Lithium Secondary Battery, Battery Module and Battery Pack

A lithium secondary battery includes a cathode having a cathode active material, an anode having an anode active material, a separator, and an electrolyte. The cathode active material comprises a lithium composite transition metal compound having Ni, Co, and Mn, and has single particles and/or pseudo-single particles. Each single particle consists of one nodule, and each pseudo-single crystal is a composite of 30 or fewer nodules. The single particles and/or pseudo-single particles have an average particle diameter (D50) of 1 μm or more.