared by appropriately mixing the positive electrode active material, the binder, the conductive agent, N-methyl-2-pyrrolidone (NMP), and a polyol having a boiling point higher than that of NMP. Make it.
　ＮＭＰよりも沸点が高いポリオールの具体例としては、例えば、グリセロールや、トリメチロールプロパンなどが挙げられる。 Specific examples of the polyol having a boiling point higher than that of NMP include glycerol and trimethylolpropane.
　ポリオールの沸点は、ＮＭＰの沸点よりも４０℃以上高いことが好ましく、８０℃以上高いことがより好ましい。なお、ＮＭＰの沸点は、２０４℃である。グリセロールの沸点は、２９０℃であり、ＮＭＰの沸点よりも８６℃高い。トリメチロールプロパンの沸点は、２９５℃であり、ＮＭＰの沸点よりも９１℃高い。 The boiling point of the polyol is preferably 40 ° C. or more higher than the boiling point of NMP, more preferably 80 ° C. or more. The boiling point of NMP is 204 ° C. The boiling point of glycerol is 290 ° C., which is 86 ° C. higher than that of NMP. The boiling point of trimethylolpropane is 295 ° C., which is 91 ° C. higher than that of NMP.
　次に、上記調製したスラリーを正極集電体１２ａの少なくとも一方の面の上に塗布するスラリー塗布工程を行う。これにより、図３に示すように、正極集電体１２ａの少なくとも一方の面の上に、正極合剤層１２ｃを形成する。具体的には、本実施形態では、スラリー塗布工程において、スラリーを正極集電体１２ａの両面の上に塗布することにより、正極集電体１２ａの両面の上に、正極合剤層１２ｃを形成する。正極合剤層１２ｃを乾燥させることによって、図２に示す正極活物質層１２ｂを形成する乾燥工程を行う。この乾燥工程と、上記スラリー調製工程と、スラリー塗布工程とを行うことによって、正極活物質層１２ｂを形成する形成工程を行う。 Next, a slurry application step of applying the prepared slurry onto at least one surface of the positive electrode current collector 12a is performed. Thereby, as shown in FIG. 3, the positive electrode mixture layer 12c is formed on at least one surface of the positive electrode current collector 12a. Specifically, in the present embodiment, in the slurry application step, the positive electrode mixture layer 12c is formed on both surfaces of the positive electrode current collector 12a by applying the slurry on both surfaces of the positive electrode current collector 12a. To do. A drying step for forming the positive electrode active material layer 12b shown in FIG. 2 is performed by drying the positive electrode mixture layer 12c. By performing this drying step, the slurry preparation step, and the slurry application step, a forming step for forming the positive electrode active material layer 12b is performed.
　正極合剤層１２ｃの乾燥方法は、特に限定されない。例えば、正極合剤層１２ｃを加熱することにより乾燥してもよいし、正極合剤層１２ｃを減圧雰囲気中に配置することにより乾燥してもよい。また、正極合剤層１２ｃを減圧しながら加熱することにより乾燥してもよい。 The drying method of the positive electrode mixture layer 12c is not particularly limited. For example, the positive electrode mixture layer 12c may be dried by heating, or the positive electrode mixture layer 12c may be dried by placing it in a reduced-pressure atmosphere. Moreover, you may dry by heating the positive mix layer 12c, decompressing.
　なお、正極合剤層１２ｃの乾燥は、ＮＭＰ及びポリオールが完全に除去されるまで行う必要は必ずしもない。正極活物質層１２ｂの特性が大きく低下しない範囲でＮＭＰ及びポリオールが正極活物質層１２ｂに残留していてもよい。具体的には、正極活物質層１２ｂにおけるポリオール及びＮＭＰのそれぞれの含有率は、１００ｐｐｍ以下であればよい。 It is not always necessary to dry the positive electrode mixture layer 12c until NMP and polyol are completely removed. NMP and polyol may remain in the positive electrode active material layer 12b as long as the characteristics of the positive electrode active material layer 12b are not significantly deteriorated. Specifically, each content rate of the polyol and NMP in the positive electrode active material layer 12b should just be 100 ppm or less.
　本実施形態では、ポリオールは、ＮＭＰよりも沸点が高い。よって、乾燥工程の少なくとも初期において、正極合剤層１２ｃにおけるＮＭＰ及びポリオールの質量に対するＮＭＰの質量の比（（ＮＭＰの質量）／（（ＮＭＰの質量）＋（ポリオールの質量）））が小さくなる。 In this embodiment, polyol has a higher boiling point than NMP. Therefore, at least at the initial stage of the drying step, the ratio of the mass of NMP to the mass of NMP and polyol in the positive electrode mixture layer 12c ((NMP mass) / ((NMP mass) + (polyol mass))) becomes small. .
　ここで、結着剤は、ＰＶＤＦ及びＰＶＤＦ単位を有するフッ素樹脂の少なくとも一方からなる。このため、結着剤のＮＭＰへの溶解度は、結着剤のポリオールへの溶解度よりも高い。すなわち、ＮＭＰは、結着剤に対する良溶媒である。ポリオールは、結着剤に対する貧溶媒である。よって、乾燥工程の少なくとも初期において、正極合剤層１２ｃにおける良溶媒であるＮＭＰの含有率が低くなり、貧溶媒であるポリオールの含有率が高くなる。従って、形成工程の少なくとも初期において正極合剤層１２ｃにおける結着剤の溶解度が低くなっていく。その結果、結着剤がゲル状に析出する。よって、その後のさらなる乾燥により、多孔質であり、柔軟性に優れた正極活物質層１２ｂが形成される。また、形成される正極活物質層１２ｂは、多孔質であるため、吸液性に優れている。 Here, the binder is composed of at least one of PVDF and a fluororesin having a PVDF unit. For this reason, the solubility of the binder in NMP is higher than the solubility of the binder in the polyol. That is, NMP is a good solvent for the binder. The polyol is a poor solvent for the binder. Therefore, at least in the initial stage of the drying step, the content of NMP, which is a good solvent, in the positive electrode mixture layer 12c is reduced, and the content of polyol, which is a poor solvent, is increased. Therefore, the solubility of the binder in the positive electrode mixture layer 12c is lowered at least in the initial stage of the formation process. As a result, the binder is precipitated in a gel form. Therefore, the positive electrode active material layer 12b which is porous and excellent in flexibility is formed by subsequent drying. Moreover, since the formed positive electrode active material layer 12b is porous, it has excellent liquid absorbency.
