LITHIUM SECONDARY BATTERY

A lithium secondary battery which includes an electrode assembly in which a positive electrode plate, a negative electrode plate, and a separator interposed between the positive electrode plate and the negative electrode plate are wound in one direction, a battery can in which the electrode assembly is accommodated, and a sealing body which seals an open end of the battery can. The positive electrode plate includes positive electrode active material comprising single particles, quasi-single particles, or a combination thereof, and the positive electrode active material has Dof 1.0 μm or more.