Lithium secondary battery

A lithium secondary battery, comprising:

• a positive electrode comprising a positive active material of Chemical Formula 1, a plate-like conductive material, and a spherical conductive material;
• a negative electrode including a negative active material;
• and
• an electrolyte,
• wherein the positive electrode has a W value defined by Equation 1 of 0.9 to 2:
• LiaNixCoyMezO2 [Chemical Formula 1]
• wherein, in Chemical Formula 1, 0.9≤a≤1.1, 0.5≤x≤0.90, 0.05≤y≤0.5, 0.01≤z≤0.5, x+y+z=1, and
• Me is Mn or Al,
• W=Raman spectrum peak intensity ratio (IA1g/IEg) of a peak intensity (IA1g) of A1g peak (500 cm−1 to 600 cm−1) relative to a peak intensity (IEg) of Eg peak (400 cm−1 to 470 cm−1) [Equation 1]