　従って、本実施形態の製造方法により製造された正極１２は、柔軟性及び吸液性に優れている。よって、その正極１２を備える非水電解質二次電池１は、高い信頼性及び生産性を有する。また、非水電解質二次電池１は、優れた放電負荷特性を有する。 Therefore, the positive electrode 12 manufactured by the manufacturing method of the present embodiment is excellent in flexibility and liquid absorption. Therefore, the nonaqueous electrolyte secondary battery 1 including the positive electrode 12 has high reliability and productivity. The nonaqueous electrolyte secondary battery 1 has excellent discharge load characteristics.
　より柔軟性に優れた正極活物質層１２ｂをえる観点からは、ポリオールの沸点は、ＮＭＰの沸点よりも４０℃以上高いことが好ましく、８０℃以上高いことがより好ましい。ポリオールの沸点とＮＭＰの沸点との差が小さすぎると、乾燥工程において、正極合剤層１２ｃにおけるＮＭＰの含有率が十分に低くならず、十分に優れた柔軟性が得られない場合がある。一方、ポリオールの沸点が高すぎると、ポリオールの乾燥が困難となる場合がある。 From the viewpoint of obtaining a positive electrode active material layer 12b having more flexibility, the boiling point of the polyol is preferably 40 ° C. or higher, more preferably 80 ° C. or higher than the boiling point of NMP. If the difference between the boiling point of the polyol and the boiling point of NMP is too small, the NMP content in the positive electrode mixture layer 12c is not sufficiently lowered in the drying step, and a sufficiently excellent flexibility may not be obtained. On the other hand, if the boiling point of the polyol is too high, it may be difficult to dry the polyol.
　スラリーにおいて、ポリオールは、結着剤１００質量部に対して５質量部以上の割合で含まれていることが好ましく、１０質量部以上の割合で含まれていることがより好ましい。ポリオールの含有量が少なすぎると、十分に優れた柔軟性が得られない場合がある。また、ポリオールは、結着剤１００質量部に対して５０質量部以下の割合で含まれていることが好ましく、４０質量部以下の割合で含まれていることがより好ましい。ポリオールの含有量が多すぎると、正極活物質層１２ｂと正極集電体１２ａとの密着性が低くなりすぎる場合がある。 In the slurry, the polyol is preferably contained in a proportion of 5 parts by mass or more with respect to 100 parts by mass of the binder, and more preferably in a proportion of 10 parts by mass or more. If the polyol content is too low, sufficiently good flexibility may not be obtained. Further, the polyol is preferably contained in a proportion of 50 parts by mass or less, more preferably 40 parts by mass or less, with respect to 100 parts by mass of the binder. When there is too much content of a polyol, the adhesiveness of the positive electrode active material layer 12b and the positive electrode collector 12a may become low too much.
　スラリーにおいて、ＮＭＰは、結着剤１００質量部に対して１０００質量部～３０００質量部の割合で含まれていることが好ましく、１５００質量部～２５００質量部の割合で含まれていることがより好ましい。ＮＭＰの含有量が多すぎると、粘度が低くなることによりスラリーが沈降し易く、よって塗布を行いにくくなる場合がある。一方、ＮＭＰの含有量が少なすぎると、スラリーの粘度が高くなることによりスラリーを集電体に塗布することが困難になる場合がある。 In the slurry, NMP is preferably contained in a proportion of 1000 to 3000 parts by mass with respect to 100 parts by mass of the binder, and more preferably in a proportion of 1500 to 2500 parts by mass. preferable. When the content of NMP is too large, the slurry is likely to settle due to a decrease in viscosity, and thus it may be difficult to perform coating. On the other hand, if the content of NMP is too small, it may be difficult to apply the slurry to the current collector due to an increase in the viscosity of the slurry.
　（実施例１）
　アルミニウム及びマグネシウムがそれぞれ１．０モル％固溶しており、且つ０．０５モル％のジルコニウムが表面に付着したＬｉＣｏＯ２粒子を正極活物質として用意した。 Example 1
LiCoO 2 particles in which 1.0 mol% of aluminum and magnesium were each dissolved and 0.05 mol% of zirconium adhered to the surface were prepared as a positive electrode active material.
　次に、上記ＬｉＣｏＯ２粒子と、導電剤としてのアセチレンブラック（ＡＢ）と、結着剤としてのポリフッ化ビニリデン（ＰＶＤＦ）と、良溶媒であるＮ－メチル－２－ピロリドン（ＮＭＰ）とを混練した。その後、貧溶媒であるグリセロールを含むＮ－メチル－２－ピロリドン溶液を混練物にさらに加えて攪拌し、正極形成用スラリーを作製した。なお、正極形成用スラリーにおけるＬｉＣｏＯ２、ＡＢ及びＰＶＤＦの質量比は、ＬｉＣｏＯ２：ＡＢ：ＰＶＤＦ＝９５：２．５：２．５とした。正極形成用スラリーにおけるＰＶＤＦとグリセロールとの質量比は、ＰＶＤＦ：グリセロール＝１００：３５とした。 Next, the LiCoO 2 particles, acetylene black (AB) as a conductive agent, polyvinylidene fluoride (PVDF) as a binder, and N-methyl-2-pyrrolidone (NMP) as a good solvent are kneaded. did. Thereafter, an N-methyl-2-pyrrolidone solution containing glycerol as a poor solvent was further added to the kneaded product and stirred to prepare a positive electrode forming slurry. The mass ratio of LiCoO 2 , AB, and PVDF in the positive electrode forming slurry was LiCoO 2 : AB: PVDF = 95: 2.5: 2.5. The mass ratio of PVDF and glycerol in the positive electrode forming slurry was PVDF: glycerol = 100: 35.
　次に、上記正極形成用スラリーを厚み１５μｍであるアルミニウム箔からなる正極集電体の両面の上に塗布し正極合剤層を形成した。その後、正極合剤層を、８０℃で乾燥させることにより、正極活物質層を形成した。以上の工程により、実施例１に係る正極ａ１を作製した。 Next, the positive electrode forming slurry was applied on both surfaces of a positive electrode current collector made of an aluminum foil having a thickness of 15 μm to form a positive electrode mixture layer. Thereafter, the positive electrode mixture layer was dried at 80 ° C. to form a positive electrode active material layer. Through the above steps, a positive electrode a1 according to Example 1 was produced.
　なお、正極ａ１における充填密度は、３．９ｇ／ｃｃであった。 In addition, the packing density in the positive electrode a1 was 3.9 g / cc.
　（比較例１）
　貧溶媒であるグリセロールを加えなかったこと以外は、上記実施例１と同様にして、比較例１に係る正極ｂ１を作製した。 (Comparative Example 1)
A positive electrode b1 according to Comparative Example 1 was produced in the same manner as in Example 1 except that glycerol as a poor solvent was not added.
