▎ 摘　　要

NOVELTY - A positive electrode comprises a mixture layer containing an active material made of lithium nickel-cobalt manganate, a binder, graphene and a polymer dispersant, and a current collector. The mixture layer contains 0.4-1.2 pts. wt. graphene in terms of carbonaceous solids with respect to 100 pts. wt. active material. The electrode has a capacity ratio (N/P ratio) of 1.05-1.1. When a 2032-type coin cell containing the positive electrode, a negative electrode comprising a mixture layer containing 98 pts. wt. graphite, 1 pt. wt. carboxymethylcellulose and 1 pt. wt. styrene-butadiene rubber on a copper foil, a separator, 61 mol/L lithium hexafluorophosphate, and an electrolyte solution containing ethylene carbonate and dimethyl carbonate in a volume ratio of 3:7 is used, the direct current internal resistance value is 10 Ω or less. The ratio of the resistance value of the mixture layer to the DC internal resistance value is 0.01 or more. USE - Positive electrode for lithium ion secondary battery (claimed). Uses include but are not limited to smart phones, mobile phones, portable devices, hybrid vehicles, electric vehicles and household electrical storage appliance. ADVANTAGE - The anode provides lithium ion secondary battery having excellent safety and durability. DETAILED DESCRIPTION - A positive electrode comprises a mixture layer containing an active material made of lithium nickel-cobalt manganate (LiNixMnyCo1-x-yO2), a binder, graphene and a polymer dispersant, and a current collector. The mixture layer contains 0.4-1.2 pts. wt. graphene in terms of carbonaceous solids with respect to 100 pts. wt. active material. The electrode has a capacity ratio (N/P ratio) of 1.05-1.1. When a 2032-type coin cell containing the positive electrode, a negative electrode comprising a mixture layer containing 98 pts. wt. graphite, 1 pt. wt. carboxymethylcellulose and 1 pt. wt. styrene-butadiene rubber on a copper foil, a separator sandwiched between the positive electrode and the negative electrode, 61 mol/L lithium hexafluorophosphate, and an electrolyte solution containing ethylene carbonate and dimethyl carbonate in a volume ratio of 3:7 is used, the direct current internal resistance value is 10 Ω or less. The ratio of the resistance value of the mixture layer to the DC internal resistance value is 0.01 or more.