Patent ID: 8936872
Filing Date: 2015-01-20
Classification: H01M,Y02E,Y02T

Abstract:
1. A lithium-ion secondary battery comprising a positive electrode, a negative electrode and an electrolyte, said positive electrode and negative electrode being configured by binding an active material layer, including an electrode active material and a binder, to a collector, wherein the binder used for at least one of the positive electrode or negative electrode includes polymer particles comprising a cross-linked nitrile group containing polymer composed of a copolymer of at least a nitrile group containing monomer and a monomer having a carbon-carbon double bond and an epoxy group, or a cross-linked polymer having a polyalkylene oxide chain in its main chain composed of a copolymer of at least a monomer containing an epoxy and a monomer having a carbon-carbon double bond and an epoxy group, and wherein the polymer particles satisfy the following properties: swelling degree of a sheet-like molded body, which is obtained by pressure molding of only the polymer particles, in an organic electrolyte obtained by dissolving a lithium salt into carbonates, is 5 to 50% as an increase in length, and lithium ion conductivity of the polymer particles swollen by the organic electrolyte is 1×10 and when the nitrile group is present, the ratio of nitrile group containing monomer unit in the polymer is 30 to 95 wt %.