　（比較例２）
　アルミニウム及びマグネシウムがそれぞれ１．０モル％固溶しており、且つ０．０５モル％のジルコニウムが表面に付着したＬｉＣｏＯ２粒子を正極活物質として用意した。 (Comparative Example 2)
LiCoO 2 particles in which 1.0 mol% of aluminum and magnesium were each dissolved and 0.05 mol% of zirconium adhered to the surface were prepared as a positive electrode active material.
　次に、上記ＬｉＣｏＯ２粒子と、導電剤としてのアセチレンブラック（ＡＢ）と、アセト酢酸エチルとを混練した。その後、ＰＶＤＦとアセト酢酸エチルとの混合物を混練物にさらに加え、１２０℃で攪拌することにより、正極形成用スラリーを作製した。なお、正極形成用スラリーにおけるＬｉＣｏＯ２、ＡＢ及びＰＶＤＦの質量比は、ＬｉＣｏＯ２：ＡＢ：ＰＶＤＦ＝９５：２．５：２．５とした。正極形成用スラリーにおけるＰＶＤＦとアセト酢酸エチルとの質量比は、ＰＶＤＦ：アセト酢酸エチル＝１００：１５２０とした。 Next, the LiCoO 2 particles, acetylene black (AB) as a conductive agent, and ethyl acetoacetate were kneaded. Thereafter, a mixture of PVDF and ethyl acetoacetate was further added to the kneaded product and stirred at 120 ° C. to prepare a positive electrode forming slurry. The mass ratio of LiCoO 2 , AB, and PVDF in the positive electrode forming slurry was LiCoO 2 : AB: PVDF = 95: 2.5: 2.5. The mass ratio of PVDF to ethyl acetoacetate in the positive electrode forming slurry was PVDF: ethyl acetoacetate = 100: 1520.
　次に、上記正極形成用スラリーを厚み１５μｍであるアルミニウム箔からなる正極集電体の両面の上に塗布し正極合剤層を形成した。その後、正極合剤層を、８０℃で乾燥させることにより、正極活物質層を形成した。以上の工程により、比較例２に係る正極ｂ２を作製した。正極ｂ２における充填密度は、３．９ｇ／ｃｃであった。 Next, the positive electrode forming slurry was applied on both surfaces of a positive electrode current collector made of an aluminum foil having a thickness of 15 μm to form a positive electrode mixture layer. Thereafter, the positive electrode mixture layer was dried at 80 ° C. to form a positive electrode active material layer. The positive electrode b2 which concerns on the comparative example 2 was produced according to the above process. The packing density in the positive electrode b2 was 3.9 g / cc.
　なお、ＰＶＤＦのアセト酢酸エチルに対する溶解度は、ＰＶＤＦのＮＭＰに対する溶解度よりも低い。よって、アセト酢酸エチルは、貧溶媒である。 Note that the solubility of PVDF in ethyl acetoacetate is lower than the solubility of PVDF in NMP. Thus, ethyl acetoacetate is a poor solvent.
　（比較例３）
　ＮＭＰ及びグリセロールの代わりに、ジメチルイミダゾリジノン及びシクロヘキサノン（質量比で、ジメチルイミダゾリジノン：シクロヘキサノン＝５０：５０）を用いたこと以外は、上記実施例１と同様にして比較例３に係る正極ｂ３を作製した。 (Comparative Example 3)
A positive electrode according to Comparative Example 3 in the same manner as in Example 1, except that dimethylimidazolidinone and cyclohexanone (mass ratio, dimethylimidazolidinone: cyclohexanone = 50: 50) were used instead of NMP and glycerol. b3 was produced.
　（実施例２）
　乾燥温度を１２０℃にしたこと以外は、上記実施例１に係る正極ａ１と同様にして実施例２に係る正極ａ２を作製した。 (Example 2)
A positive electrode a2 according to Example 2 was produced in the same manner as the positive electrode a1 according to Example 1 except that the drying temperature was set to 120 ° C.
　（比較例４）
　グリセロールを加えなかったこと以外は、実施例２に係る正極ａ２と同様にして比較例４に係る正極ｂ４を作製した。 (Comparative Example 4)
A positive electrode b4 according to Comparative Example 4 was produced in the same manner as the positive electrode a2 according to Example 2, except that glycerol was not added.
　（比較例５）
　グリセロールの代わりにエチレングリコールを加えたこと以外は、実施例２に係る正極ａ２と同様にして比較例５に係る正極ｂ５を作製した。 (Comparative Example 5)
A positive electrode b5 according to Comparative Example 5 was produced in the same manner as the positive electrode a2 according to Example 2, except that ethylene glycol was added instead of glycerol.
　（比較例６）
　グリセロールの代わりにテトラエチレングリコールジメチルエーテルを加えたこと以外は、実施例２に係る正極ａ２と同様にして比較例６に係る正極ｂ６を作製した。 (Comparative Example 6)
A positive electrode b6 according to Comparative Example 6 was produced in the same manner as the positive electrode a2 according to Example 2, except that tetraethylene glycol dimethyl ether was added instead of glycerol.
　（正極の柔軟性の評価）
　上記実施例１，２及び比較例１～６において作製した正極ａ１、ａ２、ｂ１～ｂ６のそれぞれの柔軟性を以下の要領で評価した。 (Evaluation of flexibility of positive electrode)
The flexibility of each of the positive electrodes a1, a2, and b1 to b6 produced in Examples 1 and 2 and Comparative Examples 1 to 6 was evaluated as follows.
