Patent ID: 8883348

Claim:
A method for producing an electrode for a lithium ion secondary battery, comprising steps of: applying a material mixture containing active material particles capable of reversibly absorbing and desorbing lithium on a current collector comprising aluminum foil or aluminum alloy foil having a thickness of 10 to 25 μm; heating said current collector carrying said material mixture at 200 to 350° C. to soften said current collector; rolling said softened current collector carrying said material mixture with a linear pressure of 10 kN/cm to 15 kN/cm, so that said active material particles are partially embedded in said current collector, wherein: after the step of rolling, a surface of said current collector has recesses in which said active material particles are partially embedded, and shapes of the recesses conform to shapes of embedded portions of said active material particles, respectively, and in a cut surface obtained by simultaneously cutting said material mixture and said current collector vertically to an electrode plane, the maximum depth of said recesses is not less than 3.1 μm, said active material particles contain a lithium-containing composite oxide, and said lithium-containing composite oxide is represented by the formula (1): Li x Co 1-y-z Ni y M z O 2 , where M is at least one element selected from the group consisting of Mn, Ti, Y, Nb, Mo, W, Al, Mg, Ca, Sr and Ba, and 0.97≦x≦1.1, 0.05≦y≦1 and 0≦z≦0.35 are satisfied.