Patent ID: 8367240

Claim:
A lithium secondary battery comprising a first electrode, a second electrode, a separator disposed between said first electrode and said second electrode, and an electrolyte having lithium ion conductivity, said first electrode and said second electrode being wound with said separator disposed therebetween to form an electrode assembly, wherein: said first electrode includes a current collector and an active material layer carried on one face of said current collector, said active material layer includes columnar particles projecting from said one face of said current collector and having a bottom and a head, said plurality of columnar particles being slanted with respect to a direction N normal to said one face of the current collector with the head being tilted toward a position at which the winding is completed, and said plurality of columnar particles bend such that a convex side of the plurality of bent columnar particles faces the current collector wherein an angle formed between a direction from the bottom toward the head of said plurality of columnar particles and the direction N is 20° to 70°.