　まず、正極ａ１、ａ２、ｂ１～ｂ６を、５０ｍｍ×２０ｍｍのサイズに切り出し、柔軟性評価用のサンプルを作製した。図４に示すように、そのサンプルＳの両端を、幅３０ｍｍのアクリル板２０に両面テープ（ニチバン株式会社製「ナイスタック　ＮＷ－２０」）を用いて貼付した。次に、日本電産シンポ株式会社製小型卓上試験機（「ＦＧＳ－ＴＶ」及び「ＦＧＰ－０．５」）を用いて、一定速度（２０ｍｍ／分）でサンプルＳの中央を、中央部に折れ込みが発生するまで押圧した。そして、その押圧工程において付与された最大荷重を測定した。この最大加重を指標として正極ａ１、ａ２、ｂ１～ｂ６の柔軟性（極板硬さ）を評価した。比較例１に係る正極ｂ１の最大加重を１００として規格化したときの正極ａ１、ｂ１～ｂ３の最大荷重を下記の表１に示す。比較例４に係る正極ｂ４の最大加重を１００として規格化したときの正極ａ２、ｂ４～ｂ６の最大荷重を下記の表２に示す。 First, the positive electrodes a1, a2, and b1 to b6 were cut into a size of 50 mm × 20 mm to prepare a sample for evaluating flexibility. As shown in FIG. 4, both ends of the sample S were attached to an acrylic plate 20 having a width of 30 mm using a double-sided tape (“Nystack NW-20” manufactured by Nichiban Co., Ltd.). Next, the center of the sample S is moved to the center at a constant speed (20 mm / min) using a small desktop testing machine (“FGS-TV” and “FGP-0.5”) manufactured by Nidec Sympo Corporation. Pressing was performed until folding occurred. And the maximum load provided in the pressing process was measured. Using this maximum weight as an index, the flexibility (electrode plate hardness) of the positive electrodes a1, a2, and b1 to b6 was evaluated. Table 1 below shows the maximum loads of the positive electrodes a1, b1 to b3 when the maximum load of the positive electrode b1 according to Comparative Example 1 is normalized as 100. Table 2 below shows the maximum loads of the positive electrodes a2, b4 to b6 when the maximum load of the positive electrode b4 according to Comparative Example 4 is normalized as 100.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
　表１に示す結果から、正極ａ１は、正極ｂ１よりも柔軟性に優れていることが分かる。また、表２に示す結果から、正極ａ２は、正極ｂ４よりも柔軟性に優れていることが分かる。このことから、ＮＭＰに加えてグリセロールを含有させることにより正極の有軟性を向上できることが分かる。 From the results shown in Table 1, it can be seen that the positive electrode a1 is more flexible than the positive electrode b1. Moreover, from the results shown in Table 2, it can be seen that the positive electrode a2 is more flexible than the positive electrode b4. This shows that the softness of the positive electrode can be improved by adding glycerol in addition to NMP.
　それに対して、表１に示すように、貧溶媒であるアセト酢酸エチルを用いた比較例２では、ＮＭＰを用いた比較例１よりも正極の柔軟性が向上しなかった。この結果から、貧溶媒を単独で用いた場合には、正極の柔軟性を向上できないことが分かる。 In contrast, as shown in Table 1, in Comparative Example 2 using ethyl acetoacetate as a poor solvent, the flexibility of the positive electrode was not improved as compared with Comparative Example 1 using NMP. This result shows that the flexibility of the positive electrode cannot be improved when the poor solvent is used alone.
　また、良溶媒であるジメチルイミダゾリジノンと、貧溶媒であるシクロヘキサノンとを用いた比較例３では、ＮＭＰを用いた比較例１よりも正極の柔軟性が向上しなかった。この結果から、良溶媒としてジメチルイミダゾリジノンを用い、貧溶媒としてシクロヘキサノンを用いた場合は、正極の柔軟性を向上できないことが分かる。 In Comparative Example 3 using dimethylimidazolidinone as a good solvent and cyclohexanone as a poor solvent, the flexibility of the positive electrode was not improved as compared with Comparative Example 1 using NMP. From this result, it is understood that the flexibility of the positive electrode cannot be improved when dimethylimidazolidinone is used as a good solvent and cyclohexanone is used as a poor solvent.
　表２に示すように、ポリオールであるものの、ＮＭＰよりも沸点が低いエチレングリコール（沸点：１９６℃）を用いた比較例５では、正極の柔軟性を向上できなかった。これは、エチレングリコールが揮発しやすく、乾燥工程においてＮＭＰの含有量が多くならなかったためであると考えられる。 As shown in Table 2, although it was a polyol, the flexibility of the positive electrode could not be improved in Comparative Example 5 using ethylene glycol (boiling point: 196 ° C.) having a lower boiling point than NMP. This is considered to be because ethylene glycol was easily volatilized and the content of NMP did not increase in the drying process.
　ＮＭＰよりも沸点が高いものの、ポリオールではないテトラエチレングリコールジメチルエーテルを用いた比較例６においても、正極の柔軟性を向上できなかった。 Although the boiling point was higher than that of NMP, the flexibility of the positive electrode could not be improved also in Comparative Example 6 using tetraethylene glycol dimethyl ether which is not a polyol.
　（実験例１）
　ＰＶＤＦが溶解したＮＭＰ溶液を、アルミニウム箔の表面にドクターブレード法により塗布し、８０℃で乾燥させ、塗膜ａを作製した。次に、塗膜ａの密度を測定した。結果を下記の表３に示す。また、塗膜ａの電子顕微鏡写真を図６に示す。 (Experimental example 1)
The NMP solution in which PVDF was dissolved was applied to the surface of the aluminum foil by a doctor blade method and dried at 80 ° C. to prepare a coating film a. Next, the density of the coating film a was measured. The results are shown in Table 3 below. Moreover, the electron micrograph of the coating film a is shown in FIG.
　（実験例２）
　ＰＶＤＦが溶解したＮＭＰ溶液と、グリセロールを添加したＮＭＰとを攪拌することにより混合した。この液中におけるＮＭＰとグリセロールとの質量比（ＮＭＰ：グリセロール）は、９８．６：２．７であり、ＰＶＤＦとグリセロールとの質量比（ＰＶＤＦ：グリセロールと）は、１００：２０であった。 (Experimental example 2)
The NMP solution in which PVDF was dissolved and NMP to which glycerol was added were mixed by stirring. The mass ratio of NMP to glycerol (NMP: glycerol) in this solution was 98.6: 2.7, and the mass ratio of PVDF to glycerol (PVDF: glycerol) was 100: 20.
　次に、上記液を、アルミニウム箔の表面にドクターブレード法により塗布し、８０℃で乾燥させ、塗膜ｂを作製した。次に、塗膜ｂの密度を測定した。結果を下記の表３に示す。また、塗膜ｂの電子顕微鏡写真を図７に示す。 Next, the above solution was applied to the surface of the aluminum foil by a doctor blade method and dried at 80 ° C. to prepare a coating film b. Next, the density of the coating film b was measured. The results are shown in Table 3 below. Moreover, the electron micrograph of the coating film b is shown in FIG.
　（実験例３）
　ＮＭＰとグリセロールとの質量比（ＮＭＰ：グリセロール）を、９７．３：５．５とし、ＰＶＤＦとグリセロールとの質量比（ＰＶＤＦ：グリセロールと）を、１００：４０としたこと以外は、上記実験例２と同様にして、塗膜ｃを作製した。次に、塗膜ｃの密度を測定した。結果を下記の表３に示す。また、塗膜ｃの電子顕微鏡写真を図８に示す。 (Experimental example 3)
The above experimental example except that the mass ratio of NMP to glycerol (NMP: glycerol) was 97.3: 5.5 and the mass ratio of PVDF to glycerol (PVDF: glycerol) was 100: 40 In the same manner as in Example 2, a coating film c was produced. Next, the density of the coating film c was measured. The results are shown in Table 3 below. Moreover, the electron micrograph of the coating film c is shown in FIG.
