JP2017016950A5 - - Google Patents

Claims (13)

A lithium ion secondary battery comprising a positive electrode, a negative electrode, a separator, and an electrolyte solution in a battery container, wherein the negative electrode has a current collector and a negative electrode mixture applied to the current collector, and the negative electrode composite material includes an anode active material and Fukyokuyo binder, the lithium ion secondary battery negative electrode binder containing an acrylic resin and polyvinylidene fluoride. The lithium ion secondary battery according to claim 1, wherein the acrylic resin includes a structural unit derived from a nitrile group-containing monomer. The lithium ion secondary battery according to claim 2, wherein the acrylic resin further includes a structural unit derived from a carboxyl group-containing monomer. The lithium ion secondary according to claim 3, wherein a ratio of the structural unit derived from the carboxyl group-containing monomer to 1 mol of the structural unit derived from the nitrile group-containing monomer is 0.01 mol to 0.2 mol. battery. The lithium ion secondary battery according to any one of claims 2 to 4, wherein the acrylic resin further includes a structural unit derived from a monomer represented by the following formula (II).

(Wherein R ₁ Is hydrogen or methyl group, R ₂ Is hydrogen or a monovalent hydrocarbon group, n is an integer from 1 to 50
Number)   The lithium ion secondary battery according to any one of claims 2 to 5, wherein the acrylic resin further includes a structural unit derived from a monomer represented by the following formula (III).

(Wherein R ₃ Is hydrogen or methyl group, R ₄ Is an alkyl group having 4 to 100 carbon atoms) Mass ratio of the polyvinylidene fluoride and the acrylic resin is 80: 20 to 10: lithium ion secondary battery according to any one of claims 1 to 6 is 90. The acrylic resin, a lithium ion secondary battery according to any one of claims 1 to 7 to 5% by weight or less based on the total amount of the negative electrode mixture. The lithium ion secondary battery according to any one of claims 1 to 8, wherein a content ratio of the negative electrode binder with respect to a mass of the negative electrode mixture is 0.1 mass% to 20 mass%. The negative active material is a carbon material, X-rays diffraction hexagonal carbon layers as measured from the (XRD) (d (002) ) of claims 1 to 9 is 0.33 nm ~ 0.40 nm The lithium ion secondary battery according to any one of the above. The negative active material is a lithium-ion secondary battery according to any one of claims 1 to 10 charge state in potential becomes 0.1V against lithium potential (State of charge) is 60% or more . The density of the negative electrode mixture is 0.7 g / cm. ³ ~ 2g / cm ³ The lithium ion secondary battery according to any one of claims 1 to 11. The lithium ion secondary battery according to any one of claims 1 to 12, wherein a TI value of the slurry of the negative electrode mixture is 2.0 or more.