A positive electrode contains a first active material and a second active material. The first active material and the second active material each contain a lithium composite oxide containing at least manganese (Mn), nickel (Ni), and cobalt (Co) as transition metals. The first active material has a particulate shape. An average porosity V1 in a particle of the first active material satisfies 10[%]≤V1≤30[%]. An average particle diameter D1 of the first active material satisfies 6 [μm]≤D1≤20 [μm]. The second active material has a particulate shape. An average porosity V2 in a particle of the second active material satisfies 0[%]≤V2≤10[%]. An average particle diameter D2 of the second active material satisfies 1 [μm]≤D2≤6 [μm].