　（実験例４）
　ＰＶＤＦと、アセト酢酸エチルとを１２０℃で攪拌することにより、ＰＶＤＦが溶解したアセト酢酸エチル溶液を得た。このアセト酢酸エチル溶液を、１２０℃に保持したまま、アルミニウム箔の表面にドクターブレード法により塗布し、８０℃で乾燥させ、塗膜ｄを作製した。次に、塗膜ｄの密度を測定した。結果を下記の表３に示す。また、塗膜ｄの電子顕微鏡写真を図９に示す。 (Experimental example 4)
By stirring PVDF and ethyl acetoacetate at 120 ° C., an ethyl acetoacetate solution in which PVDF was dissolved was obtained. The ethyl acetoacetate solution was applied to the surface of the aluminum foil by a doctor blade method while being kept at 120 ° C., and dried at 80 ° C. to prepare a coating film d. Next, the density of the coating film d was measured. The results are shown in Table 3 below. Moreover, the electron micrograph of the coating film d is shown in FIG.
　（実験例５）
　ＰＶＤＦをジメチルイミダゾリジノンとシクロヘキサノンとの混合溶液（質量比でジメチルイミダゾリジノン：シクロヘキサノン＝５０：５０）に溶解させた。得られた溶液を、アルミニウム箔の表面にドクターブレード法により塗布し、８０℃で乾燥させ、塗膜ｅを作製した。次に、塗膜ｅの密度を測定した。結果を下記の表３に示す。また、塗膜ｅの電子顕微鏡写真を図１０に示す。 (Experimental example 5)
PVDF was dissolved in a mixed solution of dimethylimidazolidinone and cyclohexanone (dimethylimidazolidinone: cyclohexanone = 50: 50 by mass ratio). The obtained solution was applied to the surface of the aluminum foil by a doctor blade method and dried at 80 ° C. to prepare a coating film e. Next, the density of the coating film e was measured. The results are shown in Table 3 below. Moreover, the electron micrograph of the coating film e is shown in FIG.
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000003
　上記表３及び図６～図１０に示す結果から、ＮＭＰに加えてグリセロールを添加した塗膜ｂ及び塗膜ｃでは、ＮＭＰのみを用いた塗膜ａよりも空隙が多く、密度が低かった。それに対して、アセト酢酸エチルを用いた塗膜ｄ、及びジメチルイミダゾリジノンとシクロヘキサノンとを用いた塗膜ｅは、ＮＭＰを用いた塗膜ａと、同等の密度であり、空隙の体積は実質的に増加しなかった。 From the results shown in Table 3 and FIGS. 6 to 10, the coating film b and coating film c in which glycerol was added in addition to NMP had more voids and lower density than the coating film a using only NMP. On the other hand, the coating film d using ethyl acetoacetate and the coating film e using dimethylimidazolidinone and cyclohexanone have the same density as the coating film a using NMP, and the void volume is substantially equal. Did not increase.
　（実施例３）
　正極形成用スラリーにおけるＰＶＤＦとグリセロールとの質量比を、ＰＶＤＦ：グリセロール＝１００：５としたこと以外は、上記実施例２に係る正極ａ２と同様にして実施例３に係る正極ａ３を作製した。 (Example 3)
A positive electrode a3 according to Example 3 was produced in the same manner as the positive electrode a2 according to Example 2 except that the mass ratio of PVDF and glycerol in the positive electrode forming slurry was PVDF: glycerol = 100: 5.
　（実施例４）
　正極形成用スラリーにおけるＰＶＤＦとグリセロールとの質量比を、ＰＶＤＦ：グリセロール＝１００：１０としたこと以外は、上記実施例２に係る正極ａ２と同様にして実施例４に係る正極ａ４を作製した。 Example 4
A positive electrode a4 according to Example 4 was produced in the same manner as the positive electrode a2 according to Example 2 except that the mass ratio of PVDF and glycerol in the positive electrode forming slurry was PVDF: glycerol = 100: 10.
　（実施例５）
　正極形成用スラリーにおけるＰＶＤＦとグリセロールとの質量比を、ＰＶＤＦ：グリセロール＝１００：２０としたこと以外は、上記実施例２に係る正極ａ２と同様にして実施例５に係る正極ａ５を作製した。 (Example 5)
A positive electrode a5 according to Example 5 was produced in the same manner as the positive electrode a2 according to Example 2, except that the mass ratio of PVDF to glycerol in the positive electrode forming slurry was PVDF: glycerol = 100: 20.
　（実施例６）
　正極形成用スラリーにおけるＰＶＤＦとグリセロールとの質量比を、ＰＶＤＦ：グリセロール＝１００：４０としたこと以外は、上記実施例２に係る正極ａ２と同様にして実施例６に係る正極ａ６を作製した。 (Example 6)
A positive electrode a6 according to Example 6 was produced in the same manner as the positive electrode a2 according to Example 2 except that the mass ratio of PVDF to glycerol in the positive electrode forming slurry was PVDF: glycerol = 100: 40.
　（実施例７）
　正極形成用スラリーにおけるＰＶＤＦとグリセロールとの質量比を、ＰＶＤＦ：グリセロール＝１００：５０としたこと以外は、上記実施例２に係る正極ａ２と同様にして実施例７に係る正極ａ７を作製した。 (Example 7)
A positive electrode a7 according to Example 7 was produced in the same manner as the positive electrode a2 according to Example 2 except that the mass ratio of PVDF to glycerol in the positive electrode forming slurry was PVDF: glycerol = 100: 50.
　（正極の柔軟性の評価）
　上記柔軟性の評価方法と同様の方法により、正極ａ３～ａ７の柔軟性を評価した。結果を、下記の表４に示す。なお、表４に示す極板硬さは、比較例４に係る正極ｂ４の値を１００とした規格化値である。 (Evaluation of flexibility of positive electrode)
The flexibility of the positive electrodes a3 to a7 was evaluated by the same method as the above-described flexibility evaluation method. The results are shown in Table 4 below. In addition, the electrode plate hardness shown in Table 4 is a normalized value with the value of the positive electrode b4 according to Comparative Example 4 being 100.
