CATHODE FOR SODIUM SECONDARY BATTERY, AND SODIUM SECONDARY BATTERY COMPRISING SAME

The present invention relates to a positive electrode for a sodium secondary battery, the positive electrode including a current collector, a first positive electrode active material layer disposed on the current collector, and a second positive electrode active material layer disposed on the first positive electrode active material layer, wherein the first positive electrode active material layer includes a first positive electrode active material, and the second positive electrode active material layer includes a second positive electrode active material, wherein the first positive electrode active material includes sodium composite transition metal oxide particles having an O3 octahedral crystal structure, and the second positive electrode active material includes sodium composite transition metal oxide particles having a P2 orthorhombic crystal structure, wherein a ratio of the average particle diameter (D) between the first positive electrode active material and the second positive electrode active material is 2:1 to 3:1.