| abstract |
In a lithium secondary battery provided by the present invention, a positive electrode active material is constituted by a lithium composite oxide having at least lithium, nickel, and/or cobalt as main constituent elements, a porosity of a positive electrode active material layer is 30% or more and 40% or less, and a porosity of a negative electrode active material layer is 30% or more and 45% or less. Further, a void volume ratio (Sa/Sb) between a void volume (Sa) per unit area of the positive electrode active material layer and a void volume (Sb) per unit area of the negative electrode active material layer satisfies 0.9≦(Sa/Sb)≦1.4. |