Figure JPOXMLDOC01-appb-T000004
Figure JPOXMLDOC01-appb-T000004
　表４に示す結果から、正極の柔軟性を向上する観点からは、ＰＶＤＦに対するグリセロールの質量比（グリセロール／ＰＶＤＦ）は、５／１００以上であることが好ましく、１０／１００以上であることがより好ましく、２０／１００以上であることがさらに好ましいことが分かる。 From the results shown in Table 4, from the viewpoint of improving the flexibility of the positive electrode, the mass ratio of glycerol to PVDF (glycerol / PVDF) is preferably 5/100 or more, and more preferably 10/100 or more. It can be seen that 20/100 or more is more preferable.
　（密着性の評価）
　正極ａ３～ａ７における正極集電体と正極活物質層との密着強度を、下記の要領で９０℃剥離試験法によって評価した。 (Evaluation of adhesion)
The adhesion strength between the positive electrode current collector and the positive electrode active material layer in the positive electrodes a3 to a7 was evaluated by a 90 ° C. peel test method in the following manner.
　具体的には、７０ｍｍ×２０ｍｍサイズの両面テープ（ニチバン株式会社製「ナイスタック　ＮＷ－２０」）を用いて１２０ｍｍ×３０ｍｍサイズのアクリル板に正極を貼付した。次に、貼付された正極の端部を日本電産シンポ株式会社製小型卓上試験機（「ＦＧＳ－ＴＶ」及び「ＦＧＰ－５」）を用いて、正極活物質層の表面に対して９０℃の方向に、５０ｍｍ／分の一定速度で５５ｍｍ引っ張り、剥離時の強度を測定した。 Specifically, a positive electrode was attached to an acrylic plate of 120 mm × 30 mm size using a double-sided tape of 70 mm × 20 mm size (“Nystack NW-20” manufactured by Nichiban Co., Ltd.). Next, the end of the applied positive electrode was placed at 90 ° C. with respect to the surface of the positive electrode active material layer using a small desktop tester (“FGS-TV” and “FGP-5”) manufactured by Nidec Sympo Corporation. In this direction, the film was pulled 55 mm at a constant speed of 50 mm / min, and the strength at the time of peeling was measured.
　結果を、下記の表５に示す。なお、表５に示す密着強度は、実施例３に係る正極ａ３の値を１００とした規格化値である。 The results are shown in Table 5 below. In addition, the adhesion strength shown in Table 5 is a normalized value with the value of the positive electrode a3 according to Example 3 as 100.
Figure JPOXMLDOC01-appb-T000005
Figure JPOXMLDOC01-appb-T000005
　表５に示す結果から、正極活物質層と正極集電体との密着強度を高く保つ観点からは、ＰＶＤＦに対するグリセロールの質量比（グリセロール／ＰＶＤＦ）は、５０／１００以下であることが好ましく、４０／１００以下であることがさらに好ましいことが分かる。 From the results shown in Table 5, from the viewpoint of maintaining high adhesion strength between the positive electrode active material layer and the positive electrode current collector, the mass ratio of glycerol to PVDF (glycerol / PVDF) is preferably 50/100 or less, It can be seen that the ratio is more preferably 40/100 or less.
　従って、正極の優れた柔軟性と、高い密着強度とを両立させる観点からは、ＰＶＤＦに対するグリセロールの質量比（グリセロール／ＰＶＤＦ）は、５／１００～５０／１００であることが好ましく、１０／１００～４０／１００であることがより好ましいことが分かる。 Therefore, from the viewpoint of achieving both excellent flexibility of the positive electrode and high adhesion strength, the mass ratio of glycerol to PVDF (glycerol / PVDF) is preferably 5/100 to 50/100. It can be seen that a value of ˜40 / 100 is more preferable.
　（正極の吸液性の評価）
　上記実施例２において作製した正極ａ２と、比較例４において作製した正極ｂ４とのそれぞれの吸液性を以下の要領で評価した。 (Evaluation of liquid absorbency of positive electrode)
The liquid absorption properties of the positive electrode a2 prepared in Example 2 and the positive electrode b4 manufactured in Comparative Example 4 were evaluated in the following manner.
　まず、正極ａ２，ｂ４の上に１マイクロリットルのプロピレンカーボネートをマイクロシリンジを用いて静かに滴下した。そして、正極ａ２，ｂ４にプロピレンカーボネートが吸収されるまでの時間を計測した。比較例に係る正極ｂ４の吸収時間を１００としたときの正極ａ２，ｂ４の吸収時間を下記の表６に示す。 First, 1 microliter of propylene carbonate was gently dropped on the positive electrodes a2 and b4 using a microsyringe. And time until propylene carbonate was absorbed by positive electrode a2 and b4 was measured. The absorption times of the positive electrodes a2 and b4 when the absorption time of the positive electrode b4 according to the comparative example is 100 are shown in Table 6 below.
Figure JPOXMLDOC01-appb-T000006
Figure JPOXMLDOC01-appb-T000006
　表６に示す結果から、ＮＭＰに加えてグリセロールを加えることにより、正極の吸液性を高めることができることが分かる。 From the results shown in Table 6, it can be seen that the liquid absorbability of the positive electrode can be increased by adding glycerol in addition to NMP.
　（実施例８）
　〔正極の作製〕
　実施例２と同様にして正極を作製した。 (Example 8)
[Production of positive electrode]
A positive electrode was produced in the same manner as in Example 2.
　〔負極の作製〕
　負極活物質としての黒鉛と、結着剤としてのスチレンブタジエンゴムと、増粘剤としてのカルボキシメチルセルロースとを、質量比で、黒鉛：スチレンブタジエンゴム：カルボキシメチルセルロース＝９８：１：１となるように水溶液中にて混練することにより負極形成用スラリーを作製した。この負極形成用スラリーを銅箔からなる負極集電体の両面の上に塗布し、乾燥した後、圧延することにより負極を作製した。 (Production of negative electrode)
Graphite as a negative electrode active material, styrene butadiene rubber as a binder, and carboxymethyl cellulose as a thickener so that graphite: styrene butadiene rubber: carboxymethyl cellulose = 98: 1: 1 by mass ratio. A slurry for forming a negative electrode was prepared by kneading in an aqueous solution. This negative electrode forming slurry was applied on both sides of a negative electrode current collector made of copper foil, dried, and then rolled to prepare a negative electrode.
　〔非水電解液の作製〕
　エチレンカーボネート（ＥＣ）と、ジエチルカーボネート（ＤＥＣ）とを体積比で３：７となるように混合した溶媒にＬｉＰＦ６を１．０モル／リットルとなるように加えることにより、非水電解液を作製した。 [Preparation of non-aqueous electrolyte]
By adding LiPF 6 to a solvent in which ethylene carbonate (EC) and diethyl carbonate (DEC) are mixed at a volume ratio of 3: 7 so as to be 1.0 mol / liter, a non-aqueous electrolyte is obtained. Produced.
