Cylindrical-Type Lithium Secondary Battery, and Battery Pack Comprising the Same

A lithium secondary battery includes: a battery case; an electrode assembly accommodated in the battery case; and an electrolyte. The electrode assembly includes a positive electrode including a positive electrode active material, a separator, and a negative electrode including a negative electrode active material. The electrolyte includes LiPF, and ethylene carbonate. The lithium secondary battery has a form factor ratio of a diameter (r) to a height (h) of the battery case that is 0.4 or more, and satisfies Equation (1): Wis an amount of the LiPFexpressed as a percentage relative to a total weight of the electrolyte. Wis an amount of the ethylene carbonate expressed as a percentage relative to the total weight of the electrolyte. Wdenotes the total weight (g) of the electrolyte in the lithium secondary battery. A battery pack comprises the lithium secondary battery.