Patent ID: 8734990

Claim:
A lithium secondary battery comprising a positive electrode for lithium secondary batteries, being a positive electrode used in lithium secondary batteries, comprising: a positive electrode collector; a barrier layer on the positive electrode collector, and comprising a composition having a conductive material, and at least one type of water-insoluble polymer that is soluble in organic solvents but insoluble in water, as a first binder wherein a content of the water-insoluble polymer in the barrier layer is 55 to 85 mass % with respect to 100 mass % of a total amount of the conductive material plus the water-insoluble polymer, and wherein the barrier layer is formed by heating the collector having the composition thereon up to 140 to 150° C.; and a positive electrode active material layer, being stacked on the barrier layer, and having a positive electrode active material, and at least one type of aqueous polymer that is insoluble in organic solvents but soluble or dispersible In water, as a second binder; a thickness of the barrier layer is 1 μm to 2 μm, a thickness of the positive electrode active material layer is 30 μm to 80 μm, and both an initial internal resistance value and an internal resistance after 500 cycles of charge-discharge under an environment temperature of 60° C. are lower than 40 mΩ.