　〔非水電解質二次電池の組み立て〕
　上記正極及び上記負極のそれぞれにリード端子を取り付け、セパレータを介して渦巻き状に巻き取ったものをプレスして扁平状に押しつぶすことにより電極体を作製した。この電極体を、電池外装体としてのアルミニウムラミネート内に挿入した後、上記非水電解液を注入した。以上の工程により、実施例８に係る非水電解質二次電池Ａを完成させた。なお、充電終止電圧が４．４Ｖ、設計容量が７５０ｍＡｈとなるように電池設計を行った。 [Assembly of non-aqueous electrolyte secondary battery]
A lead terminal was attached to each of the positive electrode and the negative electrode, and an electrode body was prepared by pressing a spiral wound through a separator and crushing it into a flat shape. The electrode body was inserted into an aluminum laminate as a battery outer package, and then the non-aqueous electrolyte was injected. Through the above steps, the nonaqueous electrolyte secondary battery A according to Example 8 was completed. The battery was designed so that the end-of-charge voltage was 4.4 V and the design capacity was 750 mAh.
　（比較例７）
　比較例４と同様にして作製した正極を用いたこと以外は、実施例８と同様にして比較例７に係る電池Ｂを作製した。 (Comparative Example 7)
A battery B according to Comparative Example 7 was produced in the same manner as in Example 8, except that the positive electrode produced in the same manner as in Comparative Example 4 was used.
　（放電容量の評価）
　上記実施例８及び比較例７において作成した非水電解質二次電池Ａ，Ｂのそれぞれを、１．０Ｉｔ（７５０ｍＡ）の電流で電池の電圧が４．４Ｖとなるまで定電流充電を行った。その後、４．４Ｖの定電圧で電流が１／２０Ｉｔ（３７．５ｍＡ）となるまで充電を行った。次に、１．０Ｉｔ（７５０ｍＡ）の電流で電池の電圧が２．７５Ｖとなるまで定電流放電を行った。そして、電池Ａ，Ｂの１．０Ｉｔでの放電容量を測定した。結果を下記の表７に示す。 (Evaluation of discharge capacity)
Each of the nonaqueous electrolyte secondary batteries A and B prepared in Example 8 and Comparative Example 7 was charged with a constant current at a current of 1.0 It (750 mA) until the battery voltage reached 4.4V. Thereafter, charging was performed at a constant voltage of 4.4 V until the current became 1/20 It (37.5 mA). Next, constant current discharge was performed at a current of 1.0 It (750 mA) until the battery voltage reached 2.75V. Then, the discharge capacities of the batteries A and B at 1.0 It were measured. The results are shown in Table 7 below.
　（放電負荷特性の評価）
　放電容量の評価後、放電容量評価と同条件で、電池を充電した後、３．０Ｉｔ（２２５０ｍＡ）の電流で電池の電圧が２．７５Ｖとなるまで定電流放電を行うことで、３．０Ｉｔでの放電容量を測定した。そして、下記の式（１）を用いて、３．０Ｉｔでの負荷率（％）を算出した。結果を下記の表７に示す。また、放電曲線を図１１に示す。 (Evaluation of discharge load characteristics)
After the evaluation of the discharge capacity, after charging the battery under the same conditions as the evaluation of the discharge capacity, a constant current discharge is performed until the voltage of the battery reaches 2.75 V with a current of 3.0 It (2250 mA). The discharge capacity at was measured. And the load factor (%) in 3.0 It was computed using the following formula (1). The results are shown in Table 7 below. A discharge curve is shown in FIG.
　３．０Ｉｔでの負荷率（％）＝（（３．０Ｉｔでの放電容量）／（１．０Ｉｔでの放電容量））×１００　　　………　（１） Load factor at 3.0 It (%) = ((Discharge capacity at 3.0 It) / (Discharge capacity at 1.0 It)) × 100 (1)
Figure JPOXMLDOC01-appb-T000007
Figure JPOXMLDOC01-appb-T000007
　表７及び図１１に示す結果から、ＮＭＰにグリセロールを添加することにより、非水電解質二次電池の放電負荷特性を向上できることが分かる。 From the results shown in Table 7 and FIG. 11, it can be seen that the discharge load characteristics of the nonaqueous electrolyte secondary battery can be improved by adding glycerol to NMP.
　上記のような効果が得られる理由は、定かではないが、正極活物質層に微細な空隙が多数形成されるため、電解液の拡散が容易になると共に、電解液の保持性も向上するためであると考えられる。 The reason why the above effects can be obtained is not clear, but since a large number of fine voids are formed in the positive electrode active material layer, the electrolyte solution can be easily diffused and the electrolyte retainability is also improved. It is thought that.
１…非水電解質二次電池
１０…電極体
１１…負極
１２…正極
１２ａ…正極集電体
１２ｂ…正極活物質層
１２ｃ…正極合剤層
１３…セパレータ
１７…電池容器
２０…アクリル板 DESCRIPTION OF SYMBOLS 1 ... Nonaqueous electrolyte secondary battery 10 ... Electrode body 11 ... Negative electrode 12 ... Positive electrode 12a ... Positive electrode collector 12b ... Positive electrode active material layer 12c ... Positive electrode mixture layer 13 ... Separator 17 ... Battery container 20 ... Acrylic board

Claims (4)

  1. 　正極集電体と、前記正極集電体の上に形成されており、正極活物質と、ポリフッ化ビニリデン及びポリフッ化ビニリデン単位を有するフッ素樹脂の少なくとも一方からなる結着剤とを含む正極活物質層とを備える非水電解質二次電池用正極の製造方法であって、
    　前記正極活物質と、前記結着剤と、Ｎ－メチル－２－ピロリドンと、Ｎ－メチル－２－ピロリドンよりも沸点が高いポリオールとを含むスラリーを前記正極集電体の上に塗布することにより形成した正極合剤層を乾燥させることにより前記正極活物質層を形成する形成工程を備える、非水電解質二次電池用正極の製造方法。     A positive electrode active material formed on the positive electrode current collector, the positive electrode active material, and a binder comprising at least one of polyvinylidene fluoride and a fluororesin having a polyvinylidene fluoride unit. A method for producing a positive electrode for a non-aqueous electrolyte secondary battery comprising a layer,
    Applying a slurry containing the positive electrode active material, the binder, N-methyl-2-pyrrolidone, and a polyol having a boiling point higher than that of N-methyl-2-pyrrolidone onto the positive electrode current collector. The manufacturing method of the positive electrode for nonaqueous electrolyte secondary batteries provided with the formation process which forms the said positive electrode active material layer by drying the positive mix layer formed by (1).
  2. 　前記形成工程は、前記正極活物質と、前記結着剤と、前記結着剤１００質量部に対して１０００質量部～３０００質量部のＮ－メチル－２－ピロリドンと、前記結着剤１００質量部に対して５質量部～５０質量部の前記ポリオールとを含むスラリーを調製する工程を含む、請求項１に記載の非水電解質二次電池用正極の製造方法。 In the forming step, the positive electrode active material, the binder, 1000 parts by weight to 3000 parts by weight of N-methyl-2-pyrrolidone with respect to 100 parts by weight of the binder, and 100 parts by weight of the binder. The method for producing a positive electrode for a nonaqueous electrolyte secondary battery according to claim 1, comprising a step of preparing a slurry containing 5 parts by mass to 50 parts by mass of the polyol with respect to parts.
  3. 　請求項１または２に記載の非水電解質二次電池用正極の製造方法により製造された非水電解質二次電池用正極。 A positive electrode for a non-aqueous electrolyte secondary battery manufactured by the method for manufacturing a positive electrode for a non-aqueous electrolyte secondary battery according to claim 1 or 2.
  4. 　請求項３に記載の非水電解質二次電池用正極と、負極と、非水電解質とを備える非水電解質二次電池。 A nonaqueous electrolyte secondary battery comprising the positive electrode for a nonaqueous electrolyte secondary battery according to claim 3, a negative electrode, and a nonaqueous electrolyte.
PCT/JP2012/055903 2011-03-15 2012-03-08 Method for producing positive electrode for nonaqueous electrolyte secondary batteries, positive electrode for nonaqueous electrolyte secondary batteries, and nonaqueous electrolyte secondary battery WO2012124582A1 (en)

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Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2018190703A (en) * 2016-12-09 2018-11-29 ユニチカ株式会社 Binder solution and coating liquid, and method for manufacturing power storage element electrode
WO2019010366A1 (en) * 2017-07-07 2019-01-10 Ppg Industries Ohio, Inc. Electrode binder slurry composition for lithium ion electrical storage devices
WO2019010405A1 (en) * 2017-07-07 2019-01-10 Ppg Industries Ohio, Inc. Electrode slurry composition for lithium ion electrical storage devices
JP2019071227A (en) * 2017-10-10 2019-05-09 日産自動車株式会社 Electrode for nonaqueous electrolyte secondary battery
JP2019071226A (en) * 2017-10-10 2019-05-09 日産自動車株式会社 Electrode for nonaqueous electrolyte secondary battery
JP2020526882A (en) * 2017-07-07 2020-08-31 ピーピージー・インダストリーズ・オハイオ・インコーポレイテッドＰＰＧ Ｉｎｄｕｓｔｒｉｅｓ Ｏｈｉｏ，Ｉｎｃ． Electrode Binder Slurry Composition for Lithium Ion Power Storage Equipment
US11777096B2 (en) 2017-07-07 2023-10-03 Ppg Industries Ohio, Inc. Electrode binder slurry composition for lithium ion electrical storage devices

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH1186865A (en) * 1997-09-02 1999-03-30 Denso Corp Secondary battery and manufacture thereof
JPH11273682A (en) * 1998-03-23 1999-10-08 Nippon Zeon Co Ltd Slurry for electrode of lithium ion secondary battery, binder composition, electrode and battery
JP2006172887A (en) * 2004-12-15 2006-06-29 Nissan Motor Co Ltd Manufacturing method for electrode for battery
JP2009152180A (en) * 2007-12-18 2009-07-09 Samsung Electronics Co Ltd Electrode composition for inkjet printing, electrode obtained from this, and secondary battery

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH1186865A (en) * 1997-09-02 1999-03-30 Denso Corp Secondary battery and manufacture thereof
JPH11273682A (en) * 1998-03-23 1999-10-08 Nippon Zeon Co Ltd Slurry for electrode of lithium ion secondary battery, binder composition, electrode and battery
JP2006172887A (en) * 2004-12-15 2006-06-29 Nissan Motor Co Ltd Manufacturing method for electrode for battery
JP2009152180A (en) * 2007-12-18 2009-07-09 Samsung Electronics Co Ltd Electrode composition for inkjet printing, electrode obtained from this, and secondary battery

Cited By (21)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
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JP7116461B2 (en) 2016-12-09 2022-08-10 ユニチカ株式会社 Binder solution, coating solution, and method for producing storage element electrode
CN110870107A (en) * 2017-07-07 2020-03-06 Ppg工业俄亥俄公司 Electrode binder paste composition for lithium ion storage device
US11424451B2 (en) 2017-07-07 2022-08-23 Ppg Industries Ohio, Inc. Electrode slurry composition for lithium ion electrical storage devices
CN110870107B (en) * 2017-07-07 2024-02-06 Ppg工业俄亥俄公司 Electrode binder paste composition for lithium ion electricity storage device
WO2019010405A1 (en) * 2017-07-07 2019-01-10 Ppg Industries Ohio, Inc. Electrode slurry composition for lithium ion electrical storage devices
JP2020526882A (en) * 2017-07-07 2020-08-31 ピーピージー・インダストリーズ・オハイオ・インコーポレイテッドＰＰＧ Ｉｎｄｕｓｔｒｉｅｓ Ｏｈｉｏ，Ｉｎｃ． Electrode Binder Slurry Composition for Lithium Ion Power Storage Equipment
JP2020527830A (en) * 2017-07-07 2020-09-10 ピーピージー・インダストリーズ・オハイオ・インコーポレイテッドＰＰＧ Ｉｎｄｕｓｔｒｉｅｓ Ｏｈｉｏ，Ｉｎｃ． Electrode binder slurry composition for lithium ion power storage device
AU2018297308B2 (en) * 2017-07-07 2021-09-16 Ppg Industries Ohio, Inc. Electrode binder slurry composition for lithium ion electrical storage devices
TWI754081B (en) * 2017-07-07 2022-02-01 美商片片堅俄亥俄州工業公司 Electrode binder slurry composition for lithium ion electrical storage devices
WO2019010366A1 (en) * 2017-07-07 2019-01-10 Ppg Industries Ohio, Inc. Electrode binder slurry composition for lithium ion electrical storage devices
US11843118B2 (en) 2017-07-07 2023-12-12 Ppg Industries Ohio, Inc. Electrode binder slurry composition for lithium ion electrical storage devices
US11799086B2 (en) 2017-07-07 2023-10-24 Ppg Industries Ohio, Inc. Electrode binder slurry composition for lithium ion electrical storage devices
US11777096B2 (en) 2017-07-07 2023-10-03 Ppg Industries Ohio, Inc. Electrode binder slurry composition for lithium ion electrical storage devices
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